
/*********************************************************************

	artwork.c

	Second generation artwork implementation.

	Still to do:
		- tinting
		- mechanism to disable built-in artwork

	Longer term:
		- struct mame_layer
		  {
		  	struct mame_bitmap *bitmap;
		  	int rectcount;
		  	struct rectangle rectlist[MAX_RECTS];
		  }
		- add 4 mame_layers for backdrop, overlay, bezel, ui to mame_display
		- some mechanism to let the OSD do the blending
		- MMX optimized implementations

**********************************************************************

	This file represents the second attempt at providing external
	artwork support. Some parts of this code are based on the
	original version, by Mike Balfour and Mathis Rosenhauer.

	The goal: to provide artwork support with minimal knowledge of
	the game drivers. The previous implementation required the
	game drivers to allocate extra pens, extend the screen bitmap,
	and handle a lot of the mundane details by hand. This is no
	longer the case.

	The key to all this is the .art file. A .art file is just a
	text file describing all the artwork needed for a particular
	game. It lives either in the $ARTWORK/gamename/ directory
	or in the $ARTWORK/gamename.zip file, and is called
	gamename.art.

**********************************************************************

	THE ART FILE

	The .art file is very simply formatted. It consists of any
	number of entries that look like this:

	[artname]:
		file       = [filename]
		alphafile  = [alphafilename]
		layer      = [backdrop|overlay|bezel|marquee|panel|side|flyer]
		position   = [left],[top],[right],[bottom]
		priority   = [priority]
		visible    = [visible]
		alpha      = [alpha]
		brightness = [brightness]

	Comments in the .art file follow standard C++ comment format,
	starting with a double-slash //. C-style comments are not
	recognized.

	Fields are:

	[artname] - name that is used to reference this piece of
		artwork in the game driver. Game drivers can show/hide
		pieces of artwork. It is permissible to use the same
		name for multiple pieces; in that case, a show/hide
		command from the game will affect all pieces with that
		name. This field is required.

	file - name of the PNG file containing the main artwork.
		This file should live in the same directory as the .art
		file itself. Most PNG formats are supported. If the
		PNG file does not have an alpha channel or transparent
		colors, it will be loaded fully opaque. This field is
		required.

	alphafile - name of a PNG file containing the alpha channel.
		Like the main file, this file should live in the same
		directory as the .art file. The alphafile must have the
		exact same dimensions as the main art file in order to
		be valid. When loaded, the brightness of each pixel in
		the alphafile controls the alpha channel for the
		corresponding pixel in the main art.

	layer - classifies this piece of artwork into one of several
		predefined categories. Command line options can control
		which categories of artwork are actually displayed. The
		layer is also used to group the artwork for rendering
		(see discussion of rendering below.) This field is
		required.

	position - specifies the position of this piece of artwork
		relative to the game bitmap. See the section on
		positioning, below, for the precise details. This field
		is required.

	priority - specifies the front-to-back ordering of this
		piece of art. The various artwork pieces are assembled
		from the bottom up, lowest priority to highest priority.
		If you want a piece of artwork to appear behind another
		piece of artwork, use a lower priority. The default
		priority is 0.

	visible - sets the initial visible state. By default, all
		artwork is visible. The driver code can change this state
		at runtime.

	alpha - specifies a global, additional alpha value for the
		entire piece of artwork. This alpha value is multiplied
		by the per-pixel alpha value for the loaded artwork.
		The default value is 1.0, which has no net effect on the
		loaded alpha. An alpha of 0.0 will make the entire piece
		of artwork fully transparent.

	brightness - specifies a global brightness adjustment factor
		for the entire piece of artwork. The red, green, and blue
		components of every pixel are multiplied by this value
		when the image is loaded. The default value is 1.0, which
		has no net effect on the loaded artwork. A brightness
		value of 0.0 will produce an entirely black image.

	Once the .art file is loaded, the artwork is categories into
	three groups: backdrops, overlays, and everything else. Each
	of these groups is handled in its own way.

**********************************************************************

	BLENDING

	Conceptually, here is how it all fits together:

	1. A combined backdrop bitmap is assembled. This consists of
	taking an opaque black bitmap, and alpha blending all the
	backdrop graphics, in order from lowest priority to highest,
	into it.

	2. A combined overlay bitmap is assembled. This consists of
	taking a translucent white overlay and performing a CMY blend
	of all the overlay graphics, in order from lowest priority to
	highest, into it.

	3. A combined bezel bitmap is assembled. This consists of
	taking a fully transparent bitmap, and alpha blending all the
	bezel, marquee, panel, side, and flyer graphics, in order from
	lowest to highest, into it.

	4. Depending on the user configurable artwork scale setting,
	the game bitmap is potentially expanded 2x.

	5. The combined overlay bitmap is applied to the game bitmap,
	by using the brightness of the game pixel to control the
	brightness of the corresponding overlay bitmap pixel, as
	follows:

		RGB[mix1] = (RGB[overlay] * A[overlay]) +
				(RGB[overlay] - RGB[overlay] * A[overlay]) * Y[game];

	where

		RGB[mix1] -> RGB components of final mixed bitmap
		A[overlay] -> alpha value of combined overlay
		RGB[overlay] -> RGB components of combined overlay
		Y[game] -> brightness of game pixel

	6. The result of the overlay + game blending is then added to
	the backdrop, as follows:

		RGB[mix2] = RGB[mix1] + RGB[backdrop]

	where

		RGB[mix2] -> RGB components of final mixed bitmap
		RGB[mix1] -> RGB components of game + overlay mixing
		RGB[backdrop] -> RGB components of combined backdrop graphics

	7. The combined bezel bitmap is alpha blended against the
	result of the previous operation, as follows:

		RGB[final] = (RGB[mix2] * (1 - A[bezel])) + (RGB[bezel] * A[bezel])

	where

		RGB[final] -> RGB components of final bitmap
		A[bezel] -> alpha value of combined bezel
		RGB[bezel] -> RGB components of combined bezel
		RGB[mix2] -> RGB components of game + overlay + backdrop mixing

**********************************************************************

	POSITIONING

	The positioning of the artwork is a little tricky.
	Conceptually, the game bitmap occupies the space from (0,0)
	to (1,1). If you have a piece of artwork that exactly covers
	the game area, then it too should stretch from (0,0) to (1,1).
	However, most of the time, this is not the case.

	For example, if you have, say, the Spy Hunter bezel at the
	bottom of the screen, then you will want to specify the top
	of the artwork at 1.0 and the bottom at something larger, maybe
	1.25. The nice thing about the new artwork system is that it
	will automatically stretch the bitmaps out to accomodate areas
	beyond the game bitmap, and will still keep the proper aspect
	ratio.

	Another common example is a backdrop that extends beyond all
	four corners of the game bitmap. Here is how you would handle
	that, in detail:

	Let's say you have some artwork like this:

	 <============ 883 pixels ===============>

	(1)-------------------------------------(2)  ^
	 |                  ^                    |   |
	 |              26 pixels                |   |
	 |                  v                    |   |
	 |     (5)-----------------------(6)     |   |
	 |      |                         |      |   |
	 |      |                         |      |   |
	 |      |                         |      |   |
	 |<---->|                         |      |   |
	 |  97  |      Game screen        |      |  768
	 |pixels|       700 x 500         |      | pixels
	 |      |                         |<---->|   |
	 |      |                         |  86  |   |
	 |      |                         |pixels|   |
	 |      |                         |      |   |
	 |      |                         |      |   |
	 |     (7)-----------------------(8)     |   |
	 |                  ^                    |   |
	 |              42 pixels                |   |
	 |                  v                    |   |
	(3)-------------------------------------(4)  v

	If you're looking at the raw coordinates as might seem
	logical, you would imagine that they come out like this:

		(1) is at (0,0)
		(2) is at (883,0)
		(3) is at (0,768)
		(4) is at (883,768)

		(5) is at (97,26)
		(6) is at (797,26)
		(7) is at (97,526)
		(8) is at (797,526)

	The first thing you need to do is adjust the coordinates
	so that the upper left corner of the game screen (point 5)
	is at (0,0). To do that, you need to subtract 97 from
	each X coordinate and 26 from each Y coordinate:

		(1) is at (0-97,0-26)     -> (-97,-26)
		(2) is at (883-97,0-26)   -> (786,-26)
		(3) is at (0-97,768-26)   -> (-97,742)
		(4) is at (883-97,768-26) -> (883,742)

		(5) is at (97-97,26-26)   -> (0,0)
		(6) is at (797-97,26-26)  -> (700,0)
		(7) is at (97-97,526-26)  -> (0,500)
		(8) is at (797-97,526-26) -> (700,500)

	The final thing you need to do is make it so the bottom
	right corner of the image (point 8) is at (1.0,1.0). To do
	that, you need to divide each coordinate by the width
	or height of the image

		(1) is at (-97/700,-26/500)  -> (-0.13857,-0.052)
		(2) is at (786/700,-26/500)  -> (1.122857,-0.052)
		(3) is at (-97/700,742/500)  -> (-0.13857, 1.484)
		(4) is at (883/700,742/500)  -> (1.122857, 1.484)

		(5) is at (0/700,0/500)      -> (0.0,0.0)
		(6) is at (700/700,0/500)    -> (1.0,0.0)
		(7) is at (0/700,500/500)    -> (0.0,1.0)
		(8) is at (700/700,500/500)  -> (1.0,1.0)

	Alternately, you can also provide pixel coordinates, but it will
	still be relative to the game's native resolution. So, if
	the game normally runs at 256x224, you'll need to compute
	the division factor so that the bottom right corner of the
	game (point 8) ends up at (256,224) instead of (1.0,1.0).

	Basically, if you have the original coordinates shown
	right below the image, you can compute the values needed by
	doing this for X coordinates:

		(X coordinate on artwork) - (X coordinate of game's upper-left)
		---------------------------------------------------------------
		           (width of game in artwork pixels)

	And this for Y coordinates:

		(Y coordinate on artwork) - (Y coordinate of game's upper-left)
		---------------------------------------------------------------
			       (height of game in artwork pixels)

*********************************************************************/


#include "driver.h"
#include "png.h"
#include "artwork.h"
#include "vidhrdw/vector.h"
#include <ctype.h>
#include <math.h>


/***************************************************************************

	Constants & macros

***************************************************************************/

/* maxima */
#define MAX_PIECES				1024
#define MAX_HINTS_PER_SCANLINE	4

/* fixed-point fraction helpers */
#define FRAC_BITS				24
#define FRAC_ONE				(1 << FRAC_BITS)
#define FRAC_MASK				(FRAC_ONE - 1)
#define FRAC_HALF				(FRAC_ONE / 2)

/* layer types */
enum
{
	LAYER_UNKNOWN,
	LAYER_BACKDROP,
	LAYER_OVERLAY,
	LAYER_BEZEL,
	LAYER_MARQUEE,
	LAYER_PANEL,
	LAYER_SIDE,
	LAYER_FLYER
};

/* UI transparency hack */
#define UI_TRANSPARENT_COLOR16	0xfffe
#define UI_TRANSPARENT_COLOR32	0xfffffffe

/* assemble ARGB components in the platform's preferred format */
#define ASSEMBLE_ARGB(a,r,g,b)	(((a) << ashift) | ((r) << rshift) | ((g) << gshift) | ((b) << bshift))



/***************************************************************************

	Type definitions

***************************************************************************/

struct artwork_piece
{
	/* linkage */
	struct artwork_piece *	next;

	/* raw data from the .art file */
	UINT8					layer;
	UINT8					has_alpha;
	int						priority;
	float					alpha;
	float					brightness;
	float					top;
	float					left;
	float					bottom;
	float					right;
	char *					tag;
	char *					filename;
	char *					alpha_filename;

	/* bitmaps */
	struct mame_bitmap *	rawbitmap;
	struct mame_bitmap *	prebitmap;
	struct mame_bitmap *	yrgbbitmap;
	UINT32 *				scanlinehint;
	UINT8					blendflags;

	/* derived/dynamic data */
	int						intersects_game;
	int						visible;
	struct rectangle		bounds;
};



/***************************************************************************

	Local variables

***************************************************************************/

static UINT8 rshift, gshift, bshift, ashift;
static UINT32 nonalpha_mask;
static UINT32 transparent_color;

static struct artwork_piece *artwork_list;
static int num_underlays, num_overlays, num_bezels;
static int num_pieces;

static struct mame_bitmap *underlay, *overlay, *overlay_yrgb, *bezel, *final;
static struct rectangle underlay_invalid, overlay_invalid, bezel_invalid;
static struct rectangle gamerect, screenrect;
static int gamescale;

static struct mame_bitmap *uioverlay;
static UINT32 *uioverlayhint;
static struct rectangle uibounds, last_uibounds;

static UINT32 *palette_lookup;

static int original_attributes;
static UINT8 global_artwork_enable;

static const struct overlay_piece *overlay_list;



/***************************************************************************

	Prototypes

***************************************************************************/

static int artwork_prep(void);
static int artwork_load(const struct GameDriver *gamename, int width, int height, const struct artwork_callbacks *callbacks);
static int compute_rgb_components(int depth, UINT32 rgb_components[3], UINT32 rgb32_components[3]);
static int load_bitmap(const char *gamename, struct artwork_piece *piece);
static int load_alpha_bitmap(const char *gamename, struct artwork_piece *piece, const struct png_info *original);
static int scale_bitmap(struct artwork_piece *piece, int newwidth, int newheight);
static void trim_bitmap(struct artwork_piece *piece);
static int parse_art_file(mame_file *file);
static int validate_pieces(void);
static void sort_pieces(void);
static void update_palette_lookup(struct mame_display *display);
static int update_layers(void);
static void render_game_bitmap(struct mame_bitmap *bitmap, const rgb_t *palette, struct mame_display *display);
static void render_game_bitmap_underlay(struct mame_bitmap *bitmap, const rgb_t *palette, struct mame_display *display);
static void render_game_bitmap_overlay(struct mame_bitmap *bitmap, const rgb_t *palette, struct mame_display *display);
static void render_game_bitmap_underlay_overlay(struct mame_bitmap *bitmap, const rgb_t *palette, struct mame_display *display);
static void render_ui_overlay(struct mame_bitmap *bitmap, UINT32 *dirty, const rgb_t *palette, struct mame_display *display);
static void erase_rect(struct mame_bitmap *bitmap, const struct rectangle *bounds, UINT32 color);
static void alpha_blend_intersecting_rect(struct mame_bitmap *dstbitmap, const struct rectangle *dstbounds, struct mame_bitmap *srcbitmap, const struct rectangle *srcbounds, const UINT32 *hintlist);
static void add_intersecting_rect(struct mame_bitmap *dstbitmap, const struct rectangle *dstbounds, struct mame_bitmap *srcbitmap, const struct rectangle *srcbounds);
static void cmy_blend_intersecting_rect(struct mame_bitmap *dstbitmap, struct mame_bitmap *dstyrgbbitmap, const struct rectangle *dstbounds, struct mame_bitmap *srcbitmap, struct mame_bitmap *srcyrgbbitmap, const struct rectangle *srcbounds, UINT8 blendflags);
static int generate_overlay(const struct overlay_piece *list, int width, int height);
static void add_range_to_hint(UINT32 *hintbase, int scanline, int startx, int endx);



#if 0
#pragma mark INLINES
#endif

/*-------------------------------------------------
	union_rect - compute the union of two rects
-------------------------------------------------*/

INLINE void union_rect(struct rectangle *dst, const struct rectangle *src)
{
	if (dst->max_x == 0)
		*dst = *src;
	else if (src->max_x != 0)
	{
		dst->min_x = (src->min_x < dst->min_x) ? src->min_x : dst->min_x;
		dst->max_x = (src->max_x > dst->max_x) ? src->max_x : dst->max_x;
		dst->min_y = (src->min_y < dst->min_y) ? src->min_y : dst->min_y;
		dst->max_y = (src->max_y > dst->max_y) ? src->max_y : dst->max_y;
	}
}



/*-------------------------------------------------
	compute_brightness - compute the effective
	brightness for an RGB pixel
-------------------------------------------------*/

INLINE UINT8 compute_brightness(rgb_t rgb)
{
	return (RGB_RED(rgb) * 222 + RGB_GREEN(rgb) * 707 + RGB_BLUE(rgb) * 71) / 1000;
}



/*-------------------------------------------------
	compute_pre_pixel - compute a premultiplied
	pixel
-------------------------------------------------*/

INLINE UINT32 compute_pre_pixel(UINT8 a, UINT8 r, UINT8 g, UINT8 b)
{
	/* premultiply the RGB components with the pixel's alpha */
	r = (r * a) / 0xff;
	g = (g * a) / 0xff;
	b = (b * a) / 0xff;

	/* compute the inverted alpha */
	a = 0xff - a;
	return ASSEMBLE_ARGB(a,r,g,b);
}



/*-------------------------------------------------
	compute_yrgb_pixel - compute a YRGB pixel
-------------------------------------------------*/

INLINE UINT32 compute_yrgb_pixel(UINT8 a, UINT8 r, UINT8 g, UINT8 b)
{
	/* compute the premultiplied brightness */
	int bright = (r * 222 + g * 707 + b * 71) / 1000;
	bright = (bright * a) >> 8;

	/* now assemble */
	return MAKE_ARGB(bright,r,g,b);
}



/*-------------------------------------------------
	add_and_clamp - add two pixels and clamp
	each component to the max
-------------------------------------------------*/

INLINE UINT32 add_and_clamp(UINT32 game, UINT32 underpix)
{
	UINT32 temp1 = game + underpix;
	UINT32 temp2 = game ^ underpix ^ temp1;

	/* handle overflow (carry out of top component */
	if (temp1 < game)
		temp1 |= 0xff000000;

	/* handle carry out of next component */
	if (temp2 & 0x01000000)
	{
		temp1 -= 0x01000000;
		temp1 |= 0x00ff0000;
	}

	/* handle carry out of next component */
	if (temp2 & 0x00010000)
	{
		temp1 -= 0x00010000;
		temp1 |= 0x0000ff00;
	}

	/* handle carry out of final component */
	if (temp2 & 0x00000100)
	{
		temp1 -= 0x00000100;
		temp1 |= 0x000000ff;
	}
	return temp1;
}



/*-------------------------------------------------
	blend_over - blend two pixels with overlay
-------------------------------------------------*/

INLINE UINT32 blend_over(UINT32 game, UINT32 pre, UINT32 yrgb)
{
	/* case 1: no game pixels; just return the premultiplied pixel */
	if ((game & nonalpha_mask) == 0)
		return pre;

	/* case 2: apply the effect */
	else
	{
		UINT8 bright = RGB_GREEN(game);
		UINT8 r, g, b;

		yrgb -= pre;
		r = (RGB_RED(yrgb) * bright) / 256;
		g = (RGB_GREEN(yrgb) * bright) / 256;
		b = (RGB_BLUE(yrgb) * bright) / 256;
		return pre + ASSEMBLE_ARGB(0,r,g,b);
	}
}



#if 0
#pragma mark -
#pragma mark OSD FRONTENDS
#endif

/*-------------------------------------------------
	artwork_create_display - tweak the display
	parameters based on artwork, and call through
	to osd_create_display
-------------------------------------------------*/

int artwork_create_display(struct osd_create_params *params, UINT32 *rgb_components, const struct artwork_callbacks *callbacks)
{
	int original_width = params->width;
	int original_height = params->height;
	int original_depth = params->depth;
	double min_x, min_y, max_x, max_y;
	UINT32 rgb32_components[3];
	struct artwork_piece *piece;

	/* reset UI */
	uioverlay = NULL;
	uioverlayhint = NULL;

	/* first load the artwork; if none, quit now */
	artwork_list = NULL;
	if (!artwork_load(Machine->gamedrv, original_width, original_height, callbacks))
		return 1;
	if (!artwork_list && (!callbacks->activate_artwork || !callbacks->activate_artwork(params)))
		return osd_create_display(params, rgb_components);

	/* determine the game bitmap scale factor */
	gamescale = options.artwork_res;
	if (gamescale < 1 || (params->video_attributes & VIDEO_TYPE_VECTOR))
		gamescale = 1;
	else if (gamescale > 2)
		gamescale = 2;

	/* compute the extent of all the artwork */
	min_x = min_y = 0.0;
	max_x = max_y = 1.0;
	if (!options.artwork_crop)
		for (piece = artwork_list; piece; piece = piece->next)
		{
			/* compute the outermost bounds */
			if (piece->left < min_x) min_x = piece->left;
			if (piece->right > max_x) max_x = piece->right;
			if (piece->top < min_y) min_y = piece->top;
			if (piece->bottom > max_y) max_y = piece->bottom;
		}

	/* now compute the altered width/height and the new aspect ratio */
	params->width = (int)((max_x - min_x) * (double)(original_width * gamescale) + 0.5);
	params->height = (int)((max_y - min_y) * (double)(original_height * gamescale) + 0.5);
	params->aspect_x = (int)((double)params->aspect_x * 100. * (max_x - min_x));
	params->aspect_y = (int)((double)params->aspect_y * 100. * (max_y - min_y));

	/* vector games need to fit inside the original bounds, so scale back down */
	if (params->video_attributes & VIDEO_TYPE_VECTOR)
	{
		/* shrink the width/height if over */
		if (params->width > original_width)
		{
			params->width = original_width;
			params->height = original_width * params->aspect_y / params->aspect_x;
		}
		if (params->height > original_height)
		{
			params->height = original_height;
			params->width = original_height * params->aspect_x / params->aspect_y;
		}

		/* compute the new raw width/height and update the vector info */
		original_width = (int)((double)params->width / (max_x - min_x));
		original_height = (int)((double)params->height / (max_y - min_y));
		options.vector_width = original_width;
		options.vector_height = original_height;
	}

	/* adjust the parameters */
	original_attributes = params->video_attributes;
	params->video_attributes |= VIDEO_RGB_DIRECT | VIDEO_NEEDS_6BITS_PER_GUN;
	params->depth = 32;

	/* allocate memory for the bitmaps */
	underlay = auto_bitmap_alloc_depth(params->width, params->height, 32);
	overlay = auto_bitmap_alloc_depth(params->width, params->height, 32);
	overlay_yrgb = auto_bitmap_alloc_depth(params->width, params->height, 32);
	bezel = auto_bitmap_alloc_depth(params->width, params->height, 32);
	final = auto_bitmap_alloc_depth(params->width, params->height, 32);
	if (!final || !overlay || !overlay_yrgb || !underlay || !bezel)
		return 1;

	/* allocate the UI overlay */
	uioverlay = auto_bitmap_alloc_depth(params->width, params->height, Machine->color_depth);
	if (uioverlay)
		uioverlayhint = auto_malloc(uioverlay->height * MAX_HINTS_PER_SCANLINE * sizeof(uioverlayhint[0]));
	if (!uioverlay || !uioverlayhint)
		return 1;
	fillbitmap(uioverlay, (Machine->color_depth == 32) ? UI_TRANSPARENT_COLOR32 : UI_TRANSPARENT_COLOR16, NULL);
	memset(uioverlayhint, 0, uioverlay->height * MAX_HINTS_PER_SCANLINE * sizeof(uioverlayhint[0]));

	/* compute the screen rect */
	screenrect.min_x = screenrect.min_y = 0;
	screenrect.max_x = params->width - 1;
	screenrect.max_y = params->height - 1;

	/* compute the game rect */
	gamerect.min_x = (int)(-min_x * (double)(original_width * gamescale) + 0.5);
	gamerect.min_y = (int)(-min_y * (double)(original_height * gamescale) + 0.5);
	gamerect.max_x = gamerect.min_x + original_width * gamescale - 1;
	gamerect.max_y = gamerect.min_y + original_height * gamescale - 1;

	/* now try to create the display */
	if (osd_create_display(params, rgb32_components))
		return 1;

	/* fill in our own RGB components */
	if (compute_rgb_components(original_depth, rgb_components, rgb32_components))
	{
		osd_close_display();
		return 1;
	}

	/* now compute all the artwork pieces' coordinates */
	for (piece = artwork_list; piece; piece = piece->next)
	{
		piece->bounds.min_x = (int)((piece->left - min_x) * (double)(original_width * gamescale) + 0.5);
		piece->bounds.min_y = (int)((piece->top - min_y) * (double)(original_height * gamescale) + 0.5);
		piece->bounds.max_x = (int)((piece->right - min_x) * (double)(original_width * gamescale) + 0.5) - 1;
		piece->bounds.max_y = (int)((piece->bottom - min_y) * (double)(original_height * gamescale) + 0.5) - 1;
	}

	/* now do the final prep on the artwork */
	return artwork_prep();
}



/*-------------------------------------------------
	artwork_update_video_and_audio - update the
	screen, adjusting for artwork
-------------------------------------------------*/

void artwork_update_video_and_audio(struct mame_display *display)
{
	static struct rectangle ui_changed_bounds;
	static int ui_changed;
	int artwork_changed = 0, ui_visible = 0;

	/* do nothing if no artwork */
	if (!artwork_list && !uioverlay)
	{
		osd_update_video_and_audio(display);
		return;
	}

	profiler_mark(PROFILER_ARTWORK);

	/* update the palette */
	if (display->changed_flags & GAME_PALETTE_CHANGED)
		update_palette_lookup(display);

	/* process the artwork and UI only if we're not frameskipping */
	if (display->changed_flags & GAME_BITMAP_CHANGED)
	{
		/* see if there's any UI to display this frame */
		ui_visible = (uibounds.max_x != 0);

		/* if the UI bounds changed, refresh everything */
		if (last_uibounds.min_x != uibounds.min_x || last_uibounds.min_y != uibounds.min_y ||
			last_uibounds.max_x != uibounds.max_x || last_uibounds.max_y != uibounds.max_y)
		{
			/* compute the union of the two rects */
			ui_changed_bounds = last_uibounds;
			union_rect(&ui_changed_bounds, &uibounds);
			last_uibounds = uibounds;

			/* track changes for a few frames */
			ui_changed = 3;
		}

		/* if we have changed pending, mark the artwork dirty */
		if (ui_changed)
		{
			union_rect(&underlay_invalid, &ui_changed_bounds);
			union_rect(&overlay_invalid, &ui_changed_bounds);
			union_rect(&bezel_invalid, &ui_changed_bounds);
			ui_changed--;
		}

		/* artwork disabled case */
		if (!global_artwork_enable)
		{
			fillbitmap(final, MAKE_ARGB(0,0,0,0), NULL);
			union_rect(&underlay_invalid, &screenrect);
			union_rect(&overlay_invalid, &screenrect);
			union_rect(&bezel_invalid, &screenrect);
			render_game_bitmap(display->game_bitmap, palette_lookup, display);
		}

		/* artwork enabled */
		else
		{
			/* update the underlay and overlay */
			artwork_changed = update_layers();

			/* render to the final bitmap */
			if (num_underlays && num_overlays)
				render_game_bitmap_underlay_overlay(display->game_bitmap, palette_lookup, display);
			else if (num_underlays)
				render_game_bitmap_underlay(display->game_bitmap, palette_lookup, display);
			else if (num_overlays)
				render_game_bitmap_overlay(display->game_bitmap, palette_lookup, display);
			else
				render_game_bitmap(display->game_bitmap, palette_lookup, display);

			/* apply the bezel */
			if (num_bezels)
			{
				struct artwork_piece *piece;
				for (piece = artwork_list; piece; piece = piece->next)
					if (piece->layer >= LAYER_BEZEL && piece->intersects_game)
						alpha_blend_intersecting_rect(final, &gamerect, piece->prebitmap, &piece->bounds, piece->scanlinehint);
			}
		}

		/* add UI */
		if (ui_visible)
			render_ui_overlay(uioverlay, uioverlayhint, palette_lookup, display);

		/* if artwork changed, or there's UI, we can't use dirty pixels */
		if (artwork_changed || ui_changed || ui_visible)
		{
			display->changed_flags &= ~VECTOR_PIXELS_CHANGED;
			display->vector_dirty_pixels = NULL;
		}
	}
	profiler_mark(PROFILER_END);

	/* blit the union of the game/screen rect and the UI bounds */
	display->game_bitmap_update = (artwork_changed || ui_changed) ? screenrect : gamerect;
	union_rect(&display->game_bitmap_update, &uibounds);

	/* force the visible area constant */
	display->game_visible_area = screenrect;
	display->game_bitmap = final;
	osd_update_video_and_audio(display);

	/* reset the UI bounds (but only if we rendered the UI) */
	if (display->changed_flags & GAME_BITMAP_CHANGED)
		uibounds.max_x = 0;
}



/*-------------------------------------------------
	artwork_override_screenshot_params - override
	certain parameters when saving a screenshot
-------------------------------------------------*/

void artwork_override_screenshot_params(struct mame_bitmap **bitmap, struct rectangle *rect, UINT32 *rgb_components)
{
	if ((*bitmap == Machine->scrbitmap || *bitmap == uioverlay) && artwork_list)
	{
		*rect = screenrect;

		/* snapshots require correct direct_rgb_components */
		rgb_components[0] = 0xff << rshift;
		rgb_components[1] = 0xff << gshift;
		rgb_components[2] = 0xff << bshift;
		*bitmap = final;
	}
}



/*-------------------------------------------------
	artwork_get_ui_bitmap - get the UI bitmap
-------------------------------------------------*/

struct mame_bitmap *artwork_get_ui_bitmap(void)
{
	return uioverlay ? uioverlay : Machine->scrbitmap;
}



/*-------------------------------------------------
	artwork_mark_ui_dirty - mark a portion of the
	UI bitmap dirty
-------------------------------------------------*/

void artwork_mark_ui_dirty(int minx, int miny, int maxx, int maxy)
{
	/* add to the UI overlay hint if it exists */
	if (uioverlayhint)
	{
		struct rectangle rect;
		int y;

		/* clip to visible */
		if (minx < 0)
			minx = 0;
		if (maxx >= uioverlay->width)
			maxx = uioverlay->width - 1;
		if (miny < 0)
			miny = 0;
		if (maxy >= uioverlay->height)
			maxy = uioverlay->height - 1;

		/* update the global rect */
		rect.min_x = minx;
		rect.max_x = maxx;
		rect.min_y = miny;
		rect.max_y = maxy;
		union_rect(&uibounds, &rect);

		/* add hints for each scanline */
		if (minx <= maxx)
			for (y = miny; y <= maxy; y++)
				add_range_to_hint(uioverlayhint, y, minx, maxx);
	}
}



/*-------------------------------------------------
	artwork_get_screensize - get the real screen
	size
-------------------------------------------------*/

void artwork_get_screensize(int *width, int *height)
{
	if (artwork_list)
	{
		*width = screenrect.max_x - screenrect.min_x + 1;
		*height = screenrect.max_y - screenrect.min_y + 1;
	}
	else
	{
		*width = Machine->drv->screen_width;
		*height = Machine->drv->screen_height;
	}
}



/*-------------------------------------------------
	artwork_enable - globally enable/disable
	artwork
-------------------------------------------------*/

void artwork_enable(int enable)
{
	global_artwork_enable = enable;
}



/*-------------------------------------------------
	artwork_set_overlay - set the hard-coded
	overlay for this game
-------------------------------------------------*/

void artwork_set_overlay(const struct overlay_piece *overlist)
{
	overlay_list = overlist;
}



/*-------------------------------------------------
	artwork_show - show/hide a tagged piece of art
-------------------------------------------------*/

void artwork_show(const char *tag, int show)
{
	struct artwork_piece *piece;

	/* find all the pieces that match the tag */
	for (piece = artwork_list; piece; piece = piece->next)
		if (piece->tag && !strcmp(piece->tag, tag))
		{
			/* if the state is changing, invalidate that area */
			if (piece->visible != show)
			{
				piece->visible = show;

				/* backdrop */
				if (piece->layer == LAYER_BACKDROP)
					union_rect(&underlay_invalid, &piece->bounds);

				/* overlay */
				else if (piece->layer == LAYER_OVERLAY)
					union_rect(&overlay_invalid, &piece->bounds);

				/* bezel */
				else if (piece->layer >= LAYER_BEZEL)
					union_rect(&bezel_invalid, &piece->bounds);
			}
		}
}



#if 0
#pragma mark -
#pragma mark LAYER PROCESSING
#endif

/*-------------------------------------------------
	update_layers - update any dirty areas of
	the layers
-------------------------------------------------*/

static int update_layers(void)
{
	struct artwork_piece *piece = artwork_list;
	struct rectangle combined;
	int changed = 0;

	/* update the underlays */
	if (underlay_invalid.max_x != 0)
	{
		sect_rect(&underlay_invalid, &screenrect);
		erase_rect(underlay, &underlay_invalid, 0);
		for (piece = artwork_list; piece; piece = piece->next)
			if (piece->layer == LAYER_BACKDROP && piece->visible && piece->prebitmap)
				alpha_blend_intersecting_rect(underlay, &underlay_invalid, piece->prebitmap, &piece->bounds, piece->scanlinehint);
	}

	/* update the overlays */
	if (overlay_invalid.max_x != 0)
	{
		sect_rect(&overlay_invalid, &screenrect);
		erase_rect(overlay, &overlay_invalid, transparent_color);
		erase_rect(overlay_yrgb, &overlay_invalid, ASSEMBLE_ARGB(0,0xff,0xff,0xff));
		for (piece = artwork_list; piece; piece = piece->next)
			if (piece->layer == LAYER_OVERLAY && piece->visible && piece->prebitmap)
				cmy_blend_intersecting_rect(overlay, overlay_yrgb, &overlay_invalid, piece->prebitmap, piece->yrgbbitmap, &piece->bounds, piece->blendflags);
	}

	/* update the bezels */
	if (bezel_invalid.max_x != 0)
	{
		sect_rect(&bezel_invalid, &screenrect);
		erase_rect(bezel, &bezel_invalid, transparent_color);
		for (piece = artwork_list; piece; piece = piece->next)
			if (piece->layer >= LAYER_BEZEL && piece->visible && piece->prebitmap)
				alpha_blend_intersecting_rect(bezel, &bezel_invalid, piece->prebitmap, &piece->bounds, piece->scanlinehint);
	}

	/* combine the invalid rects */
	combined = underlay_invalid;
	union_rect(&combined, &overlay_invalid);
	union_rect(&combined, &bezel_invalid);
	if (combined.max_x != 0)
	{
		/* blend into the final bitmap */
		erase_rect(final, &combined, 0);
		alpha_blend_intersecting_rect(final, &combined, underlay, &screenrect, NULL);
		add_intersecting_rect(final, &combined, overlay, &screenrect);
		alpha_blend_intersecting_rect(final, &combined, bezel, &screenrect, NULL);
		changed = 1;
	}

	/* reset the invalid rects */
	underlay_invalid.max_x = 0;
	overlay_invalid.max_x = 0;
	bezel_invalid.max_x = 0;
	return changed;
}



/*-------------------------------------------------
	erase_rect - erase the given bounds of a 32bpp
	bitmap
-------------------------------------------------*/

static void erase_rect(struct mame_bitmap *bitmap, const struct rectangle *bounds, UINT32 color)
{
	int x, y;

	/* loop over rows */
	for (y = bounds->min_y; y <= bounds->max_y; y++)
	{
		UINT32 *dest = (UINT32 *)bitmap->base + y * bitmap->rowpixels;
		for (x = bounds->min_x; x <= bounds->max_x; x++)
			dest[x] = color;
	}
}



/*-------------------------------------------------
	alpha_blend_intersecting_rect - alpha blend an
	artwork piece into a bitmap
-------------------------------------------------*/

static void alpha_blend_intersecting_rect(struct mame_bitmap *dstbitmap, const struct rectangle *dstbounds, struct mame_bitmap *srcbitmap, const struct rectangle *srcbounds, const UINT32 *hintlist)
{
	struct rectangle sect = *srcbounds;
	UINT32 dummy_range[2];
	int lclip, rclip;
	int x, y, h;

	/* compute the intersection */
	sect_rect(&sect, dstbounds);

	/* compute the source-relative left/right clip */
	lclip = sect.min_x - srcbounds->min_x;
	rclip = sect.max_x - srcbounds->min_x;

	/* set up a dummy range */
	dummy_range[0] = srcbitmap->width - 1;
	dummy_range[1] = 0;

	/* adjust the hintlist for the starting offset */
	if (hintlist)
		hintlist -= srcbounds->min_y * MAX_HINTS_PER_SCANLINE;

	/* loop over rows */
	for (y = sect.min_y; y <= sect.max_y; y++)
	{
		UINT32 *src = (UINT32 *)srcbitmap->base + (y - srcbounds->min_y) * srcbitmap->rowpixels;
		UINT32 *dest = (UINT32 *)dstbitmap->base + y * dstbitmap->rowpixels + srcbounds->min_x;
		const UINT32 *hint = hintlist ? &hintlist[y * MAX_HINTS_PER_SCANLINE] : &dummy_range[0];

		/* loop over hints */
		for (h = 0; h < MAX_HINTS_PER_SCANLINE && hint[h] != 0; h++)
		{
			int start = hint[h] >> 16;
			int stop = hint[h] & 0xffff;

			/* clip to the sect rect */
			if (start < lclip)
				start = lclip;
			else if (start > rclip)
				continue;
			if (stop > rclip)
				stop = rclip;
			else if (stop < lclip)
				continue;

			/* loop over columns */
			for (x = start; x <= stop; x++)
			{
				/* we don't bother optimizing for transparent here because we hope that the */
				/* hints have removed most of the need */
				UINT32 pix = src[x];
				UINT32 dpix = dest[x];
				int alpha = (pix >> ashift) & 0xff;

				/* alpha is inverted, so alpha 0 means fully opaque */
				if (alpha == 0)
					dest[x] = pix;

				/* otherwise, we do a proper blend */
				else
				{
					int r = ((pix >> rshift) & 0xff) + ((alpha * ((dpix >> rshift) & 0xff)) >> 8);
					int g = ((pix >> gshift) & 0xff) + ((alpha * ((dpix >> gshift) & 0xff)) >> 8);
					int b = ((pix >> bshift) & 0xff) + ((alpha * ((dpix >> bshift) & 0xff)) >> 8);

					/* add the alpha values in inverted space (looks weird but is correct) */
					int a = alpha + ((dpix >> ashift) & 0xff) - 0xff;
					if (a < 0) a = 0;
					dest[x] = ASSEMBLE_ARGB(a,r,g,b);
				}
			}
		}
	}
}



/*-------------------------------------------------
	add_intersecting_rect - add a
	artwork piece into a bitmap
-------------------------------------------------*/

static void add_intersecting_rect(struct mame_bitmap *dstbitmap, const struct rectangle *dstbounds, struct mame_bitmap *srcbitmap, const struct rectangle *srcbounds)
{
	struct rectangle sect = *srcbounds;
	int x, y, width;

	/* compute the intersection and resulting width */
	sect_rect(&sect, dstbounds);
	width = sect.max_x - sect.min_x + 1;

	/* loop over rows */
	for (y = sect.min_y; y <= sect.max_y; y++)
	{
		UINT32 *src = (UINT32 *)srcbitmap->base + (y - srcbounds->min_y) * srcbitmap->rowpixels + (sect.min_x - srcbounds->min_x);
		UINT32 *dest = (UINT32 *)dstbitmap->base + y * dstbitmap->rowpixels + sect.min_x;

		/* loop over columns */
		for (x = 0; x < width; x++)
		{
			UINT32 pix = src[x];

			/* just add and clamp */
			if (pix != transparent_color)
				dest[x] = add_and_clamp(pix, dest[x]);
		}
	}
}



/*-------------------------------------------------
	cmy_blend_intersecting_rect - CMY blend an
	artwork piece into a bitmap
-------------------------------------------------*/

static void cmy_blend_intersecting_rect(
	struct mame_bitmap *dstprebitmap, struct mame_bitmap *dstyrgbbitmap, const struct rectangle *dstbounds,
	struct mame_bitmap *srcprebitmap, struct mame_bitmap *srcyrgbbitmap, const struct rectangle *srcbounds,
	UINT8 blendflags)
{
	struct rectangle sect = *srcbounds;
	int x, y, width;

	/* compute the intersection and resulting width */
	sect_rect(&sect, dstbounds);
	width = sect.max_x - sect.min_x + 1;

	/* loop over rows */
	for (y = sect.min_y; y <= sect.max_y; y++)
	{
		UINT32 *srcpre = (UINT32 *)srcprebitmap->base + (y - srcbounds->min_y) * srcprebitmap->rowpixels + (sect.min_x - srcbounds->min_x);
		UINT32 *srcyrgb = (UINT32 *)srcyrgbbitmap->base + (y - srcbounds->min_y) * srcyrgbbitmap->rowpixels + (sect.min_x - srcbounds->min_x);
		UINT32 *destpre = (UINT32 *)dstprebitmap->base + y * dstprebitmap->rowpixels + sect.min_x;
		UINT32 *destyrgb = (UINT32 *)dstyrgbbitmap->base + y * dstyrgbbitmap->rowpixels + sect.min_x;

		/* loop over columns */
		for (x = 0; x < width; x++)
		{
			UINT32 spre = srcpre[x];
			UINT32 dpre = destpre[x];
			UINT32 syrgb = srcyrgb[x];
			UINT32 dyrgb = destyrgb[x];

			/* handle "non-blending" mode */
			if (blendflags & OVERLAY_FLAG_NOBLEND)
			{
				if ((spre & nonalpha_mask) && spre >= dpre)
				{
					destpre[x] = spre;
					destyrgb[x] = syrgb;
				}
			}

			/* simple copy if nothing at the dest */
			else if (dpre == transparent_color && dyrgb == 0)
			{
				destpre[x] = spre;
				destyrgb[x] = syrgb;
			}
			else
			{
				/* subtract CMY and alpha from each pixel */
				int sc = (~syrgb >> rshift) & 0xff;
				int sm = (~syrgb >> gshift) & 0xff;
				int sy = (~syrgb >> bshift) & 0xff;
				int sa = (~spre >> ashift) & 0xff;
				int dc = (~dyrgb >> rshift) & 0xff;
				int dm = (~dyrgb >> gshift) & 0xff;
				int dy = (~dyrgb >> bshift) & 0xff;
				int da = (~dpre >> ashift) & 0xff;
				int dr, dg, db;
				int max;

				/* add and clamp the alphas */
				da += sa;
				if (da > 0xff) da = 0xff;

				/* add the CMY */
				dc += sc;
				dm += sm;
				dy += sy;

				/* compute the maximum intensity */
				max = (dc > dm) ? dc : dm;
				max = (dy > max) ? dy : max;

				/* if that's out of range, scale by it */
				if (max > 0xff)
				{
					dc = (dc * 0xff) / max;
					dm = (dm * 0xff) / max;
					dy = (dy * 0xff) / max;
				}

				/* convert back to RGB */
				dr = dc ^ 0xff;
				dg = dm ^ 0xff;
				db = dy ^ 0xff;

				/* recompute the two pixels */
				destpre[x] = compute_pre_pixel(da,dr,dg,db);
				destyrgb[x] = compute_yrgb_pixel(da,dr,dg,db);
			}
		}
	}
}



#if 0
#pragma mark -
#pragma mark GAME BITMAP PROCESSING
#endif

/*-------------------------------------------------
	update_palette - update any dirty palette
	entries
-------------------------------------------------*/

static void update_palette_lookup(struct mame_display *display)
{
	int i, j;

	/* loop over dirty colors in batches of 32 */
	for (i = 0; i < display->game_palette_entries; i += 32)
	{
		UINT32 dirtyflags = display->game_palette_dirty[i / 32];
		if (dirtyflags)
		{
			display->game_palette_dirty[i / 32] = 0;

			/* loop over all 32 bits and update dirty entries */
			for (j = 0; j < 32; j++, dirtyflags >>= 1)
				if (dirtyflags & 1)
				{
					/* extract the RGB values */
					rgb_t rgbvalue = display->game_palette[i + j];
					int r = RGB_RED(rgbvalue);
					int g = RGB_GREEN(rgbvalue);
					int b = RGB_BLUE(rgbvalue);

					/* update the lookup table */
					palette_lookup[i + j] = ASSEMBLE_ARGB(0, r, g, b);
				}
		}
	}
}



/*-------------------------------------------------
	render_game_bitmap - render the game bitmap
	raw
-------------------------------------------------*/

#define PIXEL(x,y,srcdstbase,srcdstrpix,bits)	(*((UINT##bits *)srcdstbase##base + (y) * srcdstrpix##rowpixels + (x)))

static void render_game_bitmap(struct mame_bitmap *bitmap, const rgb_t *palette, struct mame_display *display)
{
	int srcrowpixels = bitmap->rowpixels;
	int dstrowpixels = final->rowpixels;
	void *srcbase, *dstbase;
	int width, height;
	int x, y;

	/* compute common parameters */
	width = Machine->absolute_visible_area.max_x - Machine->absolute_visible_area.min_x + 1;
	height = Machine->absolute_visible_area.max_y - Machine->absolute_visible_area.min_y + 1;
	srcbase = (UINT8 *)bitmap->base + Machine->absolute_visible_area.min_y * bitmap->rowbytes;
	dstbase = (UINT8 *)final->base + gamerect.min_y * final->rowbytes + gamerect.min_x * sizeof(UINT32);

	/* vector case */
	if (display->changed_flags & VECTOR_PIXELS_CHANGED)
	{
		vector_pixel_t offset = VECTOR_PIXEL(gamerect.min_x, gamerect.min_y);
		vector_pixel_t *list = display->vector_dirty_pixels;

		/* 16/15bpp case */
		if (bitmap->depth != 32)
		{
			while (*list != VECTOR_PIXEL_END)
			{
				vector_pixel_t coords = *list;
				x = VECTOR_PIXEL_X(coords);
				y = VECTOR_PIXEL_Y(coords);
				*list++ = coords + offset;
				PIXEL(x,y,dst,dst,32) = palette[PIXEL(x,y,src,src,16)];
			}
		}

		/* 32bpp case */
		else
		{
			while (*list != VECTOR_PIXEL_END)
			{
				vector_pixel_t coords = *list;
				x = VECTOR_PIXEL_X(coords);
				y = VECTOR_PIXEL_Y(coords);
				*list++ = coords + offset;
				PIXEL(x,y,dst,dst,32) = PIXEL(x,y,src,src,32);
			}
		}
	}

	/* 1x scale */
	else if (gamescale == 1)
	{
		/* 16/15bpp case */
		if (bitmap->depth != 32)
		{
			for (y = 0; y < height; y++)
			{
				UINT16 *src = (UINT16 *)srcbase + y * srcrowpixels + Machine->absolute_visible_area.min_x;
				UINT32 *dst = (UINT32 *)dstbase + y * dstrowpixels;
				for (x = 0; x < width; x++)
					*dst++ = palette[*src++];
			}
		}

		/* 32bpp case */
		else
		{
			for (y = 0; y < height; y++)
			{
				UINT32 *src = (UINT32 *)srcbase + y * srcrowpixels + Machine->absolute_visible_area.min_x;
				UINT32 *dst = (UINT32 *)dstbase + y * dstrowpixels;
				for (x = 0; x < width; x++)
					*dst++ = *src++;
			}
		}
	}

	/* 2x scale */
	else if (gamescale == 2)
	{
		/* 16/15bpp case */
		if (bitmap->depth != 32)
		{
			for (y = 0; y < height; y++)
			{
				UINT16 *src = (UINT16 *)srcbase + y * srcrowpixels + Machine->absolute_visible_area.min_x;
				UINT32 *dst = (UINT32 *)dstbase + y * 2 * dstrowpixels;
				for (x = 0; x < width; x++)
				{
					UINT32 val = palette[*src++];
					dst[0] = val;
					dst[1] = val;
					dst[dstrowpixels] = val;
					dst[dstrowpixels + 1] = val;
					dst += 2;
				}
			}
		}

		/* 32bpp case */
		else
		{
			for (y = 0; y < height; y++)
			{
				UINT32 *src = (UINT32 *)srcbase + y * srcrowpixels + Machine->absolute_visible_area.min_x;
				UINT32 *dst = (UINT32 *)dstbase + y * 2 * dstrowpixels;
				for (x = 0; x < width; x++)
				{
					UINT32 val = *src++;
					dst[0] = val;
					dst[1] = val;
					dst[dstrowpixels] = val;
					dst[dstrowpixels + 1] = val;
					dst += 2;
				}
			}
		}
	}
}



/*-------------------------------------------------
	render_game_bitmap_underlay - render the game
	bitmap on top of an underlay
-------------------------------------------------*/

static void render_game_bitmap_underlay(struct mame_bitmap *bitmap, const rgb_t *palette, struct mame_display *display)
{
	int srcrowpixels = bitmap->rowpixels;
	int dstrowpixels = final->rowpixels;
	void *srcbase, *dstbase, *undbase;
	int width, height;
	int x, y;

	/* compute common parameters */
	width = Machine->absolute_visible_area.max_x - Machine->absolute_visible_area.min_x + 1;
	height = Machine->absolute_visible_area.max_y - Machine->absolute_visible_area.min_y + 1;
	srcbase = (UINT8 *)bitmap->base + Machine->absolute_visible_area.min_y * bitmap->rowbytes;
	dstbase = (UINT8 *)final->base + gamerect.min_y * final->rowbytes + gamerect.min_x * sizeof(UINT32);
	undbase = (UINT8 *)underlay->base + gamerect.min_y * underlay->rowbytes + gamerect.min_x * sizeof(UINT32);

	/* vector case */
	if (display->changed_flags & VECTOR_PIXELS_CHANGED)
	{
		vector_pixel_t offset = VECTOR_PIXEL(gamerect.min_x, gamerect.min_y);
		vector_pixel_t *list = display->vector_dirty_pixels;

		/* 16/15bpp case */
		if (bitmap->depth != 32)
		{
			while (*list != VECTOR_PIXEL_END)
			{
				vector_pixel_t coords = *list;
				x = VECTOR_PIXEL_X(coords);
				y = VECTOR_PIXEL_Y(coords);
				*list++ = coords + offset;
				PIXEL(x,y,dst,dst,32) = add_and_clamp(palette[PIXEL(x,y,src,src,16)], PIXEL(x,y,und,dst,32));
			}
		}

		/* 32bpp case */
		else
		{
			while (*list != VECTOR_PIXEL_END)
			{
				vector_pixel_t coords = *list;
				x = VECTOR_PIXEL_X(coords);
				y = VECTOR_PIXEL_Y(coords);
				*list++ = coords + offset;
				PIXEL(x,y,dst,dst,32) = add_and_clamp(PIXEL(x,y,src,src,32), PIXEL(x,y,und,dst,32));
			}
		}
	}

	/* 1x scale */
	else if (gamescale == 1)
	{
		/* 16/15bpp case */
		if (bitmap->depth != 32)
		{
			for (y = 0; y < height; y++)
			{
				UINT16 *src = (UINT16 *)srcbase + y * srcrowpixels + Machine->absolute_visible_area.min_x;
				UINT32 *dst = (UINT32 *)dstbase + y * dstrowpixels;
				UINT32 *und = (UINT32 *)undbase + y * dstrowpixels;
				for (x = 0; x < width; x++)
					*dst++ = add_and_clamp(palette[*src++], *und++);
			}
		}

		/* 32bpp case */
		else
		{
			for (y = 0; y < height; y++)
			{
				UINT32 *src = (UINT32 *)srcbase + y * srcrowpixels + Machine->absolute_visible_area.min_x;
				UINT32 *dst = (UINT32 *)dstbase + y * dstrowpixels;
				UINT32 *und = (UINT32 *)undbase + y * dstrowpixels;
				for (x = 0; x < width; x++)
					*dst++ = add_and_clamp(*src++, *und++);
			}
		}
	}

	/* 2x scale */
	else if (gamescale == 2)
	{
		/* 16/15bpp case */
		if (bitmap->depth != 32)
		{
			for (y = 0; y < height; y++)
			{
				UINT16 *src = (UINT16 *)srcbase + y * srcrowpixels + Machine->absolute_visible_area.min_x;
				UINT32 *dst = (UINT32 *)dstbase + y * 2 * dstrowpixels;
				UINT32 *und = (UINT32 *)undbase + y * 2 * dstrowpixels;
				for (x = 0; x < width; x++)
				{
					UINT32 val = palette[*src++];
					dst[0] = add_and_clamp(val, und[0]);
					dst[1] = add_and_clamp(val, und[1]);
					dst[dstrowpixels] = add_and_clamp(val, und[dstrowpixels]);
					dst[dstrowpixels + 1] = add_and_clamp(val, und[dstrowpixels + 1]);
					dst += 2;
					und += 2;
				}
			}
		}

		/* 32bpp case */
		else
		{
			for (y = 0; y < height; y++)
			{
				UINT32 *src = (UINT32 *)srcbase + y * srcrowpixels + Machine->absolute_visible_area.min_x;
				UINT32 *dst = (UINT32 *)dstbase + y * 2 * dstrowpixels;
				UINT32 *und = (UINT32 *)undbase + y * 2 * dstrowpixels;
				for (x = 0; x < width; x++)
				{
					UINT32 val = *src++;
					dst[0] = add_and_clamp(val, und[0]);
					dst[1] = add_and_clamp(val, und[1]);
					dst[dstrowpixels] = add_and_clamp(val, und[dstrowpixels]);
					dst[dstrowpixels + 1] = add_and_clamp(val, und[dstrowpixels + 1]);
					dst += 2;
					und += 2;
				}
			}
		}
	}
}



/*-------------------------------------------------
	render_game_bitmap_overlay - render the game
	bitmap blended with an overlay
-------------------------------------------------*/

static void render_game_bitmap_overlay(struct mame_bitmap *bitmap, const rgb_t *palette, struct mame_display *display)
{
	int srcrowpixels = bitmap->rowpixels;
	int dstrowpixels = final->rowpixels;
	void *srcbase, *dstbase, *overbase, *overyrgbbase;
	int width, height;
	int x, y;

	/* compute common parameters */
	width = Machine->absolute_visible_area.max_x - Machine->absolute_visible_area.min_x + 1;
	height = Machine->absolute_visible_area.max_y - Machine->absolute_visible_area.min_y + 1;
	srcbase = (UINT8 *)bitmap->base + Machine->absolute_visible_area.min_y * bitmap->rowbytes;
	dstbase = (UINT8 *)final->base + gamerect.min_y * final->rowbytes + gamerect.min_x * sizeof(UINT32);
	overbase = (UINT8 *)overlay->base + gamerect.min_y * overlay->rowbytes + gamerect.min_x * sizeof(UINT32);
	overyrgbbase = (UINT8 *)overlay_yrgb->base + gamerect.min_y * overlay_yrgb->rowbytes + gamerect.min_x * sizeof(UINT32);

	/* vector case */
	if (display->changed_flags & VECTOR_PIXELS_CHANGED)
	{
		vector_pixel_t offset = VECTOR_PIXEL(gamerect.min_x, gamerect.min_y);
		vector_pixel_t *list = display->vector_dirty_pixels;

		/* 16/15bpp case */
		if (bitmap->depth != 32)
		{
			while (*list != VECTOR_PIXEL_END)
			{
				vector_pixel_t coords = *list;
				x = VECTOR_PIXEL_X(coords);
				y = VECTOR_PIXEL_Y(coords);
				*list++ = coords + offset;
				PIXEL(x,y,dst,dst,32) = blend_over(palette[PIXEL(x,y,src,src,16)], PIXEL(x,y,over,dst,32), PIXEL(x,y,overyrgb,dst,32));
			}
		}

		/* 32bpp case */
		else
		{
			while (*list != VECTOR_PIXEL_END)
			{
				vector_pixel_t coords = *list;
				x = VECTOR_PIXEL_X(coords);
				y = VECTOR_PIXEL_Y(coords);
				*list++ = coords + offset;
				PIXEL(x,y,dst,dst,32) = blend_over(PIXEL(x,y,src,src,32), PIXEL(x,y,over,dst,32), PIXEL(x,y,overyrgb,dst,32));
			}
		}
	}

	/* 1x scale */
	else if (gamescale == 1)
	{
		/* 16/15bpp case */
		if (bitmap->depth != 32)
		{
			for (y = 0; y < height; y++)
			{
				UINT16 *src = (UINT16 *)srcbase + y * srcrowpixels + Machine->absolute_visible_area.min_x;
				UINT32 *dst = (UINT32 *)dstbase + y * dstrowpixels;
				UINT32 *over = (UINT32 *)overbase + y * dstrowpixels;
				UINT32 *overyrgb = (UINT32 *)overyrgbbase + y * dstrowpixels;
				for (x = 0; x < width; x++)
					*dst++ = blend_over(palette[*src++], *over++, *overyrgb++);
			}
		}

		/* 32bpp case */
		else
		{
			for (y = 0; y < height; y++)
			{
				UINT32 *src = (UINT32 *)srcbase + y * srcrowpixels + Machine->absolute_visible_area.min_x;
				UINT32 *dst = (UINT32 *)dstbase + y * dstrowpixels;
				UINT32 *over = (UINT32 *)overbase + y * dstrowpixels;
				UINT32 *overyrgb = (UINT32 *)overyrgbbase + y * dstrowpixels;
				for (x = 0; x < width; x++)
					*dst++ = blend_over(*src++, *over++, *overyrgb++);
			}
		}
	}

	/* 2x scale */
	else if (gamescale == 2)
	{
		/* 16/15bpp case */
		if (bitmap->depth != 32)
		{
			for (y = 0; y < height; y++)
			{
				UINT16 *src = (UINT16 *)srcbase + y * srcrowpixels + Machine->absolute_visible_area.min_x;
				UINT32 *dst = (UINT32 *)dstbase + y * 2 * dstrowpixels;
				UINT32 *over = (UINT32 *)overbase + y * 2 * dstrowpixels;
				UINT32 *overyrgb = (UINT32 *)overyrgbbase + y * 2 * dstrowpixels;
				for (x = 0; x < width; x++)
				{
					UINT32 val = palette[*src++];
					dst[0] = blend_over(val, over[0], overyrgb[0]);
					dst[1] = blend_over(val, over[1], overyrgb[1]);
					dst[dstrowpixels] = blend_over(val, over[dstrowpixels], overyrgb[dstrowpixels]);
					dst[dstrowpixels + 1] = blend_over(val, over[dstrowpixels + 1], overyrgb[dstrowpixels + 1]);
					dst += 2;
					over += 2;
					overyrgb += 2;
				}
			}
		}

		/* 32bpp case */
		else
		{
			for (y = 0; y < height; y++)
			{
				UINT32 *src = (UINT32 *)srcbase + y * srcrowpixels + Machine->absolute_visible_area.min_x;
				UINT32 *dst = (UINT32 *)dstbase + y * 2 * dstrowpixels;
				UINT32 *over = (UINT32 *)overbase + y * 2 * dstrowpixels;
				UINT32 *overyrgb = (UINT32 *)overyrgbbase + y * 2 * dstrowpixels;
				for (x = 0; x < width; x++)
				{
					UINT32 val = *src++;
					dst[0] = blend_over(val, over[0], overyrgb[0]);
					dst[1] = blend_over(val, over[1], overyrgb[1]);
					dst[dstrowpixels] = blend_over(val, over[dstrowpixels], overyrgb[dstrowpixels]);
					dst[dstrowpixels + 1] = blend_over(val, over[dstrowpixels + 1], overyrgb[dstrowpixels + 1]);
					dst += 2;
					over += 2;
					overyrgb += 2;
				}
			}
		}
	}
}



/*-------------------------------------------------
	render_game_bitmap_underlay_overlay - render
	the game bitmap blended with an overlay and
	added to an underlay
-------------------------------------------------*/

static void render_game_bitmap_underlay_overlay(struct mame_bitmap *bitmap, const rgb_t *palette, struct mame_display *display)
{
	int srcrowpixels = bitmap->rowpixels;
	int dstrowpixels = final->rowpixels;
	void *srcbase, *dstbase, *undbase, *overbase, *overyrgbbase;
	int width, height;
	int x, y;

	/* compute common parameters */
	width = Machine->absolute_visible_area.max_x - Machine->absolute_visible_area.min_x + 1;
	height = Machine->absolute_visible_area.max_y - Machine->absolute_visible_area.min_y + 1;
	srcbase = (UINT8 *)bitmap->base + Machine->absolute_visible_area.min_y * bitmap->rowbytes;
	dstbase = (UINT8 *)final->base + gamerect.min_y * final->rowbytes + gamerect.min_x * sizeof(UINT32);
	undbase = (UINT8 *)underlay->base + gamerect.min_y * underlay->rowbytes + gamerect.min_x * sizeof(UINT32);
	overbase = (UINT8 *)overlay->base + gamerect.min_y * overlay->rowbytes + gamerect.min_x * sizeof(UINT32);
	overyrgbbase = (UINT8 *)overlay_yrgb->base + gamerect.min_y * overlay_yrgb->rowbytes + gamerect.min_x * sizeof(UINT32);

	/* vector case */
	if (display->changed_flags & VECTOR_PIXELS_CHANGED)
	{
		vector_pixel_t offset = VECTOR_PIXEL(gamerect.min_x, gamerect.min_y);
		vector_pixel_t *list = display->vector_dirty_pixels;

		/* 16/15bpp case */
		if (bitmap->depth != 32)
		{
			while (*list != VECTOR_PIXEL_END)
			{
				vector_pixel_t coords = *list;
				x = VECTOR_PIXEL_X(coords);
				y = VECTOR_PIXEL_Y(coords);
				*list++ = coords + offset;
				PIXEL(x,y,dst,dst,32) = add_and_clamp(blend_over(palette[PIXEL(x,y,src,src,16)], PIXEL(x,y,over,dst,32), PIXEL(x,y,overyrgb,dst,32)), PIXEL(x,y,und,dst,32));
			}
		}

		/* 32bpp case */
		else
		{
			while (*list != VECTOR_PIXEL_END)
			{
				vector_pixel_t coords = *list;
				x = VECTOR_PIXEL_X(coords);
				y = VECTOR_PIXEL_Y(coords);
				*list++ = coords + offset;
				PIXEL(x,y,dst,dst,32) = add_and_clamp(blend_over(PIXEL(x,y,src,src,32), PIXEL(x,y,over,dst,32), PIXEL(x,y,overyrgb,dst,32)), PIXEL(x,y,und,dst,32));
			}
		}
	}

	/* 1x scale */
	else if (gamescale == 1)
	{
		/* 16/15bpp case */
		if (bitmap->depth != 32)
		{
			for (y = 0; y < height; y++)
			{
				UINT16 *src = (UINT16 *)srcbase + y * srcrowpixels + Machine->absolute_visible_area.min_x;
				UINT32 *dst = (UINT32 *)dstbase + y * dstrowpixels;
				UINT32 *und = (UINT32 *)undbase + y * dstrowpixels;
				UINT32 *over = (UINT32 *)overbase + y * dstrowpixels;
				UINT32 *overyrgb = (UINT32 *)overyrgbbase + y * dstrowpixels;
				for (x = 0; x < width; x++)
					*dst++ = add_and_clamp(blend_over(palette[*src++], *over++, *overyrgb++), *und++);
			}
		}

		/* 32bpp case */
		else
		{
			for (y = 0; y < height; y++)
			{
				UINT32 *src = (UINT32 *)srcbase + y * srcrowpixels + Machine->absolute_visible_area.min_x;
				UINT32 *dst = (UINT32 *)dstbase + y * dstrowpixels;
				UINT32 *und = (UINT32 *)undbase + y * dstrowpixels;
				UINT32 *over = (UINT32 *)overbase + y * dstrowpixels;
				UINT32 *overyrgb = (UINT32 *)overyrgbbase + y * dstrowpixels;
				for (x = 0; x < width; x++)
					*dst++ = add_and_clamp(blend_over(*src++, *over++, *overyrgb++), *und++);
			}
		}
	}

	/* 2x scale */
	else if (gamescale == 2)
	{
		/* 16/15bpp case */
		if (bitmap->depth != 32)
		{
			for (y = 0; y < height; y++)
			{
				UINT16 *src = (UINT16 *)srcbase + y * srcrowpixels + Machine->absolute_visible_area.min_x;
				UINT32 *dst = (UINT32 *)dstbase + y * 2 * dstrowpixels;
				UINT32 *und = (UINT32 *)undbase + y * 2 * dstrowpixels;
				UINT32 *over = (UINT32 *)overbase + y * 2 * dstrowpixels;
				UINT32 *overyrgb = (UINT32 *)overyrgbbase + y * 2 * dstrowpixels;
				for (x = 0; x < width; x++)
				{
					UINT32 val = palette[*src++];
					dst[0] = add_and_clamp(blend_over(val, over[0], overyrgb[0]), und[0]);
					dst[1] = add_and_clamp(blend_over(val, over[1], overyrgb[1]), und[1]);
					dst[dstrowpixels] = add_and_clamp(blend_over(val, over[dstrowpixels], overyrgb[dstrowpixels]), und[dstrowpixels]);
					dst[dstrowpixels + 1] = add_and_clamp(blend_over(val, over[dstrowpixels + 1], overyrgb[dstrowpixels + 1]), und[dstrowpixels + 1]);
					dst += 2;
					und += 2;
					over += 2;
					overyrgb += 2;
				}
			}
		}

		/* 32bpp case */
		else
		{
			for (y = 0; y < height; y++)
			{
				UINT32 *src = (UINT32 *)srcbase + y * srcrowpixels + Machine->absolute_visible_area.min_x;
				UINT32 *dst = (UINT32 *)dstbase + y * 2 * dstrowpixels;
				UINT32 *und = (UINT32 *)undbase + y * 2 * dstrowpixels;
				UINT32 *over = (UINT32 *)overbase + y * 2 * dstrowpixels;
				UINT32 *overyrgb = (UINT32 *)overyrgbbase + y * 2 * dstrowpixels;
				for (x = 0; x < width; x++)
				{
					UINT32 val = *src++;
					dst[0] = add_and_clamp(blend_over(val, over[0], overyrgb[0]), und[0]);
					dst[1] = add_and_clamp(blend_over(val, over[1], overyrgb[1]), und[1]);
					dst[dstrowpixels] = add_and_clamp(blend_over(val, over[dstrowpixels], overyrgb[dstrowpixels]), und[dstrowpixels]);
					dst[dstrowpixels + 1] = add_and_clamp(blend_over(val, over[dstrowpixels + 1], overyrgb[dstrowpixels + 1]), und[dstrowpixels + 1]);
					dst += 2;
					und += 2;
					over += 2;
					overyrgb += 2;
				}
			}
		}
	}
}



/*-------------------------------------------------
	render_ui_overlay - render the UI overlay
-------------------------------------------------*/

static void render_ui_overlay(struct mame_bitmap *bitmap, UINT32 *dirty, const rgb_t *palette, struct mame_display *display)
{
	int srcrowpixels = bitmap->rowpixels;
	int dstrowpixels = final->rowpixels;
	void *srcbase, *dstbase;
	int width, height;
	int x, y, h;

	/* compute common parameters */
	width = bitmap->width;
	height = bitmap->height;
	srcbase = bitmap->base;
	dstbase = final->base;

	/* 16/15bpp case */
	if (bitmap->depth != 32)
	{
		for (y = 0; y < height; y++)
		{
			UINT16 *src = (UINT16 *)srcbase + y * srcrowpixels;
			UINT32 *dst = (UINT32 *)dstbase + y * dstrowpixels;
			UINT32 *hint = &dirty[y * MAX_HINTS_PER_SCANLINE];
			for (h = 0; h < MAX_HINTS_PER_SCANLINE && hint[h] != 0; h++)
			{
				int start = hint[h] >> 16;
				int stop = hint[h] & 0xffff;
				hint[h] = 0;

				for (x = start; x <= stop; x++)
				{
					int pix = src[x];
					if (pix != UI_TRANSPARENT_COLOR16)
					{
						dst[x] = palette[pix];
						src[x] = UI_TRANSPARENT_COLOR16;
					}
				}
			}
		}
	}

	/* 32bpp case */
	else
	{
		for (y = 0; y < height; y++)
		{
			UINT32 *src = (UINT32 *)srcbase + y * srcrowpixels;
			UINT32 *dst = (UINT32 *)dstbase + y * dstrowpixels;
			UINT32 *hint = &dirty[y * MAX_HINTS_PER_SCANLINE];
			for (h = 0; h < MAX_HINTS_PER_SCANLINE && hint[h] != 0; h++)
			{
				int start = hint[h] >> 16;
				int stop = hint[h] & 0xffff;
				hint[h] = 0;

				for (x = start; x <= stop; x++)
				{
					int pix = src[x];
					if (pix != UI_TRANSPARENT_COLOR32)
					{
						dst[x] = pix;
						src[x] = UI_TRANSPARENT_COLOR32;
					}
				}
			}
		}
	}
}



/*-------------------------------------------------
	artwork_load_artwork_file - default MAME way
	to locate an artwork file
-------------------------------------------------*/

mame_file *artwork_load_artwork_file(const struct GameDriver **driver)
{
	char filename[100];
	mame_file *artfile = NULL;

	while (*driver)
	{
		if ((*driver)->name)
		{
			sprintf(filename, "%s.art", (*driver)->name);
			artfile = mame_fopen((*driver)->name, filename, FILETYPE_ARTWORK, 0);
			if (artfile)
				break;
		}
		*driver = (*driver)->clone_of;
	}
	return artfile;
}



#if 0
#pragma mark -
#pragma mark BITMAP LOADING/MANIPULATING
#endif

/*-------------------------------------------------
	artwork_load - locate the .art file and
	read all the bitmaps
-------------------------------------------------*/

static int artwork_load(const struct GameDriver *driver, int width, int height, const struct artwork_callbacks *callbacks)
{
	const struct overlay_piece *list = overlay_list;
	struct artwork_piece *piece;
	mame_file *artfile;
	int result;

	/* reset the list of artwork */
	num_pieces = 0;
	num_underlays = 0;
	num_overlays = 0;
	num_bezels = 0;
	overlay_list = NULL;

	/* if the user turned artwork off, bail */
	if (!options.use_artwork)
		return 1;

	/* first process any hard-coded overlays */
	if (list && !generate_overlay(list, width, height))
		return 0;

	/* attempt to open the .ART file; if none, that's okay */
	artfile = callbacks->load_artwork(&driver);
	if (!artfile && !list)
		return 1;

	/* parse the file into pieces */
	if (artfile)
	{
		result = parse_art_file(artfile);
		mame_fclose(artfile);
		if (!result)
			return 0;
	}

	/* sort the pieces */
	sort_pieces();

	/* now read the artwork files */
	for (piece = artwork_list; piece; piece = piece->next)
	{
		/* convert from pixel coordinates if necessary */
		if (fabs(piece->left) > 4.0 || fabs(piece->right) > 4.0 ||
			fabs(piece->top) > 4.0 || fabs(piece->bottom) > 4.0)
		{
			piece->left /= (double)width;
			piece->right /= (double)width;
			piece->top /= (double)height;
			piece->bottom /= (double)height;
		}

		/* assign to one of the categories */
		if (piece->layer == LAYER_BACKDROP)
			num_underlays++;
		else if (piece->layer == LAYER_OVERLAY)
			num_overlays++;
		else if (piece->layer >= LAYER_BEZEL)
			num_bezels++;

		/* load the graphics */
		if (driver)
			load_bitmap(driver->name, piece);
	}
// debugging
//	fprintf(stderr, "backdrops=%d overlays=%d bezels=%d\n", num_underlays, num_overlays, num_bezels);

	return 1;
}



/*-------------------------------------------------
	open_and_read_png - open a PNG file, read it
	in, and verify that we can do something with
	it
-------------------------------------------------*/

static int open_and_read_png(const char *gamename, const char *filename, struct png_info *png)
{
	int result;
	mame_file *file;

	/* open the file */
	file = mame_fopen(gamename, filename, FILETYPE_ARTWORK, 0);
	if (!file)
		return 0;

	/* read the PNG data */
	result = png_read_file(file, png);
	mame_fclose(file);
	if (!result)
		return 0;

	/* verify we can handle this PNG */
	if (png->bit_depth > 8)
	{
		logerror("Unsupported bit depth %d (8 bit max)\n", png->bit_depth);
		free(png->image);
		return 0;
	}
	if (png->interlace_method != 0)
	{
		logerror("Interlace unsupported\n");
		free(png->image);
		return 0;
	}
	if (png->color_type != 0 && png->color_type != 3 && png->color_type != 2 && png->color_type != 6)
	{
		logerror("Unsupported color type %d\n", png->color_type);
		free(png->image);
		return 0;
	}

	/* if less than 8 bits, upsample */
	png_expand_buffer_8bit(png);
	return 1;
}



/*-------------------------------------------------
	load_bitmap - load the artwork into a bitmap
-------------------------------------------------*/

static int load_bitmap(const char *gamename, struct artwork_piece *piece)
{
	struct png_info png;
	UINT8 *src;
	int x, y;

	/* if we already have a bitmap, don't bother trying to read a file */
	if (piece->rawbitmap)
		return 1;

	/* open and read the main png file */
	if (!open_and_read_png(gamename, piece->filename, &png))
	{
		logerror("Can't load PNG file: %s\n", piece->filename);
		return 0;
	}

	/* allocate the rawbitmap and erase it */
	piece->rawbitmap = auto_bitmap_alloc_depth(png.width, png.height, 32);
	if (!piece->rawbitmap)
		return 0;
	fillbitmap(piece->rawbitmap, 0, NULL);

	/* handle 8bpp palettized case */
	if (png.color_type == 3)
	{
		/* loop over width/height */
		src = png.image;
		for (y = 0; y < png.height; y++)
			for (x = 0; x < png.width; x++, src++)
			{
				/* determine alpha */
				UINT8 alpha = (*src < png.num_trans) ? png.trans[*src] : 0xff;
				if (alpha != 0xff)
					piece->has_alpha = 1;

				/* expand to 32bpp */
				plot_pixel(piece->rawbitmap, x, y, MAKE_ARGB(alpha, png.palette[*src * 3], png.palette[*src * 3 + 1], png.palette[*src * 3 + 2]));
			}

		/* free memory for the palette */
		free(png.palette);
	}

	/* handle 8bpp grayscale case */
	else if (png.color_type == 0)
	{
		/* loop over width/height */
		src = png.image;
		for (y = 0; y < png.height; y++)
			for (x = 0; x < png.width; x++, src++)
				plot_pixel(piece->rawbitmap, x, y, MAKE_ARGB(0xff, *src, *src, *src));
	}

	/* handle 32bpp non-alpha case */
	else if (png.color_type == 2)
	{
		/* loop over width/height */
		src = png.image;
		for (y = 0; y < png.height; y++)
			for (x = 0; x < png.width; x++, src += 3)
				plot_pixel(piece->rawbitmap, x, y, MAKE_ARGB(0xff, src[0], src[1], src[2]));
	}

	/* handle 32bpp alpha case */
	else
	{
		/* loop over width/height */
		src = png.image;
		for (y = 0; y < png.height; y++)
			for (x = 0; x < png.width; x++, src += 4)
				plot_pixel(piece->rawbitmap, x, y, MAKE_ARGB(src[3], src[0], src[1], src[2]));
		piece->has_alpha = 1;
	}

	/* free the raw image data and return after loading any alpha map */
	free(png.image);
	return load_alpha_bitmap(gamename, piece, &png);
}



/*-------------------------------------------------
	load_alpha_bitmap - load the external alpha
	mask
-------------------------------------------------*/

static int load_alpha_bitmap(const char *gamename, struct artwork_piece *piece, const struct png_info *original)
{
	struct png_info png;
	UINT8 *src;
	int x, y;

	/* if no file, we succeeded */
	if (!piece->alpha_filename)
		return 1;

	/* open and read the alpha png file */
	if (!open_and_read_png(gamename, piece->alpha_filename, &png))
	{
		logerror("Can't load PNG file: %s\n", piece->alpha_filename);
		return 0;
	}

	/* must be the same size */
	if (png.height != original->height || png.width != original->width)
	{
		logerror("Alpha PNG must match original's dimensions: %s\n", piece->alpha_filename);
		return 0;
	}

	/* okay, we have alpha */
	piece->has_alpha = 1;

	/* handle 8bpp palettized case */
	if (png.color_type == 3)
	{
		/* loop over width/height */
		src = png.image;
		for (y = 0; y < png.height; y++)
			for (x = 0; x < png.width; x++, src++)
			{
				rgb_t pixel = read_pixel(piece->rawbitmap, x, y);
				UINT8 alpha = compute_brightness(MAKE_RGB(png.palette[*src * 3], png.palette[*src * 3 + 1], png.palette[*src * 3 + 2]));
				plot_pixel(piece->rawbitmap, x, y, MAKE_ARGB(alpha, RGB_RED(pixel), RGB_GREEN(pixel), RGB_BLUE(pixel)));
			}

		/* free memory for the palette */
		free(png.palette);
	}

	/* handle 8bpp grayscale case */
	else if (png.color_type == 0)
	{
		/* loop over width/height */
		src = png.image;
		for (y = 0; y < png.height; y++)
			for (x = 0; x < png.width; x++, src++)
			{
				rgb_t pixel = read_pixel(piece->rawbitmap, x, y);
				plot_pixel(piece->rawbitmap, x, y, MAKE_ARGB(*src, RGB_RED(pixel), RGB_GREEN(pixel), RGB_BLUE(pixel)));
			}
	}

	/* handle 32bpp non-alpha case */
	else if (png.color_type == 2)
	{
		/* loop over width/height */
		src = png.image;
		for (y = 0; y < png.height; y++)
			for (x = 0; x < png.width; x++, src += 3)
			{
				rgb_t pixel = read_pixel(piece->rawbitmap, x, y);
				UINT8 alpha = compute_brightness(MAKE_RGB(src[0], src[1], src[2]));
				plot_pixel(piece->rawbitmap, x, y, MAKE_ARGB(alpha, RGB_RED(pixel), RGB_GREEN(pixel), RGB_BLUE(pixel)));
			}
	}

	/* handle 32bpp alpha case */
	else
	{
		/* loop over width/height */
		src = png.image;
		for (y = 0; y < png.height; y++)
			for (x = 0; x < png.width; x++, src += 4)
			{
				rgb_t pixel = read_pixel(piece->rawbitmap, x, y);
				UINT8 alpha = compute_brightness(MAKE_RGB(src[0], src[1], src[2]));
				plot_pixel(piece->rawbitmap, x, y, MAKE_ARGB(alpha, RGB_RED(pixel), RGB_GREEN(pixel), RGB_BLUE(pixel)));
			}
	}

	/* free the raw image data */
	free(png.image);
	return 1;
}



/*-------------------------------------------------
	artwork_prep - prepare the artwork
-------------------------------------------------*/

static int artwork_prep(void)
{
	struct artwork_piece *piece;

	/* mark everything dirty */
	underlay_invalid = screenrect;
	overlay_invalid = screenrect;
	bezel_invalid = screenrect;

	/* loop through all the pieces, generating the scaled bitmaps */
	for (piece = artwork_list; piece; piece = piece->next)
	{
		/* scale to the artwork's intended dimensions */
		if (!scale_bitmap(piece, piece->bounds.max_x - piece->bounds.min_x + 1, piece->bounds.max_y - piece->bounds.min_y + 1))
			return 1;

		/* trim the bitmap down if transparent */
		trim_bitmap(piece);

		/* do we intersect the game rect? */
		piece->intersects_game = 0;
		if (piece->bounds.max_x > gamerect.min_x && piece->bounds.min_x < gamerect.max_x &&
			piece->bounds.max_y > gamerect.min_y && piece->bounds.min_y < gamerect.max_y)
			piece->intersects_game = 1;
	}
	return 0;
}



/*-------------------------------------------------
	scale_bitmap - scale the bitmap for a
	given piece of artwork
-------------------------------------------------*/

static int scale_bitmap(struct artwork_piece *piece, int newwidth, int newheight)
{
	UINT32 sx, sxfrac, sxstep, sy, syfrac, systep;
	UINT32 global_brightness, global_alpha;
	int x, y;

	/* skip if no bitmap */
	if (!piece->rawbitmap)
		return 1;

	/* allocate two new bitmaps */
	piece->prebitmap = auto_bitmap_alloc_depth(newwidth, newheight, -32);
	piece->yrgbbitmap = auto_bitmap_alloc_depth(newwidth, newheight, -32);
	if (!piece->prebitmap || !piece->yrgbbitmap)
		return 0;

	/* also allocate memory for the scanline hints */
	piece->scanlinehint = auto_malloc(newheight * MAX_HINTS_PER_SCANLINE * sizeof(piece->scanlinehint[0]));
	if (!piece->scanlinehint)
		return 0;
	memset(piece->scanlinehint, 0, newheight * MAX_HINTS_PER_SCANLINE * sizeof(piece->scanlinehint[0]));

	/* convert global brightness and alpha to fixed point */
	global_brightness = (int)(piece->brightness * 65536.0);
	global_alpha = (int)(piece->alpha * 65536.0);

	/* compute the step values */
	sxstep = (UINT32)((double)piece->rawbitmap->width * (double)(1 << 24) / (double)newwidth);
	systep = (UINT32)((double)piece->rawbitmap->height * (double)(1 << 24) / (double)newheight);
	sxfrac = (sxstep / 2) & FRAC_MASK;
	sx = (sxstep / 2) >> FRAC_BITS;
	syfrac = (systep / 2) & FRAC_MASK;
	sy = (systep / 2) >> FRAC_BITS;

	/* now do the scaling, using 4-point sampling */
	for (y = 0; y < newheight; y++)
	{
		int prevstate = 0, statex = 0;

		sxfrac = (sxstep / 2) & FRAC_MASK;
		sx = (sxstep / 2) >> FRAC_BITS;

		/* loop over columns */
		for (x = 0; x < newwidth; x++)
		{
			rgb_t pix1, pix2, pix3, pix4;
			int xweight, dx;
			int yweight, dy;
			int r, g, b, a;
			int newstate;

			/* determine the weights and which pixels to fetch */
			if (sxfrac <= FRAC_HALF)
			{
				dx = -1;
				xweight = FRAC_HALF - sxfrac;
			}
			else
			{
				dx = 0;
				xweight = FRAC_ONE - (sxfrac - FRAC_HALF);
			}

			if (syfrac <= FRAC_HALF)
			{
				dy = -1;
				yweight = FRAC_HALF - syfrac;
			}
			else
			{
				dy = 0;
				yweight = FRAC_ONE - (syfrac - FRAC_HALF);
			}

			/* reduce the resolution down to 8 bits for scaling */
			xweight >>= FRAC_BITS - 8;
			yweight >>= FRAC_BITS - 8;

			/* fetch the pixels */
			pix1 = *((UINT32 *)piece->rawbitmap->base + (sy + dy + 0) * piece->rawbitmap->rowpixels + (sx + dx + 0));
			pix2 = *((UINT32 *)piece->rawbitmap->base + (sy + dy + 0) * piece->rawbitmap->rowpixels + (sx + dx + 1));
			pix3 = *((UINT32 *)piece->rawbitmap->base + (sy + dy + 1) * piece->rawbitmap->rowpixels + (sx + dx + 0));
			pix4 = *((UINT32 *)piece->rawbitmap->base + (sy + dy + 1) * piece->rawbitmap->rowpixels + (sx + dx + 1));

			/* blend red */
			r = xweight * yweight * RGB_RED(pix1);
			r += (0x100 - xweight) * yweight * RGB_RED(pix2);
			r += xweight * (0x100 - yweight) * RGB_RED(pix3);
			r += (0x100 - xweight) * (0x100 - yweight) * RGB_RED(pix4);
			r >>= 16;
			r = (r * global_brightness) >> 16;
			if (r > 0xff) r = 0xff;

			/* blend green */
			g = xweight * yweight * RGB_GREEN(pix1);
			g += (0x100 - xweight) * yweight * RGB_GREEN(pix2);
			g += xweight * (0x100 - yweight) * RGB_GREEN(pix3);
			g += (0x100 - xweight) * (0x100 - yweight) * RGB_GREEN(pix4);
			g >>= 16;
			g = (g * global_brightness) >> 16;
			if (g > 0xff) g = 0xff;

			/* blend blue */
			b = xweight * yweight * RGB_BLUE(pix1);
			b += (0x100 - xweight) * yweight * RGB_BLUE(pix2);
			b += xweight * (0x100 - yweight) * RGB_BLUE(pix3);
			b += (0x100 - xweight) * (0x100 - yweight) * RGB_BLUE(pix4);
			b >>= 16;
			b = (b * global_brightness) >> 16;
			if (b > 0xff) b = 0xff;

			/* blend alpha */
			a = xweight * yweight * RGB_ALPHA(pix1);
			a += (0x100 - xweight) * yweight * RGB_ALPHA(pix2);
			a += xweight * (0x100 - yweight) * RGB_ALPHA(pix3);
			a += (0x100 - xweight) * (0x100 - yweight) * RGB_ALPHA(pix4);
			a >>= 16;
			a = (a * global_alpha) >> 16;
			if (a > 0xff) a = 0xff;

			/* compute the two pixel types */
			*((UINT32 *)piece->prebitmap->base + y * piece->prebitmap->rowpixels + x) = compute_pre_pixel(a,r,g,b);
			*((UINT32 *)piece->yrgbbitmap->base + y * piece->yrgbbitmap->rowpixels + x) = compute_yrgb_pixel(a,r,g,b);

			/* advance pointers */
			sxfrac += sxstep;
			sx += sxfrac >> FRAC_BITS;
			sxfrac &= FRAC_MASK;

			/* look for state changes */
			newstate = (a != 0);
			if (newstate != prevstate)
			{
				prevstate = newstate;

				/* if starting a new run of non-transparent pixels, remember the start point */
				if (newstate)
					statex = x;

				/* otherwise, add the current run */
				else
					add_range_to_hint(piece->scanlinehint, y, statex, x - 1);
			}
		}

		/* add the final range */
		if (prevstate)
			add_range_to_hint(piece->scanlinehint, y, statex, x - 1);

		/* advance pointers */
		syfrac += systep;
		sy += syfrac >> FRAC_BITS;
		syfrac &= FRAC_MASK;
	}

	/* guess it worked! */
	return 1;
}



/*-------------------------------------------------
	trim_bitmap - remove any transparent borders
	from a scaled image
-------------------------------------------------*/

static void trim_bitmap(struct artwork_piece *piece)
{
	UINT32 *hintbase = piece->scanlinehint;
	int top, bottom, left, right;
	int x, y, height, width;

	/* skip if no bitmap */
	if (!piece->rawbitmap)
		return;

	/* don't trim overlay bitmaps */
	if (piece->layer == LAYER_OVERLAY)
		return;

	/* scan from the top down, looking for empty rows */
	height = piece->prebitmap->height;
	width = piece->prebitmap->width;
	for (top = 0; top < height; top++)
		if (hintbase[top * MAX_HINTS_PER_SCANLINE] != 0)
			break;

	/* scan from the bottom up, looking for empty rows */
	for (bottom = height - 1; bottom >= top; bottom--)
		if (hintbase[bottom * MAX_HINTS_PER_SCANLINE] != 0)
			break;

	/* now find the min/max */
	left = width - 1;
	right = 0;
	for (y = top; y <= bottom; y++)
	{
		const UINT32 *hintdata = &hintbase[y * MAX_HINTS_PER_SCANLINE];

		/* check the minimum against the left */
		if (hintdata[0] && (hintdata[0] >> 16) < left)
			left = hintdata[0] >> 16;

		/* find the maximum */
		for (x = 0; x < MAX_HINTS_PER_SCANLINE; x++)
			if (hintdata[x] && (hintdata[x] & 0xffff) > right)
				right = hintdata[x] & 0xffff;
	}

	logerror("Trimming bitmap from (%d,%d)-(%d,%d) to (%d,%d)-(%d,%d)\n",
			piece->bounds.min_x, piece->bounds.min_y, piece->bounds.max_x, piece->bounds.max_y,
			piece->bounds.min_x + left, piece->bounds.min_y + top, piece->bounds.min_x + right, piece->bounds.min_y + bottom);

	/* skip if all is normal */
	if (left == 0 && top == 0 && right == width - 1 && bottom == height - 1)
		return;

	/* now shift the bitmap data */
	for (y = top; y <= bottom; y++)
	{
		UINT32 *hintsrc = &hintbase[y * MAX_HINTS_PER_SCANLINE];
		UINT32 *hintdst = &hintbase[(y - top) * MAX_HINTS_PER_SCANLINE];
		UINT32 *dst1 = (UINT32 *)piece->prebitmap->base + (y - top) * piece->prebitmap->rowpixels;
		UINT32 *dst2 = (UINT32 *)piece->yrgbbitmap->base + (y - top) * piece->yrgbbitmap->rowpixels;
		UINT32 *src1 = (UINT32 *)piece->prebitmap->base + y * piece->prebitmap->rowpixels + left;
		UINT32 *src2 = (UINT32 *)piece->yrgbbitmap->base + y * piece->yrgbbitmap->rowpixels + left;

		memmove(dst1, src1, (right - left + 1) * sizeof(UINT32));
		memmove(dst2, src2, (right - left + 1) * sizeof(UINT32));

		/* adjust the hints */
		for (x = 0; x < MAX_HINTS_PER_SCANLINE; x++)
		{
			UINT32 data = hintsrc[x];
			if (data)
				data -= (left << 16) | left;
			hintdst[x] = data;
		}
	}

	/* and adjust the info */
	piece->bounds.max_x = piece->bounds.min_x + right;
	piece->bounds.min_x += left;
	piece->bounds.max_y = piece->bounds.min_y + bottom;
	piece->bounds.min_y += top;
}




#if 0
#pragma mark -
#pragma mark PIECE LIST MANAGEMENT
#endif

/*-------------------------------------------------
	create_new_piece - allocate a new piece
	entry
-------------------------------------------------*/

static struct artwork_piece *create_new_piece(const char *tag)
{
	/* allocate a new piece */
	struct artwork_piece *newpiece = auto_malloc(sizeof(struct artwork_piece));
	if (!newpiece)
		return NULL;
	num_pieces++;

	/* initialize to default values */
	memset(newpiece, 0, sizeof(*newpiece));
	newpiece->layer = LAYER_UNKNOWN;
	newpiece->has_alpha = 0;
	newpiece->priority = 0;
	newpiece->alpha = 1.0;
	newpiece->brightness = 1.0;
	newpiece->filename = NULL;
	newpiece->alpha_filename = NULL;
	newpiece->intersects_game = 0;
	newpiece->visible = 1;

	/* allocate space for the filename */
	newpiece->tag = auto_malloc(strlen(tag) + 1);
	if (!newpiece->tag)
		return NULL;
	strcpy(newpiece->tag, tag);

	/* link into the list */
	newpiece->next = artwork_list;
	artwork_list = newpiece;
	return newpiece;
}



/*-------------------------------------------------
	artwork_sort_compare - qsort compare function
	to sort pieces by priority
-------------------------------------------------*/

static int CLIB_DECL artwork_sort_compare(const void *item1, const void *item2)
{
	const struct artwork_piece *piece1 = *((const struct artwork_piece **)item1);
	const struct artwork_piece *piece2 = *((const struct artwork_piece **)item2);
	if (piece1->layer < piece2->layer)
		return -1;
	else if (piece1->layer > piece2->layer)
		return 1;
	else if (piece1->priority < piece2->priority)
		return -1;
	else if (piece1->priority > piece2->priority)
		return 1;
	else
		return 0;
}



/*-------------------------------------------------
	sort_pieces - sort the pieces by priority
-------------------------------------------------*/

static void sort_pieces(void)
{
	struct artwork_piece *array[MAX_PIECES];
	struct artwork_piece *piece;
	int i = 0;

	/* copy the list into the array, filtering as we go */
	for (piece = artwork_list; piece; piece = piece->next)
	{
		switch (piece->layer)
		{
			case LAYER_BACKDROP:
				if (options.use_artwork & ARTWORK_USE_BACKDROPS)
					array[i++] = piece;
				break;

			case LAYER_OVERLAY:
				if (options.use_artwork & ARTWORK_USE_OVERLAYS)
					array[i++] = piece;
				break;

			default:
				if (options.use_artwork & ARTWORK_USE_BEZELS)
					array[i++] = piece;
				break;
		}
	}
	num_pieces = i;
	if (num_pieces == 0)
	{
		artwork_list = NULL;
		return;
	}

	/* now sort it */
	if (num_pieces > 1)
		qsort(array, num_pieces, sizeof(array[0]), artwork_sort_compare);

	/* now reassemble the list */
	artwork_list = piece = array[0];
	for (i = 1; i < num_pieces; i++)
	{
		piece->next = array[i];
		piece = piece->next;
	}
	piece->next = NULL;
}



/*-------------------------------------------------
	validate_pieces - make sure we got valid data
-------------------------------------------------*/

static int validate_pieces(void)
{
	struct artwork_piece *piece;

	/* verify each one */
	for (piece = artwork_list; piece; piece = piece->next)
	{
		/* make sure we have a filename */
		if ((!piece->filename || strlen(piece->filename) == 0) && !piece->rawbitmap)
		{
			logerror("Artwork piece '%s' has no file!\n", piece->tag);
			return 0;
		}

		/* make sure we have a layer */
		if (piece->layer == LAYER_UNKNOWN)
		{
			logerror("Artwork piece '%s' has no layer!\n", piece->tag);
			return 0;
		}

		/* make sure we have a position */
		if (piece->left == 0 && piece->right == 0)
		{
			logerror("Artwork piece '%s' has no position!\n", piece->tag);
			return 0;
		}

		/* make sure the position is valid */
		if (piece->left >= piece->right || piece->top >= piece->bottom)
		{
			logerror("Artwork piece '%s' has invalid position data!\n", piece->tag);
			return 0;
		}
	}

	return 1;
}



#if 0
#pragma mark -
#pragma mark OVERLAY GENERATION
#endif

/*-------------------------------------------------
	generate_rect_piece - generate a rectangular
	overlay piece
-------------------------------------------------*/

static int generate_rect_piece(struct artwork_piece *piece, const struct overlay_piece *data, int width, int height)
{
	int gfxwidth, gfxheight;

	/* extract coordinates */
	piece->top = data->top;
	piece->left = data->left;
	piece->bottom = data->bottom;
	piece->right = data->right;

	/* convert from pixel coordinates if necessary */
	if (fabs(piece->left) > 4.0 || fabs(piece->right) > 4.0 ||
		fabs(piece->top) > 4.0 || fabs(piece->bottom) > 4.0)
	{
		piece->left /= (double)width;
		piece->right /= (double)width;
		piece->top /= (double)height;
		piece->bottom /= (double)height;
	}

	/* compute the effective width/height */
	gfxwidth = (int)((piece->right - piece->left) * (double)width * 2.0 + 0.5);
	gfxheight = (int)((piece->bottom - piece->top) * (double)height * 2.0 + 0.5);

	/* allocate a source bitmap 2x the game bitmap's size */
	piece->rawbitmap = auto_bitmap_alloc_depth(gfxwidth, gfxheight, 32);
	if (!piece->rawbitmap)
		return 0;

	/* fill the bitmap */
	fillbitmap(piece->rawbitmap, data->color, NULL);
	return 1;
}



/*-------------------------------------------------
	generate_disk_piece - generate a disk-shaped
	overlay piece
-------------------------------------------------*/

static void render_disk(struct mame_bitmap *bitmap, int r, UINT32 color)
{
	int xc = bitmap->width / 2, yc = bitmap->height / 2;
	int x = 0, twox = 0;
	int y = r;
	int twoy = r+r;
	int p = 1 - r;
	int i;

	while (x < y)
	{
		x++;
		twox +=2;
		if (p < 0)
			p += twox + 1;
		else
		{
			y--;
			twoy -= 2;
			p += twox - twoy + 1;
		}

		for (i = 0; i < twox; i++)
		{
			plot_pixel(bitmap, xc-x+i, yc-y, color);
			plot_pixel(bitmap, xc-x+i, yc+y-1, color);
		}

		for (i = 0; i < twoy; i++)
		{
			plot_pixel(bitmap, xc-y+i, yc-x, color);
			plot_pixel(bitmap, xc-y+i, yc+x-1, color);
		}
	}
}


static int generate_disk_piece(struct artwork_piece *piece, const struct overlay_piece *data, int width, int height)
{
	double x = data->left, y = data->top, r = data->right;
	struct rectangle temprect;
	int gfxwidth, gfxradius;

	/* convert from pixel coordinates if necessary */
	if (fabs(x) > 4.0 || fabs(y) > 4.0 || fabs(r) > 4.0)
	{
		x /= (double)width;
		y /= (double)height;
		r /= (double)width;
	}

	/* generate coordinates */
	piece->top = y - r * (double)width / (double)height;
	piece->left = x - r;
	piece->bottom = y + r * (double)width / (double)height;
	piece->right = x + r;

	/* compute the effective width/height */
	gfxwidth = (int)((piece->right - piece->left) * (double)width * 2.0 + 0.5);
	gfxradius = (int)(r * (double)width * 2.0 + 0.5);

	/* allocate a source bitmap 2x the game bitmap's size */
	piece->rawbitmap = auto_bitmap_alloc_depth(gfxwidth, gfxwidth, 32);
	if (!piece->rawbitmap)
		return 0;

	/* fill the bitmap with white */
	temprect.min_x = temprect.min_y = 0;
	temprect.max_x = piece->rawbitmap->width - 1;
	temprect.max_y = piece->rawbitmap->height - 1;
	erase_rect(piece->rawbitmap, &temprect, MAKE_ARGB(0,0xff,0xff,0xff));

	/* now render the disk */
	render_disk(piece->rawbitmap, gfxradius, data->color);
	return 1;
}



/*-------------------------------------------------
	generate_overlay - generate an overlay with
	the given pieces
-------------------------------------------------*/

static int generate_overlay(const struct overlay_piece *list, int width, int height)
{
	struct artwork_piece *piece;
	int priority = 0;

	/* loop until done */
	while (list->type != OVERLAY_TYPE_END)
	{
		/* first create a new piece to use */
		piece = create_new_piece(OVERLAY_TAG);
		if (!piece)
			return 0;

		/* fill in the basics */
		piece->has_alpha = 1;
		piece->layer = LAYER_OVERLAY;
		piece->priority = priority++;
		piece->blendflags = list->type & OVERLAY_FLAG_MASK;

		/* switch off the type */
		switch (list->type & ~OVERLAY_FLAG_MASK)
		{
			case OVERLAY_TYPE_RECTANGLE:
				if (!generate_rect_piece(piece, list, width, height))
					return 0;
				break;

			case OVERLAY_TYPE_DISK:
				if (!generate_disk_piece(piece, list, width, height))
					return 0;
				break;
		}

		/* next */
		list++;
	}

	return 1;
}



#if 0
#pragma mark -
#pragma mark ART FILE PARSING
#endif

/*-------------------------------------------------
	strip_space - strip leading/trailing spaces
-------------------------------------------------*/

static char *strip_space(char *string)
{
	char *start, *end;

	/* skip over leading space */
	for (start = string; *start && isspace(*start); start++) ;

	/* NULL terminate over trailing space */
	for (end = start + strlen(start) - 1; end > start && isspace(*end); end--) *end = 0;
	return start;
}



/*-------------------------------------------------
	parse_tag_value - parse a tag/value pair
-------------------------------------------------*/

static int parse_tag_value(struct artwork_piece *piece, const char *tag, const char *value)
{
	/* handle the various tags */
	if (!strcmp(tag, "layer"))
	{
		if (!strcmp(value, "backdrop"))
			piece->layer = LAYER_BACKDROP;
		else if (!strcmp(value, "overlay"))
			piece->layer = LAYER_OVERLAY;
		else if (!strcmp(value, "bezel"))
			piece->layer = LAYER_BEZEL;
		else if (!strcmp(value, "marquee"))
			piece->layer = LAYER_MARQUEE;
		else if (!strcmp(value, "panel"))
			piece->layer = LAYER_PANEL;
		else if (!strcmp(value, "side"))
			piece->layer = LAYER_SIDE;
		else if (!strcmp(value, "flyer"))
			piece->layer = LAYER_FLYER;
		else
			return 0;
		return 1;
	}
	else if (!strcmp(tag, "priority"))
	{
		return (sscanf(value, "%d", &piece->priority) == 1);
	}
	else if (!strcmp(tag, "visible"))
	{
		return (sscanf(value, "%d", &piece->visible) == 1);
	}
	else if (!strcmp(tag, "alpha"))
	{
		return (sscanf(value, "%f", &piece->alpha) == 1);
	}
	else if (!strcmp(tag, "brightness"))
	{
		return (sscanf(value, "%f", &piece->brightness) == 1);
	}
	else if (!strcmp(tag, "position"))
	{
		return (sscanf(value, "%f,%f,%f,%f", &piece->left, &piece->top, &piece->right, &piece->bottom) == 4);
	}
	else if (!strcmp(tag, "file"))
	{
		piece->filename = auto_malloc(strlen(value) + 1);
		if (piece->filename)
			strcpy(piece->filename, value);
		return (piece->filename != NULL);
	}
	else if (!strcmp(tag, "alphafile"))
	{
		piece->alpha_filename = auto_malloc(strlen(value) + 1);
		if (piece->alpha_filename)
			strcpy(piece->alpha_filename, value);
		return (piece->alpha_filename != NULL);
	}
	return 0;
}



/*-------------------------------------------------
	parse_art_file - parse a .art file
-------------------------------------------------*/

static int parse_art_file(mame_file *file)
{
	struct artwork_piece *current = NULL;
	char *tag, *value, *p;
	char buffer[1000];

	/* loop until we run out of lines */
	while (mame_fgets(buffer, sizeof(buffer), file))
	{
		/* strip off any comments */
		p = strstr(buffer, "//");
		if (p)
			*p = 0;

		/* strip off leading/trailing spaces */
		tag = strip_space(buffer);

		/* anything left? */
		if (tag[0] == 0)
			continue;

		/* is this the start of a new entry? */
		if (tag[strlen(tag) - 1] == ':')
		{
			/* strip the space off the rest */
			tag[strlen(tag) - 1] = 0;
			tag = strip_space(tag);

			/* create an entry for the new piece */
			current = create_new_piece(tag);
			if (!current)
				return 0;
			continue;
		}

		/* is this a tag/value pair? */
		value = strchr(tag, '=');
		if (value)
		{
			/* strip spaces off of both parts */
			*value++ = 0;
			tag = strip_space(tag);
			value = strip_space(value);

			/* convert both strings to lowercase */
			for (p = tag; *p; p++) *p = tolower(*p);
			for (p = value; *p; p++) *p = tolower(*p);

			/* now parse the result */
			if (current && parse_tag_value(current, tag, value))
				continue;
		}

		/* what the heck is it? */
		logerror("Invalid line in .ART file:\n%s\n", buffer);
	}

	/* validate the artwork */
	return validate_pieces();
}



#if 0
#pragma mark -
#pragma mark MISC UTILITIES
#endif

/*-------------------------------------------------
	compute_rgb_components - compute the RGB
	components
-------------------------------------------------*/

static int compute_rgb_components(int depth, UINT32 rgb_components[3], UINT32 rgb32_components[3])
{
	UINT32 temp;
	int r, g, b;

	/* first convert the RGB components we got back into shifts */
	for (temp = rgb32_components[0], rshift = 0; !(temp & 1); temp >>= 1)
		rshift++;
	for (temp = rgb32_components[1], gshift = 0; !(temp & 1); temp >>= 1)
		gshift++;
	for (temp = rgb32_components[2], bshift = 0; !(temp & 1); temp >>= 1)
		bshift++;

	/* compute the alpha shift for the leftover byte */
	nonalpha_mask = rgb32_components[0] | rgb32_components[1] | rgb32_components[2];
	temp = ~nonalpha_mask;
	for (ashift = 0; !(temp & 1); temp >>= 1)
		ashift++;

	/* compute a transparent color; this is in the premultiplied space, so alpha is inverted */
	transparent_color = ASSEMBLE_ARGB(0xff,0x00,0x00,0x00);

	/* allocate a palette lookup */
	palette_lookup = auto_malloc(65536 * sizeof(palette_lookup[0]));
	if (!palette_lookup)
		return 1;

	/* switch off the depth */
	switch (depth)
	{
		case 16:
			/* do nothing */
			break;

		case 32:
			/* copy original components */
			memcpy(rgb_components, rgb32_components, sizeof(rgb_components));
			break;

		case 15:
			/* make up components */
			rgb_components[0] = 0x7c00;
			rgb_components[1] = 0x03e0;
			rgb_components[2] = 0x001f;

			/* now build up the palette */
			for (r = 0; r < 32; r++)
				for (g = 0; g < 32; g++)
					for (b = 0; b < 32; b++)
					{
						int rr = (r << 3) | (r >> 2);
						int gg = (g << 3) | (g >> 2);
						int bb = (b << 3) | (b >> 2);
						palette_lookup[(r << 10) | (g << 5) | b] = ASSEMBLE_ARGB(0, rr, gg, bb);
					}
			break;
	}

	return 0;
}



/*-------------------------------------------------
	add_range_to_hint - add a given range to the
	hint record for the specified scanline
-------------------------------------------------*/

static void add_range_to_hint(UINT32 *hintbase, int scanline, int startx, int endx)
{
	int closestdiff = 100000, closestindex = -1;
	int i;

	/* first address the correct hint */
	hintbase += scanline * MAX_HINTS_PER_SCANLINE;

	/* first, look for an intersection */
	for (i = 0; i < MAX_HINTS_PER_SCANLINE; i++)
	{
		UINT32 hint = hintbase[i];
		int hintstart = hint >> 16;
		int hintend = hint & 0xffff;
		int diff;

		/* stop if we hit a 0 */
		if (hint == 0)
			break;

		/* do we intersect? */
		if (startx <= hintend && endx >= hintstart)
		{
			closestindex = i;
			goto intersect;
		}

		/* see how close we are to this entry */
		if (hintend < startx)
			diff = startx - hintend;
		else
			diff = hintstart - endx;

		/* if this is the closest, remember it */
		if (diff < closestdiff)
		{
			closestdiff = diff;
			closestindex = i;
		}
	}

	/* okay, we didn't find an intersection; do we have room to add? */
	if (i < MAX_HINTS_PER_SCANLINE)
	{
		UINT32 newhint = (startx << 16) | endx;

		/* if there's nothing there yet, just assign to the first entry */
		if (i == 0)
			hintbase[0] = newhint;

		/* otherwise, shuffle the existing entries to make room for us */
		else
		{
			/* determine our new index */
			i = closestindex;
			if (hintbase[i] < newhint)
				i++;

			/* shift things over */
			if (i < MAX_HINTS_PER_SCANLINE - 1)
				memmove(&hintbase[i+1], &hintbase[i], (MAX_HINTS_PER_SCANLINE - (i+1)) * sizeof(hintbase[0]));
			hintbase[i] = newhint;
		}
		return;
	}

intersect:
	/* intersect with the closest entry */
	{
		UINT32 hint = hintbase[closestindex];
		int hintstart = hint >> 16;
		int hintend = hint & 0xffff;

		/* compute the intersection */
		if (startx < hintstart)
			hintstart = startx;
		if (endx > hintend)
			hintend = endx;
		hintbase[closestindex] = (hintstart << 16) | hintend;
	}
}
