xref: /dports/games/scummvm/scummvm-2.5.1/engines/ags/lib/allegro/color.cpp

/* ScummVM - Graphic Adventure Engine
 *
 * ScummVM is the legal property of its developers, whose names
 * are too numerous to list here. Please refer to the COPYRIGHT
 * file distributed with this source distribution.
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version 2
 * of the License, or (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
 *
 */

#include "ags/lib/allegro/color.h"
#include "ags/lib/allegro/system.h"
#include "ags/lib/allegro/aintern.h"
#include "ags/shared/core/types.h"
#include "ags/shared/util/stream.h"
#include "ags/globals.h"
#include "common/textconsole.h"
#include "common/system.h"
#include "graphics/palette.h"

namespace AGS3 {

#define VGA_COLOR_TRANS(x) ((x) * 255 / 63)

void color::readFromFile(AGS::Shared::Stream *file) {
	r = file->ReadByte();
	g = file->ReadByte();
	b = file->ReadByte();
	filler = file->ReadByte();
}

void color::writeToFile(AGS::Shared::Stream *file) const {
	file->WriteByte(r);
	file->WriteByte(g);
	file->WriteByte(b);
	file->WriteByte(filler);
}

static void convertPalette(const PALETTE src, byte dest[PALETTE_SIZE]) {
	const color *cSrc = (const color *)src;
	for (int i = 0; i < PALETTE_COUNT; ++i, cSrc++, dest += 3) {
		dest[0] = VGA_COLOR_TRANS(cSrc->r);
		dest[1] = VGA_COLOR_TRANS(cSrc->g);
		dest[2] = VGA_COLOR_TRANS(cSrc->b);
	}
}

static void applyPalette() {
	if (g_system->getScreenFormat().bytesPerPixel == 1) {
		byte pal[PALETTE_SIZE];
		convertPalette(_G(current_palette), pal);
		g_system->getPaletteManager()->setPalette(pal, 0, PALETTE_COUNT);
	}
}

void set_palette(const PALETTE p) {
	for (int idx = 0; idx < PAL_SIZE; ++idx)
		_G(current_palette)[idx] = p[idx];

	applyPalette();
}

void set_palette_range(const PALETTE p, int from, int to, int retracesync) {
	for (int i = from; i <= to; ++i) {
		_G(current_palette)[i] = p[i];
	}

	applyPalette();
}

int makecol15(int r, int g, int b) {
	return (((r >> 3) << _G(_rgb_r_shift_15)) |
	        ((g >> 3) << _G(_rgb_g_shift_15)) |
	        ((b >> 3) << _G(_rgb_b_shift_15)));
}

int makecol16(int r, int g, int b) {
	return (((r >> 3) << _G(_rgb_r_shift_16)) |
	        ((g >> 2) << _G(_rgb_g_shift_16)) |
	        ((b >> 3) << _G(_rgb_b_shift_16)));
}

int makecol24(int r, int g, int b) {
	return ((r << _G(_rgb_r_shift_24)) |
	        (g << _G(_rgb_g_shift_24)) |
	        (b << _G(_rgb_b_shift_24)));
}

int makecol32(int r, int g, int b) {
	return ((r << _G(_rgb_r_shift_32)) |
	        (g << _G(_rgb_g_shift_32)) |
	        (b << _G(_rgb_b_shift_32)));
}

int makeacol32(int r, int g, int b, int a) {
	return ((r << _G(_rgb_r_shift_32)) |
	        (g << _G(_rgb_g_shift_32)) |
	        (b << _G(_rgb_b_shift_32)) |
	        (a << _G(_rgb_a_shift_32)));
}

int getr8(int c) {
	return (int)_G(current_palette)[c].r;
}

int getg8(int c) {
	return (int)_G(current_palette)[c].g;
}

int getb8(int c) {
	return (int)_G(current_palette)[c].b;
}

int getr15(int c) {
	return _rgb_scale_5[(c >> _G(_rgb_r_shift_15)) & 0x1F];
}

int getg15(int c) {
	return _rgb_scale_5[(c >> _G(_rgb_g_shift_15)) & 0x1F];
}

int getb15(int c) {
	return _rgb_scale_5[(c >> _G(_rgb_b_shift_15)) & 0x1F];
}

int getr16(int c) {
	return _rgb_scale_5[(c >> _G(_rgb_r_shift_16)) & 0x1F];
}

int getg16(int c) {
	return _rgb_scale_6[(c >> _G(_rgb_g_shift_16)) & 0x3F];
}

int getb16(int c) {
	return _rgb_scale_5[(c >> _G(_rgb_b_shift_16)) & 0x1F];
}

int getr24(int c) {
	return ((c >> _G(_rgb_r_shift_24)) & 0xFF);
}

int getg24(int c) {
	return ((c >> _G(_rgb_g_shift_24)) & 0xFF);
}

int getb24(int c) {
	return ((c >> _G(_rgb_b_shift_24)) & 0xFF);
}

int getr32(int c) {
	return ((c >> _G(_rgb_r_shift_32)) & 0xFF);
}

int getg32(int c) {
	return ((c >> _G(_rgb_g_shift_32)) & 0xFF);
}

int getb32(int c) {
	return ((c >> _G(_rgb_b_shift_32)) & 0xFF);
}

int geta32(int c) {
	return ((c >> _G(_rgb_a_shift_32)) & 0xFF);
}

int makecol(byte r, byte g, byte b) {
	return (b) | (g << 8) | (r << 16);
}

int makecol8(byte r, byte g, byte b) {
	return (b) | (g << 8) | (r << 16);
}

void get_color(int idx, RGB *p) {
	*p = _G(current_palette)[idx];
}

void get_palette_range(PALETTE p, int from, int to) {
	Common::copy(&_G(current_palette)[from], &_G(current_palette)[to + 1], &p[from]);
}

void get_palette(PALETTE p) {
	get_palette_range(p, 0, PAL_SIZE - 1);
}

void fade_interpolate(AL_CONST PALETTE source, AL_CONST PALETTE dest, PALETTE output, int pos, int from, int to) {
	assert(pos >= 0 && pos <= 64);
	assert(from >= 0 && from < PAL_SIZE);
	assert(to >= 0 && to < PAL_SIZE);

	for (int c = from; c <= to; c++) {
		output[c].r = ((int)source[c].r * (63 - pos) + (int)dest[c].r * pos) / 64;
		output[c].g = ((int)source[c].g * (63 - pos) + (int)dest[c].g * pos) / 64;
		output[c].b = ((int)source[c].b * (63 - pos) + (int)dest[c].b * pos) / 64;
	}
}

void select_palette(AL_CONST PALETTE p) {
	int c;

	for (c = 0; c < PAL_SIZE; c++) {
		_G(prev_current_palette)[c] = _G(current_palette)[c];
		_G(current_palette)[c] = p[c];
	}

	applyPalette();
}

void unselect_palette(void) {
	int c;

	for (c = 0; c < PAL_SIZE; c++)
		_G(current_palette)[c] = _G(prev_current_palette)[c];

	applyPalette();
}

void set_blender_mode(BlenderMode m, int r, int g, int b, int a) {
	_G(_blender_mode) = m;
	_G(trans_blend_alpha) = a;
	_G(trans_blend_red) = r;
	_G(trans_blend_green) = g;
	_G(trans_blend_blue) = b;
}

void set_alpha_blender(void) {
	set_blender_mode(kSourceAlphaBlender, 0, 0, 0, 0);
}

void set_trans_blender(int r, int g, int b, int a) {
	set_blender_mode(kRgbToRgbBlender, r, g, b, a);
}

/* makecol_depth:
 *  Converts R, G, and B values (ranging 0-255) to whatever pixel format
 *  is required by the specified color depth.
 */
int makecol_depth(int color_depth, int r, int g, int b) {
	switch (color_depth) {

	case 8:
		return makecol8(r, g, b);

	case 15:
		return makecol15(r, g, b);

	case 16:
		return makecol16(r, g, b);

	case 24:
		return makecol24(r, g, b);

	case 32:
		return makecol32(r, g, b);
	}

	return 0;
}



/* makeacol_depth:
 *  Converts R, G, B, and A values (ranging 0-255) to whatever pixel format
 *  is required by the specified color depth.
 */
int makeacol_depth(int color_depth, int r, int g, int b, int a) {
	switch (color_depth) {

	case 8:
		return makecol8(r, g, b);

	case 15:
		return makecol15(r, g, b);

	case 16:
		return makecol16(r, g, b);

	case 24:
		return makecol24(r, g, b);

	case 32:
		return makeacol32(r, g, b, a);
	}

	return 0;
}

/* getr_depth:
 *  Extracts the red component (ranging 0-255) from a pixel in the format
 *  being used by the specified color depth.
 */
int getr_depth(int color_depth, int c) {
	switch (color_depth) {

	case 8:
		return getr8(c);

	case 15:
		return getr15(c);

	case 16:
		return getr16(c);

	case 24:
		return getr24(c);

	case 32:
		return getr32(c);
	}

	return 0;
}



/* getg_depth:
 *  Extracts the green component (ranging 0-255) from a pixel in the format
 *  being used by the specified color depth.
 */
int getg_depth(int color_depth, int c) {
	switch (color_depth) {

	case 8:
		return getg8(c);

	case 15:
		return getg15(c);

	case 16:
		return getg16(c);

	case 24:
		return getg24(c);

	case 32:
		return getg32(c);
	}

	return 0;
}



/* getb_depth:
 *  Extracts the blue component (ranging 0-255) from a pixel in the format
 *  being used by the specified color depth.
 */
int getb_depth(int color_depth, int c) {
	switch (color_depth) {

	case 8:
		return getb8(c);

	case 15:
		return getb15(c);

	case 16:
		return getb16(c);

	case 24:
		return getb24(c);

	case 32:
		return getb32(c);
	}

	return 0;
}



/* geta_depth:
 *  Extracts the alpha component (ranging 0-255) from a pixel in the format
 *  being used by the specified color depth.
 */
int geta_depth(int color_depth, int c) {
	if (color_depth == 32)
		return geta32(c);

	return 0;
}



/* getr:
 *  Extracts the red component (ranging 0-255) from a pixel in the format
 *  being used by the current video mode.
 */
int getr(int c) {
	return getr_depth(_G(_color_depth), c);
}



/* getg:
 *  Extracts the green component (ranging 0-255) from a pixel in the format
 *  being used by the current video mode.
 */
int getg(int c) {
	return getg_depth(_G(_color_depth), c);
}



/* getb:
 *  Extracts the blue component (ranging 0-255) from a pixel in the format
 *  being used by the current video mode.
 */
int getb(int c) {
	return getb_depth(_G(_color_depth), c);
}



/* geta:
 *  Extracts the alpha component (ranging 0-255) from a pixel in the format
 *  being used by the current video mode.
 */
int geta(int c) {
	return geta_depth(_G(_color_depth), c);
}



/* 1.5k lookup table for color matching */
static unsigned int col_diff[3 * 128];



/* bestfit_init:
 *  Color matching is done with weighted squares, which are much faster
 *  if we pregenerate a little lookup table...
 */
static void bestfit_init(void) {
	int i;

	for (i = 1; i < 64; i++) {
		int k = i * i;
		col_diff[0 + i] = col_diff[0 + 128 - i] = k * (59 * 59);
		col_diff[128 + i] = col_diff[128 + 128 - i] = k * (30 * 30);
		col_diff[256 + i] = col_diff[256 + 128 - i] = k * (11 * 11);
	}
}



/* bestfit_color:
 *  Searches a palette for the color closest to the requested R, G, B value.
 */
int bestfit_color(AL_CONST PALETTE pal, int r, int g, int b) {
	int i, coldiff, lowest, bestfit;

	assert(r >= 0 && r <= 63);
	assert(g >= 0 && g <= 63);
	assert(b >= 0 && b <= 63);

	if (col_diff[1] == 0)
		bestfit_init();

	bestfit = 0;
	lowest = INT_MAX;

	/* only the transparent (pink) color can be mapped to index 0 */
	if ((r == 63) && (g == 0) && (b == 63))
		i = 0;
	else
		i = 1;

	while (i < PAL_SIZE) {
		AL_CONST RGB *rgb = &pal[i];
		coldiff = (col_diff + 0)[(rgb->g - g) & 0x7F];
		if (coldiff < lowest) {
			coldiff += (col_diff + 128)[(rgb->r - r) & 0x7F];
			if (coldiff < lowest) {
				coldiff += (col_diff + 256)[(rgb->b - b) & 0x7F];
				if (coldiff < lowest) {
					bestfit = rgb - pal;    /* faster than `bestfit = i;' */
					if (coldiff == 0)
						return bestfit;
					lowest = coldiff;
				}
			}
		}
		i++;
	}

	return bestfit;
}



/* makecol8:
 *  Converts R, G, and B values (ranging 0-255) to an 8 bit paletted color.
 *  If the global _G(rgb_map) table is initialised, it uses that, otherwise
 *  it searches through the current palette to find the best match.
 */
int makecol8(int r, int g, int b) {
	if (_G(rgb_map))
		return _G(rgb_map)->data[r >> 3][g >> 3][b >> 3];
	else
		return bestfit_color(_G(current_palette), r >> 2, g >> 2, b >> 2);
}



/* hsv_to_rgb:
 *  Converts from HSV colorspace to RGB values.
 */
void hsv_to_rgb(float h, float s, float v, int *r, int *g, int *b) {
	float f, x, y, z;
	int i;

	assert(s >= 0 && s <= 1);
	assert(v >= 0 && v <= 1);

	v *= 255.0f;

	if (s == 0.0f) { /* ok since we don't divide by s, and faster */
		*r = *g = *b = v + 0.5f;
	} else {
		h = fmod(h, 360.0f) / 60.0f;
		if (h < 0.0f)
			h += 6.0f;

		i = (int)h;
		f = h - i;
		x = v * s;
		y = x * f;
		v += 0.5f; /* round to the nearest integer below */
		z = v - x;

		switch (i) {

		case 6:
		case 0:
			*r = v;
			*g = z + y;
			*b = z;
			break;

		case 1:
			*r = v - y;
			*g = v;
			*b = z;
			break;

		case 2:
			*r = z;
			*g = v;
			*b = z + y;
			break;

		case 3:
			*r = z;
			*g = v - y;
			*b = v;
			break;

		case 4:
			*r = z + y;
			*g = z;
			*b = v;
			break;

		case 5:
			*r = v;
			*g = z;
			*b = v - y;
			break;
		}
	}
}



/* rgb_to_hsv:
 *  Converts an RGB value into the HSV colorspace.
 */
void rgb_to_hsv(int r, int g, int b, float *h, float *s, float *v) {
	int delta;

	assert(r >= 0 && r <= 255);
	assert(g >= 0 && g <= 255);
	assert(b >= 0 && b <= 255);

	if (r > g) {
		if (b > r) {
			/* b>r>g */
			delta = b - g;
			*h = 240.0f + ((r - g) * 60) / (float)delta;
			*s = (float)delta / (float)b;
			*v = (float)b * (1.0f / 255.0f);
		} else {
			/* r>g and r>b */
			delta = r - MIN(g, b);
			*h = ((g - b) * 60) / (float)delta;
			if (*h < 0.0f)
				*h += 360.0f;
			*s = (float)delta / (float)r;
			*v = (float)r * (1.0f / 255.0f);
		}
	} else {
		if (b > g) {
			/* b>g>=r */
			delta = b - r;
			*h = 240.0f + ((r - g) * 60) / (float)delta;
			*s = (float)delta / (float)b;
			*v = (float)b * (1.0f / 255.0f);
		} else {
			/* g>=b and g>=r */
			delta = g - MIN(r, b);
			if (delta == 0) {
				*h = 0.0f;
				if (g == 0)
					*s = *v = 0.0f;
				else {
					*s = (float)delta / (float)g;
					*v = (float)g * (1.0f / 255.0f);
				}
			} else {
				*h = 120.0f + ((b - r) * 60) / (float)delta;
				*s = (float)delta / (float)g;
				*v = (float)g * (1.0f / 255.0f);
			}
		}
	}
}



/* create_rgb_table:
 *  Fills an RGB_MAP lookup table with conversion data for the specified
 *  palette. This is the faster version by Jan Hubicka.
 *
 *  Uses alg. similar to floodfill - it adds one seed per every color in
 *  palette to its best position. Then areas around seed are filled by
 *  same color because it is best approximation for them, and then areas
 *  about them etc...
 *
 *  It does just about 80000 tests for distances and this is about 100
 *  times better than normal 256*32000 tests so the calculation time
 *  is now less than one second at all computers I tested.
 */
void create_rgb_table(RGB_MAP *table, AL_CONST PALETTE pal, void (*callback)(int pos)) {
#define UNUSED 65535
#define LAST 65532

	/* macro add adds to single linked list */
#define add(i)    (next[(i)] == UNUSED ? (next[(i)] = LAST, \
                   (first != LAST ? (next[last] = (i)) : (first = (i))), \
                   (last = (i))) : 0)

	/* same but w/o checking for first element */
#define add1(i)   (next[(i)] == UNUSED ? (next[(i)] = LAST, \
                   next[last] = (i), \
                   (last = (i))) : 0)

	/* calculates distance between two colors */
#define dist(a1, a2, a3, b1, b2, b3) \
	(col_diff[ ((a2) - (b2)) & 0x7F] + \
	 (col_diff + 128)[((a1) - (b1)) & 0x7F] + \
	 (col_diff + 256)[((a3) - (b3)) & 0x7F])

	/* converts r,g,b to position in array and back */
#define pos(r, g, b) \
	(((r) / 2) * 32 * 32 + ((g) / 2) * 32 + ((b) / 2))

#define depos(pal, r, g, b) \
	((b) = ((pal) & 31) * 2, \
	 (g) = (((pal) >> 5) & 31) * 2, \
	 (r) = (((pal) >> 10) & 31) * 2)

	/* is current color better than pal1? */
#define better(r1, g1, b1, pal1) \
	(((int)dist((r1), (g1), (b1), \
	            (pal1).r, (pal1).g, (pal1).b)) > (int)dist2)

	/* checking of position */
#define dopos(rp, gp, bp, ts) \
	if ((rp > -1 || r > 0) && (rp < 1 || r < 61) && \
	        (gp > -1 || g > 0) && (gp < 1 || g < 61) && \
	        (bp > -1 || b > 0) && (bp < 1 || b < 61)) { \
		i = first + rp * 32 * 32 + gp * 32 + bp; \
		if (!data[i]) { \
			data[i] = val; \
			add1(i); \
		} \
		else if ((ts) && (data[i] != val)) { \
			dist2 = (rp ? (col_diff+128)[(r+2*rp-pal[val].r) & 0x7F] : r2) + \
			        (gp ? (col_diff    )[(g+2*gp-pal[val].g) & 0x7F] : g2) + \
			        (bp ? (col_diff+256)[(b+2*bp-pal[val].b) & 0x7F] : b2); \
			if (better((r+2*rp), (g+2*gp), (b+2*bp), pal[data[i]])) { \
				data[i] = val; \
				add1(i); \
			} \
		} \
	}

	int i, curr, r, g, b, val, dist2;
	unsigned int r2, g2, b2;
	unsigned short next[32 * 32 * 32];
	unsigned char *data;
	int first = LAST;
	int last = LAST;
	int count = 0;
	int cbcount = 0;

#define AVERAGE_COUNT   18000

	if (col_diff[1] == 0)
		bestfit_init();

	memset(next, 255, sizeof(next));
	memset(table->data, 0, sizeof(char) * 32 * 32 * 32);

	data = (unsigned char *)table->data;

	/* add starting seeds for floodfill */
	for (i = 1; i < PAL_SIZE; i++) {
		curr = pos(pal[i].r, pal[i].g, pal[i].b);
		if (next[curr] == UNUSED) {
			data[curr] = i;
			add(curr);
		}
	}

	/* main floodfill: two versions of loop for faster growing in blue axis */
	while (first != LAST) {
		depos(first, r, g, b);

		/* calculate distance of current color */
		val = data[first];
		r2 = (col_diff + 128)[((pal[val].r) - (r)) & 0x7F];
		g2 = (col_diff)[((pal[val].g) - (g)) & 0x7F];
		b2 = (col_diff + 256)[((pal[val].b) - (b)) & 0x7F];

		/* try to grow to all directions */
		dopos(0, 0, 1, 1);
		dopos(0, 0, -1, 1);
		dopos(1, 0, 0, 1);
		dopos(-1, 0, 0, 1);
		dopos(0, 1, 0, 1);
		dopos(0, -1, 0, 1);

		/* faster growing of blue direction */
		if ((b > 0) && (data[first - 1] == val)) {
			b -= 2;
			first--;
			b2 = (col_diff + 256)[((pal[val].b) - (b)) & 0x7F];

			dopos(-1, 0, 0, 0);
			dopos(1, 0, 0, 0);
			dopos(0, -1, 0, 0);
			dopos(0, 1, 0, 0);

			first++;
		}

		/* get next from list */
		i = first;
		first = next[first];
		next[i] = UNUSED;

		/* second version of loop */
		if (first != LAST) {
			depos(first, r, g, b);

			val = data[first];
			r2 = (col_diff + 128)[((pal[val].r) - (r)) & 0x7F];
			g2 = (col_diff)[((pal[val].g) - (g)) & 0x7F];
			b2 = (col_diff + 256)[((pal[val].b) - (b)) & 0x7F];

			dopos(0, 0, 1, 1);
			dopos(0, 0, -1, 1);
			dopos(1, 0, 0, 1);
			dopos(-1, 0, 0, 1);
			dopos(0, 1, 0, 1);
			dopos(0, -1, 0, 1);

			if ((b < 61) && (data[first + 1] == val)) {
				b += 2;
				first++;
				b2 = (col_diff + 256)[((pal[val].b) - (b)) & 0x7f];

				dopos(-1, 0, 0, 0);
				dopos(1, 0, 0, 0);
				dopos(0, -1, 0, 0);
				dopos(0, 1, 0, 0);

				first--;
			}

			i = first;
			first = next[first];
			next[i] = UNUSED;
		}

		count++;
		if (count == (cbcount + 1) * AVERAGE_COUNT / 256) {
			if (cbcount < 256) {
				if (callback)
					callback(cbcount);
				cbcount++;
			}
		}
	}

	/* only the transparent (pink) color can be mapped to index 0 */
	if ((pal[0].r == 63) && (pal[0].g == 0) && (pal[0].b == 63))
		table->data[31][0][31] = 0;

	if (callback)
		while (cbcount < 256)
			callback(cbcount++);
}



/* create_light_table:
 *  Constructs a lighting color table for the specified palette. At light
 *  intensity 255 the table will produce the palette colors directly, and
 *  at level 0 it will produce the specified R, G, B value for all colors
 *  (this is specified in 0-63 VGA format). If the callback function is
 *  not NULL, it will be called 256 times during the calculation, allowing
 *  you to display a progress indicator.
 */
void create_light_table(COLOR_MAP *table, AL_CONST PALETTE pal, int r, int g, int b, void (*callback)(int pos)) {
	int r1, g1, b1, r2, g2, b2, x, y;
	unsigned int t1, t2;

	assert(table);
	assert(r >= 0 && r <= 63);
	assert(g >= 0 && g <= 63);
	assert(b >= 0 && b <= 63);

	if (_G(rgb_map)) {
		for (x = 0; x < PAL_SIZE - 1; x++) {
			t1 = x * 0x010101;
			t2 = 0xFFFFFF - t1;

			r1 = (1 << 24) + r * t2;
			g1 = (1 << 24) + g * t2;
			b1 = (1 << 24) + b * t2;

			for (y = 0; y < PAL_SIZE; y++) {
				r2 = (r1 + pal[y].r * t1) >> 25;
				g2 = (g1 + pal[y].g * t1) >> 25;
				b2 = (b1 + pal[y].b * t1) >> 25;

				table->data[x][y] = _G(rgb_map)->data[r2][g2][b2];
			}
		}
		if (callback)
			(*callback)(x);
	} else {
		for (x = 0; x < PAL_SIZE - 1; x++) {
			t1 = x * 0x010101;
			t2 = 0xFFFFFF - t1;

			r1 = (1 << 23) + r * t2;
			g1 = (1 << 23) + g * t2;
			b1 = (1 << 23) + b * t2;

			for (y = 0; y < PAL_SIZE; y++) {
				r2 = (r1 + pal[y].r * t1) >> 24;
				g2 = (g1 + pal[y].g * t1) >> 24;
				b2 = (b1 + pal[y].b * t1) >> 24;

				table->data[x][y] = bestfit_color(pal, r2, g2, b2);
			}
		}

		if (callback)
			(*callback)(x);
	}

	for (y = 0; y < PAL_SIZE; y++)
		table->data[255][y] = y;
}



/* create_trans_table:
 *  Constructs a translucency color table for the specified palette. The
 *  r, g, and b parameters specifiy the solidity of each color component,
 *  ranging from 0 (totally transparent) to 255 (totally solid). Source
 *  color #0 is a special case, and is set to leave the destination
 *  unchanged, so that masked sprites will draw correctly. If the callback
 *  function is not NULL, it will be called 256 times during the calculation,
 *  allowing you to display a progress indicator.
 */
void create_trans_table(COLOR_MAP *table, AL_CONST PALETTE pal, int r, int g, int b, void (*callback)(int pos)) {
	int tmp[768], *q;
	int x, y, i, j, k;
	unsigned char *p;
	int tr, tg, tb;
	int add;

	assert(table);
	assert(r >= 0 && r <= 255);
	assert(g >= 0 && g <= 255);
	assert(b >= 0 && b <= 255);

	/* This is a bit ugly, but accounts for the solidity parameters
	   being in the range 0-255 rather than 0-256. Given that the
	   precision of r,g,b components is only 6 bits it shouldn't do any
	   harm. */
	if (r > 128)
		r++;
	if (g > 128)
		g++;
	if (b > 128)
		b++;

	if (_G(rgb_map))
		add = 255;
	else
		add = 127;

	for (x = 0; x < 256; x++) {
		tmp[x * 3] = pal[x].r * (256 - r) + add;
		tmp[x * 3 + 1] = pal[x].g * (256 - g) + add;
		tmp[x * 3 + 2] = pal[x].b * (256 - b) + add;
	}

	for (x = 1; x < PAL_SIZE; x++) {
		i = pal[x].r * r;
		j = pal[x].g * g;
		k = pal[x].b * b;

		p = table->data[x];
		q = tmp;

		if (_G(rgb_map)) {
			for (y = 0; y < PAL_SIZE; y++) {
				tr = (i + * (q++)) >> 9;
				tg = (j + * (q++)) >> 9;
				tb = (k + * (q++)) >> 9;
				p[y] = _G(rgb_map)->data[tr][tg][tb];
			}
		} else {
			for (y = 0; y < PAL_SIZE; y++) {
				tr = (i + * (q++)) >> 8;
				tg = (j + * (q++)) >> 8;
				tb = (k + * (q++)) >> 8;
				p[y] = bestfit_color(pal, tr, tg, tb);
			}
		}

		if (callback)
			(*callback)(x - 1);
	}

	for (y = 0; y < PAL_SIZE; y++) {
		table->data[0][y] = y;
		table->data[y][y] = y;
	}

	if (callback)
		(*callback)(255);
}

} // namespace AGS3