/*
* OpenTyrian: A modern cross-platform port of Tyrian
* Copyright (C) 2007-2009 The OpenTyrian Development Team
*
* 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 "palette.h"
#include "file.h"
#include "nortsong.h"
#include "opentyr.h"
#include "video.h"
#include <assert.h>
static Uint32 rgb_to_yuv( int r, int g, int b );
#define PALETTE_COUNT 23
Palette palettes[PALETTE_COUNT];
int palette_count;
static Palette palette;
Uint32 rgb_palette[256], yuv_palette[256];
Palette colors;
void JE_loadPals( void )
{
FILE *f = dir_fopen_die(data_dir(), "palette.dat", "rb");
palette_count = ftell_eof(f) / (256 * 3);
assert(palette_count
== PALETTE_COUNT
);
for (int p = 0; p < palette_count; ++p)
{
for (int i = 0; i < 256; ++i)
{
// The VGA hardware palette used only 6 bits per component, so the values need to be rescaled to
// 8 bits. The naive way to do this is to simply do (c << 2), padding it with 0's, however this
// makes the maximum value 252 instead of the proper 255. A trick to fix this is to use the upper 2
// bits of the original value instead. This ensures that the value goes to 255 as the original goes
// to 63.
palettes[p][i].r = (c << 2) | (c >> 4);
palettes[p][i].g = (c << 2) | (c >> 4);
palettes[p][i].b = (c << 2) | (c >> 4);
}
}
}
void set_palette( Palette colors, unsigned int first_color, unsigned int last_color )
{
SDL_Surface *const surface = SDL_GetVideoSurface();
const uint bpp = surface->format->BitsPerPixel;
for (uint i = first_color; i <= last_color; ++i)
{
palette[i] = colors[i];
if (bpp != 8)
{
rgb_palette[i] = SDL_MapRGB(surface->format, palette[i].r, palette[i].g, palette[i].b);
yuv_palette[i] = rgb_to_yuv(palette[i].r, palette[i].g, palette[i].b);
}
}
if (bpp == 8)
SDL_SetColors(surface, palette, first_color, last_color - first_color + 1);
}
void set_colors( SDL_Color color, unsigned int first_color, unsigned int last_color )
{
SDL_Surface *const surface = SDL_GetVideoSurface();
const uint bpp = surface->format->BitsPerPixel;
for (uint i = first_color; i <= last_color; ++i)
{
palette[i] = color;
if (bpp != 8)
{
rgb_palette[i] = SDL_MapRGB(surface->format, palette[i].r, palette[i].g, palette[i].b);
yuv_palette[i] = rgb_to_yuv(palette[i].r, palette[i].g, palette[i].b);
}
}
if (bpp == 8)
SDL_SetColors(surface, palette, first_color, last_color - first_color + 1);
}
void init_step_fade_palette( int diff[256][3], Palette colors, unsigned int first_color, unsigned int last_color )
{
for (unsigned int i = first_color; i <= last_color; i++)
{
diff[i][0] = (int)colors[i].r - palette[i].r;
diff[i][1] = (int)colors[i].g - palette[i].g;
diff[i][2] = (int)colors[i].b - palette[i].b;
}
}
void init_step_fade_solid( int diff[256][3], SDL_Color color, unsigned int first_color, unsigned int last_color )
{
for (unsigned int i = first_color; i <= last_color; i++)
{
diff[i][0] = (int)color.r - palette[i].r;
diff[i][1] = (int)color.g - palette[i].g;
diff[i][2] = (int)color.b - palette[i].b;
}
}
void step_fade_palette( int diff[256][3], int steps, unsigned int first_color, unsigned int last_color )
{
SDL_Surface *const surface = SDL_GetVideoSurface();
const uint bpp = surface->format->BitsPerPixel;
for (unsigned int i = first_color; i <= last_color; i++)
{
int delta[3] = { diff[i][0] / steps, diff[i][1] / steps, diff[i][2] / steps };
diff[i][0] -= delta[0];
diff[i][1] -= delta[1];
diff[i][2] -= delta[2];
palette[i].r += delta[0];
palette[i].g += delta[1];
palette[i].b += delta[2];
if (bpp != 8)
{
rgb_palette[i] = SDL_MapRGB(surface->format, palette[i].r, palette[i].g, palette[i].b);
yuv_palette[i] = rgb_to_yuv(palette[i].r, palette[i].g, palette[i].b);
}
}
if (bpp == 8)
SDL_SetColors(surface, palette, 0, 256);
}
void fade_palette( Palette colors, int steps, unsigned int first_color, unsigned int last_color )
{
SDL_Surface *const surface = SDL_GetVideoSurface();
const uint bpp = surface->format->BitsPerPixel;
static int diff[256][3];
init_step_fade_palette(diff, colors, first_color, last_color);
for (; steps > 0; steps--)
{
setdelay(1);
step_fade_palette(diff, steps, first_color, last_color);
if (bpp != 8)
JE_showVGA();
wait_delay();
}
}
void fade_solid( SDL_Color color, int steps, unsigned int first_color, unsigned int last_color )
{
SDL_Surface *const surface = SDL_GetVideoSurface();
const uint bpp = surface->format->BitsPerPixel;
static int diff[256][3];
init_step_fade_solid(diff, color, first_color, last_color);
for (; steps > 0; steps--)
{
setdelay(1);
step_fade_palette(diff, steps, first_color, last_color);
if (bpp != 8)
JE_showVGA();
wait_delay();
}
}
void fade_black( int steps )
{
SDL_Color black = { 0, 0, 0 };
fade_solid(black, steps, 0, 255);
}
void fade_white( int steps )
{
SDL_Color white = { 255, 255, 255 };
fade_solid(white, steps, 0, 255);
}
static Uint32 rgb_to_yuv( int r, int g, int b )
{
int y = (r + g + b) >> 2,
u = 128 + ((r - b) >> 2),
v = 128 + ((-r + 2 * g - b) >> 3);
return (y << 16) + (u << 8) + v;
}