Files
scummvm-cursorfix/engines/ultima/nuvie/screen/dither.cpp
2026-02-02 04:50:13 +01:00

114 lines
2.8 KiB
C++

/* 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 3 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, see <http://www.gnu.org/licenses/>.
*
*/
#include "ultima/nuvie/core/nuvie_defs.h"
#include "ultima/nuvie/files/nuvie_io_file.h"
#include "ultima/nuvie/misc/u6_misc.h"
#include "ultima/nuvie/conf/configuration.h"
#include "ultima/nuvie/screen/dither.h"
namespace Ultima {
namespace Nuvie {
//dither EGA to CGA
static const uint8 dither_cga_tbl[0x10] = {0, 3, 3, 3, 13, 13, 13, 3, 3, 13, 15, 3, 13, 13, 15, 15};
//static const uint8 dither_cga_tbl[0x10] = {0,1,1,1,2 ,2 ,2 ,1,1,2 ,3 ,1,2 ,2 ,3, 3};
Dither::Dither(const Configuration *cfg) : config(cfg), dither(nullptr), mode(DITHER_NONE) {
set_mode();
if (mode != DITHER_NONE)
load_data();
}
Dither::~Dither() {
if (dither)
free(dither);
}
bool Dither::load_data() {
Common::Path path;
NuvieIOFileRead file;
config_get_path(config, "dither", path);
if (file.open(path) == false)
return false;//fixme better error handling
dither = (uint8 *)malloc(0x200);
if (dither == nullptr)
return false;
file.readToBuf(dither, 0x200);
file.close();
return true;
}
void Dither::set_mode() {
Std::string str_dither_mode;
config->value("config/general/dither_mode", str_dither_mode);
if (str_dither_mode == "none")
mode = DITHER_NONE;
else if (str_dither_mode == "cga") {
mode = DITHER_CGA;
} else if (str_dither_mode == "ega") {
mode = DITHER_EGA;
} else
mode = DITHER_NONE;
return;
}
bool Dither::dither_bitmap(unsigned char *src_buf, uint16 src_w, uint16 src_h, bool has_transparency) {
if (!dither || mode == DITHER_NONE)
return false;
for (int y = 0; y < src_h; y++) {
for (int x = 0; x < src_w; x++) {
uint8 pixel = src_buf[y * src_w + x];
if (has_transparency && pixel == 0xff)
continue;
if (pixel >= 0xe0 && pixel != 0xff)
pixel &= 0xf;
if (((x & 1) ^ (y & 1)) == 0)
pixel = dither[0x100 + pixel];
else
pixel = dither[pixel];
if (mode == DITHER_CGA)
pixel = dither_cga_tbl[pixel];
src_buf[y * src_w + x] = pixel;
}
}
return true;
}
} // End of namespace Nuvie
} // End of namespace Ultima