bsnes/fc/video/video.cpp

70 lines
1.8 KiB
C++

#include <fc/fc.hpp>
#include <cmath>
#define VIDEO_CPP
namespace Famicom {
Video video;
void Video::generate_palette(bool color_emulation) {
for(unsigned n = 0; n < (1 << 9); n++) palette[n] = generate_color(n, 2.0, 0.0, 1.0, 1.0, color_emulation ? 1.8 : 2.2);
}
Video::Video() {
palette = new unsigned[1 << 9]();
}
Video::~Video() {
delete[] palette;
}
uint32_t Video::generate_color(
unsigned n, double saturation, double hue,
double contrast, double brightness, double gamma
) {
signed color = (n & 0x0f), level = color < 0xe ? (n >> 4) & 3 : 1;
static const double black = 0.518, white = 1.962, attenuation = 0.746;
static const double levels[8] = {
0.350, 0.518, 0.962, 1.550,
1.094, 1.506, 1.962, 1.962,
};
double lo_and_hi[2] = {
levels[level + 4 * (color == 0x0)],
levels[level + 4 * (color < 0xd)],
};
double y = 0.0, i = 0.0, q = 0.0;
auto wave = [](signed p, signed color) { return (color + p + 8) % 12 < 6; };
for(signed p = 0; p < 12; p++) {
double spot = lo_and_hi[wave(p, color)];
if(((n & 0x040) && wave(p, 12))
|| ((n & 0x080) && wave(p, 4))
|| ((n & 0x100) && wave(p, 8))
) spot *= attenuation;
double v = (spot - black) / (white - black);
v = (v - 0.5) * contrast + 0.5;
v *= brightness / 12.0;
y += v;
i += v * std::cos((3.141592653 / 6.0) * (p + hue));
q += v * std::sin((3.141592653 / 6.0) * (p + hue));
}
i *= saturation;
q *= saturation;
auto gammaAdjust = [=](double f) { return f < 0.0 ? 0.0 : std::pow(f, 2.2 / gamma); };
unsigned r = 65535.0 * gammaAdjust(y + 0.946882 * i + 0.623557 * q);
unsigned g = 65535.0 * gammaAdjust(y + -0.274788 * i + -0.635691 * q);
unsigned b = 65535.0 * gammaAdjust(y + -1.108545 * i + 1.709007 * q);
return interface->videoColor(n, uclamp<16>(r), uclamp<16>(g), uclamp<16>(b));
}
}