Files
rgbds/src/gfx/pal_sorting.cpp
Sylvie 9783671399 Simplify some C++ abstractions (#1518)
* Remove namespaces
* Prefer `bool operator==`, not `friend auto operator==`
* Prefer not to use `using`
* Use a `constexpr` function instead of a template for `flipTable`
2024-09-26 00:07:27 -04:00

83 lines
2.2 KiB
C++

/* SPDX-License-Identifier: MIT */
#include "gfx/pal_sorting.hpp"
#include <algorithm>
#include "helpers.hpp"
#include "gfx/main.hpp"
void sortIndexed(
std::vector<Palette> &palettes,
int palSize,
png_color const *palRGB,
int palAlphaSize,
png_byte *palAlpha
) {
options.verbosePrint(Options::VERB_LOG_ACT, "Sorting palettes using embedded palette...\n");
auto pngToRgb = [&palRGB, &palAlphaSize, &palAlpha](int index) {
auto const &c = palRGB[index];
return Rgba(
c.red, c.green, c.blue, palAlpha && index < palAlphaSize ? palAlpha[index] : 0xFF
);
};
for (Palette &pal : palettes) {
std::sort(RANGE(pal), [&](uint16_t lhs, uint16_t rhs) {
// Iterate through the PNG's palette, looking for either of the two
for (int i = 0; i < palSize; ++i) {
uint16_t color = pngToRgb(i).cgbColor();
if (color == Rgba::transparent) {
continue;
}
// Return whether lhs < rhs
if (color == rhs) {
return false;
}
if (color == lhs) {
return true;
}
}
unreachable_(); // This should not be possible
});
}
}
void sortGrayscale(
std::vector<Palette> &palettes, std::array<std::optional<Rgba>, 0x8001> const &colors
) {
options.verbosePrint(Options::VERB_LOG_ACT, "Sorting grayscale-only palette...\n");
// This method is only applicable if there are at most as many colors as colors per palette, so
// we should only have a single palette.
assume(palettes.size() == 1);
Palette &palette = palettes[0];
std::fill(RANGE(palette.colors), Rgba::transparent);
for (auto const &slot : colors) {
if (!slot.has_value() || slot->isTransparent()) {
continue;
}
palette[slot->grayIndex()] = slot->cgbColor();
}
}
static unsigned int legacyLuminance(uint16_t color) {
uint8_t red = color & 0b11111;
uint8_t green = color >> 5 & 0b11111;
uint8_t blue = color >> 10;
return 2126 * red + 7152 * green + 722 * blue;
}
void sortRgb(std::vector<Palette> &palettes) {
options.verbosePrint(Options::VERB_LOG_ACT, "Sorting palettes by \"\"\"luminance\"\"\"...\n");
for (Palette &pal : palettes) {
std::sort(RANGE(pal), [](uint16_t lhs, uint16_t rhs) {
return legacyLuminance(lhs) > legacyLuminance(rhs);
});
}
}