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Use transparent instead of repeating 0x8000

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This commit is contained in:
Rangi
2026-07-14 10:34:27 -04:00
committed by Rangi
parent 1ed22cc518
commit cb34fe18f7
1 changed files with 5 additions and 5 deletions
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include/gfx/rgba.hpp
+5 -5
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@@ -20,6 +20,10 @@ struct Rgba {
explicit constexpr Rgba(uint32_t rgba = 0) explicit constexpr Rgba(uint32_t rgba = 0)
: red(rgba >> 24), green(rgba >> 16), blue(rgba >> 8), alpha(rgba) {} : red(rgba >> 24), green(rgba >> 16), blue(rgba >> 8), alpha(rgba) {}
// CGB colors are RGB555, so we use bit 15 to signify that the color is transparent instead
// Since the rest of the bits don't matter then, we return 0x8000 (1 << 15) exactly.
static constexpr uint16_t transparent = 0b1'00000'00000'00000;
static constexpr Rgba fromCGBColor(uint16_t color) { static constexpr Rgba fromCGBColor(uint16_t color) {
constexpr auto _5to8 = [](uint8_t channel) -> uint8_t { constexpr auto _5to8 = [](uint8_t channel) -> uint8_t {
channel &= 0b11111; // For caller's convenience channel &= 0b11111; // For caller's convenience
@@ -29,7 +33,7 @@ struct Rgba {
_5to8(color), _5to8(color),
_5to8(color >> 5), _5to8(color >> 5),
_5to8(color >> 10), _5to8(color >> 10),
static_cast<uint8_t>(color & 0x8000 ? 0x00 : 0xFF), static_cast<uint8_t>(color & transparent ? 0x00 : 0xFF),
}; };
} }
@@ -44,10 +48,6 @@ struct Rgba {
bool operator==(Rgba const &rhs) const { return toCSS() == rhs.toCSS(); } bool operator==(Rgba const &rhs) const { return toCSS() == rhs.toCSS(); }
// CGB colors are RGB555, so we use bit 15 to signify that the color is transparent instead
// Since the rest of the bits don't matter then, we return 0x8000 exactly.
static constexpr uint16_t transparent = 0b1'00000'00000'00000;
static constexpr uint8_t transparency_threshold = 0x10; static constexpr uint8_t transparency_threshold = 0x10;
bool isTransparent() const { return alpha < transparency_threshold; } bool isTransparent() const { return alpha < transparency_threshold; }
static constexpr uint8_t opacity_threshold = 0xF0; static constexpr uint8_t opacity_threshold = 0xF0;