gzdoom-gles/src/v_colortables.h

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#pragma once
// extracted from v_video.h because this caused circular dependencies between v_video.h and textures.h
// Translucency tables
// RGB32k is a normal R5G5B5 -> palette lookup table.
// Use a union so we can "overflow" without warnings.
// Otherwise, we get stuff like this from Clang (when compiled
// with -fsanitize=bounds) while running:
// src/v_video.cpp:390:12: runtime error: index 1068 out of bounds for type 'uint8_t [32]'
// src/r_draw.cpp:273:11: runtime error: index 1057 out of bounds for type 'uint8_t [32]'
union ColorTable32k
{
uint8_t RGB[32][32][32];
uint8_t All[32 *32 *32];
};
extern ColorTable32k RGB32k;
// [SP] RGB666 support
union ColorTable256k
{
uint8_t RGB[64][64][64];
uint8_t All[64 *64 *64];
};
extern ColorTable256k RGB256k;
// Col2RGB8 is a pre-multiplied palette for color lookup. It is stored in a
// special R10B10G10 format for efficient blending computation.
// --RRRRRrrr--BBBBBbbb--GGGGGggg-- at level 64
// --------rrrr------bbbb------gggg at level 1
extern uint32_t Col2RGB8[65][256];
// Col2RGB8_LessPrecision is the same as Col2RGB8, but the LSB for red
// and blue are forced to zero, so if the blend overflows, it won't spill
// over into the next component's value.
// --RRRRRrrr-#BBBBBbbb-#GGGGGggg-- at level 64
// --------rrr#------bbb#------gggg at level 1
extern uint32_t *Col2RGB8_LessPrecision[65];
// Col2RGB8_Inverse is the same as Col2RGB8_LessPrecision, except the source
// palette has been inverted.
extern uint32_t Col2RGB8_Inverse[65][256];
// "Magic" numbers used during the blending:
// --000001111100000111110000011111 = 0x01f07c1f
// -0111111111011111111101111111111 = 0x3FEFFBFF
// -1000000000100000000010000000000 = 0x40100400
// ------10000000001000000000100000 = 0x40100400 >> 5
// --11111-----11111-----11111----- = 0x40100400 - (0x40100400 >> 5) aka "white"
// --111111111111111111111111111111 = 0x3FFFFFFF