dreamcast/palette.hpp
Zack Buhman bcaa9789cf texture_memory_alloc: rework texture memory allocation
The previous texture_memory_alloc.hpp was written based on an
incorrect understanding of the "32-bit" and "64-bit" texture memory
address mapping.

The primary motivation is to rearrange the texture memory address map
so that "textures" (64-bit access) do not overlap with 32-bit
accesses, such as REGION_BASE or PARAM_BASE.
2024-05-12 17:06:00 +08:00

63 lines
1.3 KiB
C++

#pragma once
#include "holly/core_bits.hpp"
constexpr inline uint16_t rgb565(uint8_t r, uint8_t g, uint8_t b)
{
return ((r >> 3) << 11) | ((g >> 2) << 5) | ((b >> 3) << 0);
}
constexpr inline uint16_t grey565(uint8_t i)
{
return ((i >> 3) << 11) | ((i >> 2) << 5) | ((i >> 3) << 0);
}
constexpr inline uint16_t argb4444(uint8_t i)
{
return (i << 12) | (15 << 8) | (15 << 4) | (15 << 0);
}
template <int C>
void palette_data();
template <>
void palette_data<256>()
{
holly.PAL_RAM_CTRL = pal_ram_ctrl::pixel_format::rgb565;
// ranging in intensity from rgb565(0, 0, 0) to rgb565(31, 63, 31)
for (int i = 0; i < 256; i += 1) {
holly.PALETTE_RAM[i] = grey565(i);
}
}
template <>
void palette_data<16>()
{
holly.PAL_RAM_CTRL = pal_ram_ctrl::pixel_format::argb4444;
// ranging in intensity from rgb565(0, 0, 0) to rgb565(31, 63, 31)
for (uint32_t i = 0; i < 16; i++) {
holly.PALETTE_RAM[i] = argb4444(i);
}
}
template <>
void palette_data<2>()
{
holly.PAL_RAM_CTRL = pal_ram_ctrl::pixel_format::argb1555;
holly.PALETTE_RAM[0] = 0x0000;
holly.PALETTE_RAM[1] = 0xffff;
}
template <>
void palette_data<3>()
{
holly.PAL_RAM_CTRL = pal_ram_ctrl::pixel_format::argb1555;
holly.PALETTE_RAM[0] = 0x0000;
holly.PALETTE_RAM[1] = 0xffff;
holly.PALETTE_RAM[2] = 0x8000;
}