2025-07-17 19:53:11 +10:00

246 lines
6.6 KiB
C

#include "rspq.h"
#include "rdpq.h"
#include "rdpq_rect.h"
#include "rdpq_mode.h"
#include "rdpq_debug.h"
#include "display.h"
// This is a severely cutdown version of libdragon's OpenGL implementation
#define VTX_SHIFT 5
#define TEX_SHIFT 8
static uint32_t gpup_id;
//DEFINE_RSP_UCODE(rsp_gpu);
extern uint8_t _binary_build_n64_rsp_gpu_text_bin_start[];
extern uint8_t _binary_build_n64_rsp_gpu_data_bin_start[];
extern uint8_t _binary_build_n64_rsp_gpu_meta_bin_start[];
extern uint8_t _binary_build_n64_rsp_gpu_text_bin_end[0];
extern uint8_t _binary_build_n64_rsp_gpu_data_bin_end[0];
extern uint8_t _binary_build_n64_rsp_gpu_meta_bin_end[0];
static rsp_ucode_t rsp_gpu = (rsp_ucode_t){
.code = _binary_build_n64_rsp_gpu_text_bin_start,
.code_end = _binary_build_n64_rsp_gpu_text_bin_end,
.data = _binary_build_n64_rsp_gpu_data_bin_start,
.data_end = _binary_build_n64_rsp_gpu_data_bin_end,
.meta = _binary_build_n64_rsp_gpu_meta_bin_start,
.meta_end = _binary_build_n64_rsp_gpu_meta_bin_end,
.name = "rsp_gpu"
};
enum {
GPU_CMD_SET_BYTE = 0x0,
GPU_CMD_SET_SHORT = 0x1,
GPU_CMD_SET_WORD = 0x2,
GPU_CMD_SET_LONG = 0x3,
GPU_CMD_DRAW_QUAD = 0x4,
GPU_CMD_MATRIX_LOAD = 0x5,
GPU_CMD_PUSH_RDP = 0x6,
};
typedef struct {
int16_t vp_scale[4];
int16_t vp_offset[4];
uint16_t tex_size[2];
uint16_t tex_offset[2];
uint16_t tri_cmd;
uint16_t tri_cull;
} __attribute__((aligned(8), packed)) gpu_state;
__attribute__((always_inline))
static inline void gpu_set_byte(uint32_t offset, uint8_t value)
{
rspq_write(gpup_id, GPU_CMD_SET_BYTE, offset, value);
}
__attribute__((always_inline))
static inline void gpu_set_short(uint32_t offset, uint16_t value)
{
rspq_write(gpup_id, GPU_CMD_SET_SHORT, offset, value);
}
__attribute__((always_inline))
static inline void gpu_set_word(uint32_t offset, uint32_t value)
{
rspq_write(gpup_id, GPU_CMD_SET_WORD, offset, value);
}
__attribute__((always_inline))
static inline void gpu_set_long(uint32_t offset, uint64_t value)
{
rspq_write(gpup_id, GPU_CMD_SET_LONG, offset, value >> 32, value & 0xFFFFFFFF);
}
#define RDP_CMD_SYNC_PIPE 0xE7000000
#define RDP_CMD_SET_BLEND_COLOR 0xF9000000
__attribute__((always_inline))
static inline void gpu_push_rdp(uint32_t a1, uint64_t a2)
{
rdpq_write(2, gpup_id, GPU_CMD_PUSH_RDP, 0, a1, a2);
}
static float gpu_vp_scale[3];
static float gpu_vp_offset[3];
static bool gpu_texturing;
static void* gpu_pointer;
static int gpu_stride;
#define GPU_ATTR_Z (1 << 8)
#define GPU_ATTR_TEX (1 << 9)
#define GPU_ATTR_SHADE (1 << 10)
#define GPU_ATTR_EDGE (1 << 11)
static uint8_t gpu_attr_z, gpu_attr_tex;
static void gpuUpdateFormat(void)
{
uint16_t cmd = 0xC000 | GPU_ATTR_SHADE | GPU_ATTR_EDGE;
if (gpu_attr_z) cmd |= GPU_ATTR_Z;
if (gpu_attr_tex) cmd |= GPU_ATTR_TEX;
gpu_set_short(offsetof(gpu_state, tri_cmd), cmd);
}
static void gpuSetTexSize(uint16_t width, uint16_t height)
{
gpu_set_word(offsetof(gpu_state, tex_size[0]), (width << 16) | height);
}
static void gpuSetTexOffset(uint16_t width, uint16_t height)
{
gpu_set_word(offsetof(gpu_state, tex_offset[0]), (width << 16) | height);
}
static inline void write_shorts(rspq_write_t *w, const uint16_t *s, uint32_t count)
{
for (uint32_t i = 0; i < count; i += 2)
{
uint32_t packed = ((uint32_t)s[i] << 16) | (uint32_t)s[i+1];
rspq_write_arg(w, packed);
}
}
static inline void gpu_matrix_write(rspq_write_t* w, const float* m)
{
uint16_t integer[16];
uint16_t fraction[16];
for (uint32_t i = 0; i < 16; i++)
{
int32_t fixed = m[i] * (1<<16);
integer[i] = (uint16_t)((fixed & 0xFFFF0000) >> 16);
fraction[i] = (uint16_t)(fixed & 0x0000FFFF);
}
write_shorts(w, integer, 16);
write_shorts(w, fraction, 16);
}
static void gpuLoadMatrix(const float* m)
{
rspq_write_t w = rspq_write_begin(gpup_id, GPU_CMD_MATRIX_LOAD, 17);
rspq_write_arg(&w, 0); // padding
gpu_matrix_write(&w, m);
rspq_write_end(&w);
}
static inline void put_word(rspq_write_t* s, uint16_t v1, uint16_t v2)
{
rspq_write_arg(s, v2 | (v1 << 16));
}
static void upload_vertex(rspq_write_t* s, uint32_t index)
{
char* ptr = gpu_pointer + index * gpu_stride;
float* vtx = (float*)(ptr + 0);
put_word(s, vtx[0] * (1<<VTX_SHIFT),
vtx[1] * (1<<VTX_SHIFT));
put_word(s, vtx[2] * (1<<VTX_SHIFT),
1.0f * (1<<VTX_SHIFT));
uint32_t* col = (uint32_t*)(ptr + 12);
rspq_write_arg(s, *col);
if (gpu_texturing) {
float* tex = (float*)(ptr + 16);
put_word(s, tex[0] * (1<<TEX_SHIFT),
tex[1] * (1<<TEX_SHIFT));
} else {
put_word(s, 0,
0);
}
}
static void gpuDrawArrays(uint32_t first, uint32_t count)
{
for (uint32_t i = 0; i < count; i += 4)
{
rspq_write_t s = rspq_write_begin(gpup_id, GPU_CMD_DRAW_QUAD, 17);
rspq_write_arg(&s, 0); // padding
for (uint32_t j = 0; j < 4; j++)
{
upload_vertex(&s, first + i + j);
}
rspq_write_end(&s);
}
}
static void gpuDepthRange(float n, float f)
{
gpu_vp_scale[2] = (f - n) * 0.5f;
gpu_vp_offset[2] = n + (f - n) * 0.5f;
gpu_set_short(offsetof(gpu_state, vp_scale[2]), gpu_vp_scale[2] * 4);
gpu_set_short(offsetof(gpu_state, vp_offset[2]), gpu_vp_offset[2] * 4);
}
static void gpuViewport(int x, int y, int w, int h)
{
gpu_vp_scale[0] = w * 0.5f;
gpu_vp_scale[1] = h * -0.5f;
gpu_vp_offset[0] = x + w * 0.5f;
gpu_vp_offset[1] = y + h * 0.5f;
// Screen coordinates are s13.2
#define SCREEN_XY_SCALE 4.0f
#define SCREEN_Z_SCALE 32767.0f
// * 2.0f to compensate for RSP reciprocal missing 1 bit
uint16_t scale_x = gpu_vp_scale[0] * SCREEN_XY_SCALE * 2.0f;
uint16_t scale_y = gpu_vp_scale[1] * SCREEN_XY_SCALE * 2.0f;
uint16_t scale_z = gpu_vp_scale[2] * SCREEN_Z_SCALE * 2.0f;
uint16_t offset_x = gpu_vp_offset[0] * SCREEN_XY_SCALE;
uint16_t offset_y = gpu_vp_offset[1] * SCREEN_XY_SCALE;
uint16_t offset_z = gpu_vp_offset[2] * SCREEN_Z_SCALE;
gpu_set_long(
offsetof(gpu_state, vp_scale),
((uint64_t)scale_x << 48) | ((uint64_t)scale_y << 32) | ((uint64_t)scale_z << 16));
gpu_set_long(
offsetof(gpu_state, vp_offset),
((uint64_t)offset_x << 48) | ((uint64_t)offset_y << 32) | ((uint64_t)offset_z << 16));
}
static void gpuSetCullFace(bool enabled) {
// 1 = cull backfaces
// 2 = don't cull
gpu_set_short(offsetof(gpu_state, tri_cull), enabled ? 1 : 2);
}
static void gpu_init() {
gpup_id = rspq_overlay_register(&rsp_gpu);
gpuDepthRange(0, 1);
}
static void gpu_close() {
rspq_wait();
rspq_overlay_unregister(gpup_id);
}