mirror of https://github.com/bsnes-emu/bsnes.git
89 lines
2.2 KiB
C
89 lines
2.2 KiB
C
|
#include "camera.h"
|
||
|
|
|
||
|
|
static int8_t dither_random(uint8_t x, uint8_t y)
|
||
|
|
{
|
||
|
|
static bool once = false;
|
||
|
|
static int8_t random[128*112];
|
||
|
|
if (!once) {
|
||
|
|
unsigned int r = 0x1337c0de;
|
||
|
|
for (int i = 0; i < sizeof(random); i++) {
|
||
|
|
random[i] = r % 85 - 42;
|
||
|
|
r += 11;
|
||
|
|
r *= 25214903917;
|
||
|
|
}
|
||
|
|
once = true;
|
||
|
|
}
|
||
|
|
|
||
|
|
return random[x + y * 128];
|
||
|
|
}
|
||
|
|
|
||
|
|
uint8_t GB_camera_read_image(GB_gameboy_t *gb, uint16_t addr)
|
||
|
|
{
|
||
|
|
uint8_t tile_x = addr / 0x10 % 0x10;
|
||
|
|
uint8_t tile_y = addr / 0x10 / 0x10;
|
||
|
|
|
||
|
|
uint8_t y = ((addr >> 1) & 0x7) + tile_y * 8;
|
||
|
|
uint8_t bit = addr & 1;
|
||
|
|
|
||
|
|
uint8_t ret = 0;
|
||
|
|
|
||
|
|
for (uint8_t x = tile_x * 8; x < tile_x * 8 + 8; x++) {
|
||
|
|
|
||
|
|
int color = gb->camera_get_pixel_callback? ~gb->camera_get_pixel_callback(gb, x,y) : (rand() & 0xFF);
|
||
|
|
|
||
|
|
/* Dither using a deterministic random */
|
||
|
|
color += dither_random(x, y);
|
||
|
|
if (color > 255) {
|
||
|
|
color = 255;
|
||
|
|
}
|
||
|
|
else if (color < 0) {
|
||
|
|
color = 0;
|
||
|
|
}
|
||
|
|
|
||
|
|
ret <<= 1;
|
||
|
|
ret |= (color >> (6 + bit)) & 1;
|
||
|
|
}
|
||
|
|
|
||
|
|
return ret;
|
||
|
|
}
|
||
|
|
|
||
|
|
void GB_set_camera_get_pixel_callback(GB_gameboy_t *gb, GB_camera_get_pixel_callback_t callback)
|
||
|
|
{
|
||
|
|
gb->camera_get_pixel_callback = callback;
|
||
|
|
}
|
||
|
|
|
||
|
|
void GB_set_camera_update_request_callback(GB_gameboy_t *gb, GB_camera_update_request_callback_t callback)
|
||
|
|
{
|
||
|
|
gb->camera_update_request_callback = callback;
|
||
|
|
}
|
||
|
|
|
||
|
|
void GB_camera_updated(GB_gameboy_t *gb)
|
||
|
|
{
|
||
|
|
gb->camera_registers[0] = 0;
|
||
|
|
}
|
||
|
|
|
||
|
|
void GB_camera_write_register(GB_gameboy_t *gb, uint16_t addr, uint8_t value)
|
||
|
|
{
|
||
|
|
addr &= 0x7F;
|
||
|
|
if (addr == 0) {
|
||
|
|
if ((value & 1) && gb->camera_update_request_callback) {
|
||
|
|
/* If no callback is set, ignore the write as if the camera is instantly done */
|
||
|
|
gb->camera_update_request_callback(gb);
|
||
|
|
gb->camera_registers[0] = 1;
|
||
|
|
}
|
||
|
|
}
|
||
|
|
else {
|
||
|
|
if (addr >= 0x36) {
|
||
|
|
GB_log(gb, "Wrote invalid camera register %02x: %2x\n", addr, value);
|
||
|
|
}
|
||
|
|
/* Todo: find out what these registers do */
|
||
|
|
gb->camera_registers[addr] = value;
|
||
|
|
}
|
||
|
|
}
|
||
|
|
uint8_t GB_camera_read_register(GB_gameboy_t *gb, uint16_t addr)
|
||
|
|
{
|
||
|
|
if ((addr & 0x7F) == 0) {
|
||
|
|
return gb->camera_registers[0];
|
||
|
|
}
|
||
|
|
return 0;
|
||
|
|
}
|