diff options
Diffstat (limited to 'src/ppusim/pixel.c')
| -rw-r--r-- | src/ppusim/pixel.c | 39 |
1 files changed, 33 insertions, 6 deletions
diff --git a/src/ppusim/pixel.c b/src/ppusim/pixel.c index 96ee998..2163c10 100644 --- a/src/ppusim/pixel.c +++ b/src/ppusim/pixel.c @@ -39,7 +39,7 @@ static uint8_t hh_ppusim_bg_pixel(unsigned x, unsigned y) { uint8_t cidx = 0; uint16_t tile_pixel_idx = hh_ppusim_apply_transform(loc_x, loc_y, HH_RESIZE(bam, 14, 14), HH_RESIZE(bam, 13, 13)); uint16_t tile_idx = HH_RESIZE(bam, 9, 0); - hh_ppu_addr_t ttm_addr = tile_idx + tile_pixel_idx / 5; + hh_ppu_addr_t ttm_addr = tile_idx * HH_PPU_VRAM_TMM_SPRITE_SIZE + tile_pixel_idx / 5; uint8_t word_bit_addr = (tile_pixel_idx % 5) * 3; hh_ppu_data_t tmm = g_hh_ppusim_vram[HH_PPU_VRAM_TMM_OFFSET + ttm_addr]; cidx |= HH_RESIZE(bam, 12, 10) << 3; @@ -47,13 +47,40 @@ static uint8_t hh_ppusim_bg_pixel(unsigned x, unsigned y) { return cidx; } +/* @brief get current fg pixel cidx */ +static uint8_t hh_ppusim_fg_pixel(unsigned x, unsigned y) { + x += 16; + y += 16; + uint8_t cidx = 0; + for (unsigned i = 0; i < HH_PPU_FG_SPRITE_COUNT; i++) { + unsigned fam_offset = i * HH_PPU_VRAM_FAM_ENTRY_SIZE; + hh_ppu_data_t* fam = &g_hh_ppusim_vram[HH_PPU_VRAM_FAM_OFFSET + fam_offset]; + unsigned sprite_y = HH_RESIZE(fam[0], 15, 13) | HH_RESIZE(fam[1], 4, 0) << 3; + unsigned sprite_x = HH_RESIZE(fam[1], 13, 5); + if (x < sprite_x) continue; + if (x >= sprite_x + HH_PPU_SPRITE_WIDTH) continue; + if (y < sprite_y) continue; + if (y >= sprite_y + HH_PPU_SPRITE_HEIGHT) continue; + unsigned loc_x = x - sprite_x; + unsigned loc_y = y - sprite_y; + uint16_t tile_pixel_idx = hh_ppusim_apply_transform(loc_x, loc_y, HH_RESIZE(fam[1], 15, 15), HH_RESIZE(fam[1], 14, 14)); + uint16_t tile_idx = HH_RESIZE(fam[0], 9, 0); + hh_ppu_addr_t ttm_addr = tile_idx * HH_PPU_VRAM_TMM_SPRITE_SIZE + tile_pixel_idx / 5; + uint8_t word_bit_addr = (tile_pixel_idx % 5) * 3; + hh_ppu_data_t tmm = g_hh_ppusim_vram[HH_PPU_VRAM_TMM_OFFSET + ttm_addr]; + unsigned cidx_col = HH_RESIZE(tmm, word_bit_addr+2, word_bit_addr); + if (cidx_col == 0) continue; + unsigned cidx_pal = HH_RESIZE(fam[0], 12, 10); + cidx = (cidx_col << 0) | (cidx_pal << 3); + break; + } + return cidx; +} + void hh_ppusim_pixel(SDL_Renderer* r, unsigned x, unsigned y) { - // loop through foreground sprites to get highest priority cidx uint8_t bg_cidx = hh_ppusim_bg_pixel(x, y); - // check if palette color cidx of foreground is 0 - // lookup color from PAL - // hh_ppusim_draw - uint8_t cidx = bg_cidx; + uint8_t fg_cidx = hh_ppusim_fg_pixel(x, y); + uint8_t cidx = (fg_cidx & HH_MASK(3)) == 0 ? bg_cidx : fg_cidx; hh_ppu_data_t pal_rgb = g_hh_ppusim_vram[HH_PPU_VRAM_PAL_OFFSET + cidx]; hh_ppu_rgb_color_t rgb = { HH_RESIZE(pal_rgb, 11, 8), |