diff options
Diffstat (limited to 'src/ppusim')
| -rw-r--r-- | src/ppusim/pixel.c | 45 |
1 files changed, 44 insertions, 1 deletions
diff --git a/src/ppusim/pixel.c b/src/ppusim/pixel.c index 3a09ccd..96ee998 100644 --- a/src/ppusim/pixel.c +++ b/src/ppusim/pixel.c @@ -1,6 +1,10 @@ #include <SDL2/SDL.h> +#include <stdbool.h> +#include "ppu/internals.h" +#include "ppusim/mem.h" #include "ppusim/sim.h" +#include "ppu/consts.h" static void hh_ppusim_draw(SDL_Renderer* r, unsigned px, unsigned py, unsigned cr, unsigned cg, unsigned cb) { SDL_SetRenderDrawColor(r, cr, cg, cb, 255); @@ -12,11 +16,50 @@ static void hh_ppusim_draw(SDL_Renderer* r, unsigned px, unsigned py, unsigned c }); } +/* transform xy if tile is flipped */ +static uint16_t hh_ppusim_apply_transform(unsigned x, unsigned y, bool fliph, bool flipv) { + unsigned tx = fliph ? HH_PPU_SPRITE_WIDTH - x - 1 : x; + unsigned ty = flipv ? HH_PPU_SPRITE_HEIGHT - y - 1 : y; + return ty * HH_PPU_SPRITE_WIDTH + tx; +} + +/* @brief get current bg pixel cidx */ +static uint8_t hh_ppusim_bg_pixel(unsigned x, unsigned y) { + hh_ppu_data_t* aux = &g_hh_ppusim_vram[HH_PPU_VRAM_AUX_OFFSET]; + unsigned bg_shift_y = HH_RESIZE(aux[0], 7, 0); + unsigned bg_shift_x = HH_RESIZE(aux[0], 15, 8) | HH_RESIZE(aux[1], 0, 0) << 8; + unsigned abs_x = bg_shift_x + x; + unsigned abs_y = bg_shift_y + y; + unsigned grid_x = abs_x / HH_PPU_SPRITE_WIDTH; + unsigned grid_y = abs_y / HH_PPU_SPRITE_HEIGHT; + unsigned loc_x = abs_x - grid_x * HH_PPU_SPRITE_WIDTH; + unsigned loc_y = abs_y - grid_y * HH_PPU_SPRITE_HEIGHT; + unsigned bam_offset = grid_y * HH_PPU_BG_CANVAS_TILES_H + grid_x; + hh_ppu_data_t bam = g_hh_ppusim_vram[HH_PPU_VRAM_BAM_OFFSET + bam_offset]; + 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; + 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; + cidx |= HH_RESIZE(tmm, word_bit_addr+2, word_bit_addr) << 0; + return cidx; +} + void hh_ppusim_pixel(SDL_Renderer* r, unsigned x, unsigned y) { // loop through foreground sprites to get highest priority cidx - // get background 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; + 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), + HH_RESIZE(pal_rgb, 7, 4), + HH_RESIZE(pal_rgb, 3, 0) + }; + hh_ppusim_draw(r, x, y, rgb[0] << 4, rgb[1] << 4, rgb[2] << 4); } |