diff options
| -rw-r--r-- | chip8.c | 30 | ||||
| -rw-r--r-- | chip8.h | 2 | ||||
| -rw-r--r-- | main.c | 13 |
3 files changed, 29 insertions, 16 deletions
@@ -79,10 +79,17 @@ chip8_init() { memory[0x0 + i] = chip8_fontset[i]; } + + uint8_t sinv[] = {0xBA, 0x7C, 0xD6, 0xFE, 0x54, 0xAA}; + // temp + for (uint8_t i = 0; i < 6; i++) + { + memory[0x200+i] = sinv[i]; + } } void -chip8_draw_sprite(int startx, int starty, uint8_t mem, uint8_t size) +chip8_draw_sprite(int startx, int starty, uint16_t mem, uint8_t size) { /* * draw sprite located at loc of height size at startx,starty @@ -90,7 +97,7 @@ chip8_draw_sprite(int startx, int starty, uint8_t mem, uint8_t size) uint8_t byte = 0; uint8_t mask = 0x1; - uint8_t destbit = 0x0; + V[0xF] = 0; /* set collision register to 0 */ for (uint8_t byteoffset = 0; byteoffset < size; byteoffset++) { /* loop through each byte from mem to mem+size */ @@ -98,21 +105,18 @@ chip8_draw_sprite(int startx, int starty, uint8_t mem, uint8_t size) int bit = 0; for (mask = 0x80; mask != 0; mask >>= 1) { - if (byte&mask) - { - destbit = 1; - video[WIDTH*starty+(startx+bit)] = 0xFFFFFF; - } - else + if (byte & mask) { - destbit = 0; - video[WIDTH*starty+(startx+bit)] = 0x0; + uint32_t pixel = WIDTH*(starty%HEIGHT)+((startx%WIDTH)+bit); + if (video[pixel] != 0) + { + /* if the video bit is already set, we need to set the collision register */ + V[0xF] = 1; + } + video[pixel] ^= 0xFFFFFF; } - printf("%d", destbit); bit++; } starty++; - puts(""); } - puts("---"); } @@ -17,6 +17,6 @@ int load_rom(); void chip8_init(); -void chip8_draw_sprite(int startx, int starty, uint8_t mem, uint8_t size); +void chip8_draw_sprite(int startx, int starty, uint16_t mem, uint8_t size); #endif @@ -12,7 +12,7 @@ * http://www.emulator101.com/chip-8-sprites.html */ -#define VIDEO_SCALE 10 +#define VIDEO_SCALE 5 SDL_Window *window; SDL_Renderer *renderer; @@ -109,6 +109,7 @@ int main(int argc, char *argv[]) uint32_t frame_time; int do_quit = 0; + chip8_draw_sprite(0, 0, 0xD*5, 0x5); chip8_draw_sprite(5, 0, 0xE*5, 0x5); chip8_draw_sprite(10, 0, 0xA*5, 0x5); @@ -127,13 +128,21 @@ int main(int argc, char *argv[]) chip8_draw_sprite(30, 9, 0xE*5, 0x5); chip8_draw_sprite(35, 9, 0xf*5, 0x5); + chip8_draw_sprite(0, 20, 0x200, 0x6); + chip8_draw_sprite(8, 20, 0x200, 0x6); + chip8_draw_sprite(16, 20, 0x200, 0x6); + chip8_draw_sprite(18, 20, 0x200, 0x6); + + chip8_draw_sprite(61, 25, 0x200, 0x6); + chip8_draw_sprite(50, 30, 0x200, 0x6); while(!do_quit) { frame_start = SDL_GetTicks(); // logic - update_video(); + if (draw_flag) + update_video(); frame_time = SDL_GetTicks() - frame_start; if (frame_delay > frame_time) |