diff options
| -rw-r--r-- | memory.c | 16 | ||||
| -rw-r--r-- | ppu.c | 4 |
2 files changed, 11 insertions, 9 deletions
@@ -6,26 +6,28 @@ static inline uint8_t memory_read(struct nes_state *state, uint32_t offset) { ppu_tick(state); // apu_tick(state); + uint8_t result = 0; + if(offset >= 0x8000) { // MOST - return state->mapper_function.prg_rom_read(state, offset); + result = state->mapper_function.prg_rom_read(state, offset); - } else if((offset < 0x2000)) { // SECOND - return state->ram[offset & 0x07ff]; + } else if(offset < 0x2000) { // SECOND + result = state->ram[offset & 0x07ff]; } else if(offset < 0x4000) { // THIRD - return ppu_read(state, offset); + result = ppu_read(state, offset); } else if(offset >= 0x6000) { - return state->mapper_function.prg_ram_read(state, offset); + result = state->mapper_function.prg_ram_read(state, offset); } else if(offset == 0x4016 || offset == 0x4017) { uint32_t index = offset & 1; uint8_t value = (state->ppu.input_latch[index] >> state->ppu.input_bit[index]) & 1; state->ppu.input_bit[index]++; - return value | 0x40; // Bit 6 open bus high, bit 7 low + result = value | 0x40; // Bit 6 open bus high, bit 7 low } - return 0; + return result; } __attribute__((hot)) @@ -28,7 +28,7 @@ __attribute__((hot)) static inline void ppu_evaluate_sprites(struct nes_state *state) { struct ppu_state *restrict ppu = &state->ppu; uint8_t sprite_height = (ppu->reg_ctrl & 0x20) ? 16 : 8; - uint8_t n = 0; + uint32_t n = 0; uint8_t * restrict src = ppu->oam; uint8_t * restrict dst = ppu->secondary_oam; @@ -47,7 +47,7 @@ static inline void ppu_evaluate_sprites(struct nes_state *state) { dst += 4; n++; } else { - ppu->reg_status |= 0x20; + ppu->reg_status |= 0x20; // NOTE(peter): sprite overflow break; } } |