OPRI

IsaacMarovitz · Feb 2, 2024 · 7e2e645 · 7e2e645
1 parent 0f398bd
commit 7e2e645
Showing 1 changed file with 7 additions and 5 deletions.
diff --git a/src/components/ppu.rs b/src/components/ppu.rs
@@ -30,6 +30,7 @@ pub struct PPU {
  vram: [u8; 0x4000],
  vram_bank: usize,
  oam: [u8; 0xA0],
+ opri: bool,
  bgprio: [Priority; SCREEN_W],
  pub interrupts: Interrupts,
  pub frame_buffer: Vec<u8>,
@@ -155,6 +156,7 @@ impl PPU {
  vram: [0; 0x4000],
  vram_bank: 0,
  oam: [0; 0xA0],
+ opri: true,
  bgprio: [Priority::Normal; SCREEN_W],
  interrupts: Interrupts::empty(),
  frame_buffer: vec![0x00; 4 * SCREEN_W * SCREEN_H],
@@ -445,6 +447,7 @@ impl PPU {
  continue;
  }
 
+ // TODO: Respect OPRI
  if previous_px == px {
  if previous_address < sprite_address {
  continue;
@@ -533,7 +536,7 @@ impl Memory for PPU {
  match a {
  0x8000..=0x9FFF => {
  if self.ppu_mode != PPUMode::Draw {
- self.vram[self.vram_bank * 0x2000 + a as usize - 0x8000]
+ self.vram[(self.vram_bank * 0x2000) + a as usize - 0x8000]
  } else {
  0xFF
  }
@@ -588,8 +591,7 @@ impl Memory for PPU {
  a | b
  }
  }
- // TODO: Object Priority Mode
- 0xFF6C => 0x00,
+ 0xFF6C => self.opri,
  _ => panic!("Read to unsupported PPU address ({:#06x})!", a),
  }
  }
@@ -598,7 +600,7 @@ impl Memory for PPU {
  match a {
  0x8000..=0x9FFF => {
  if self.ppu_mode != PPUMode::Draw {
- self.vram[self.vram_bank * 0x2000 + a as usize - 0x8000] = v
+ self.vram[(self.vram_bank * 0x2000) + a as usize - 0x8000] = v
  }
  }
  0xFE00..=0xFE9F => {
@@ -672,7 +674,7 @@ impl Memory for PPU {
  }
  }
  // TODO: Object Priority Mode
- 0xFF6C => {}
+ 0xFF6C => self.opri = v != 0,
  _ => panic!("Write to unsupported PPU address ({:#06x})!", a),
  }
  }