diff options
| -rw-r--r-- | src/ppu.rs | 51 |
1 files changed, 20 insertions, 31 deletions
@@ -148,12 +148,12 @@ impl<'a, 'b> PPU<'a, 'b> { #[inline(always)] fn reset_cx(&mut self) { - self.v = (self.v & !0x001fu16) | (self.t & 0x001f); + self.v = (self.v & !0x041fu16) | (self.t & 0x041f); } #[inline(always)] fn reset_y(&mut self) { - self.v = (self.v & !0x73e0u16) | (self.t & 0x73e0); + self.v = (self.v & !0x7be0u16) | (self.t & 0x7be0); } fn clear_sprite(&mut self) { @@ -234,41 +234,21 @@ impl<'a, 'b> PPU<'a, 'b> { } } - fn get_bgpixel(&self) -> u8 { - let bg_idx = ((self.bg_bitmap[1] & 1) << 1) | (self.bg_bitmap[0] & 1); - match bg_idx { - 0x0 => 0x0, /* transparent */ - _ => { - let bg_pl = ((self.bg_palette[1] & 1) << 1) | (self.bg_palette[0] & 1); - self.mem.read(0x3f00 | (bg_pl << 2) as u16 | bg_idx as u16) - } - } - } - - fn get_sppixel(&self, idx: usize) -> u8 { - let sp_idx = ((self.sp_bitmap[idx][1] & 1) << 1) | (self.sp_bitmap[idx][0] & 1); - match sp_idx { - 0x0 => 0x0, - _ => { - let attr = self.oam2[idx].attr; - self.mem.read(0x3f10 | ((attr & 3) << 2) as u16 | sp_idx as u16) - } - } - } - fn render_pixel(&mut self) { - let bg = self.get_bgpixel(); - let mut sp = 0x0; + let bg_pidx = ((self.bg_bitmap[1] & 1) << 1) | (self.bg_bitmap[0] & 1); + let mut sp_pidx = 0x0; + let mut sp_idx = 0; let mut pri = 0x1; for i in 0..8 { if self.sp_cnt[i] != 0 { continue; } /* not active */ - match self.get_sppixel(i as usize) { + match ((self.sp_bitmap[i][1] & 1) << 1) | (self.sp_bitmap[i][0] & 1) { 0x0 => (), - c => { - if self.sp_zero_insight && bg != 0 && i == 0 { + pidx => { + if self.sp_zero_insight && bg_pidx != 0 && i == 0 { self.ppustatus |= 1 << 6; /* set sprite zero hit */ } - sp = c; + sp_pidx = pidx; + sp_idx = i; pri = (self.oam2[i].attr >> 5) & 1; break; } @@ -278,7 +258,16 @@ impl<'a, 'b> PPU<'a, 'b> { assert!(self.scanline < 240); self.scr.put(self.cycle as u8 - 1, self.scanline as u8, - if pri == 0 || bg == 0 { sp } else { bg }); + if (pri == 0 || bg_pidx == 0) && sp_pidx != 0 { + self.mem.read(0x3f10 | + ((self.oam2[sp_idx].attr & 3) << 2) as u16 | + sp_pidx as u16) + } else { + self.mem.read(0x3f00 | + (((self.bg_palette[1] & 1) << 3) | + ((self.bg_palette[0] & 1) << 2)) as u16 | + bg_pidx as u16) + }); } pub fn tick(&mut self) -> bool { |