diff options
Diffstat (limited to 'src')
| -rw-r--r-- | src/memory.rs | 2 | ||||
| -rw-r--r-- | src/ppu.rs | 99 |
2 files changed, 40 insertions, 61 deletions
diff --git a/src/memory.rs b/src/memory.rs index 10980e7..707ce7e 100644 --- a/src/memory.rs +++ b/src/memory.rs @@ -6,7 +6,7 @@ use mos6502::CPU; use cartridge::MirrorType; use mapper::RefMapper; use controller::Controller; -use core::cell::{RefCell, Cell}; +use core::cell::Cell; use core::ptr::null_mut; use core::mem::size_of; @@ -1,7 +1,8 @@ #![allow(dead_code)] use memory::{VMem, PPUMemory, CPUBus}; -use core::mem::{size_of, transmute}; use utils::{Read, Write, load_prefix, save_prefix}; +use core::mem::{size_of, transmute}; +use core::cmp::min; pub trait Screen { fn put(&mut self, x: u8, y: u8, color: u8); @@ -44,10 +45,8 @@ pub struct PPU<'a> { bg_bit_high: u8, /* sprites */ oam: [Sprite; 64], - oam2: [usize; 8], - sp_pixel: [u32; 8], - sp_idx: [usize; 8], - sp_cnt: [u8; 8], + oam2: [u8; 8], + sp_cache: [u16; 256], /* pre-computed sp value */ vblank: bool, pub vblank_lines: bool, buffered_read: u8, @@ -266,18 +265,6 @@ impl<'a> PPU<'a> { } #[inline(always)] - fn shift_sprites(&mut self) { - for (i, c) in self.sp_cnt.iter_mut().enumerate() { - if self.sp_idx[i] > 0xff { break } - let c0 = *c; - match c0 { - 0 => self.sp_pixel[i] >>= 4, - _ => *c = c0 - 1 - } - } - } - - #[inline(always)] fn shift_bgtile(&mut self) { self.bg_pixel >>= 4; } @@ -322,7 +309,7 @@ impl<'a> PPU<'a> { #[inline(always)] fn clear_sprite(&mut self) { debug_assert!(self.scanline != 261); - self.oam2 = [0x100; 8]; + self.oam2 = [0xff; 8]; } fn eval_sprite(&mut self) { @@ -338,7 +325,7 @@ impl<'a> PPU<'a> { for (i, s) in self.oam.iter().enumerate() { let y = s.y as u16; if y <= scanline && scanline < y + h { - self.oam2[nidx] = i; + self.oam2[nidx] = i as u8; nidx += 1; if nidx == 8 { n = i + 1; @@ -376,11 +363,10 @@ impl<'a> PPU<'a> { fn fetch_sprite(&mut self) { if self.scanline == 261 { return } /* we use scanline here because s.y is the (actual y) - 1 */ - self.sp_idx = [0x100; 8]; - for (i, v) in self.oam2.iter().enumerate() { - let j = *v; - if j > 0xff { break } - let s = &self.oam[j]; + self.sp_cache = [0xffff; 256]; + for &j in self.oam2.iter() { + if j == 0xff { break } + let s = &self.oam[j as usize]; let vflip = (s.attr & 0x80) == 0x80; let y0 = self.scanline - s.y as u16; let (ptable, tidx, y) = match self.get_spritesize() { @@ -395,8 +381,6 @@ impl<'a> PPU<'a> { y & 0x7) } }; - self.sp_idx[i] = j; - self.sp_cnt[i] = s.x; let mut low = self.mem.read_mapper(ptable | ((tidx as u16) << 4) | 0x0 | y as u16); let mut high = self.mem.read_mapper(ptable | ((tidx as u16) << 4) | 0x8 | y as u16); if (s.attr & 0x40) == 0x40 { @@ -404,46 +388,44 @@ impl<'a> PPU<'a> { high = PPU::reverse_byte(high); } let attr = s.attr & 3; - let mut t = 0u32; - for _ in 0..8 { - t = (t << 4) | ((attr << 2) | ((high & 1) << 1) | (low & 1)) as u32; + let x_max = min(s.x as usize + 8, 256); + /* pre-compute sprite pixels */ + for p in (&mut self.sp_cache[s.x as usize .. x_max]).iter_mut().rev() { + if *p == 0xffff { + let sp = ((attr << 2) | ((high & 1) << 1) | (low & 1)) as u16; + if sp & 3 != 0x0 { + *p = ((if j == 0 {1} else {0}) << 15) | /* if zero sprite */ + (((s.attr >> 5) as u16 & 1) << 8) | /* priority flag */ + sp; + } + } high >>= 1; low >>= 1; } - self.sp_pixel[i] = t; } } fn render_pixel(&mut self) { let x = self.cycle - 1; - let bg = ((self.bg_pixel >> (self.x << 2)) & 0xf) as u16; - let bg_pidx = - if x >= 8 || self.get_show_leftmost_bg() { - if self.get_show_bg() {bg & 3} else {0} - } else {0}; - let mut sp_pidx = 0x0; + let show_bg = self.get_show_bg(); + let show_sp = self.get_show_sp(); + + let bg = if show_bg && (x >= 8 || self.get_show_leftmost_bg()) + {(self.bg_pixel >> (self.x << 2)) & 0xf} else {0} as u16; + let bg_pidx = bg & 3; let mut pri = 0x1; let mut sp = 0; - let show_sp = self.get_show_sp(); - if x >= 8 || self.get_show_leftmost_sp() { - for i in 0..8 { - if self.sp_idx[i] > 0xff { break } - if self.sp_cnt[i] != 0 { continue; } /* not active */ - let s = &self.oam[self.sp_idx[i]]; - sp = if show_sp {(self.sp_pixel[i] & 0xf) as u16} else { 0 }; - match sp & 3 { - 0x0 => (), - pidx => { - if bg_pidx != 0 && self.sp_idx[i] == 0 && - x != 0xff && s.y != 0xff { - self.ppustatus |= PPU::FLAG_SPRITE_ZERO; /* set sprite zero hit */ - } - sp_pidx = pidx; - pri = (s.attr >> 5) & 1; - break; - } + let mut sp_pidx = 0x0; + if show_sp && (x >= 8 || self.get_show_leftmost_sp()) { + let p = self.sp_cache[x as usize]; + if p != 0xffff { + if (p >> 15 == 1) && bg_pidx != 0 && x != 0xff { + self.ppustatus |= PPU::FLAG_SPRITE_ZERO; /* set sprite zero hit */ } - } + pri = (p >> 8) & 1; + sp = p & 0x00ff; + sp_pidx = sp & 3; + } } debug_assert!(0 < self.cycle && self.cycle < 257); debug_assert!(self.scanline < 240); @@ -479,10 +461,8 @@ impl<'a> PPU<'a> { bg_nt: 0, bg_attr: 0, bg_bit_low: 0, bg_bit_high: 0, oam: [Sprite{y: 0, tile: 0, attr: 0, x: 0}; 64], - oam2: [0x100; 8], - sp_idx: [0x100; 8], - sp_pixel: [0; 8], - sp_cnt: [0; 8], + oam2: [0xff; 8], + sp_cache: [0xffff; 256], vblank: false, vblank_lines: true, buffered_read, @@ -564,7 +544,6 @@ impl<'a> PPU<'a> { } if visible_cycle { self.render_pixel(); - self.shift_sprites(); } self.shift_bgtile(); } else if cycle == 257 { |