diff --git a/src/mmu.rs b/src/mmu.rs index acfb3abad6e48cafb5cec0baf1802dd701a4ecc9..32f22f5d0c6add33bad84410b95794675b1a74d8 100644 --- a/src/mmu.rs +++ b/src/mmu.rs @@ -78,10 +78,15 @@ impl Mmu { } 0xf00 => { if addr >= 0xff80 { - self.ppu.hram[(addr & 0x7f) as usize] + self.ppu.hram[(addr & 0x007f) as usize] } else { - println!("WRITING TO IO control"); - 0x00 + match addr & 0x00f0 { + 0x40 | 0x50 | 0x60 | 0x70 => self.ppu.read(addr), + _ => { + println!("READING FROM Unknown IO control 0x{:04x}", addr); + 0x00 + } + } } } addr => panic!("Reading from unknown location 0x{:04x}", addr), @@ -134,9 +139,16 @@ impl Mmu { } 0xf00 => { if addr >= 0xff80 { - self.ppu.hram[(addr & 0x7f) as usize] = value; + self.ppu.hram[(addr & 0x007f) as usize] = value; } else { - println!("WRITING TO IO control"); + match addr & 0x00f0 { + 0x40 | 0x50 | 0x60 | 0x70 => { + self.ppu.write(addr, value); + } + _ => { + println!("WRITING TO Unknown IO control 0x{:04x}", addr); + } + } } } addr => panic!("Writing in unknown location 0x{:04x}", addr), diff --git a/src/ppu.rs b/src/ppu.rs index 7e1d7e351ffdcd8bc35dcbdbca266926802ef872..adcb432238b9298eebeae9c1dcf4590c89d5dbf1 100644 --- a/src/ppu.rs +++ b/src/ppu.rs @@ -1,9 +1,19 @@ pub const VRAM_SIZE: usize = 8192; pub const HRAM_SIZE: usize = 128; +pub const PALETTE_SIZE: usize = 4; +pub const RGBA_SIZE: usize = 4; pub struct Ppu { pub vram: [u8; VRAM_SIZE], pub hram: [u8; HRAM_SIZE], + pub palette: [[u8; RGBA_SIZE]; PALETTE_SIZE], + pub scy: u8, + pub scx: u8, + pub line: u8, + pub switch_bg: bool, + pub bg_map: bool, + pub bg_tile: bool, + pub switch_lcd: bool, } impl Ppu { @@ -11,6 +21,57 @@ impl Ppu { Ppu { vram: [0u8; VRAM_SIZE], hram: [0u8; HRAM_SIZE], + palette: [[0u8; RGBA_SIZE]; PALETTE_SIZE], + scy: 0x0, + scx: 0x0, + line: 0x0, + switch_bg: false, + bg_map: false, + bg_tile: false, + switch_lcd: false, + } + } + + pub fn clock() {} + + pub fn read(&mut self, addr: u16) -> u8 { + match addr & 0x00ff { + 0x0040 => { + let value = if self.switch_bg { 0x01 } else { 0x00 } + | if self.bg_map { 0x08 } else { 0x00 } + | if self.bg_tile { 0x10 } else { 0x00 } + | if self.switch_lcd { 0x80 } else { 0x00 }; + value + } + 0x0042 => self.scy, + 0x0043 => self.scx, + 0x0044 => self.line, + addr => panic!("Reading from unknown PPU location 0x{:04x}", addr), + } + } + + pub fn write(&mut self, addr: u16, value: u8) { + match addr & 0x00ff { + 0x0040 => { + self.switch_bg = value & 0x01 == 0x01; + self.bg_map = value & 0x08 == 0x08; + self.bg_tile = value & 0x10 == 0x10; + self.switch_lcd = value & 0x80 == 0x80; + } + 0x0042 => self.scy = value, + 0x0043 => self.scx = value, + 0x0047 => { + for index in 0..PALETTE_SIZE { + match (value >> (index * 2)) & 3 { + 0 => self.palette[index] = [255, 255, 255, 255], + 1 => self.palette[index] = [192, 192, 192, 255], + 2 => self.palette[index] = [96, 96, 96, 255], + 3 => self.palette[index] = [0, 0, 0, 255], + color_index => panic!("Invalid palette color index {:04x}", color_index), + } + } + } + addr => panic!("Writing in unknown PPU location 0x{:04x}", addr), } } }