diff options
Diffstat (limited to 'src/display.rs')
| -rw-r--r-- | src/display.rs | 359 |
1 files changed, 359 insertions, 0 deletions
diff --git a/src/display.rs b/src/display.rs new file mode 100644 index 0000000..8db432f --- /dev/null +++ b/src/display.rs @@ -0,0 +1,359 @@ +// Very readable, much clean wow. + +use crate::consts::DISPLAY_UPDATE_SLEEP_TIME_MICROS; +use crate::state::MemError; +use minifb::{Window, WindowOptions}; +use std::time::SystemTime; + +const COLORS: [u32; 4] = [0x00e0f8d0, 0x0088c070, 0x346856, 0x00081820]; + +const LINE_DOTS: u64 = 456; + +mod lcdc_flags { + pub const _BG_PRIORITY: u8 = 0b1; + pub const OBJ_ENABLE: u8 = 0b10; + pub const OBJ_SIZE: u8 = 0b100; + pub const BG_TILEMAP_AREA: u8 = 0b1000; + pub const BG_TILEDATA_AREA: u8 = 0b10000; + pub const WIN_ENABLE: u8 = 0b100000; + pub const WIN_TILEMAP_AREA: u8 = 0b1000000; + pub const LCD_ENABLE: u8 = 0b10000000; +} + +pub enum DisplayInterrupt { + Vblank, + Stat, + Both, + None, +} + +#[derive(Debug)] +pub struct Display { + window: Window, + framebuffer: [u32; 160 * 144], + bg_buffer: [u8; 160 * 144], + + tiledata: [u8; 0x3000], + bg_map_attr: [u8; 0x400], + tilemaps: [u8; 0x800], + oam: [u8; 0xa0], + + pub cram: [u8; 0x80], + pub bg_palette: u8, + pub obj_palettes: [u8; 2], + pub viewport_y: u8, + pub viewport_x: u8, + pub lcdc: u8, + pub ly: u8, + pub lyc: u8, + pub lcd_interrupt_mode: u8, + pub vram_bank: u8, + + pub cgb_mode: bool, + + pub window_x: u8, + pub window_y: u8, + + last_dt: SystemTime, + + pub stat: u64, +} + +impl Display { + pub fn new() -> Self { + Self { + window: Window::new( + "Gameboy Emulator", + 512, 461, + /* 1200, 1080, */ + WindowOptions::default(), + ) + .unwrap(), + framebuffer: [0; 160 * 144], + bg_buffer: [0; 160 * 144], + tiledata: [0; 0x3000], + bg_map_attr: [0; 0x400], + cram: [0; 0x80], + tilemaps: [0; 0x800], + oam: [0; 0xa0], + bg_palette: 0, + vram_bank: 0, + obj_palettes: [0; 2], + viewport_y: 0, + viewport_x: 0, + lcdc: 0, + ly: 0, + window_x: 0, + window_y: 0, + last_dt: SystemTime::now(), + stat: 0, + lyc: 0, + cgb_mode: false, + lcd_interrupt_mode: 0xff, + } + } + + pub fn cls(&mut self) { + self.framebuffer = [COLORS[0]; 160 * 144]; + } + + pub fn update(&mut self) { + self.window + .update_with_buffer(&self.framebuffer, 160, 144) + .unwrap(); + } + + pub fn color_palette(&self, color_byte: u8, palette: u8, cgb_mode: bool) -> u32 { + if cgb_mode { + let color_pointer = palette * 8 + color_byte * 2; + let color16b: u16 = (self.cram[color_pointer as usize] as u16) + | ((self.cram[color_pointer as usize + 1] as u16) << 8); + + let red = ((0b11111 & color16b) << 3) as u32; + let green = (((color16b >> 5) & 0b11111) << 3) as u32; + let blue = (((color16b >> 10) & 0b11111) << 3) as u32; + + (red << 16) | (green << 8) | blue + } else { + COLORS[((palette >> (color_byte << 1)) & 0b11) as usize] + } + } + + pub fn print_tile(&mut self, tile: u8, x: u8, y: u8, l: usize, bg_map_attr: u8) { + let tile_pointer = if self.lcdc & lcdc_flags::BG_TILEDATA_AREA != 0 { + ((tile as u16) << 4) as usize + } else { + ((tile as i8 as i32) * 16) as usize + 0x1000 + } + if bg_map_attr & 0b1000 != 0 { 0x1800 } else { 0 }; + + for b in (0..8).rev() { + let data = (((self.tiledata[tile_pointer + l * 2] as u8) >> b) & 1) + | ((((self.tiledata[tile_pointer + l * 2 + 1] as u8) >> b) & 1) << 1); + + let pxx = (x as i32 + 7 - b as i32) as u8; + let pxy = y as i32; + + if pxy < 144 && pxx < 160 { + self.framebuffer[pxy as usize * 160 + pxx as usize] = self.color_palette( + data, + if self.cgb_mode { + bg_map_attr & 0b111 + } else { + self.bg_palette + }, + self.cgb_mode, + ); + self.bg_buffer[pxy as usize * 160 + pxx as usize] = data; + } + } + } + pub fn print_all_tiles(&mut self) { + for i in 0..=255 { + for l in 0..8 { + self.print_tile(i, (i % 20) * 8, (i / 20) * 8, l, 0); + } + } + } + + pub fn w(&mut self, addr: u16, value: u8) -> Result<(), MemError> { + if self.vram_bank == 0 { + if addr < 0x1800 { + self.tiledata[addr as usize] = value; + } else if addr >= 0x7e00 { + self.oam[addr as usize - 0x7e00] = value; + } else { + self.tilemaps[addr as usize - 0x1800] = value; + } + } else { + if addr < 0x1800 { + self.tiledata[addr as usize + 0x1800] = value; + } else if addr < 0x1c00 { + self.bg_map_attr[addr as usize - 0x1800] = value; + } + } + Ok(()) + } + + pub fn r(&self, addr: u16) -> Result<u8, MemError> { + if self.vram_bank == 0 { + if addr < 0x1800 { + Ok(self.tiledata[addr as usize]) + } else if addr >= 0x7e00 { + Ok(self.oam[addr as usize - 0x7e00]) + } else { + Ok(self.tilemaps[addr as usize - 0x1800]) + } + } else { + if addr < 0x1800 { + Ok(self.tiledata[addr as usize + 0x1800]) + } else if addr < 0x1c00 { + Ok(self.bg_map_attr[addr as usize - 0x1800]) + } else { + Ok(0) + } + } + } + + pub fn print_bg(&mut self) { + let tilemap_pointer = if self.lcdc & lcdc_flags::BG_TILEMAP_AREA != 0 { + 0x400 + } else { + 0 + }; + + let y_tile = (self.ly + self.viewport_y) as usize; + + for x in 0..32 { + let tile = self.tilemaps[tilemap_pointer + (y_tile / 8) * 32 + x]; + let bg_map_attr = self.bg_map_attr[(y_tile / 8) * 32 + x]; + self.print_tile( + tile, + x as u8 * 8 - self.viewport_x, + self.ly, + (y_tile % 8) as usize, + bg_map_attr, + ); + } + } + + pub fn print_win(&mut self) { + if self.lcdc & lcdc_flags::WIN_ENABLE == 0 { + return; + } + + let tilemap_pointer = if self.lcdc & lcdc_flags::WIN_TILEMAP_AREA != 0 { + 0x400 + } else { + 0 + }; + + let y_tile = (self.ly - self.window_y) as usize; + + for x in 0..32 { + if tilemap_pointer + (y_tile / 8) * 32 + x >= 2048 { + return; + } + let tile = self.tilemaps[tilemap_pointer + (y_tile / 8) * 32 + x]; + if x * 8 + self.window_x as usize - 7 < 160 && self.ly >= self.window_y { + self.print_tile( + tile, + x as u8 * 8 + self.window_x - 7, + self.ly, + (y_tile % 8) as usize, + 0, + ); + } + } + } + + pub fn print_obj(&mut self) { + if self.lcdc & lcdc_flags::OBJ_ENABLE == 0 { + return; + } + + // Making unreadable magic code is my brand + for o in (0..40).rev() { + let mut y = self.oam[o * 4] - 9; + let x = self.oam[o * 4 + 1]; + let mut tile = self.oam[o * 4 + 2]; + let opts = self.oam[o * 4 + 3]; + let bg_priority_flag = opts & 0b10000000 != 0; + let x_flip = opts & 0b100000 != 0; + let y_flip = opts & 0b1000000 != 0; + let palette = (opts >> 4) & 1; + let tile_vram = if self.cgb_mode && opts & 0b1000 != 0 { + 0x1800 + } else { + 0 + }; + let cgb_palette = opts & 0b111; + let obj_size = if self.lcdc & lcdc_flags::OBJ_SIZE != 0 { + tile &= 0xfe; + y += 8; + 16 + } else { + 8 + }; + + let tile_pointer = ((tile as u16) << 4) as usize + tile_vram; + + if y < self.ly || y >= self.ly + obj_size { + continue; + } + + let l = if y_flip { + y - self.ly + } else { + obj_size - 1 - (y - self.ly) + }; + + for b in 0..8 { + let pxx = if x_flip { + x as i32 + b as i32 - 8 as u8 as i32 + } else { + x as i32 + 7 - b as i32 - 8 as u8 as i32 + }; + let pxy = self.ly as i32; + + let data = (((self.tiledata[tile_pointer + l as usize * 2] as u8) >> b) & 1) + | ((((self.tiledata[tile_pointer + l as usize * 2 + 1] as u8) >> b) & 1) << 1); + + if pxy < 144 && pxx < 160 && pxy >= 0 && pxx >= 0 { + if data != 0 + && !((bg_priority_flag/* && self.lcdc & lcdc_flags::BG_PRIORITY != 0 */) + && self.bg_buffer[pxy as usize * 160 + pxx as usize] != 0) + { + self.framebuffer[pxy as usize * 160 + pxx as usize] = self.color_palette( + data, + if self.cgb_mode { + cgb_palette + 8 + } else { + self.obj_palettes[palette as usize] + }, + self.cgb_mode, + ); + } + } + } + } + } + + pub fn update_display(&mut self, cycles: u64) -> DisplayInterrupt { + let mut ret_interrupt = DisplayInterrupt::None; + self.stat += cycles; + if self.lcdc & lcdc_flags::LCD_ENABLE != 0 && self.stat >= LINE_DOTS { + self.print_bg(); + self.print_win(); + self.print_obj(); + self.ly = (self.ly + 1) % 154; + self.stat %= LINE_DOTS; + if self.ly == 0x90 { + ret_interrupt = DisplayInterrupt::Vblank; + if self.lcd_interrupt_mode == 1 { + ret_interrupt = DisplayInterrupt::Both; + } + if SystemTime::now() + .duration_since(self.last_dt) + .unwrap() + .as_micros() + > DISPLAY_UPDATE_SLEEP_TIME_MICROS as u128 + { + self.update(); + self.last_dt = SystemTime::now(); + } + } + if self.ly < 0x90 && (self.lcd_interrupt_mode == 0 || self.lcd_interrupt_mode == 2) { + ret_interrupt = DisplayInterrupt::Stat; + } + + if self.lcd_interrupt_mode == 3 && self.ly == self.lyc + 1 { + ret_interrupt = DisplayInterrupt::Stat; + } + } + if self.lcdc & lcdc_flags::LCD_ENABLE == 0 { + self.ly = 0; + } + + return ret_interrupt; + } +} |