Implement window rendering

src/cpu/render_operations.rs

@@ -7,6 +7,9 @@ const OAM_ADDRESS: u16 = 0xFE00;
 
 const SPRITE_SIZE: u16 = 4;
 
+const WY_ADDRESS: u16 = 0xFF4A;
+const WX_ADDRESS: u16 = 0xFF4B;
+
 pub struct Sprite {
     pub y_pos: i32,
     pub x_pos: i32,
@@ -23,7 +26,7 @@ impl CPU {
         self.memory.read_byte(0xFF40) & (1 << 7) == (1 << 7)
     }
 
-    pub fn get_lcdc_window_tile_map_high(&self) -> bool {
+    pub fn get_lcdc_window_tile_high_map(&self) -> bool {
         self.memory.read_byte(0xFF40) & (1 << 6) == (1 << 6)
     }
 
@@ -35,7 +38,7 @@ impl CPU {
         self.memory.read_byte(0xFF40) & (1 << 4) == (1 << 4)
     }
 
-    pub fn get_lcdc_bg_tile_map(&self) -> bool {
+    pub fn get_lcdc_bg_tile_high_map(&self) -> bool {
         self.memory.read_byte(0xFF40) & (1 << 3) == (1 << 3)
     }
 
@@ -64,6 +67,14 @@ impl CPU {
         self.memory.read_byte(SCX_ADDRESS)
     }
 
+    pub fn get_window_wy(&mut self) -> u8 {
+        self.memory.read_byte(WY_ADDRESS)
+    }
+
+    pub fn get_window_wx(&mut self) -> u8 {
+        self.memory.read_byte(WX_ADDRESS)
+    }
+
     // VRAM getters
     pub fn get_vram_tile_line(
         &self,

src/rendering/line_rendering.rs

@@ -7,8 +7,6 @@ const DOTS_PER_LINE: u32 = 456;
 
 const SCAN_DOTS: u32 = 80;
 const MIN_DRAW_DOTS: u32 = 172;
-#[allow(dead_code)]
-const MIN_HBLANK_DOTS: u32 = 87;
 
 const SCANLINES_ACTUAL: u8 = 144;
 const SCANLINES_EXTRA: u8 = 10;
@@ -20,45 +18,64 @@ pub fn oam_scan(_cpu: &CPU) {}
 
 // Mode 3
 pub fn draw_line(cpu: &mut CPU, game_diplay: &mut Image, palette: &[Color; 4]) {
-    let high_map: bool = false;
-    let high_addressing: bool = !cpu.get_lcdc_bg_window_tile_data();
-
     let scx = cpu.get_lcd_scx();
     let scy = cpu.get_lcd_scy();
+
     let line: u8 = cpu.get_lcd_y_coordinate();
 
     let mut display_x: u32 = 0;
-    let mut line_x_pos = scx as u32 % 8;
+
+    let mut bg_line_x_pos = scx as u32 % 8;
+
+    let high_adressing = !cpu.get_lcdc_bg_window_tile_data();
 
     // Draw Background
     for xtile in 0..TILES_PER_LINE {
-        let tile_index = cpu.get_vram_tile_map_entry(
-            high_map,
+        // Fetch Background Line Data
+        let bg_tile_idx = cpu.get_vram_tile_map_entry(
+            cpu.get_lcdc_bg_tile_high_map(),
             (((line + scy) / 8) as u16 % 0x100) * 32 + (xtile + (scx as u16 / 8)) % 32,
         );
-        let line_data =
-            cpu.get_vram_tile_line(high_addressing, tile_index as u16, (line + scy) % 8);
+        let bg_line = cpu.get_vram_tile_line(high_adressing, bg_tile_idx as u16, (line + scy) % 8);
 
-        for x_pixel in (line_x_pos % 8)..8 {
+        for x_pixel in (bg_line_x_pos as usize % 8)..8 {
             if display_x >= game_diplay.width() as u32 {
                 break;
             }
 
-            if (line as usize * game_diplay.width() + display_x as usize)
-                >= game_diplay.get_image_data().len()
-            {
-                log::warn!("Pixel out of bounds: x: {}, y: {}", display_x, line);
-                continue;
-            }
-
-            game_diplay.set_pixel(
-                display_x,
-                line as u32,
-                palette[line_data[x_pixel as usize] as usize],
-            );
+            game_diplay.set_pixel(display_x, line as u32, palette[bg_line[x_pixel] as usize]);
 
             display_x += 1;
-            line_x_pos += 1;
+            bg_line_x_pos += 1;
+        }
+    }
+
+    // Draw Window
+    if cpu.get_lcdc_window_enable() {
+        let wd_offset_y = cpu.get_window_wy();
+        let wd_offset_x = cpu.get_window_wx() as i32 - 7;
+
+        for xtile in 0..20 {
+            // Fetch Window Line Data
+
+            if line >= wd_offset_y {
+                let wd_tile_idx = cpu.get_vram_tile_map_entry(
+                    cpu.get_lcdc_window_tile_high_map(),
+                    ((line - wd_offset_y) as u16 / 8) * 32 + (xtile - wd_offset_x) as u16,
+                );
+                let wd_line = cpu.get_vram_tile_line(high_adressing, wd_tile_idx as u16, line % 8);
+
+                for x_pixel in 0..8 as usize {
+                    let x_coord: i32 = xtile as i32 * 8 + x_pixel as i32 + wd_offset_x;
+                    if x_coord >= 0 && line >= wd_offset_y {
+                        game_diplay.set_pixel(
+                            x_coord as u32,
+                            line as u32,
+                            palette[wd_line[x_pixel] as usize],
+                        );
+                    }
+                }
+            }
         }
     }
 
@@ -67,14 +84,15 @@ pub fn draw_line(cpu: &mut CPU, game_diplay: &mut Image, palette: &[Color; 4]) {
 
     // Draw Objects (Sprites)
     for sprite_idx in 0..40 {
-        let mut sprite = cpu.get_oam_entry(sprite_idx);
+        let sprite = cpu.get_oam_entry(sprite_idx);
 
         if (line as i32) >= sprite.y_pos - 16 && (line as i32) < sprite.y_pos - 8 {
-            let line_data = cpu.get_vram_tile_line(
-                false,
-                sprite.tile_idx,
-                (line + 16 - sprite.y_pos as u8) % 8,
-            );
+            let mut tile_line = (line + 16 - sprite.y_pos as u8) % 8;
+            if sprite.y_flip {
+                tile_line = 7 - tile_line;
+            }
+
+            let line_data = cpu.get_vram_tile_line(false, sprite.tile_idx, tile_line);
 
             sprites_drawn += 1;
 
@@ -102,8 +120,6 @@ pub fn draw_line(cpu: &mut CPU, game_diplay: &mut Image, palette: &[Color; 4]) {
             }
         }
     }
-
-    //log::info!("Sprites Drawn: {}", sprites_drawn);
 }
 
 pub struct Ppu {