sprite limiting

desktop/src/main.rs

@@ -33,8 +33,8 @@ fn main() {
     let app = app::App::default();
     // let buf: Vec<u8> = include_bytes!("./roms/DisableRegTestROM.bin").to_vec();
     // let buf: Vec<u8> = include_bytes!("../../notes/pc.md").to_vec();
-    // let buf: Vec<u8> = include_bytes!("/home/cake/Genesis/Ristar (UE) (Aug 1994) [!].bin").to_vec();
-    let buf: Vec<u8> = include_bytes!("/home/cake/sonic/roms/s2.bin").to_vec();
+    // let buf: Vec<u8> = include_bytes!("/home/cake/Genesis/Toy Story (U) [!].bin").to_vec();
+    let buf: Vec<u8> = include_bytes!("/home/cake/sonic/roms/s1.bin").to_vec();
 
     let mut emu = Megadrive::new(buf);
 

emu/src/gfx.rs

@@ -132,16 +132,20 @@ impl Gfx {
         emu: &'a mut Megadrive,
         mut line_high: &'a mut [u8],
         cram_rgb: &[(u8, u8, u8); 64],
-        sprites: &Vec<crate::vdp::Sprite>,
         screen_y: usize,
         screen_width: usize,
     ) {
-        // let max_sprites = if screen_width == 320 { 20 } else { 16 };
-        // let max_pixels = if screen_width == 320 { 320 } else { 256 };
+        let max_sprites = if screen_width == 320 { 20 } else { 16 };
+        let mut pixel_quota = if screen_width == 320 { 320 } else { 256 };
 
         let mut line_low = emu.gfx.line_slice(screen_y);
 
-        for sprite in sprites.iter().rev() {
+        let sprites = emu.core.mem.vdp.sprites(screen_y);
+
+        'draw_sprites: for (i, sprite) in sprites.iter().rev().enumerate() {
+            if i >= max_sprites {
+                break;
+            }
             let target = if sprite.priority == 0 { &mut line_low } else { &mut line_high };
             let sprite_y = screen_y as isize - sprite.y_coord();
             let tiles = &emu.core.mem.vdp.VRAM[sprite.tile..];
@@ -177,6 +181,11 @@ impl Gfx {
                         }
                     }
                 }
+
+                pixel_quota -= 1;
+                if pixel_quota == 0 {
+                    break 'draw_sprites;
+                }
             }
         }
     }

emu/src/lib.rs

@@ -115,12 +115,14 @@ impl Megadrive {
         let (plane_a, plane_b) = self.core.mem.vdp.nametables();
         let (hscroll_a, hscroll_b) = self.core.mem.vdp.hscroll(screen_y);
         let screen_width = self.core.mem.vdp.screen_width();
-        let sprites = self.core.mem.vdp.sprites(screen_y);
         let cram_rgb = self.core.mem.vdp.cram_rgb();
 
         // TODO: use slices for RGB copy
         // TODO: move clear_screen here
 
+        // TODO: try rendering with PIXI / web perf
+        // TODO: remove parts to hit 60
+
         // 0xFE is an invalid MD colour we use as a marker
         const MARKER: u8 = 0xFE;
 
@@ -160,7 +162,6 @@ impl Megadrive {
             self,
             &mut line_high,
             &cram_rgb,
-            &sprites,
             screen_y,
             screen_width,
         );

web/src/lib.rs

@@ -26,9 +26,7 @@ pub fn gamepad_p1(value: usize) {
     unsafe { EMU.core.mem.io.gamepad[0].set(value) }
 }
 
-// lazy_mut! {
-//     static mut CANVAS: [u8; 320 * 240 * 4] = [0; 320 * 240 * 4];
-// }
+// static mut CANVAS: [u8; 320 * 240 * 4] = [0; 320 * 240 * 4];
 
 // #[wasm_bindgen]
 // pub fn canvas() -> *const u8 {