trying to render planeb

desktop/src/main.rs

@@ -26,7 +26,7 @@ fn main() {
     let mut toggle = Button::new(400, 300, 80, 40, "stop");
     let mut but = Button::new(400, 350, 80, 40, "frame");
     let mut step = Button::new(400, 400, 80, 40, "step");
-    let mut stepby = IntInput::new(400, 450, 80, 40, "step by");
+    let stepby = IntInput::new(400, 450, 80, 40, "step by");
     let mut info = TextDisplay::new(0, 0, 500, 300, "asm");
     stepby.set_value("1");
 

emu/src/lib.rs

@@ -55,7 +55,7 @@ impl Megadrive {
     }
 
     pub fn frame(&mut self) {
-        /* cycle counts taken from drx/kiwi */
+        /* cycle counts initially taken from drx/kiwi */
 
         self.clear_screen();
 
@@ -95,9 +95,7 @@ impl Megadrive {
             self.core.mem.vdp.set_status(vdp::VINT_MASK);
         }
 
-        self.core.execute(200);
-
-        self.core.execute(3420-788);
+        self.core.execute(3420-588);
 
         for _ in screen_height..262 {
             self.core.execute(3420);
@@ -113,6 +111,7 @@ impl Megadrive {
         };
     }
 
+    #[allow(unused_variables)]
     fn fire_beam(&mut self, line: usize) {
         let (cellw, cellh) = self.core.mem.vdp.scroll_size();
         let screen_width = self.core.mem.vdp.screen_width();
@@ -125,8 +124,7 @@ impl Megadrive {
         let hscroll_mode = self.core.mem.vdp.registers[0xB] & 3;
         let planea_nametable =
             ((self.core.mem.vdp.registers[4] >> 3) as u32 & 3) << 10;
-        let planeb_nametable =
-            (self.core.mem.vdp.registers[4] as u32 & 3) << 10;
+
 
         let index = match hscroll_mode {
             0 => 0,
@@ -138,10 +136,57 @@ impl Megadrive {
 
         let hscroll = hscroll_addr + (index * 4); // 3 ?
 
-        for cell in 0..screen_width {
+        let planeb_nametable =
+            (self.core.mem.vdp.registers[4] as u32 & 3) << 10;
 
+        let planeb = &self.core.mem.vdp.VRAM[planeb_nametable as usize..];
+
+
+        let tiles = (0..cellw).map(|i| {
+            let offset = (i as usize * 2) ;
+            if i as usize + 1 > planeb.len() { return 0 }
+            (planeb[offset] as usize & 7) << 8 | planeb[offset + 1] as usize
+        }).collect::<Vec<_>>();
+
+        // println!("{:?} {:?}", tiles, tiles.len());
+
+        let tile_y = line & 7;
+        let y_offset = tile_y * 4;
+
+
+
+        // for i in 0..0xFF {
+        //     print!("{:b} ", planeb[i]);
+        // }
+
+        // println!("");
+
+        // tile is 32 bytes
+
+        for pixel in 0..screen_width {
+            if let Some(tile) = tiles.get(pixel / 8) {
+                let x_offset = pixel & 6;
+                let px = self.core.mem.vdp.VRAM[(tile * 32) + x_offset + y_offset];
+
+                let px = if pixel & 1 == 1 {
+                    px >> 4
+                } else {
+                    px & 0xF
+                };
+
+                let (r, g, b) = self.core.mem.vdp.color(0, px as _);
+
+                let screen_offset = (pixel + (line * screen_width)) * 3;
+
+                self.screen[screen_offset] = r;
+                self.screen[screen_offset + 1] = g;
+                self.screen[screen_offset + 2] = b;
+            }
         }
 
 
+
+
+
     }
 }

emu/src/vdp.rs

@@ -55,19 +55,23 @@ impl VDP {
         }
     }
 
-    pub fn cram_rgb(&self) -> [(u8, u8, u8); 64] {
-        let mut rgb = [(0, 0, 0); 64];
-        for (i, color) in self.CRAM.iter().enumerate() {
-            rgb[i] = cram_to_rgb(*color);
-        }
-        rgb
+    pub fn color(&self, line: usize, index: usize) -> (u8, u8, u8) {
+        cram_to_rgb(self.CRAM[index + (line * 0x10)])
     }
 
     pub fn bg_color(&self) -> (u8, u8, u8) {
         let vdp_bg = self.registers[7];
         let index = vdp_bg & 0xF;
         let line = (vdp_bg >> 4) & 3;
-        cram_to_rgb(self.CRAM[(index + (line * 0x10)) as usize])
+        self.color(line as _, index as _)
+    }
+
+    pub fn cram_rgb(&self) -> [(u8, u8, u8); 64] {
+        let mut rgb = [(0, 0, 0); 64];
+        for (i, color) in self.CRAM.iter().enumerate() {
+            rgb[i] = cram_to_rgb(*color);
+        }
+        rgb
     }
 
     pub fn screen_width(&self) -> usize {
@@ -104,6 +108,7 @@ impl VDP {
 
     pub fn scroll_size(&self) -> (u8, u8) {
         let to_cells = |size| (size + 1) * 32;
+        // TODO: 96 is invalid
         (
             to_cells(self.registers[0x10] & 3),
             to_cells((self.registers[0x10] >> 4) & 3),