src/main.zig

@@ -16,7 +16,6 @@ const gba_height = @import("ppu.zig").height;
 const buf_pitch = @import("ppu.zig").buf_pitch;
 
 pub const enable_logging: bool = false;
-const is_binary: bool = false;
 
 pub fn main() anyerror!void {
     // Allocator for Emulator + CLI
@@ -49,6 +48,7 @@ pub fn main() anyerror!void {
     cpu.fastBoot();
 
     if (enable_logging) {
+        const is_binary: bool = true;
         const file_name = if (is_binary) "zba.bin" else "zba.log";
 
         const file = try std.fs.cwd().createFile(file_name, .{ .read = true });

src/scheduler.zig

@@ -36,26 +36,26 @@ pub const Scheduler = struct {
                     std.debug.panic("[Scheduler] Somehow, a u64 overflowed", .{});
                 },
                 .HBlank => {
-                    // The End of a Hblank (During Draw or Vblank)
-                    const old_scanline = bus.io.vcount.scanline.read();
-                    const scanline = (old_scanline + 1) % 228;
+                    // The End of a Hblank
+                    const scanline = bus.io.vcount.scanline.read();
+                    const new_scanline = scanline + 1;
 
-                    bus.io.vcount.scanline.write(scanline);
-                    bus.io.dispstat.hblank.unset();
+                    // TODO: Should this be done @ end of Draw instead of end of Hblank?
+                    bus.ppu.drawScanline(&bus.io);
 
-                    if (scanline < 160) {
+                    bus.io.vcount.scanline.write(new_scanline);
+
+                    if (new_scanline < 160) {
                         // Transitioning to another Draw
                         self.push(.Draw, self.tick + (240 * 4));
                     } else {
                         // Transitioning to a Vblank
-                        if (scanline < 227) bus.io.dispstat.vblank.set() else bus.io.dispstat.vblank.unset();
-
-                        self.push(.VBlank, self.tick + (240 * 4));
+                        bus.io.dispstat.vblank.set();
+                        self.push(.VBlank, self.tick + (308 * 4));
                     }
                 },
                 .Draw => {
                     // The end of a Draw
-                    bus.ppu.drawScanline(&bus.io);
 
                     // Transitioning to a Hblank
                     bus.io.dispstat.hblank.set();
@@ -63,7 +63,23 @@ pub const Scheduler = struct {
                 },
                 .VBlank => {
                     // The end of a Vblank
-                    self.push(.HBlank, self.tick + (68 * 4));
+
+                    const scanline = bus.io.vcount.scanline.read();
+                    const new_scanline = scanline + 1;
+                    bus.io.vcount.scanline.write(new_scanline);
+
+                    if (new_scanline == 227) bus.io.dispstat.vblank.unset();
+
+                    if (new_scanline < 228) {
+                        // Transition to another Vblank
+                        self.push(.VBlank, self.tick + (308 * 4));
+                    } else {
+                        // Transition to another Draw
+                        bus.io.vcount.scanline.write(0); // Reset Scanline
+
+                        // DISPSTAT was disabled on scanline 227
+                        self.push(.Draw, self.tick + (240 * 4));
+                    }
                 },
             }
         }