chore: added APU automated testing

frontends/sdl/README.md

@@ -79,7 +79,7 @@ cargo vcpkg -v build
 It's possible to run the emulator in headless mode using the `--headless` parameter:
 
 ```bash
-cargo run  -- --rom-path ../../res/roms/test/blargg/cpu/cpu_instrs.gb --cycles 100000000  --headless --device stdout --unlimited
+cargo run -- --rom-path ../../res/roms/test/blargg/cpu/cpu_instrs.gb --cycles 100000000 --headless --device stdout --unlimited
 ```
 
 ## Features

frontends/sdl/src/test.rs

@@ -64,11 +64,37 @@ mod tests {
             Some(50000000),
             TestOptions::default(),
         );
-        compare_images(&result, "res/test/blargg/instr_timing/instr_timing.png");
         let image_result = compare_images(&result, "res/test/blargg/instr_timing/instr_timing.png");
         assert_eq!(image_result, true);
     }
 
+    #[test]
+    fn test_blargg_dmg_sound() {
+        let result: [u8; FRAME_BUFFER_SIZE] = run_image_test(
+            "../../res/roms/test/blargg/dmg_sound/01-registers.gb",
+            Some(50000000),
+            TestOptions::default(),
+        );
+        let image_result = compare_images(&result, "res/test/blargg/dmg_sound/01-registers.png");
+        assert_eq!(image_result, true);
+
+        let result: [u8; FRAME_BUFFER_SIZE] = run_image_test(
+            "../../res/roms/test/blargg/dmg_sound/02-len ctr.gb",
+            Some(50000000),
+            TestOptions::default(),
+        );
+        let image_result = compare_images(&result, "res/test/blargg/dmg_sound/02-len ctr.png");
+        assert_eq!(image_result, true);
+
+        let result: [u8; FRAME_BUFFER_SIZE] = run_image_test(
+            "../../res/roms/test/blargg/dmg_sound/03-trigger.gb",
+            Some(100000000),
+            TestOptions::default(),
+        );
+        let image_result = compare_images(&result, "res/test/blargg/dmg_sound/03-trigger.png");
+        assert_eq!(image_result, true);
+    }
+
     #[test]
     fn test_dmg_acid2() {
         let result: [u8; FRAME_BUFFER_SIZE] = run_image_test(

src/apu.rs

@@ -444,14 +444,10 @@ impl Apu {
             }
         };
 
-        println!("APU read: 0x{:04X} = 0x{:02X}", addr, value);
-
         value
     }
 
     pub fn write(&mut self, addr: u16, value: u8) {
-        println!("APU write: 0x{:04X} = 0x{:02X}", addr, value);
-
         // in case the sound is disabled then ignores writes
         // to any register aside from the sound on/off
         if !self.sound_enabled && addr != 0xff26 {