shithub: cstory

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Cleanup and documentation

--- a/src/Backends/Audio/WiiU-Software.cpp

+++ b/src/Backends/Audio/WiiU-Software.cpp

@@ -77,11 +77,14 @@

 static void FrameCallback(void)

 {

-	// Just assume both voices are in-sync

+	// We use a double-buffer: while the Wii U is busy playing one half of the buffer, we update the other.

+	// The buffer is 10ms long in total, and this function runs every 3ms.

+

+	// Just assume both voices are in-sync, and only check the first one

 	AXVoiceOffsets offsets;

 	AXGetVoiceOffsets(voices[0], &offsets);

-	unsigned int current_buffer = offsets.currentOffset > (buffer_length / 2) ? 1 : 0;

+	unsigned int current_buffer = offsets.currentOffset > (buffer_length / 2) ? 1 : 0;	// TODO - should probably be '>='

 	static unsigned int last_buffer = 1;

@@ -91,8 +94,10 @@

 		for (unsigned int i = 0; i < buffer_length; ++i)

 			stream_buffer_float[i] = 0.0f;

+		// Fill mixer buffer

 		FillMixerBuffer(stream_buffer_float, buffer_length / 2);

+		// Deinterlate samples, convert them to S16, and write them to the double-buffers

 		short *left_output_buffer = &stream_buffers[0][(buffer_length / 2) * last_buffer];

 		short *right_output_buffer = &stream_buffers[1][(buffer_length / 2) * last_buffer];

@@ -116,11 +121,12 @@

 			else if (right_sample > 1.0f)

 				right_sample = 1.0f;

-			// Deinterlate, and convert to S16

+			// Convert to S16 and store in double-buffers

 			*left_output_buffer_pointer++ = left_sample * 32767.0f;

 			*right_output_buffer_pointer++ = right_sample * 32767.0f;

 		}

+		// Make sure the sound hardware can see our data

 		DCStoreRange(left_output_buffer, buffer_length / 2 * sizeof(short));

 		DCStoreRange(right_output_buffer, buffer_length / 2 * sizeof(short));

@@ -149,8 +155,13 @@

 	buffer_length = output_frequency / 100;	// 10ms buffer

-	stream_buffer_float = (float*)malloc(buffer_length * sizeof(float) * 2);

+	// Create and initialise two 'voices': each one will stream its own

+	// audio - one for the left speaker, and one for the right. 

+	// The software-mixer outputs interlaced float samples, so create

+	// a buffer for it here.

+	stream_buffer_float = (float*)malloc(buffer_length * sizeof(float) * 2);	// TODO - should probably by divided by two

+

 	if (stream_buffer_float != NULL)

 	{

 		stream_buffers[0] = (short*)malloc(buffer_length * sizeof(short));

@@ -189,14 +200,14 @@

 							AXSetVoiceSrcRatio(voices[i], 1.0f);	// We use the native sample rate

 							AXSetVoiceSrcType(voices[i], AX_VOICE_SRC_TYPE_NONE);

-

-							AXVoiceOffsets offs;

-							offs.dataType = AX_VOICE_FORMAT_LPCM16;

-							offs.endOffset = buffer_length;

-							offs.loopingEnabled = AX_VOICE_LOOP_ENABLED;

-							offs.loopOffset = 0;

-							offs.currentOffset = 0;

-							offs.data = stream_buffers[i];

+							AXVoiceOffsets offs = {

+								.dataType = AX_VOICE_FORMAT_LPCM16,

+								.loopingEnabled = AX_VOICE_LOOP_ENABLED,

+								.loopOffset = 0,

+								.endOffset = buffer_length,

+								.currentOffset = 0,

+								.data = stream_buffers[i]

+							};

 							AXSetVoiceOffsets(voices[i], &offs);

 							AXSetVoiceState(voices[i], AX_VOICE_STATE_PLAYING);

@@ -204,6 +215,9 @@

 							AXVoiceEnd(voices[i]);

 						}

+						// Register the frame callback.

+						// Apparently, this fires every 3ms - we will use

+						// it to update the stream buffers when needed.

 						AXRegisterAppFrameCallback(FrameCallback);

 						return true;

--- a/src/Backends/WiiU/Window-Software-Polygon.cpp

+++ b/src/Backends/WiiU/Window-Software-Polygon.cpp

@@ -164,6 +164,7 @@

 ATTRIBUTE_HOT void WindowBackend_Software_Display(void)

 {

+	// Convert frame from RGB24 to RGBA32, and upload it to the GPU texture

 	unsigned char *framebuffer = (unsigned char*)GX2RLockSurfaceEx(&screen_texture.surface, 0, (GX2RResourceFlags)0);

 	const unsigned char *in_pointer = fake_framebuffer;

@@ -184,6 +185,7 @@

 	WHBGfxBeginRender();

+	// Draw to the TV

 	WHBGfxBeginRenderTV();

 	WHBGfxClearColor(0.0f, 0.0f, 0.0f, 1.0f);

 	GX2SetPixelTexture(&screen_texture, shader_group.pixelShader->samplerVars[0].location);

@@ -196,6 +198,7 @@

 	GX2DrawEx(GX2_PRIMITIVE_MODE_QUADS, 4, 0, 1);

 	WHBGfxFinishRenderTV();

+	// Draw to the gamepad

 	WHBGfxBeginRenderDRC();

 	WHBGfxClearColor(0.0f, 0.0f, 0.0f, 1.0f);

 	GX2SetPixelTexture(&screen_texture, shader_group.pixelShader->samplerVars[0].location);