dolphin/Source/Plugins/Plugin_DSP_HLE/Src/PCHW/Mixer.cpp

// Copyright (C) 2003-2008 Dolphin Project.

// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, version 2.0.

// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU General Public License 2.0 for more details.

// A copy of the GPL 2.0 should have been included with the program.
// If not, see http://www.gnu.org/licenses/

// Official SVN repository and contact information can be found at
// http://code.google.com/p/dolphin-emu/


// This queue solution is temporary. I'll implement something more efficient later.
#include <queue> // System

#include "Thread.h" // Common
#include "ConsoleWindow.h"

#include "../Config.h" // Local
#include "../Globals.h"
#include "../DSPHandler.h"
#include "../Debugger/File.h"
#include "../main.h"

#include "Mixer.h"
#include "FixedSizeQueue.h"

namespace {

Common::CriticalSection push_sync;

// On real hardware, this fifo is much, much smaller. But timing is also tighter than under Windows, so...
const int queue_minlength = 1024 * 4;
const int queue_maxlength = 1024 * 28;

FixedSizeQueue<s16, queue_maxlength> sample_queue;

}  // namespace

volatile bool mixer_HLEready = false;
volatile int queue_size = 0;

void Mixer(short *buffer, int numSamples, int bits, int rate, int channels)
{
	// silence
	memset(buffer, 0, numSamples * 2 * sizeof(short));

	if (g_dspInitialize.pEmulatorState) {
		if (*g_dspInitialize.pEmulatorState != 0)
			return;
	}

	// first get the DTK Music
	if (g_Config.m_EnableDTKMusic)
	{
		g_dspInitialize.pGetAudioStreaming(buffer, numSamples);
	}

	Mixer_MixUCode(buffer, numSamples, bits, rate, channels);

	push_sync.Enter();
	int count = 0;
	while (queue_size > queue_minlength && count < numSamples * 2) {
		int x = buffer[count];
		x += sample_queue.front();
		if (x > 32767) x = 32767;
		if (x < -32767) x = -32767;
		buffer[count++] = x;
		sample_queue.pop();
		x = buffer[count];
		x += sample_queue.front();
		if (x > 32767) x = 32767;
		if (x < -32767) x = -32767;
		buffer[count++] = x;
		sample_queue.pop();
		queue_size-=2;
	}
	push_sync.Leave();
}

void Mixer_MixUCode(short *buffer, int numSamples, int bits, int rate, 
					int channels) {
	//if this was called directly from the HLE, and not by timeout
	if (g_Config.m_EnableHLEAudio && mixer_HLEready)
	{
		IUCode* pUCode = CDSPHandler::GetInstance().GetUCode();
		if (pUCode != NULL)
			pUCode->MixAdd(buffer, numSamples);
	}
}

void Mixer_PushSamples(short *buffer, int num_stereo_samples, int sample_rate)
{
	if (!soundStream)
		return;

	if (queue_size == 0)
	{
		queue_size = queue_minlength;
		for (int i = 0; i < queue_minlength; i++)
			sample_queue.push((s16)0);
	}

	static int PV1l=0,PV2l=0,PV3l=0,PV4l=0;
	static int PV1r=0,PV2r=0,PV3r=0,PV4r=0;
	static int acc=0;     
 
#ifdef _WIN32
	if (GetAsyncKeyState(VK_TAB))
		return;
#endif

	// Write Other Audio
    if (g_Config.m_EnableThrottle)
	{
        /* This is only needed for non-AX sound, currently directly
           streamed and DTK sound. For AX we call SoundStream::Update in
           AXTask() for example. */
        while (queue_size > queue_maxlength / 2) {
			// Urgh.
			if (g_dspInitialize.pEmulatorState) {
				if (*g_dspInitialize.pEmulatorState != 0)
					return;
			}
			soundStream->Update();
            Common::SleepCurrentThread(0);
        }

        //convert into config option?
        const int mode = 2;

        push_sync.Enter();
        while (num_stereo_samples) 
        {
            acc += sample_rate;
            while (num_stereo_samples && (acc >= 48000))
            {
                PV4l=PV3l;
                PV3l=PV2l;
                PV2l=PV1l;
                PV1l=*(buffer++); //32bit processing
                PV4r=PV3r;
                PV3r=PV2r;
                PV2r=PV1r;
                PV1r=*(buffer++); //32bit processing
                num_stereo_samples--;
                acc-=48000;
            }

            // defaults to nearest
            s32 DataL = PV1l;
            s32 DataR = PV1r;

            if (mode == 1) //linear
            {
                DataL = PV1l + ((PV2l - PV1l)*acc)/48000;
                DataR = PV1r + ((PV2r - PV1r)*acc)/48000;
            }
            else if (mode == 2) //cubic
            {
                s32 a0l = PV1l - PV2l - PV4l + PV3l;
                s32 a0r = PV1r - PV2r - PV4r + PV3r;
                s32 a1l = PV4l - PV3l - a0l;
                s32 a1r = PV4r - PV3r - a0r;
                s32 a2l = PV1l - PV4l;
                s32 a2r = PV1r - PV4r;
                s32 a3l = PV2l;
                s32 a3r = PV2r;

                s32 t0l = ((a0l    )*acc)/48000;
                s32 t0r = ((a0r    )*acc)/48000;
                s32 t1l = ((t0l+a1l)*acc)/48000;
                s32 t1r = ((t0r+a1r)*acc)/48000;
                s32 t2l = ((t1l+a2l)*acc)/48000;
                s32 t2r = ((t1r+a2r)*acc)/48000;
                s32 t3l = ((t2l+a3l));
                s32 t3r = ((t2r+a3r));

                DataL = t3l;
                DataR = t3r;
            }

            int l = DataL, r = DataR;
            if (l < -32767) l = -32767;
            if (r < -32767) r = -32767;
            if (l > 32767) l = 32767;
            if (r > 32767) r = 32767;
            sample_queue.push(l);
            sample_queue.push(r);
            queue_size += 2;
        }
        push_sync.Leave();
    }
}