sgi_audiodrv.cpp

Go to the documentation of this file.

//
// 1997/09/27 21:38:01
//

#include "audiodrv.h"

audioDriver::audioDriver()
{
        // Reset everything.
        errorString = "None";
        frequency = 0;
        channels = 0;
        encoding = 0;
        precision = 0;
        audio = (config = NULL);
}

bool audioDriver::IsThere()
{
        // Check device availability and write permissions.
        return (access(AUDIODEVICE,W_OK)==0);
}

bool audioDriver::Open(udword inFreq, int inPrecision, int inChannels,
                                           int inFragments, int inFragBase)
{
        // Transfer input parameters to this object.
        // May later be replaced with driver defaults.
        frequency = inFreq;

        long chpars[] = {AL_OUTPUT_RATE, 0};
 
        // Frequency
 
        chpars[1] = frequency;
        ALsetparams(AL_DEFAULT_DEVICE, chpars, 2);
        ALgetparams(AL_DEFAULT_DEVICE, chpars, 2);
        config = ALnewconfig();
 
        // Set sample format
 
        ALsetsampfmt(config, AL_SAMPFMT_TWOSCOMP);
        encoding = SIDEMU_SIGNED_PCM;  // unlike other systems
        
        // Mono output
 
        ALsetchannels(config, AL_MONO);
        channels = SIDEMU_MONO;
 
        // 8-bit sampleSize
 
        ALsetwidth(config, AL_SAMPLE_8);
        precision = SIDEMU_8BIT;
 
        // Allocate an audio port
 
        if((audio = ALopenport("SIDPLAY sound", "w", config)) == NULL)
    {
                errorString = "AUDIO: Could not open audio port.";
                oserror();
                ALfreeconfig(config);
                return false;  //(1);
    }
 
        // Allocate sound buffers
        blockSize = frequency;
        ALsetqueuesize(config,blockSize);
        
        return true;
}

// Close an opened audio device, free any allocated buffers and
// reset any variables that reflect the current state.
void audioDriver::Close()
{
        if (audio != NULL)
    {
                ALcloseport(audio);
                ALfreeconfig(config);
                audio = (config = NULL);
    }
}

void audioDriver::Play(ubyte* pBuffer, int bufferSize)
{
        if (audio != NULL)
        {
                ALwritesamps(audio,pBuffer,bufferSize);
        }
}

---