// ======================================================================
// W space: Multi star - fractal sound creation tool
// (CC) 2009 Jens Koeplinger, http://www.jenskoeplinger.com/P
// License: Creative Commons Attribution "Share Alike 3.0 Unported"
// http://creativecommons.org/licenses/by-sa/3.0
// See main file "wspacemultistarsound.c" for what this means to you!
// ======================================================================
// lib-multistar-util.h
// ----------------------------------------------------------------------
// utilities library
//
// Examples:
/*

    FILE *filePointer;
    int totalDataLength;

    filePointer = fopen("soundfile.wav", "wb");
    totalDataLength = 3528000; // 20 seconds 16 bit stereo at 44.1kHz

       ...

    writeOutputWaveFileHeader();

       ...

    writeTwoByteInteger(filePointer, 16);
    fprintf(filePointer, "data");
    writeFourByteInteger(filePointer, totalDataLength);

*/
// ---------------------------------------------------------------------- 

void writeTwoByteInteger(FILE *fp, int byteToWrite) {
// only values from negative 0xFFFF to positive 0xFFFF are allowed

    if (byteToWrite < 0) {
    // add 0x10000 to negative values

        fputc((int) (byteToWrite + 0x10000)         & 0xFF, fp);
        fputc((int) ((byteToWrite + 0x10000) >> 8)  & 0xFF, fp);

    } else {

        fputc((int)  byteToWrite        & 0xFF, fp);
        fputc((int) (byteToWrite >> 8)  & 0xFF, fp);

    }

}

// ---------------------------------------------------------------------- 

void writeFourByteInteger(FILE *fp, int byteToWrite) {
// only positive values between 0 and 0xFFFFFFFF are allowed

    fputc((int)  byteToWrite        & 0xFF, fp);
    fputc((int) (byteToWrite >> 8)  & 0xFF, fp);
    fputc((int) (byteToWrite >> 16) & 0xFF, fp);
    fputc((int) (byteToWrite >> 24) & 0xFF, fp);

}

// ---------------------------------------------------------------------- 

void writeOutputWaveFileHeader() {
// opens the output wave file for writing, and
// writes header information; currently supported
// format: 16 bit stereo at 44.1kHz sampling rate.
//
// IN:  totalDataLength is the length (in bytes) of the sample
//      fp is a file pointer; closed
// OUT: fp (file pointer; file will be open)

    printf("Open file for output: ");
    printf(outFileName);
    printf("\n");

    fp = fopen(outFileName, "wb");

    printf("... write header\n");

    fprintf(fp, "RIFF");                            // put text RIFF
    writeFourByteInteger(fp, totalDataLength + 36); // length of data + header
    fprintf(fp, "WAVEfmt ");                        // write the text "WAVEfmt "
    writeFourByteInteger(fp, 0x10);                 // write 0x10 (four byte)
    writeTwoByteInteger(fp, 1);                     // write 0x01 (two byte)
    writeTwoByteInteger(fp, 2);                     // 2 channels (=stereo)
    writeFourByteInteger(fp, 44100);                // sampled at 44.1kHz
    writeFourByteInteger(fp, 176400);               // bytes per second (=sampling rate * 4)
    writeTwoByteInteger(fp, 4);                     // bytes per sample: 4 (both channels)
    writeTwoByteInteger(fp, 16);                    // write bits per channel per sample: 16
    fprintf(fp, "data");                            // write the text "data"
    writeFourByteInteger(fp, totalDataLength);      // total length of the data

    // Header is written,
    // file is open;
    // may the data come!

    printf("... done.\n");

}

// ---------------------------------------------------------------------- 

void closeOutputWaveFile() {

    printf("Close file\n");
    fclose(fp);
    printf("... done.\n");

}

// ----------------------------------------------------------------------