psio.c

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#include "psio.h"

#define FILE_BUFFER_CAPACITY    (1024*4)


FILE *PsOpen(const char *FileName,
    int XMin, int YMin, int XMax, int YMax)
{
    FILE *File = NULL;
        
    if(!(File = fopen(FileName, "wb")))
        return NULL;
    
    /* Tell File to use buffering */
    setvbuf(File, 0, _IOFBF, FILE_BUFFER_CAPACITY);
    
    /* Adjust bounding box so that bottom-left is always (0,0) */
    XMax -= XMin;
    YMax -= YMin;
    
    if(fprintf(File,
        "%%!PS-Adobe-2.0\n"
        "%%%%BoundingBox: 0 0 %d %d\n"
        "<< /PageSize [%d %d] >> setpagedevice\n", XMax, YMax, XMax, YMax) < 0
        || ((XMin != 0 || YMin != 0) && fprintf(File,
        "gsave %d %d translate\n", -XMin, -YMin) < 0)
        || ferror(File))
        {
            fclose(File);
            File = NULL;
        }

    return File;
}


int PsClose(FILE *File)
{
    if(!File
        || fprintf(File, "showpage\n") < 0
        || ferror(File)
        || fclose(File))
        return 0;
    
    return 1;
}


int PsSetDistillerParams(FILE *File, const char *Params)
{
    if(!File
        || fprintf(File,
        "systemdict /setdistillerparams known {\n"
        "<< %s >> setdistillerparams\n"
        "} if\n", Params) < 0)
        return 0;
    else
        return 1;
}


static int WriteASCII85(FILE *File, const uint8_t *Data, int NumBytes)
{
    unsigned long Tuple, Plain[4];
    unsigned int Encoded[5];
    int i, k, LineCount, Padding;
    
    
    /* Write ASCII85-encoded data */
    for(i = 0, LineCount = 0; i < NumBytes; i += 4)
    {
        for(k = 0; k < 4; k++)  /* Get four bytes */
            Plain[k] = Data[i + k];
        
        Tuple = (Plain[0] << 24) | (Plain[1] << 16)
            | (Plain[2] << 8) | Plain[3];
        
        for(k = 4; k >= 0; k--) /* Convert to radix 85 */
        {
            Encoded[k] = Tuple % 85;
            Tuple /= 85;
        }
        
        for(k = 0; k < 5; k++)  /* Write ASCII85 tuple */
            fputc(33 + Encoded[k], File);
        
        /* Periodically emit newlines */
        if(++LineCount >= 15)
        {
            LineCount = 0;
            
            if(fprintf(File, "\n") < 0)
                return 0;
        }
    }
    
    /* Write final tuple */
    if(i < NumBytes)
    {
        for(k = 0; i + k < NumBytes; k++)
            Plain[k] = Data[i + k];
        
        for(Padding = 0; k < 4; k++, Padding++)
            Plain[k] = 0;
        
        Tuple = (Plain[0] << 24) | (Plain[1] << 16)
            | (Plain[2] << 8) | Plain[3];
        
        for(k = 4; k >= 0; k--) /* Convert to radix 85 */
        {
            Encoded[k] = Tuple % 85;
            Tuple /= 85;
        }
        
        for(k = 0; k < 5 - Padding; k++)  /* Write ASCII85 tuple */
            fputc(33 + Encoded[k], File);
        
        if(++LineCount >= 15
            && fprintf(File, "\n") < 0)
            return 0;
    }
    
    if(fprintf(File, "~>\n") < 0 || ferror(File))
        return 0;
    
    return 1;
}


int PsWriteGrayImage(FILE *File,
    const uint8_t *Image, int Width, int Height)
{
    /* Specify ASCII85 sRGB 8-bit color image data */
    if(!File || !Image || fprintf(File,
        "gsave\n"
        "/DeviceGray setcolorspace\n"
        "0 %d translate %d %d scale\n"
        "<< /ImageType 1\n"
        "   /Width %d\n"
        "   /Height %d\n"
        "   /ImageMatrix [%d 0 0 -%d 0 0]\n"
        "   /BitsPerComponent 8\n"
        "   /Decode [0 1]\n"
        "   /DataSource currentfile /ASCII85Decode filter\n"
        "   /Interpolate false\n"
        ">> image\n",
        Height, Width, Height,
        Width, Height, Width, Height) < 0
        || !WriteASCII85(File, Image, Width*Height)
        || fprintf(File, "grestore\n") < 0)
        return 0;
    else
        return 1;
}


int PsWriteColorImage(FILE *File,
    const uint8_t *Image, int Width, int Height)
{
    /* Specify ASCII85 sRGB 8-bit color image data */
    if(!File || !Image || fprintf(File,
        "gsave\n"
        "/DeviceRGB setcolorspace\n"
        "0 %d translate %d %d scale\n"
        "<< /ImageType 1\n"
        "   /Width %d\n"
        "   /Height %d\n"
        "   /ImageMatrix [%d 0 0 -%d 0 0]\n"
        "   /BitsPerComponent 8\n"
        "   /Decode [0 1 0 1 0 1]\n"
        "   /DataSource currentfile /ASCII85Decode filter\n"
        "   /Interpolate false\n"
        ">> image\n",
        Height, Width, Height,
        Width, Height, Width, Height) < 0
        || !WriteASCII85(File, Image, 3*Width*Height)
        || fprintf(File, "grestore\n") < 0)
        return 0;
    else
        return 1;
}