#ifndef PIXELBUFFER_H
#define PIXELBUFFER_H

/*
 * All the available pixel formats.  This list will probably grow over time.  As
 * you can probably tell, they are nomenclatural.  PF_ starts each one, then
 * one letter for each channel followed by a number for each channel saying how
 * many bits long it is.  Should this be revised to channel-number-channel-number
 * style naming?
 */

#if (__GNUC__>=3) /* For GCC version 3 and up, you have to do this to avoid possible
                     size optimization that can happen unless you force inlining. */
#   define ALWAYS_INLINE __inline __attribute__((always_inline))
#else
#   define ALWAYS_INLINE __inline
#endif

#define PF_R8G8B8A8	0
#define PF_B8G8R8A8	1
#define PF_R8G8B8	2
#define PF_B8G8R8	3
#define PF_I8		4
#define PF_A8		5
#define PF_ANY		6

/*
 * This took me 3 days.  You gotta respect that.  Anyway, it basically has a
 * bunch of functions for managing pixel buffers.  I must credit the people at
 * Blitz.  I learned a lot about this type of thing from their BlitzMax TPixmap
 * type.  Read the following documentation to see the purpose of each function.
 */

#ifdef __cplusplus
extern "C" {
#endif

/* Copy raw pixel data from one buffer to the other.  They must both exist. */
int PixelBufferCopy(unsigned char *in,unsigned char *out,
    int format,unsigned int count);
/* Convert raw pixel data from one buffer to the other.  They must both exist. */
int PixelBufferConvert(unsigned char *in,int in_format,
    unsigned char *out,int out_format,unsigned int count);

#ifdef __cplusplus
}
#endif

/* Get information of the aspects of a format. */

ALWAYS_INLINE unsigned int PixelFormatBytesPerPixel(int format)
{
    switch (format)
    {
    case PF_R8G8B8A8:
        return 4;
    case PF_B8G8R8A8:
        return 4;
    case PF_R8G8B8:
        return 3;
    case PF_B8G8R8:
        return 3;
    case PF_I8:
        return 1;
    case PF_A8:
        return 1;
    }
    return 0;
}

ALWAYS_INLINE unsigned int PixelFormatColorBitsPerPixel(int format)
{
    switch (format)
    {
    case PF_R8G8B8A8:
        return 24;
    case PF_B8G8R8A8:
        return 24;
    case PF_R8G8B8:
        return 24;
    case PF_B8G8R8:
        return 24;
    case PF_I8:
        return 0;
    case PF_A8:
        return 0;
    }
    return 0;
}

ALWAYS_INLINE unsigned int PixelFormatRed(int format)
{
    switch (format)
    {
    case PF_R8G8B8A8:
        return 8;
    case PF_B8G8R8A8:
        return 8;
    case PF_R8G8B8:
        return 8;
    case PF_B8G8R8:
        return 8;
    case PF_I8:
        return 0;
    case PF_A8:
        return 0;
    }
    return 0;
}

ALWAYS_INLINE unsigned int PixelFormatGreen(int format)
{
    switch (format)
    {
    case PF_R8G8B8A8:
        return 8;
    case PF_B8G8R8A8:
        return 8;
    case PF_R8G8B8:
        return 8;
    case PF_B8G8R8:
        return 8;
    case PF_I8:
        return 0;
    case PF_A8:
        return 0;
    }
    return 0;
}

ALWAYS_INLINE unsigned int PixelFormatBlue(int format)
{
    switch (format)
    {
    case PF_R8G8B8A8:
        return 8;
    case PF_B8G8R8A8:
        return 8;
    case PF_R8G8B8:
        return 8;
    case PF_B8G8R8:
        return 8;
    case PF_I8:
        return 0;
    case PF_A8:
        return 0;
    }
    return 0;
}

ALWAYS_INLINE unsigned int PixelFormatAlpha(int format)
{
    switch (format)
    {
    case PF_R8G8B8A8:
        return 8;
    case PF_B8G8R8A8:
        return 8;
    case PF_R8G8B8:
        return 0;
    case PF_B8G8R8:
        return 0;
    case PF_I8:
        return 0;
    case PF_A8:
        return 8;
    }
    return 0;
}

ALWAYS_INLINE unsigned int PixelFormatIntensity(int format)
{
    switch (format)
    {
    case PF_R8G8B8A8:
        return 0;
    case PF_B8G8R8A8:
        return 0;
    case PF_R8G8B8:
        return 0;
    case PF_B8G8R8:
        return 0;
    case PF_I8:
        return 8;
    case PF_A8:
        return 0;
    }
    return 0;
}

/*
 * I really did write all of these from scratch.  Kneel. They are used by
 * the main conversion function, which is merely provided for convenience.
 */

int PixelBufferConvertR8G8B8A8toB8G8R8A8(unsigned char *in,unsigned char *out,unsigned int count);
int PixelBufferConvertR8G8B8A8toR8G8B8(unsigned char *in,unsigned char *out,unsigned int count);
int PixelBufferConvertR8G8B8A8toB8G8R8(unsigned char *in,unsigned char *out,unsigned int count);
int PixelBufferConvertR8G8B8A8toI8(unsigned char *in,unsigned char *out,unsigned int count);
int PixelBufferConvertR8G8B8A8toA8(unsigned char *in,unsigned char *out,unsigned int count);

int PixelBufferConvertB8G8R8A8toR8G8B8A8(unsigned char *in,unsigned char *out,unsigned int count);
int PixelBufferConvertB8G8R8A8toR8G8B8(unsigned char *in,unsigned char *out,unsigned int count);
int PixelBufferConvertB8G8R8A8toB8G8R8(unsigned char *in,unsigned char *out,unsigned int count);
int PixelBufferConvertB8G8R8A8toI8(unsigned char *in,unsigned char *out,unsigned int count);
int PixelBufferConvertB8G8R8A8toA8(unsigned char *in,unsigned char *out,unsigned int count);

int PixelBufferConvertR8G8B8toR8G8B8A8(unsigned char *in,unsigned char *out,unsigned int count);
int PixelBufferConvertR8G8B8toB8G8R8A8(unsigned char *in,unsigned char *out,unsigned int count);
int PixelBufferConvertR8G8B8toB8G8R8(unsigned char *in,unsigned char *out,unsigned int count);
int PixelBufferConvertR8G8B8toI8(unsigned char *in,unsigned char *out,unsigned int count);
int PixelBufferConvertR8G8B8toA8(unsigned char *in,unsigned char *out,unsigned int count);

int PixelBufferConvertB8G8R8toR8G8B8A8(unsigned char *in,unsigned char *out,unsigned int count);
int PixelBufferConvertB8G8R8toB8G8R8A8(unsigned char *in,unsigned char *out,unsigned int count);
int PixelBufferConvertB8G8R8toR8G8B8(unsigned char *in,unsigned char *out,unsigned int count);
int PixelBufferConvertB8G8R8toI8(unsigned char *in,unsigned char *out,unsigned int count);
int PixelBufferConvertB8G8R8toA8(unsigned char *in,unsigned char *out,unsigned int count);

int PixelBufferConvertI8toR8G8B8A8(unsigned char *in,unsigned char *out,unsigned int count);
int PixelBufferConvertI8toB8G8R8A8(unsigned char *in,unsigned char *out,unsigned int count);
int PixelBufferConvertI8toR8G8B8(unsigned char *in,unsigned char *out,unsigned int count);
int PixelBufferConvertI8toB8G8R8(unsigned char *in,unsigned char *out,unsigned int count);
int PixelBufferConvertI8toA8(unsigned char *in,unsigned char *out,unsigned int count);

int PixelBufferConvertA8toR8G8B8A8(unsigned char *in,unsigned char *out,unsigned int count);
int PixelBufferConvertA8toB8G8R8A8(unsigned char *in,unsigned char *out,unsigned int count);
int PixelBufferConvertA8toR8G8B8(unsigned char *in,unsigned char *out,unsigned int count);
int PixelBufferConvertA8toB8G8R8(unsigned char *in,unsigned char *out,unsigned int count);
int PixelBufferConvertA8toI8(unsigned char *in,unsigned char *out,unsigned int count);

#endif