formats.h

typedef unsigned int COLOROPTYPE [4];
typedef void (*PIXELGETPROC) (const unsigned char* bits, COLOROPTYPE col);
typedef void (*PIXELSETPROC) (unsigned char* bits, const COLOROPTYPE col);

#include <memory.h>

struct r5g6b5
{
        unsigned int r :5;
        unsigned int g :6;
        unsigned int b :5;
};

struct x1r5g5b5
{
        unsigned int x :1;
        unsigned int r :5;
        unsigned int g :5;
        unsigned int b :5;
};


void argb_get (const unsigned char* bits, COLOROPTYPE col)
{
        col[0] = *bits;
        col[1] = *(bits+1);
        col[2] = *(bits+2);
        col[3] = *(bits+3);
}

void argb_set (unsigned char* bits, const COLOROPTYPE col)
{
        *bits     = col[0];
        *(bits+1) = col[1];
        *(bits+2) = col[2];
        *(bits+3) = col[3];
}

void rgb8_get (const unsigned char* bits, COLOROPTYPE col)
{
        col[0] = *bits;
        col[1] = *(bits+1);
        col[2] = *(bits+2);
}

void rgb8_set (unsigned char* bits, const COLOROPTYPE col)
{
        *bits     = col[0];
        *(bits+1) = col[1];
        *(bits+2) = col[2];
}

void r5g6b5_get (const unsigned char* bits, COLOROPTYPE col)
{
        r5g6b5 b;
        memcpy(&b, bits, sizeof(short));
        col[0] = b.r;
        col[1] = b.g;
        col[2] = b.b;
}

void r5g6b5_set (unsigned char* bits, const COLOROPTYPE col)
{
        r5g6b5 c;
        c.r = col[0];
        c.g = col[1];
        c.b = col[2];
        memcpy(bits, &c, sizeof(short));
}

void x1r5g5b5_get (const unsigned char* bits, COLOROPTYPE col)
{
        x1r5g5b5 c;
        memcpy(&c, bits, sizeof(short));
        col[0] = c.r;
        col[1] = c.g;
        col[2] = c.b;
}

void x1r5g5b5_set (unsigned char* bits, const COLOROPTYPE col)
{
        x1r5g5b5 c;
        c.r = col[0];
        c.g = col[1];
        c.b = col[2];
        memcpy(bits, &c, sizeof(short));
}

void a8_get (const unsigned char* bits, COLOROPTYPE col)
{
        col[0] = *bits;
        col[1] = col[2] = col[0];
}

void a8_set (unsigned char* bits, const COLOROPTYPE col)
{
        *bits     = col[0];
}


const static float one_over_255 = 1.0/255.0;

void frgb_get (const unsigned char* bits, COLOROPTYPE col)
{
        const float* fbits = (const float*)bits;
        col[0] = (unsigned int)(fbits[0]*255.0);
        col[1] = (unsigned int)(fbits[1]*255.0);
        col[2] = (unsigned int)(fbits[2]*255.0);
}

void frgb_set (unsigned char* bits, const COLOROPTYPE col)
{
        float* fbits = (float*)bits;
        fbits[0] = float(col[0])*one_over_255;
        fbits[1] = float(col[1])*one_over_255;
        fbits[2] = float(col[2])*one_over_255;
}

void frgba_get (const unsigned char* bits, COLOROPTYPE col)
{
        const float* fbits = (const float*)bits;
        col[0] = (unsigned int)(fbits[0]*255.0);
        col[1] = (unsigned int)(fbits[1]*255.0);
        col[2] = (unsigned int)(fbits[2]*255.0);
        col[3] = (unsigned int)(fbits[3]*255.0);
}

void frgba_set (unsigned char* bits, const COLOROPTYPE col)
{
        float* fbits = (float*)bits;
        fbits[0] = float(col[0])*one_over_255;
        fbits[1] = float(col[1])*one_over_255;
        fbits[2] = float(col[2])*one_over_255;
        fbits[3] = float(col[3])*one_over_255;
}


void fa_get (const unsigned char* bits, COLOROPTYPE col)
{
        const float* fbits = (const float*)bits;
        col[0] = (unsigned int)(fbits[0]*255.0);
        col[1] = col[2] = col[0];
}

void fa_set (unsigned char* bits, const COLOROPTYPE col)
{
        float* fbits = (float*)bits;
        fbits[0] = float(col[0])*one_over_255;
}


inline void zero_color(COLOROPTYPE x)
{
        x[0] = x[1] = x[2] = x[3] = 0;
}

inline void add_color(COLOROPTYPE x, const COLOROPTYPE a)
{
        x[0]+=a[0];
        x[1]+=a[1];
        x[2]+=a[2];
        x[3]+=a[3];
}

inline void shift_right_color(COLOROPTYPE x, unsigned int shift)
{
        x[0] = x[0] >> shift;
        x[1] = x[1] >> shift;
        x[2] = x[2] >> shift;
        x[3] = x[3] >> shift;
}