linux/drivers/video/fb_draw.h

#ifndef _FB_DRAW_H
#define _FB_DRAW_H

#include <asm/types.h>

    /*
     *  Compose two values, using a bitmask as decision value
     *  This is equivalent to (a & mask) | (b & ~mask)
     */

static inline unsigned long
comp(unsigned long a, unsigned long b, unsigned long mask)
{
    return ((a ^ b) & mask) ^ b;
}

    /*
     *  Create a pattern with the given pixel's color
     */

#if BITS_PER_LONG == 64
static inline unsigned long
pixel_to_pat( u32 bpp, u32 pixel)
{
	switch (bpp) {
	case 1:
		return 0xfffffffffffffffful*pixel;
	case 2:
		return 0x5555555555555555ul*pixel;
	case 4:
		return 0x1111111111111111ul*pixel;
	case 8:
		return 0x0101010101010101ul*pixel;
	case 12:
		return 0x0001001001001001ul*pixel;
	case 16:
		return 0x0001000100010001ul*pixel;
	case 24:
		return 0x0000000001000001ul*pixel;
	case 32:
		return 0x0000000100000001ul*pixel;
	default:
		panic("pixel_to_pat(): unsupported pixelformat\n");
    }
}
#else
static inline unsigned long
pixel_to_pat( u32 bpp, u32 pixel)
{
	switch (bpp) {
	case 1:
		return 0xfffffffful*pixel;
	case 2:
		return 0x55555555ul*pixel;
	case 4:
		return 0x11111111ul*pixel;
	case 8:
		return 0x01010101ul*pixel;
	case 12:
		return 0x00001001ul*pixel;
	case 16:
		return 0x00010001ul*pixel;
	case 24:
		return 0x00000001ul*pixel;
	case 32:
		return 0x00000001ul*pixel;
	default:
		panic("pixel_to_pat(): unsupported pixelformat\n");
    }
}
#endif
#endif /* FB_DRAW_H */