[Linux-fbdev-devel] colors

[<ste...@nt...>]

hi

i'm new to framebuffer development. i want to write a small library for 
my embedded system(MPC823L) with a lcd(SHARP LQ64D341). i use the 
framebufferdriver(lcd823.c) from the denx.de kernel tree.

my problem now is to get control over the colors. i use this to open the 
framebuffer:

int fbfd = 0;
long int screensize = 0;
unsigned char *fbp = 0;
struct fb_fix_screeninfo finfo;
struct fb_var_screeninfo vinfo;

...

fbfd = open("/dev/fb", O_RDWR);
if (ioctl(fbfd, FBIOGET_FSCREENINFO, &finfo)) {
if (ioctl(fbfd, FBIOGET_VSCREENINFO, &vinfo)) {
screensize = vinfo.xres * vinfo.yres * vinfo.bits_per_pixel / 8;
fbp = (unsigned char*)mmap(0, screensize, PROT_READ | PROT_WRITE,
				MAP_SHARED, fbfd, 0);


to set a pixel i use something like this:

setPixel(int x, int y, int color){
	long int location;
	location = (x+vinfo.xoffset) * (vinfo.bits_per_pixel/8) 					+ (y+vinfo.yoffset) * finfo.line_length;					*(fbp 
+ location) = color;
	}
}

but what is the structure of the var color(should the type be unsigned 
char?)? what is red, green and blue?
i know that the driver uses pseudocolor and 8bit per pixel.

thanks for helping

stefan