KELP 이규명님 프레임버퍼 테스트 소스 ....

자료출처 : http://www.kelp.or.kr

== 다시 나온 pixel 찍기 소스
===============================
/*
* fbpixel2.c : Frame buffer draw pixel example(using mmap)
*
* Copyright(C) 2002 holelee
*
*/

#include <stdio.h>
#include <stdlib.h> /* for exit */
#include <unistd.h> /* for open/close .. */
#include <fcntl.h> /* for O_RDWR */
#include <sys/ioctl.h> /* for ioctl */
#include <sys/mman.h> /* for mmap */
#include <linux/fb.h> /* for fb_var_screeninfo, FBIOGET_VSCREENINFO */

#define FBDEVFILE "/dev/fb"

typedef unsigned char ubyte;

unsigned short makepixel(ubyte r, ubyte g, ubyte b)
{
return (unsigned short)(((r>>3)<<11)|((g>>2)<<5)|(b>>3));
}

int main()
{
int fbfd;
int ret;
struct fb_var_screeninfo fbvar;
unsigned short pixel;
int offset;
unsigned short *pfbdata;

fbfd = open(FBDEVFILE, O_RDWR);
if(fbfd < 0)
{
perror("fbdev open");
exit(1);
}

ret = ioctl(fbfd, FBIOGET_VSCREENINFO, &fbvar);
if(ret < 0)
{
perror("fbdev ioctl");
exit(1);
}

if(fbvar.bits_per_pixel != 16)
{
fprintf(stderr, "bpp is not 16\n");
exit(1);
}

pfbdata = (unsigned short *) mmap(0, fbvar.xres*fbvar.yres*16/8, PROT_READ|PROT_WRITE, MAP_SHARED, fbfd, 0);

if((unsigned)pfbdata == (unsigned)-1)
{
perror("fbdev mmap");
exit(1);
}

/* red pixel @ (0,0) */
pixel = makepixel(255,0,0); /* red pixel */
*pfbdata = pixel;

/* green pixel @ (100,50) */
offset = 50*fbvar.xres+100;
pixel = makepixel(0,255,0); /* green pixel */
*(pfbdata+offset) = pixel; /* draw pixel */


/* blue pixel @ (50,100) */
offset = 100*fbvar.xres+50;
pixel = makepixel(0,0,255); /* blue pixel */
*(pfbdata+offset) = pixel; /* draw pixel */

/* white pixel @ (100,100) */
offset = 100*fbvar.xres+100;
pixel = makepixel(255,255,255); /* white pixel */
*(pfbdata+offset) = pixel; /* draw pixel */

munmap(pfbdata, fbvar.xres*fbvar.yres*16/8);
close(fbfd);
exit(0);
return 0;
}