c语言实现对lcd屏清屏操作

#include <stdio.h> #include <stdlib.h> #include <string.h> #include <unistd.h> #include <sys/types.h> #include <sys/stat.h> #include <sys/ioctl.h> #include <sys/mman.h> #include <linux/fb.h> #include <fcntl.h> #include <errno.h> #define SUCCESS 1 #define FAILURE 0 int cls_screen (int x, int y, int w, int h) { int fd = 0; struct fb_var_screeninfo vinfo; struct fb_fix_screeninfo finfo; long int screen_size = 0; unsigned char *fb_mem, *temp; int i = 0; fd = open ("/dev/fb0",O_RDWR); if (ioctl(fd, FBIOGET_VSCREENINFO, &vinfo) == -1) { printf("Failed FBIOGET_VSCREENINFO on /dev/fb0 (%s)\n",strerror(errno)); close(fd); return FAILURE; } if (ioctl(fd, FBIOGET_FSCREENINFO, &finfo) == -1) { printf("Failed FBIOGET_FSCREENINFO on /dev/fb0 (%s)\n",strerror(errno)); close(fd); return FAILURE; } screen_size = vinfo.xres * vinfo.yres * vinfo.bits_per_pixel / 8; fb_mem = mmap(NULL,screen_size,PROT_READ|PROT_WRITE,MAP_SHARED,fd,0); temp = fb_mem; if(w >= vinfo.xres - x) w = vinfo.xres; if(h >= vinfo.yres - y) h = vinfo.yres; for (i=0;i < h;i++) { memset (temp, 0, w * vinfo.bits_per_pixel / 8); temp = temp + vinfo.xres * vinfo.bits_per_pixel / 8; } strcpy(temp,origin_mem); munmap(NULL,screen_size); return SUCCESS; }