ok6410LCD测试程序

1.在屏幕上分别显示红绿蓝三个长方形:

 

#ifndef LCD_APP_H#define LCD_APP_H/*自定义结构体用来在用户空间里管理帧缓冲的信息*/typedef struct fd_dev{int fd;//帧缓冲设备文件描述符void *pfb;//指向帧缓冲映射到用户空间的首地址int xres,yres,siz;//一帧图像的宽度、高度和大小int bpp;//每个像素的位数}fb_dev_t;/*实现缓冲设备的打开和关闭操作的接口*/int fb_open(fb_dev_t *fbd,char *fbn){struct fb_var_screeninfo vinfo;if(-1 == (fbd->fd=open(fbn,O_RDWR))){printf("Error:cannot open framebuffer device.\n");_exit(EXIT_FAILURE);}/*获取LCD的可变参数*/ioctl(fbd->fd,FBIOGET_VSCREENINFO,&vinfo);//将可变参数的中的相关数据保存到自定的结构体fbd中fbd->xres = vinfo.xres;fbd->yres = vinfo.yres;fbd->bpp = vinfo.bits_per_pixel;fbd->siz = fbd->xres * fbd->yres *fbd->bpp/8;printf("%dx%d,%dbpp,screensize = %d\n",fbd->xres,fbd->yres,fbd->bpp,fbd->siz);/*将帧缓冲映射到内存*/fbd->pfb = mmap(0,fbd->siz,PROT_READ|PROT_WRITE,MAP_SHARED,fbd->fd,0);if((int)fbd->pfb == -1){printf("Error:failed to map framebuffer device to memory.\n");_exit(EXIT_FAILURE);}return 0;}int fb_close(fb_dev_t *fbd){munmap(fbd->pfb,fbd->siz);//解除映射close(fbd->fd);//关闭设备文件}/*填充制定的巨型区域*/int fb_drawrect(fb_dev_t *fbd,int x0,int y0,int w,int h,int color){int x,y;for(y=y0;y<y0+h;y++){for(x = x0;x<x0+w;x++)*((short*)(fbd->pfb)+y*fbd->xres+x)=color;}return 0;} #endif

测试程序lcd_app.c

#include <unistd.h>#include <stdio.h>#include <stdlib.h>#include <fcntl.h>#include <linux/fb.h>#include <sys/mman.h>#include "lcd_app.h"#include "bmplib.h"#define FB_DEV_NAME "/dev/fb0"#define RED_COLOR565 0x0F100#define GREEN_COLOR565 0x007E0#define BLUE_COLOR565  0x0001Fint main(int argc,char *argv[]){fb_dev_t *fbd;fbd = (fb_dev_t*)malloc(sizeof(fb_dev_t));fb_open(fbd,FB_DEV_NAME);if(fbd->bpp == 16){printf("Red/Green/Blue Screen\n");fb_drawrect(fbd,0,0,fbd->xres,fbd->yres/3,RED_COLOR565);fb_drawrect(fbd,0,fbd->yres/3,fbd->xres,fbd->yres*2/3,GREEN_COLOR565);fb_drawrect(fbd,0,fbd->yres*2/3,fbd->xres,fbd->yres,BLUE_COLOR565);}elseprintf("16 bits only!\n");       //fb_drawbmp(fbd,0,0,argv[1]);fb_close(fbd);return 0;}

 

 

 

 

 

 

2.在lcd上显示位图bmplib.h

#ifndef BMPLIB_H#define BMPLIB_Htypedef struct{/*位图头文件*/char type[2];//文件类型，必须为"BM"(0x4D42)char siz[4];//文件的大小char reserved[4];//保留，必须为0char off[4];//位图阵列相对于文件头的偏移字节}bmp_file_header_t;typedef struct{/*位图信息头*/char siz[4];char width[4];//位图的宽度char height[4];//位图的高度char planes[2];//目标设备的位平面数，必须设置为1char bitcount[2];//每个像素的位数,1,4,8,或24char compress[3];//位图阵列的压缩方法，0=不压缩char img_siz[4];//图像大小(字节)char xpel[4];//目标设备水平每米像素的个数char ypel[4];//目标像素垂直每米像素的个数char clr_used[4];//位图实际使用的颜色表的颜色数char clr_important[4];//重要颜色索引的个数}bmp_info_header_t;/*bitmap格式的图像文件会带有54字节的信息头，其中包含了图像和文件的基本信息，紧接在文件头之后的就是实际的图像数据*/typedef struct{char blue;char green;char red;char reserved;}rgb_32_t;/*对位图进行操作*/typedef struct{rgb_32_t *curp;//指向当前像素点int width,height,bitcount,siz;//图形长宽、大小等信息int fd;//图像文件描述符void *data;//图像有效数据}bmp_t;//字符形到整形的转换int char_to_int(char *ch){return *((int*)ch);}/*打开位图操作*/int bmp_open(bmp_t *bmp,char *bmpn){bmp_file_header_t fhr;//位图文件头bmp_info_header_t ihr;//位图信息头if(-1 == (bmp->fd=open(bmpn,O_RDONLY))){printf("Error:cannot open framebuffer device.\n");_exit(EXIT_FAILURE);}read(bmp->fd,&fhr,sizeof(bmp_file_header_t));//读取文件头read(bmp->fd,&ihr,sizeof(bmp_info_header_t));//读取信息头bmp->width = char_to_int(ihr.width);bmp->height = char_to_int(ihr.height);bmp->bitcount = char_to_int(ihr.bitcount);//像素位数bmp->siz = (bmp->width *bmp->height*bmp->bitcount)/8;printf("bmp->width = %d\n",bmp->width);printf("bmp->height = %d\n",bmp->height);printf("bmp->bitcount = %d\n",bmp->bitcount);printf("bmp->siz = %d\n",bmp->siz);bmp->data = malloc(bmp->siz);//为位图数据分配存储空间read(bmp->fd,bmp->data,bmp->siz);//读取数据bmp->curp = (rgb_32_t *)bmp->data;//获取当前像素点return 0;}int bmp_close(bmp_t *bmp){close(bmp->fd);free(bmp->data);return 1;}/*因为开发板的帧缓冲区在驱动中被设置为16位数据表示一个像素点，因此需要对24或32位的位图进行转换，使用下面的函数*/static inline short transfer_to_16bit(char r,char g,char b){return ((r>>3)<<11)|((g>>2)<<5)|(b>>3);}static inline short bmp_get_pixel_16bit(bmp_t *bmp){//将当前位图转化为16位位图信息return transfer_to_16bit(bmp->curp->red,bmp->curp->green,bmp->curp->blue);}//移动到下一像素点static inline void bmp_next_pixel(bmp_t *bmp){if(24==bmp->bitcount)//如果是24位位图bmp->curp = (rgb_32_t*)((int)bmp->curp+3);else if(32 == bmp->bitcount)//如果是32位位图bmp->curp = (rgb_32_t*)((int)bmp->curp+4);}/*绘制位图*/int fb_drawbmp(fb_dev_t *fbd,int x0,int y0,char *bmpn){int x,y,x1,y1;bmp_t bmp;bmp_open(&bmp,bmpn);x1 = x0+bmp.width;y1 = y0+bmp.height;for(y = y1;y>y0;y--){for(x = x0;x<x1;x++){//如果超出LCD屏幕坐标范围if(x>fbd->xres||y>fbd->yres){bmp_next_pixel(&bmp);//移动到下一个像素点continue;}*((short*)(fbd->pfb)+y*fbd->xres+x) = bmp_get_pixel_16bit(&bmp);bmp_next_pixel(&bmp);//移动到下一像素点}}bmp_close(&bmp);return 0;}#endif

测试程序:

lcd_bmp.c

#include <unistd.h>#include <stdio.h>#include <stdlib.h>#include <fcntl.h>#include <linux/fb.h>#include <sys/mman.h>#include "lcd_app.h"#include "bmplib.h"#define FB_DEV_NAME "/dev/fb0"#define RED_COLOR565 0x0F100#define GREEN_COLOR565 0x007E0#define BLUE_COLOR565  0x0001Fint main(int argc,char *argv[]){fb_dev_t *fbd;fbd = (fb_dev_t*)malloc(sizeof(fb_dev_t));fb_open(fbd,FB_DEV_NAME);/*if(fbd->bpp == 16){printf("Red/Green/Blue Screen\n");fb_drawrect(fbd,0,0,fbd->xres,fbd->yres/3,RED_COLOR565);fb_drawrect(fbd,0,fbd->yres/3,fbd->xres,fbd->yres*2/3,GREEN_COLOR565);fb_drawrect(fbd,0,fbd->yres*2/3,fbd->xres,fbd->yres,BLUE_COLOR565);}elseprintf("16 bits only!\n");*/       fb_drawbmp(fbd,0,0,argv[1]);fb_close(fbd);return 0;}

位图程序测试方法，例如这里有一张名为clock.bmp的图片

编译上述文件后生成lcd_bmp

运行如下命令:

./lcd_bmp clock.bmp

 

 

实验现象: