求助,framebuffer问题
小弟初学framebuffer,想要画直线,找了网上一段程序,只能画出横线,其他线显示的都是一堆点,分析了好久都找不出问题,拜托各位帮助!#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <math.h>
#include <stdint.h>
#include <unistd.h>
#include <fcntl.h>
#include <sys/ioctl.h>
#include <sys/mman.h>
#include <asm/page.h>
#include <linux/fb.h>
#define TRUE 1
#define FALSE 0
#define MIN(x,y) ((x)>(y)?(y):(x))
#define MAX(x,y) ((x)>(y)?(x):(y))
typedef struct fbdev{
int fb;
unsigned long fb_mem_offset;
unsigned long fb_mem;
struct fb_fix_screeninfo fb_fix;
struct fb_var_screeninfo fb_var;
char dev;
} FBDEV, *PFBDEV;
typedef struct point{
int x;
int y;
int z;
} POINT, *PPOINT;
void draw_dot (PFBDEV pFbdev, POINT p, uint8_t r, uint8_t g, uint8_t b);
void draw_line(PFBDEV pFbdev, POINT p1, POINT p2, uint8_t r, uint8_t g, uint8_t b);
int fb_open(PFBDEV pFbdev)
{
pFbdev->fb = open(pFbdev->dev, O_RDWR);
if(pFbdev->fb < 0)
{
printf("Error opening %s: %m. Check kernel config\n", pFbdev->dev);
return FALSE;
}
if (-1 == ioctl(pFbdev->fb,FBIOGET_VSCREENINFO,&(pFbdev->fb_var)))
{
printf("ioctl FBIOGET_VSCREENINFO\n");
return FALSE;
}
if (-1 == ioctl(pFbdev->fb,FBIOGET_FSCREENINFO,&(pFbdev->fb_fix)))
{
printf("ioctl FBIOGET_FSCREENINFO\n");
return FALSE;
}
pFbdev->fb_mem_offset = (unsigned long)(pFbdev->fb_fix.smem_start) & (~PAGE_MASK);
pFbdev->fb_mem = (unsigned long int)mmap(NULL, pFbdev->fb_fix.smem_len +
pFbdev->fb_mem_offset,
PROT_READ | PROT_WRITE, MAP_SHARED, pFbdev->fb, 0);
if (-1L == (long) pFbdev->fb_mem)
{
printf("mmap error! mem:%ld offset:%ld\n", pFbdev->fb_mem,
pFbdev->fb_mem_offset);
return FALSE;
}
/*
printf("depth(bits per pixel) =%d\n",fb.fb_var.bits_per_pixel);
printf("smemlen = %d\n",fb.fb_fix.smem_len);
printf("fix_line(in byte) = %d\n",fb.fb_fix.line_length);
*/
return TRUE;
}
void fb_close(PFBDEV pFbdev)
{
close(pFbdev->fb);
pFbdev->fb=-1;
}
void fb_memcpy(void *addr, void *color, size_t len)
{
memcpy(addr, color, len);
}
void draw_dot (PFBDEV pFbdev, POINT p, uint8_t r, uint8_t g, uint8_t b)
{
uint32_t offset;
uint8_t color;
color = b;
color = g;
color = r;
color = 0x0;
offset = p.y*pFbdev->fb_fix.line_length+4*p.x;
fb_memcpy((void*)(pFbdev->fb_mem + pFbdev->fb_mem_offset + offset), color, 4);
}
void draw_line(PFBDEV pFbdev, POINT p1, POINT p2, uint8_t r, uint8_t g, uint8_t b)
{
POINT p;
int x,y;
for( x=MIN(p1.x,p2.x); x<=MAX(p1.x,p2.x); x++ )
{
y = (p2.y-p1.y)*(x-p1.x)/(p2.x-p1.x) + p1.y;
p.x = x;
p.y = y;
draw_dot(pFbdev, p, r, g, b);
}
}
int main(void)
{
FBDEV fb;
memset(&fb, 0, sizeof(FBDEV));
strcpy(fb.dev, "/dev/fb0");
if(fb_open(&fb)==FALSE)
{
printf("open frame buffer error\n");
return 0;
}
POINT p1, p2;
p1.x = 300;
p1.y = 450;
p2.x = 600;
p2.y = 450;
draw_line( &fb, p1, p2, 0xff, 0x0, 0x0 );
fb_close(&fb);
return 0;
} 求求各位老大了,帮帮忙! 分辨率问题......
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