C 如何在绘制多个帧时停止linux帧缓冲区以自动清除
我正在写一个gif解码器,这个图像是一个动画图像。当我写第一帧时,它显示得很好。当我显示第二帧时,它只显示更改的像素。其他像素将自动更改为黑色。我不知道为什么 我的第一帧有完整的图片。 第二帧再次只更改了像素,并且包含其余未更改的像素 现在,当我绘制第二个缓冲区时,它也会重新绘制不变的像素。未更改的像素被绘制为黑色(或者确切地说,在监视器中,我看到这些未更改的像素不存在)。此时它必须绘制第二帧。它绘制更改的像素(这是正确的),但它也重新绘制未更改的像素。这个不变的像素被视为黑色(即没有颜色)。我觉得这是一个令人耳目一新的问题。或者可能是别的什么。谢谢你的帮助 必需:它应该重新绘制完整的图像。 简而言之,这是我函数的一个片段 不幸的是,它清除了以前的显示-linux帧缓冲区。 我想停止清除linux帧缓冲区 这是完整的文件C 如何在绘制多个帧时停止linux帧缓冲区以自动清除,c,linux,linux-kernel,kernel,C,Linux,Linux Kernel,Kernel,我正在写一个gif解码器,这个图像是一个动画图像。当我写第一帧时,它显示得很好。当我显示第二帧时,它只显示更改的像素。其他像素将自动更改为黑色。我不知道为什么 我的第一帧有完整的图片。 第二帧再次只更改了像素,并且包含其余未更改的像素 现在,当我绘制第二个缓冲区时,它也会重新绘制不变的像素。未更改的像素被绘制为黑色(或者确切地说,在监视器中,我看到这些未更改的像素不存在)。此时它必须绘制第二帧。它绘制更改的像素(这是正确的),但它也重新绘制未更改的像素。这个不变的像素被视为黑色(即没有颜色)。我
/** This is using the Direct Fb calls here; and is tightly coupled with Linux Framebuffer **/
static int fbfd = 0;
static struct fb_var_screeninfo vinfo;
static struct fb_fix_screeninfo finfo;
static long int screensize = 0;
static char *fbp = 0;
static int x = 0, y = 0;
static long int location = 0;
/** This is a clone to linux Frame buffer, and will be called to dump on Framebuffer **/
char *local_display_mem;
/** local functions **/
static void SetBackground(FrameData *tempInfo);
static void SetPixel(char *fbp, unsigned int x, unsigned int y, Byte red, Byte green, Byte blue);
/** This is the entry function to initialize the display **/
void display_init()
{
// Open the file for reading and writing
fbfd = open("/dev/fb0", O_RDWR);
if (fbfd == -1)
{
perror("cannot open framebuffer device");
exit(1);
}
#ifdef DEBUG
printf("The framebuffer device was opened successfully.\n");
#endif
/** Read the Screen Information **/
if (ioctl(fbfd, FBIOGET_FSCREENINFO, &finfo) == -1)
{
perror("Driver error-- reading fixed information");
exit(1);
}
// Get variable screen information
if (ioctl(fbfd, FBIOGET_VSCREENINFO, &vinfo) == -1)
{
perror("Error reading variable information");
exit(1);
}
#ifdef DEBUG
printf("%dx%d, %dbpp\n", vinfo.xres, vinfo.yres, vinfo.bits_per_pixel);
#endif
// Figure out the size of the screen in bytes
screensize = vinfo.xres * vinfo.yres * vinfo.bits_per_pixel / 8;
// Map the device to memory
fbp = (char *)mmap(0, screensize, PROT_READ | PROT_WRITE, MAP_SHARED, fbfd, 0);
local_display_mem = (char*)malloc(screensize);
if ((int)fbp == -1)
{
perror("Error: mmap failed\r\n");
exit(1);
}
#ifdef DEBUG
printf("The framebuffer device was mapped to memory successfully.\n");
#endif
printf("Shreyas..Display Initialized..\r\n");
//munmap(fbp, screensize);
//close(fbfd);
}
/** This function is called by gif_read to display the Image **/
void Display(FrameData *FrameInfo)
{
short int ImageStartX = 0;
short int ImageStartY = 0;
int Index = 0;
printf("\r\n INFO: Display Called.\r\n");
while(1)
{
Index = 0;
ImageStartX = (FrameInfo->frameScreenInfo.LeftPosition);
ImageStartY = (FrameInfo->frameScreenInfo.TopPosition);
while(ImageStartY < ((FrameInfo->frameScreenInfo.ImageHeight)+(FrameInfo->frameScreenInfo.TopPosition)))
{
while(ImageStartX < ((FrameInfo->frameScreenInfo.ImageWidth)+(FrameInfo->frameScreenInfo.LeftPosition)))
{
if(FrameInfo->frame[Index] != FrameInfo->transperencyindex)
{
SetPixel(local_display_mem,ImageStartX,ImageStartY,((FrameInfo->CMAP)+(FrameInfo->frame[Index]))->Red,((FrameInfo->CMAP)+(FrameInfo->frame[Index]))->Green,((FrameInfo->CMAP)+(FrameInfo->frame[Index]))->Blue);
}
Index++;
ImageStartX++;
}
ImageStartY++;
ImageStartX=(FrameInfo->frameScreenInfo.LeftPosition);
}
printf("INFO:..Dumping Framebuffer\r\n");
memcpy(fbp,local_display_mem,screensize);
/** Tune this multiplication to meet the right output on the display **/
usleep((FrameInfo->InterFrameDelay)*100000);
if( FrameInfo->DisposalMethod == 2)
{
printf("set the Background\r\n");
SetBackground(FrameInfo);
}
FrameInfo = FrameInfo->Next;
}
}
static void SetBackground(FrameData *tempInfo)
{
unsigned int ImageStartX=0;
unsigned int ImageStartY=0;
ImageStartX=(tempInfo->frameScreenInfo.LeftPosition);
ImageStartY=(tempInfo->frameScreenInfo.TopPosition);
while(ImageStartY<(tempInfo->frameScreenInfo.ImageHeight))
{
while(ImageStartX<(tempInfo->frameScreenInfo.ImageWidth))
{
SetPixel(local_display_mem,ImageStartX,ImageStartY,255,255,255);
ImageStartX++;
}
ImageStartX=(tempInfo->frameScreenInfo.LeftPosition);
ImageStartY++;
}
}
static void SetPixel(char *fbp_lc, unsigned int x, unsigned int y, Byte red, Byte green, Byte blue)
{
//printf("Shreyas..set pixel called\r\n");
location = (x+vinfo.xoffset) * (vinfo.bits_per_pixel/8) +
(y+vinfo.yoffset) * finfo.line_length;
if (vinfo.bits_per_pixel == 32)
{
*(fbp_lc + location) = blue; // Some blue
*(fbp_lc + location + 1) = green; // A little green
*(fbp_lc + location + 2) = red; // A lot of red
*(fbp_lc + location + 3) = 0; // No transparency
//location += 4;
}
else
{ //assume 16bpp
unsigned short int t = red<<11 | green << 5 | blue;
*((unsigned short int*)(fbp_lc + location)) = t;
}
//printf("Shreyas..set pixel exit called\r\n");
}
/** This is windows version of display function, and it works correctly.
void Display(FrameData *FrameInfo)
{
short int ImageStartX=0;
short int ImageStartY=0;
int Index=0;
DisplayCntrl=GetDC(hWnd);
printf("Shreyas.. Display Init is called\r\n");
//display_init();
while(1)
{
Index=0;
ImageStartX=(FrameInfo->frameScreenInfo.LeftPosition);
ImageStartY=(FrameInfo->frameScreenInfo.TopPosition);
while(ImageStartY<((FrameInfo->frameScreenInfo.ImageHeight)+(FrameInfo->frameScreenInfo.TopPosition)))
{
while(ImageStartX<((FrameInfo->frameScreenInfo.ImageWidth)+(FrameInfo->frameScreenInfo.LeftPosition)))
{
if(FrameInfo->frame[Index]!=FrameInfo->transperencyindex)
SetPixel(DisplayCntrl,ImageStartX,ImageStartY,RGB(((FrameInfo->CMAP)+(FrameInfo->frame[Index]))->Red,((FrameInfo->CMAP)+(FrameInfo->frame[Index]))->Green,((FrameInfo->CMAP)+(FrameInfo->frame[Index]))->Blue));
Index++;
ImageStartX++;
}
ImageStartY++;
ImageStartX=(FrameInfo->frameScreenInfo.LeftPosition);
}
Sleep((FrameInfo->InterFrameDelay*10));
WaitForSingleObject(hWnd,10);
if( FrameInfo->DisposalMethod==2)
{
SETBACKGROUND(FrameInfo);
}
FrameInfo=FrameInfo->Next;
}
}
/**这里使用的是直接Fb呼叫;并且与Linux帧缓冲区紧密耦合**/
静态int fbfd=0;
静态结构fb_var_screenfo vinfo;
静态结构fb\u fix\u screenfo finfo;
静态长整型屏幕大小=0;
静态字符*fbp=0;
静态整数x=0,y=0;
静态长整型位置=0;
/**这是到linux帧缓冲区的克隆,将被调用以在帧缓冲区上转储**/
字符*本地显示\内存;
/**局部函数**/
静态无效背景(FrameData*tempInfo);
静态void SetPixel(字符*fbp,无符号整数x,无符号整数y,字节红色,字节绿色,字节蓝色);
/**这是用于初始化显示的输入函数**/
void display_init()
{
//打开文件进行读写
fbfd=打开(“/dev/fb0”,O_RDWR);
如果(fbfd==-1)
{
perror(“无法打开帧缓冲区设备”);
出口(1);
}
#ifdef调试
printf(“帧缓冲区设备已成功打开。\n”);
#恩迪夫
/**阅读屏幕信息**/
如果(ioctl(fbfd、FBIOGET_FSCREENINFO和finfo)=-1)
{
perror(“驱动程序错误——读取固定信息”);
出口(1);
}
//获取可变屏幕信息
如果(ioctl(fbfd、FBIOGET\U VSCREENINFO和vinfo)=-1)
{
perror(“错误读取变量信息”);
出口(1);
}
#ifdef调试
printf(“%dx%d,%dbpp\n”,vinfo.xres,vinfo.yres,vinfo.bits每像素);
#恩迪夫
//计算屏幕的大小(以字节为单位)
屏幕大小=vinfo.xres*vinfo.yres*vinfo.bits_/u像素/8;
//将设备映射到内存
fbp=(字符*)mmap(0,屏幕大小,保护读取,保护写入,地图共享,fbfd,0);
本地显示内存=(字符*)malloc(屏幕大小);
如果((int)fbp==-1)
{
perror(“错误:mmap失败\r\n”);
出口(1);
}
#ifdef调试
printf(“帧缓冲区设备已成功映射到内存。\n”);
#恩迪夫
printf(“shryas..Display Initialized..\r\n”);
//munmap(fbp,屏幕大小);
//关闭(fbfd);
}
/**gif_read调用此函数以显示图像**/
无效显示(帧数据*帧信息)
{
短int ImageStartX=0;
短整数ImageStartY=0;
int指数=0;
printf(“\r\n信息:显示调用。\r\n”);
而(1)
{
指数=0;
ImageStartX=(FrameInfo->frameScreenInfo.LeftPosition);
ImageStartY=(FrameInfo->frameScreenInfo.TopPosition);
而(ImageStartY<((FrameInfo->frameScreenInfo.ImageHeight)+(FrameInfo->frameScreenInfo.TopPosition)))
{
而(ImageStartX<((FrameInfo->framescreenfo.ImageWidth)+(FrameInfo->framescreenfo.LeftPosition)))
{
if(FrameInfo->frame[Index]!=FrameInfo->transperencyindex)
{
SetPixel(本地显示内存、ImageStartX、ImageStartY,((框架信息->CMAP)+(框架信息->框架[索引])->红色、((框架信息->框架[索引])+(框架信息->框架[索引])->绿色、((框架信息->CMAP)+(框架信息->框架[索引])->蓝色);
}
索引++;
ImageStartX++;
}
ImageStartY++;
ImageStartX=(FrameInfo->frameScreenInfo.LeftPosition);
}
printf(“信息:…转储帧缓冲区\r\n”);
memcpy(fbp、本地显示、屏幕尺寸);
/**调整此乘法以满足显示器上的正确输出**/
usleep((帧信息->帧间延迟)*100000);
如果(FrameInfo->DisposalMethod==2)
{
printf(“设置背景\r\n”);
挫折背景(FrameInfo);
}
FrameInfo=FrameInfo->Next;
}
}
静态无效设置背景(FrameData*tempInfo)
{
无符号int-ImageStartX=0;
无符号整数ImageStartY=0;
ImageStartX=(tempInfo->frameScreenInfo.LeftPosition);
ImageStartY=(tempInfo->frameScreenInfo.TopPosition);
while(ImageStartYframeScreenInfo.ImageHeight))
{
while(ImageStartXframeScreenInfo.ImageWidth))
{
SetPixel(本地显示内存,ImageStartX,ImageStartY,255255);
ImageStartX++;
}
ImageStartX=(tempInfo->frameScreenInfo.LeftPosition);
ImageStartY++;
}
}
静态void SetPixel(字符*fbp_lc,无符号整数x,无符号整数y,字节红色,字节绿色,字节蓝色)
{
//printf(“shryas..set像素名为\r\n”);
位置=(x+vinfo.xoffset)*(每像素vinfo.bits\u/8)+
(y+vinfo.yoffset)*finfo.line_长度;
if(vinfo.bits_/_像素==32)
{
*(fbp_lc+位置)=蓝色;//一些蓝色
*(fbp_lc+location+1)=绿色;//有点绿色
*(fbp_lc+location+2)=红色;//大量红色
*(fbp_lc+位置+3)=0//
extern hWnd;
HDC DisplayCntrl;
void SETBACKGROUND(FrameData *tempInfo)
{
unsigned int ImageStartX=0;
unsigned int ImageStartY=0;
ImageStartX=(tempInfo->frameScreenInfo.LeftPosition);
ImageStartY=(tempInfo->frameScreenInfo.TopPosition);
while(ImageStartY<(tempInfo->frameScreenInfo.ImageHeight))
{
while(ImageStartX<(tempInfo->frameScreenInfo.ImageWidth))
{
SetPixel(DisplayCntrl,ImageStartX,ImageStartY,RGB(255,255,255));
ImageStartX++;
}
ImageStartX=(tempInfo->frameScreenInfo.LeftPosition);
ImageStartY++;
}
}
void Display(FrameData *FrameInfo)
{
short int ImageStartX=0;
short int ImageStartY=0;
int Index=0;
DisplayCntrl=GetDC(hWnd);
printf("the size of short int is %d",sizeof(short int));
while(1)
{
Index=0;
ImageStartX=(FrameInfo->frameScreenInfo.LeftPosition);
ImageStartY=(FrameInfo->frameScreenInfo.TopPosition);
while(ImageStartY<((FrameInfo->frameScreenInfo.ImageHeight)+(FrameInfo->frameScreenInfo.TopPosition)))
{
while(ImageStartX<((FrameInfo->frameScreenInfo.ImageWidth)+(FrameInfo->frameScreenInfo.LeftPosition)))
{
if(FrameInfo->frame[Index]!=FrameInfo->transperencyindex)
{
SetPixel(DisplayCntrl,ImageStartX,ImageStartY,RGB(((FrameInfo->CMAP)+(FrameInfo->frame[Index]))->Red,((FrameInfo->CMAP)+(FrameInfo->frame[Index]))->Green,((FrameInfo->CMAP)+(FrameInfo->frame[Index]))->Blue));
}
Index++;
ImageStartX++;
}
ImageStartY++;
ImageStartX=(FrameInfo->frameScreenInfo.LeftPosition);
}
Sleep((FrameInfo->InterFrameDelay*10));
WaitForSingleObject(hWnd,10);
if( FrameInfo->DisposalMethod==2)
{
SETBACKGROUND(FrameInfo);
}
FrameInfo=FrameInfo->Next;
}
}