opengl中使用两个PBO进行纹理更新，哪位大神懂？

千纸鹤的天 2015-06-15 10:34:19

opengl中使用两个PBO进行纹理更新，内存中的像素数据怎么也更新不进去，哪位大神懂？



glewinit();

 glGenBuffersARB(2, pboIds);

 glBindBufferARB(GL_PIXEL_UNPACK_BUFFER_ARB, pboIds[0]);glBufferDataARB(GL_PIXEL_UNPACK_BUFFER_ARB, DATA_SIZE, 0, GL_STREAM_DRAW_ARB);

glBindBufferARB(GL_PIXEL_UNPACK_BUFFER_ARB, pboIds[1]);

 glBufferDataARB(GL_PIXEL_UNPACK_BUFFER_ARB, DATA_SIZE, 0, GL_STREAM_DRAW_ARB);

 glBindBufferARB(GL_PIXEL_UNPACK_BUFFER_ARB, 0);

static int index = 0;

 int nextIndex = 0; 

index = (index + 1) % 2;

nextIndex = (index + 1) % 2;

glBindTexture(GL_TEXTURE_2D, textureId);

glBindBufferARB(GL_PIXEL_UNPACK_BUFFER_ARB, pboIds[index]);

glBindBufferARB(GL_PIXEL_UNPACK_BUFFER_ARB, pboIds[nextIndex]);

glTexSubImage2D(GL_TEXTURE_2D, 0, 0, 0, WIDTH, HEIGHT,

                GL_BGRA, GL_UNSIGNED_BYTE, 0);

glBufferDataARB(GL_PIXEL_UNPACK_BUFFER_ARB, DATA_SIZE, 0, GL_STREAM_DRAW_ARB);



GLubyte* ptr = (GLubyte*)glMapBufferARB(GL_PIXEL_UNPACK_BUFFER_ARB, GL_WRITE_ONLY_ARB);

if(ptr){

*******//getedata();

}

glBindBufferARB(GL_PIXEL_UNPACK_BUFFER_ARB, 0);glGenTextures(1, &textureId);

    glBindTexture(GL_TEXTURE_2D, textureId);

    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);

    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);

    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP);

    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP);

    glTexImage2D(GL_TEXTURE_2D, 0, GL_RGB, IMAGE_WIDTH, IMAGE_HEIGHT, 0, PIXEL_FORMAT, GL_UNSIGNED_BYTE, (GLvoid*)imageData);

    glBindTexture(GL_TEXTURE_2D, 0);

其中imagedata是内容为空的指针，用glTexSubImage2D(GL_TEXTURE_2D, 0, 0, 0, WIDTH, HEIGHT,
GL_BGRA, GL_UNSIGNED_BYTE, 0);更新纹理数据， if （ptr）｛｝中我是使用了MF GDI获取桌面试试图像，然后把桌面图像从内存DC中保存到ptr中，这样做的结果就是显示不出来图像也就是会所数据根本没更新到纹理内存中，，，，我觉得主要问题应该在if ptr中，这里我把ptr当成一个普通的内存指针用，不知道这样可以么？有大神懂么求解答。分不够可以加求解答啊求解答

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