Question

我正在尝试使用此帖子进行屏幕外渲染 http://www.idevgames.com/forums/thread-1785-post-54500.html#pid54500

首先我启动FBO。

glGenTextures(1, &tex);
glBindTexture(GL_TEXTURE_2D, tex);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, 512, 512, 0,  GL_RGBA, GL_UNSIGNED_BYTE, NULL);
glBindTexture(GL_TEXTURE_2D, 0);
glGenFramebuffersOES(1, &fbo);
glBindFramebufferOES(GL_FRAMEBUFFER_OES, fbo);
glFramebufferTexture2DOES(GL_FRAMEBUFFER_OES, GL_COLOR_ATTACHMENT0_OES, GL_TEXTURE_2D, tex, 0);

GLenum status = glCheckFramebufferStatusOES(GL_FRAMEBUFFER_OES); 
if (status != GL_FRAMEBUFFER_COMPLETE_OES) { 
    NSLog(@"failed to make complete framebuffer object %x", status);
    exit(-1);
}

然后我画到我的纹理

GLint oldFBO, oldViewPort[4];
glGetIntegerv(GL_FRAMEBUFFER_BINDING_OES, &oldFBO);
glGetIntegerv(GL_VIEWPORT, oldViewPort);
glBindTexture(GL_TEXTURE_2D, 0);
glBindFramebufferOES(GL_FRAMEBUFFER_OES, listFrameBuffers[i]);
glViewport(0, 0, 512, 512);
glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);

// draw code here
glBindFramebufferOES(GL_FRAMEBUFFER_OES, oldFBO);
glViewport(oldViewPort[0], oldViewPort[1], oldViewPort[2], oldViewPort[3]);

然后我画每一帧。

当我完成框架调用附加到framebuffer的glSwapBuffers纹理变得清晰 （但是当我在glSwapBuffers一切正常后每次绘制到帧缓冲区时）。

Answer 1

所以，任务完成了。我刚刚将绘制代码改为此

GLint oldFBO, oldViewPort[4];
glGetIntegerv(GL_FRAMEBUFFER_BINDING_OES, &oldFBO);
glGetIntegerv(GL_VIEWPORT, oldViewPort);
glBindTexture(GL_TEXTURE_2D, 0);
glBindFramebufferOES(GL_FRAMEBUFFER_OES, listFrameBuffers[i]);
glViewport(0, 0, 512, 512);
//glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT); // HERE
glDisable(GL_DEPTH_TEST); // AND HERE

// draw code here

glBindFramebufferOES(GL_FRAMEBUFFER_OES, oldFBO);
glViewport(oldViewPort[0], oldViewPort[1], oldViewPort[2], oldViewPort[3]);

它有效！：）

iOS渲染到纹理：为什么它是清晰的

1 个答案: