iphone - OpenGL ES 2.0 FBO 创建出错并出现未知错误

Question

我已经为此苦苦挣扎了一段时间，对我来说，这段代码崩溃的原因未知。我正在创建一个 FBO，绑定(bind)一个纹理，然后第一个 glDrawArrays() 在我的 iPhone 模拟器上崩溃并显示“EXC_BAD_ACCESS”。

这是我用来创建 FBO 的代码(并绑定(bind)纹理和...)

glGenFramebuffers(1, &lastFrameBuffer);
glGenRenderbuffers(1, &lastFrameDepthBuffer);
glGenTextures(1, &lastFrameTexture);

glBindTexture(GL_TEXTURE1, lastFrameTexture);
glTexImage2D(GL_TEXTURE_2D, 0, GL_RGB, 768, 1029, 0, GL_RGBA, GL_UNSIGNED_SHORT_5_6_5, NULL);
glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);

//Bind/alloc depthbuf
glBindRenderbuffer(GL_RENDERBUFFER, lastFrameDepthBuffer);
glRenderbufferStorage(GL_RENDERBUFFER, GL_DEPTH_COMPONENT16, 768, 1029);

glBindFramebuffer(GL_FRAMEBUFFER, lastFrameBuffer);

//binding the texture to the FBO :D
glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_TEXTURE_2D, lastFrameTexture, 0);

// attach the renderbuffer to depth attachment point
glFramebufferRenderbuffer(GL_FRAMEBUFFER, GL_DEPTH_ATTACHMENT, GL_RENDERBUFFER, lastFrameDepthBuffer);

[self checkFramebufferStatus];

正如您所看到的，它参与了一个对象，checkFrameBufferStatus 看起来像这样:

GLenum status = glCheckFramebufferStatus(GL_FRAMEBUFFER);
switch(status)
{
  case GL_FRAMEBUFFER_COMPLETE:
    JNLogString(@"Framebuffer complete.");
    return TRUE;

  case GL_FRAMEBUFFER_INCOMPLETE_ATTACHMENT:
    JNLogString(@"[ERROR] Framebuffer incomplete: Attachment is NOT complete.");
    return false;

  case GL_FRAMEBUFFER_INCOMPLETE_MISSING_ATTACHMENT:
    JNLogString(@"[ERROR] Framebuffer incomplete: No image is attached to FBO.");
    return false;

  case GL_FRAMEBUFFER_INCOMPLETE_DIMENSIONS:
    JNLogString(@"[ERROR] Framebuffer incomplete: Attached images have different dimensions.");
    return false;

  case GL_FRAMEBUFFER_UNSUPPORTED:
    JNLogString(@"[ERROR] Unsupported by FBO implementation.");
    return false;

   default:
    JNLogString(@"[ERROR] Unknown error.");
    return false;

JNLogString 只是一个 NSLog，在本例中它给了我:

2010-04-03 02:46:54.854 Bubbleeh[6634:207] ES2Renderer.m:372 [ERROR] Unknown error.

当我在那里调用它时。

所以，它崩溃了，诊断告诉我有一个未知的错误，我有点卡住了。我基本上是从 OpenGL ES 2.0 编程指南中复制了代码...

我做错了什么？

Answer 1

        glBindTexture(GL_TEXTURE1, lastFrameTexture);

这是不允许的，我试图将纹理绑定(bind)到第一个单元(GL_TEXTURE1)，但这应该由 glActiveTexture() 完成，而不是由 glBindTexture() 完成，glBindTexture() 想要知道纹理的类型(GL_TEXTURE_2D、GL_TEXTURE_3D)等)而不是纹理单元。为了将纹理放置在纹理单元 1 中，我现在拥有以下我认为正确的代码:

//Bind 2D Texture lastFrameTexture to texture unit 1
glActiveTexture(GL_TEXTURE1);
glBindTexture(GL_TEXTURE_2D, lastFrameTexture);