Question

I am creating a frame buffer object for Render to Texture setup. It works perfectly fine on the iPhone simulator but on the Device the glCheckFramebufferStatus(GL_FRAMEBUFFER) function returns GL_FRAMEBUFFER_UNSUPPORTED at the end of the FBO creation.
I am testing it on iPhone 3GS with iOS 5.

Here is the code:

GLenum errNo;  
GLsizei width = 320;
GLsizei height = 480;
GLuint textureHandle;
GLuint fboHandle;

glGetError();

glGenTextures(1, &textureHandle);
glBindTexture(GL_TEXTURE_2D, textureHandle);

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, width, height, 0, GL_RGBA,GL_HALF_FLOAT_OES, NULL);               

glGenFramebuffers(1, &fboHandle);
glBindFramebuffer(GL_FRAMEBUFFER,fboHandle);    
glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_TEXTURE_2D, textureHandle, 0);


errNo = glCheckFramebufferStatus(GL_FRAMEBUFFER);
if(GL_FRAMEBUFFER_COMPLETE != errNo){
    printf("Unable to create FBO. errNo: %x\n",errNo);
}

I am clueless. How should I debug this problem ?

Answer 1

Found the solution. GL_HALF_FLOAT is not supported on iPhone. I used GL_UNSIGNED_BYTE instead and it works now.

Does not work:

glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, width, height, 0, GL_RGBA,GL_HALF_FLOAT_OES, NULL);               

Works:

glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, width, height, 0, GL_RGBA,GL_UNSIGNED_BYTE, NULL);