Drawing into OpenGL ES framebuffer and getting UIImage from it on iPhone

Question

I\'m trying to do offscreen rendering of some primitives in OpenGL ES on iOS. The code is as follows:

// context and neccesary buffers
@interface RendererGL
{
           


        

Answer 1

the first problem is that I was creating EAGLContext for OpenGL ES 2.0, but functions which I used were for OpenGL ES 1.1. The solution is to set constant to kEAGLRenderingAPIOpenGLES1

the second - I did not set model and projection matricies (if I use 1.1)

glViewport(0, 0, width, height);
glMatrixMode(GL_PROJECTION);
glLoadIdentity();
glOrthof(-1.0f, 1.0f, -1.5f, 1.5f, -1.0f, 1.0f);
glMatrixMode(GL_MODELVIEW);

after this all works)