Cocos2D: Upgrading from OpenGL ES 1.1 to 2.0

Question

I have recently starting upgrading my ios game to the latest Cocos2D (2.0 rc), and I am having some difficulties upgrading my texture generation code to OpenGL 2.0.

In the old version I generated images with this code:

CCRenderTexture *rt = 
[CCRenderTexture renderTextureWithWidth:WIDTH height:HEIGHT];

[rt beginWithClear:bgColor.r g:bgColor.g b:bgColor.b a:bgColor.a];

glDisable(GL_TEXTURE_2D);
glDisableClientState(GL_TEXTURE_COORD_ARRAY);

glVertexPointer(2, GL_FLOAT, 0, verts);
glColorPointer(4, GL_FLOAT, 0, colors);
glDrawArrays(GL_TRIANGLE_STRIP, 0, (GLsizei)nVerts);

glEnableClientState(GL_TEXTURE_COORD_ARRAY);
glEnable(GL_TEXTURE_2D);

[rt end];

But since OpenGL 2.0 works differently this code won't work. What is the best way to use the new OpenGL?

Answer 1

At First

• Learn the basics of OpenGL ES 2
• Learn the difference OpenGL ES 2 vs OpenGL ES 1

Resources

• http://www.khronos.org/opengles/2_X/
• http://www.khronos.org/opengles/sdk/docs/man/
• https://stackoverflow.com/questions/4784137/choose-opengl-es-1-1-or-opengl-es-2-0
• https://stackoverflow.com/questions/5682010/opengl-es-2-0-vs-opengl-es-1-1-which-is-faster

Then try sample working examples with Cocos2d & OpenGL ES v2

• http://www.cocos2d-iphone.org/forum/topic/33478
• http://www.learn-cocos2d.com/2012/01/choosing-cocos2d-version-updating-cocos2d-2-0/
• http://www.raywenderlich.com/10862/how-to-create-cool-effects-with-custom-shaders-in-opengl-es-2-0-and-cocos2d-2-x
• http://heyalda.com/drawing-with-opengl-es-2-0-in-cocos2d-2-0/

Answer 2

You say you are working on texture generation code and the function is called renderTextureWithWidth, but the arguments are never used and it looks to me like you're rendering a mesh without a texture.

Very odd.

What you want to do is convert your code to use Vertex Buffer Objects (VBO's). You can find a good tutorial on them here.