Question

How do i temporarily disable textures on opengl es 2.x for ios in the render function?
I am implementing color selection.

I am not using glkit. I am using shaders, so glDisable(GL_TEXTURE_2D) doesn’t work, nor did glBindTexture(GL_TEXTURE_2D,0)

Answer 1

Depends on what you want to achieve. If you disable a texture what do you expect to have in your rendering?

If your shader calculates the color of a fragment based on a Texture sample, if you do not bind any texture, what should it use in place of the texture? A color?

I see 2 options:

A – use 2 shaders, one supporting textures, one using fixed colors (or vertex colors if you load the attribute)

B – use a single shader and pilot the rendering (texture or colors) using uniforms.

The option B offers much more performance.

Edit to first question on how to do it:

if (Texture == 0) {
    gl_FragColor = vec4(1.0,0.0,0.0,0.0);  //red color
} else{
    gl_FragColor = texture2D(Texture, TexCoordOut);
}