title: Update texture in fragment shader in Cocos2d
body: <p>I'm trying to update texture in fragment shader without any luck. Looks like shader reads texture just once and then no updates. Here is my code:</p>
  
  <ol>
  <li><p>Shader init</p>
  
  <pre><code>CCGLProgram *shader = [[CCGLProgram alloc] initWithVertexShaderFilename:@"vertex.vsh" fragmentShaderFilename:@"fragment.fsh"];
  [shader addAttribute:@"P" index:0];
  [shader addAttribute:@"Cl" index:1];
  [shader addAttribute:@"st" index:2];
  [shader link];
  [shader updateUniforms];
  mutableSprite.shaderProgram = shader;
  uniformAlphaTexture = glGetUniformLocation(shader-&gt;_program, "alphaTexture");
  </code></pre></li>
  <li><p>Shader update</p>
  
  <pre><code>CCGLProgram *shader = mutableSprite.shaderProgram;
  [shader use];
  ccGLBindTexture2DN(1, alphaSprite.texture.name);
  glUniform1i(uniformAlphaTexture, 1);
  </code></pre></li>
  </ol>
  
  <p>So I'm sending alphaSprite to the shader. The first time it looks fine but after adding holes(rgba) to alphaSprite and calling code #2 there is no update of texture inside the shader, it still uses initial alphaSprite texture.</p>