OpenGLGraphicsContextCustomShader workflow


I’m trying to use OpenGLGraphicsContextCustomShader to draw a complex background in a component. My whole app is attached to an OpenGLContext. The background should only be redrawn when the component was resized. It is first drawn into “bgImage” then I call:

if(auto *context = OpenGLContext::getContextAttachedTo(*this))
  context->executeOnGLThread([&] (OpenGLContext& callerContext) {
  }, true);

In my paint method I then run the following. “shader” is my OpenGLGraphicsContextCustomShader object.

shader.fillRect(g.getInternalContext(), getLocalBounds());

And I created this callback for the shader:

shader.onShaderActivated = [&] (OpenGLShaderProgram &program) {
    program.setUniform("texture", (GLint) texture.getTextureID());

My fragmentshader looks like this:

uniform sampler2D texture;
void main() {
    gl_FragColor = texture2D(texture, gl_FragCoord.xy);

The endresult is a black component. I am actually not to sure about any step along the way. I tested setting a uniform from the shader call. That worked. Texture won’t. Help!