#ifndef TRANSPARENTOPENGLCOMPONENT_H_INCLUDED
#define TRANSPARENTOPENGLCOMPONENT_H_INCLUDED

#include "JuceHeader.h"

// A Component with an attached OpenGLContext which saves the background under it,
// and within the OpenGL context draws the background first, and then calls
// its subclass's renderOverBackground method to draw.
//
// Assumptions:
// * The background is constant.
// * This component, its parent, and ancestors, do not have overlapping sibling components.

class TransparentOpenGLComponent : public juce::Component, public juce::OpenGLRenderer
{
public:
    TransparentOpenGLComponent();
    virtual ~TransparentOpenGLComponent();

    virtual void renderOverBackground (juce::Point<int> viewportSize) = 0;

    // Sub-classes overriding this must call these in their overrides.
    void newOpenGLContextCreated() override;
    void openGLContextClosing() override;

    juce::OpenGLContext openGLContext;

protected:
    juce::Image renderBackground();

private:
    void renderOpenGL() override;

    void renderParentsToBackground (juce::Graphics& g, juce::Component&);

    juce::Point<int> viewportSize;
    juce::OpenGLTexture backgroundTexture;
};

#endif  // TRANSPARENTOPENGLCOMPONENT_H_INCLUDED