GlVolumeView::RenderBufferWrapper Class Reference

#include <ImFusion/GL/GlVolumeView.h>

Helper class to allow the injection of custom render buffers surrounding the entire render pipeline. More...

Detailed Description

Helper class to allow the injection of custom render buffers surrounding the entire render pipeline.

If such an wrapper is defined and applied to the volume view, the rendering pipeline executes as follows:

• createRenderBuffer() is called before the final rendering pass to the parent view. This allows to instantiate a new RenderBuffer.
• The final rendering pass is computed, effectively rendering into the render buffer.
• drawAndBlendToParent() is called. Here, a custom shader can be executed to modify the rendering, before actually blending the buffer to the parent.

Example usage:

class GlPlaneLineRendering : public GlRenderBufferWrapper
{
public:
    ...
 
    void createRenderBuffer(const GlView& view) override
    {
        m_renderBuffer = std::make_unique<GL::OffscreenRenderHelper::RenderBuffer>(
            GL::OffscreenRenderHelper::cachedInstance().create(view.state().viewport().size()));
    }
 
    void drawAndBlendToParent(const GlView& view) override
    {
        GL::Blending blending(GL::Blending::Preset::AlphaBlending);
        GL::StateGuard guard(GL::StateGuard::DepthTest);
        glDisable(GL_DEPTH_TEST);
 
        m_prog->enable();
        ...
        GL::FullscreenSquare::cachedInstance().drawFilled();
        m_prog->disable();
 
        guard.restoreState(GL::StateGuard::DepthTest);
        glEnable(GL_DEPTH_TEST);
        m_renderBuffer->blendToParent(GL::OffscreenRenderHelper::ColorPostProcessing::DivideBySqrtAlpha);
        m_renderBuffer.reset();
    }
 
private:
    std::unique_ptr<GL::Program> m_prog;
    std::unique_ptr<GL::OffscreenRenderHelper::RenderBuffer> m_renderBuffer;
};

Public Member Functions
virtual void	createRenderBuffer (const GlView &view)=0
virtual void	drawAndBlendToParent (const GlView &view)=0

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The documentation for this class was generated from the following file:

• ImFusion/GL/GlVolumeView.h