Add post-processing effect framework

[libs/gl.git] / source / bloom.h

diff --git a/source/bloom.h b/source/bloom.h
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+++ b/source/bloom.h
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+/* $Id$
+
+This file is part of libmspgl
+Copyright © 2009  Mikko Rasa, Mikkosoft Productions
+Distributed under the LGPL
+*/
+
+#ifndef MSP_GL_BLOOM_H_
+#define MSP_GL_BLOOM_H_
+
+#include "framebuffer.h"
+#include "mesh.h"
+#include "postprocessor.h"
+#include "texture2d.h"
+#include "program.h"
+#include "programdata.h"
+
+namespace Msp {
+namespace GL {
+
+/**
+The Bloom post-processing effect causes very bright areas of the image to bleed
+into surrounding pixels.  Commonly used together with HDR rendering.
+
+The technique used is to gaussian blur the image and then blend the result with
+the original image.  With suitable parameters, this effect may also be used as
+a blur filter.
+*/
+class Bloom: public PostProcessor
+{
+private:
+       Framebuffer fbo;
+       Texture2D tex[2];
+       Program blur_shader;
+       ProgramData blur_shdata[2];
+       Program combine_shader;
+       ProgramData combine_shdata;
+       Mesh quad;
+
+public:
+       Bloom(unsigned, unsigned);
+       
+       /** Sets the σ value of the gaussian blur.  Values much larger than 4.0 are
+       likely to cause artifacts. */
+       void set_radius(float);
+
+       /** Sets the blend factor between original and blurred images.  Larger
+       values mean more blurriness. */
+       void set_strength(float);
+
+       virtual void render(const Texture2D &);
+};
+
+} // namespace GL
+} // namespace Msp
+
+#endif