SSAO.hh

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#include <QObject>

#include <OpenFlipper/BasePlugin/BaseInterface.hh>
#include <OpenFlipper/BasePlugin/RenderInterface.hh>
#include <OpenFlipper/BasePlugin/LoggingInterface.hh>

#include <ACG/Scenegraph/SceneGraph.hh>

#include <map>

class SSAOPlugin : public QObject, BaseInterface, RenderInterface, LoggingInterface
{
  Q_OBJECT
    Q_INTERFACES(BaseInterface)
    Q_INTERFACES(RenderInterface)
    Q_INTERFACES(LoggingInterface)

  Q_PLUGIN_METADATA(IID "org.OpenFlipper.Plugins.Plugin-Render-SSAO")

    
signals:
  // LoggingInterface
    void log(Logtype _type, QString _message);
    void log(QString _message);


public :

  SSAOPlugin();
  ~SSAOPlugin();

  QString name() { return (QString("SSAO Plugin")); };
  QString description( ) { return (QString(tr("Screen Space Ambient Occlusion"))); };

public slots:
  QString version() { return QString("1.0"); };

private slots:

  //BaseInterface
  void initializePlugin();
  void exit();

  // RenderInterface
  void render(ACG::GLState* _glState, Viewer::ViewerProperties& _properties);
  QString rendererName();
  void supportedDrawModes(ACG::SceneGraph::DrawModes::DrawMode& _mode);
  QString checkOpenGL();

private:

  void destroyResources();

  void destroyResources(int _viewerId);

  void reloadResources(int _viewerId, unsigned int _sceneTexWidth, unsigned int _sceneTexHeight);

  void drawQuadProj(float _x0 = -1.0f, float _y0 = 1.0f, 
    float _w = 2.0f, float _h = 2.0f);

  void traverseLightNodes(BaseNode* _node);

  void generatePeelingShaders(GLSL::StringList* _strVertexShaderOut,
    GLSL::StringList* _strFragmentShaderOut, bool _textured);

  void drawScenePass(ACG::GLState* _glState, Viewer::ViewerProperties& _properties, BaseNode* _sceneGraphRoot);

  struct ViewerResources;
  void gaussianBlurPass(const ViewerResources* _pViewer, const float* _texelSize, 
    GLenum _targetAttachement, GLuint _srcTexture);

  void generateSamplingKernel();
private:
  
  struct ViewerResources
  {
    ViewerResources() = default;

    unsigned int glWidth_ = 0;

    unsigned int glHeight_ = 0;

    unsigned int rtSceneWidth_ = 0; 
    unsigned int rtSceneHeight_ = 0;

    unsigned int rtWidth_ = 0;
    unsigned int rtHeight_ = 0;

    unsigned int rtDownWidth_ = 0;
    unsigned int rtDownHeight_ = 0;

    GLuint depthBufTex_ = 0;

    GLuint sceneNormalTex_ = 0;

    GLuint depthSSAORenderBuf_ = 0;

    GLuint depthSceneRenderBuf_ = 0;

    GLuint sceneBufTex_ = 0;

    GLuint downsampledTex_ = 0;

    GLuint downsampledTmpTex_ = 0;

    GLuint occlusionTex_ = 0;

    GLuint sceneFbo_ = 0;

    GLuint ssaoFbo_ = 0;

    GLuint blurFbo_ = 0;
  };

  std::map<int, ViewerResources> viewerRes_;

  GLSL::Shader* shaders_[10];

  enum
  { 
    PROG_INIT = 0,  // early Z pass + standard scene rendering
    PROG_DOWNSAMPLING,
    PROG_BLUR,
    PROG_SSAO,
    PROG_FINAL,
    PROG_FINAL_MSAA
  };
  
  GLSL::Program* programs_[6];

  GLuint randomVecTex_;

  static const unsigned int numSamples_;

  ACG::Vec3f samplingKernel_[128];
};