picking.hpp

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#ifndef __PICKING__
#define __PICKING___

#include <tucano/tucano.hpp>

namespace Tucano
{
namespace Effects
{

class Picking : public Tucano::Effect
{

public:

    Picking (void) {}

    virtual void initialize (void)
    {
        loadShader(worldcoords_shader, "worldcoords");
    }

    virtual void render (Tucano::Mesh& mesh, const Tucano::Camera& camera)
    {
        Eigen::Vector4f viewport = camera.getViewport();
        glViewport(viewport[0], viewport[1], viewport[2], viewport[3]);


        if (fbo.getWidth() != (viewport[2]-viewport[0]) || fbo.getHeight() != (viewport[3]-viewport[1]))
        {
            fbo.create(viewport[2]-viewport[0], viewport[3]-viewport[1], 1);
        }

        // sets the FBO first (and only) attachment as output
        fbo.clearAttachments();
        fbo.bindRenderBuffer(0);

        worldcoords_shader.bind();

        // sets all uniform variables for the phong shader
        worldcoords_shader.setUniform("projectionMatrix", camera.getProjectionMatrix());
        worldcoords_shader.setUniform("modelMatrix", mesh.getModelMatrix());
        worldcoords_shader.setUniform("viewMatrix", camera.getViewMatrix());

        mesh.setAttributeLocation(worldcoords_shader);

        glPointSize(5.0);
        glEnable(GL_DEPTH_TEST);
        mesh.render();
        glPointSize(1.0);

        worldcoords_shader.unbind();

        fbo.unbind(); // automatically returns the draw buffer to GL_BACK
    }

    Tucano::Framebuffer* getFbo (void)
    {
        return &fbo;
    }

    Eigen::Vector4f pick (const Eigen::Vector2i &pos)
    {
        return fbo.readPixel(0, pos);
    }

private:

    Tucano::Shader worldcoords_shader;

    Tucano::Framebuffer fbo;
};
}

}



#endif