GLBVRender.cc

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#include <gra/render/GLBVRender.h>
#include <esg/geometry/FDH14.h>
#include <esg/geometry/FDH6.h>
#include <gra/camera/CameraGL.h>

using namespace gra;

void GLBVRender::_render(Shader&           shader,
                         FrameBuffer&      fb,
                         Camera&           camera,
                         Scene&            scene)
{
    /*
     * first render original objects
     */
    
    if (_showObjects) {
        GLRender::_render(shader, fb, camera, scene);
    } else {
        /*
         * This render requires an OpenGL camera (CameraGL class).
         * Therefore we have to instantiate it from the general camera.
         * Although the OpenGL camera is not furher used, its instantiation
         * updates the OpenGL projection and transformation matrices.
         */
        CameraGL cameraGL(camera);
    }

    /*
     * then render volumes transparently
     */

    if (_useDisplayList && _bvDisplayList) {
        glCallList(_bvDisplayList);
        return;
    }

    if (_useDisplayList) {
        _bvDisplayList = glGenLists(1);
        glNewList(_bvDisplayList, GL_COMPILE_AND_EXECUTE);
    }

    GLboolean depthMask;
    bool      haveTransp = (_bvTransp.avgValue() > 0.0) ? true : false;

    if (haveTransp) {
        glEnable(GL_BLEND);
        glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
        glGetBooleanv(GL_DEPTH_WRITEMASK, &depthMask);
        glDepthMask(GL_FALSE);
    }

    Geometry * pGeom;
    Shape    * pShape;
    BVExplorer bvExplorer(_depth);
    bvExplorer.explore(*(scene.root()));
    while ((pGeom = bvExplorer.result())) {
        pShape = new Shape();
        pShape->setPrivateGeometry(pGeom);
        pShape->appendPrivateMaterial(_bvColor.clone());
        if (haveTransp) pShape->appendPrivateMaterial(_bvTransp.clone());
        shader.setRenderedShape(pShape, NULL);
        // shader.illuminatePoint() does nothing and then it's omitted
        delete pShape;
    }

    if (haveTransp) {
        glDisable(GL_BLEND);
        glDepthMask(depthMask);
    }
    
    if (_useDisplayList) glEndList();
}

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