C++ SbViewVolume::ortho方法代码示例

// Doc in superclass.
SbViewVolume
SoOrthographicCamera::getViewVolume(float useaspectratio) const
{
  SbViewVolume volume;

  if (useaspectratio == 0.0f) useaspectratio = this->aspectRatio.getValue();
  float halfheight = this->height.getValue() * 0.5f;
  float halfwidth = halfheight * useaspectratio;
  volume.ortho(-halfwidth, halfwidth,
               -halfheight, halfheight,
               this->nearDistance.getValue(), this->farDistance.getValue());
  
  volume.rotateCamera(this->orientation.getValue());
  volume.translateCamera(this->position.getValue());
  return volume;
}

// doc from superclass.
void
SoNurbsProfile::getVertices(SoState * state, int32_t & numvertices,
                            SbVec2f * & vertices)
{
  // FIXME: optimize by detecting when the previously calculated
  // vertices can be returned. pederb, 20000922
  int32_t numpoints;
  float * points;
  int floatspervec;
  int32_t numknots;
  float * knotvector;
  this->getTrimCurve(state, numpoints, points, floatspervec, numknots, knotvector);
  if (numpoints == 0 || numknots == 0) {
    numvertices = 0;
    vertices = NULL;
    return;
  }

  SbList <float> * coordListNurbsProfile =
    so_nurbsprofile_get_coordlist(FALSE);

  SbList <float> * nurbsProfileTempList =
    so_nurbsprofile_get_coordlist(TRUE);

  nurbsProfileTempList->truncate(0);
  for (int i = 0; i < numpoints; i++) {
    nurbsProfileTempList->append(points[i*floatspervec]);
    nurbsProfileTempList->append(points[i*floatspervec+1]);
    if (GLUWrapper()->available &&
        GLUWrapper()->versionMatchesAtLeast(1, 3, 0)) {
      nurbsProfileTempList->append(0.0f); // gluNurbs needs 3D coordinates
    }
  }
  if (GLUWrapper()->available &&
      GLUWrapper()->versionMatchesAtLeast(1, 3, 0)) {
    // we will write into this array in the GLU callback
    coordListNurbsProfile->truncate(0);

    if (this->nurbsrenderer == NULL) {
      this->nurbsrenderer = GLUWrapper()->gluNewNurbsRenderer();
      GLUWrapper()->gluNurbsCallback(this->nurbsrenderer, (GLenum) GLU_NURBS_VERTEX,
                                     (gluNurbsCallback_cb_t)nurbsprofile_tess_vertex);
      GLUWrapper()->gluNurbsProperty(this->nurbsrenderer, (GLenum) GLU_NURBS_MODE, GLU_NURBS_TESSELLATOR);
      GLUWrapper()->gluNurbsProperty(this->nurbsrenderer, (GLenum) GLU_AUTO_LOAD_MATRIX, FALSE);
      GLUWrapper()->gluNurbsProperty(this->nurbsrenderer, (GLenum) GLU_DISPLAY_MODE, GLU_POINT);
      GLUWrapper()->gluNurbsProperty(this->nurbsrenderer, (GLenum) GLU_SAMPLING_METHOD, GLU_DOMAIN_DISTANCE);
    }

    // this looks pretty good
    float cmplx = SoComplexityElement::get(state);
    cmplx += 1.0f;
    cmplx = cmplx * cmplx * cmplx;
    GLUWrapper()->gluNurbsProperty(this->nurbsrenderer, (GLenum) GLU_U_STEP, float(numpoints)*cmplx);

    // these values are not important as we're not using screen-space
    // complexity (yet)
    SbMatrix modelmatrix = SbMatrix::identity();
    SbMatrix affine, proj;
    SbViewVolume vv;
    vv.ortho(0.0f, 1.0f,
             0.0f, 1.0f,
             -1.0f, 1.0f);
    vv.getMatrices(affine, proj);
    GLint viewport[4];
    viewport[0] = 0;
    viewport[1] = 0;
    viewport[2] = 256;
    viewport[3] = 256;
    GLUWrapper()->gluLoadSamplingMatrices(this->nurbsrenderer,
                                          modelmatrix[0],
                                          proj[0],
                                          viewport);

    // generate curve
    GLUWrapper()->gluBeginCurve(this->nurbsrenderer);
    GLUWrapper()->gluNurbsCurve(this->nurbsrenderer,
                                numknots,
                                (float*)knotvector,
                                3,
                                (float*)nurbsProfileTempList->getArrayPtr(),
                                numknots - numpoints,
                                GL_MAP1_VERTEX_3);
    GLUWrapper()->gluEndCurve(this->nurbsrenderer);

    // when we get here, the GLU callback should have added the
    // points to the list
    numvertices = coordListNurbsProfile->getLength() / 2;
    vertices = (SbVec2f*) coordListNurbsProfile->getArrayPtr();
  }
  else {
    // just send the control points when GLU v1.3 is not available
    numvertices = numpoints;
    vertices = (SbVec2f*) nurbsProfileTempList->getArrayPtr();
  }
}

/**
 * Renders the label.
 */
void SoTextLabel::GLRender(SoGLRenderAction *action)
{
    if (!this->shouldGLRender(action)) return;

    // only draw text without background
    if (!this->background.getValue()) {
        inherited::GLRender(action);
        return;
    }

    SoState * state = action->getState();

    state->push();
    SoLazyElement::setLightModel(state, SoLazyElement::BASE_COLOR);

    SbBox3f box;
    SbVec3f center;
    this->computeBBox(action, box, center);

    if (!SoCullElement::cullTest(state, box, TRUE)) {
        SoMaterialBundle mb(action);
        mb.sendFirst();
        const SbMatrix & mat = SoModelMatrixElement::get(state);
        //const SbViewVolume & vv = SoViewVolumeElement::get(state);
        const SbMatrix & projmatrix = (mat * SoViewingMatrixElement::get(state) *
                                       SoProjectionMatrixElement::get(state));
        const SbViewportRegion & vp = SoViewportRegionElement::get(state);
        SbVec2s vpsize = vp.getViewportSizePixels();

        // font stuff
        //float space = this->spacing.getValue();
        //float fontsize = SoFontSizeElement::get(state);
        SbName fontname = SoFontNameElement::get(state);
        int lines = this->string.getNum();

        // get left bottom corner of the label
        SbVec3f nilpoint(0.0f, 0.0f, 0.0f);
        projmatrix.multVecMatrix(nilpoint, nilpoint);
        nilpoint[0] = (nilpoint[0] + 1.0f) * 0.5f * vpsize[0];
        nilpoint[1] = (nilpoint[1] + 1.0f) * 0.5f * vpsize[1];

#if 1
        // Unfortunately, the size of the label is stored in the pimpl class of
        // SoText2 which cannot be accessed directly. However, there is a trick
        // to get the required information: set model, viewing and projection
        // matrix to the identity matrix and also view volume to some default
        // values. SoText2::computeBBox() then calls SoText2P::getQuad which
        // returns the sizes in form of the bounding box. These values can be
        // reverse-engineered to get width and height.
        state->push();
        SoModelMatrixElement::set(state,this,SbMatrix::identity());
        SoViewingMatrixElement::set(state,this,SbMatrix::identity());
        SoProjectionMatrixElement::set(state,this,SbMatrix::identity());
        SbViewVolume vv;
        vv.ortho(-1,1,-1,1,-1,1);
        SoViewVolumeElement::set(state,this,vv);

        SbBox3f box;
        SbVec3f center;
        this->computeBBox(action, box, center);
        state->pop();

        float xmin,ymin,zmin,xmax,ymax,zmax;
        box.getBounds(xmin,ymin,zmin,xmax,ymax,zmax);
        SbVec3f v0(xmin,ymax,zmax);
        SbVec3f v1(xmax,ymax,zmax);
        SbVec3f v2(xmax,ymin,zmax);
        SbVec3f v3(xmin,ymin,zmax);
        vv.projectToScreen(v0,v0);
        vv.projectToScreen(v1,v1);
        vv.projectToScreen(v2,v2);
        vv.projectToScreen(v3,v3);

        float width,height;
        width  = (v1[0]-v0[0])*vpsize[0];
        height = (v1[1]-v3[1])*vpsize[1];
        switch (this->justification.getValue()) {
        case SoText2::RIGHT:
            nilpoint[0] -= width;
            break;
        case SoText2::CENTER:
            nilpoint[0] -= 0.5f*width;
            break;
        default:
            break;
        }

        if (lines > 1) {
            nilpoint[1] -= (float(lines-1)/(float)lines*height);
        }
#else
        // Unfortunately, the required size (in pixels) is stored in a non-accessible way
        // in the subclass SoText2. Thus, we try to get a satisfactory solution with Qt 
        // methods.
        // The font name is of the form "family:style". If 'style' is given it can be
        // 'Bold', 'Italic' or 'Bold Italic'.
        QFont font;
//.........这里部分代码省略.........