C++ (Cpp) Quad::getVertex示例

示例#1

文件： Mapper.cpp 项目： flv0/mapmap

QList<Quad> MeshTextureGraphicsItem::_split(const Quad& quad)
{
  QList<Quad> quads;

  QPointF a = quad.getVertex(0);
  QPointF b = quad.getVertex(1);
  QPointF c = quad.getVertex(2);
  QPointF d = quad.getVertex(3);

  QPointF ab = (a + b) * 0.5f;
  QPointF bc = (b + c) * 0.5f;
  QPointF cd = (c + d) * 0.5f;
  QPointF ad = (a + d) * 0.5f;

  QPointF abcd = (ab + cd) * 0.5f;

  quads.append(Quad(a, ab, abcd, ad));
  quads.append(Quad(ab, b, bc, abcd));
  quads.append(Quad(abcd, bc, c, cd));
  quads.append(Quad(ad, abcd, cd, d));

  return quads;
}

示例#2

文件： Mapper.cpp 项目： flv0/mapmap

void MeshTextureGraphicsItem::_drawQuad(const Texture& texture, const Quad& inputQuad, const Quad& outputQuad, float outputArea, float inputThreshod, float outputThreshold)
{
  QPointF oa = mapFromScene(outputQuad.getVertex(0));
  QPointF ob = mapFromScene(outputQuad.getVertex(1));
  QPointF oc = mapFromScene(outputQuad.getVertex(2));
  QPointF od = mapFromScene(outputQuad.getVertex(3));

  QPointF ia = inputQuad.getVertex(0);
  QPointF ib = inputQuad.getVertex(1);
  QPointF ic = inputQuad.getVertex(2);
  QPointF id = inputQuad.getVertex(3);

  // compute the dot products for the polygon
  float outputV1dotV2 = QPointF::dotProduct(oa-ob, oc-ob);
  float outputV3dotV4 = QPointF::dotProduct(oc-od, oa-od);
  float outputV1dotV4 = QPointF::dotProduct(oa-ob, oa-od);
  float outputV2dotV3 = QPointF::dotProduct(oc-ob, oc-od);

  // compute the dot products for the texture
  float inputV1dotV2  = QPointF::dotProduct(ia-ib, ic-ib);
  float inputV3dotV4  = QPointF::dotProduct(ic-id, ia-id);
  float inputV1dotV4  = QPointF::dotProduct(ia-ib, ia-id);
  float inputV2dotV3  = QPointF::dotProduct(ic-ib, ic-id);

  // Stopping criterion.
  if (outputArea < 200 ||
      (fabs(outputV1dotV2 - outputV3dotV4) < outputThreshold &&
       fabs(outputV1dotV4 - outputV2dotV3) < outputThreshold &&
       fabs(inputV1dotV2  - inputV3dotV4)  < inputThreshod &&
       fabs(inputV1dotV4  - inputV2dotV3)  < inputThreshod))
  {
    glBegin(GL_QUADS);
    for (int i = 0; i < outputQuad.nVertices(); i++)
    {
      Util::setGlTexPoint(texture, inputQuad.getVertex(i), mapFromScene(outputQuad.getVertex(i)));
    }
    glEnd();
  }
  else // subdivide
  {
    QList<Quad> inputSubQuads  = _split(inputQuad);
    QList<Quad> outputSubQuads = _split(outputQuad);
    for (int i = 0; i < inputSubQuads.size(); i++)
    {
      _drawQuad(texture, inputSubQuads[i], outputSubQuads[i], outputArea*0.25, inputThreshod, outputThreshold);
    }
  }
}