Quelle BSPTree.cpp Sprache: C

/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* vim: set ts=8 sts=2 et sw=2 tw=80: */
/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/. */

#include "BSPTree.h"
#include "mozilla/gfx/Polygon.h"

namespace mozilla {

class nsDisplayTransform;

namespace layers {

template <typename T>
void BSPTree<T>::BuildDrawOrder(BSPTreeNode<T>* aNode,
                                nsTArray<BSPPolygon<T>>& aLayers) const {
  const gfx::Point4D& normal = aNode->First().GetNormal();

  BSPTreeNode<T>* front = aNode->front;
  BSPTreeNode<T>* back = aNode->back;

  // Since the goal is to return the draw order from back to front, we reverse
  // the traversal order if the current polygon is facing towards the camera.
  const bool reverseOrder = normal.z > 0.0f;

  if (reverseOrder) {
    std::swap(front, back);
  }

  if (front) {
    BuildDrawOrder(front, aLayers);
  }

  for (BSPPolygon<T>& layer : aNode->layers) {
    MOZ_ASSERT(layer.geometry);

    if (layer.geometry->GetPoints().Length() >= 3) {
      aLayers.AppendElement(std::move(layer));
    }
  }

  if (back) {
    BuildDrawOrder(back, aLayers);
  }
}

template <typename T>
void BSPTree<T>::BuildTree(BSPTreeNode<T>* aRoot, PolygonList<T>& aLayers) {
  MOZ_ASSERT(!aLayers.empty());

  aRoot->layers.push_back(std::move(aLayers.front()));
  aLayers.pop_front();

  if (aLayers.empty()) {
    return;
  }

  const gfx::Polygon& plane = aRoot->First();
  MOZ_ASSERT(!plane.IsEmpty());

  const gfx::Point4D& planeNormal = plane.GetNormal();
  const gfx::Point4D& planePoint = plane.GetPoints()[0];

  PolygonList<T> backLayers, frontLayers;
  for (BSPPolygon<T>& layerPolygon : aLayers) {
    const nsTArray<gfx::Point4D>& geometry = layerPolygon.geometry->GetPoints();

    // Calculate the plane-point distances for the polygon classification.
    size_t pos = 0, neg = 0;
    nsTArray<float> distances = CalculatePointPlaneDistances(
        geometry, planeNormal, planePoint, pos, neg);

    // Back polygon
    if (pos == 0 && neg > 0) {
      backLayers.push_back(std::move(layerPolygon));
    }
    // Front polygon
    else if (pos > 0 && neg == 0) {
      frontLayers.push_back(std::move(layerPolygon));
    }
    // Coplanar polygon
    else if (pos == 0 && neg == 0) {
      aRoot->layers.push_back(std::move(layerPolygon));
    }
    // Polygon intersects with the splitting plane.
    else if (pos > 0 && neg > 0) {
      nsTArray<gfx::Point4D> backPoints, frontPoints;
      // Clip the polygon against the plane. We reuse the previously calculated
      // distances to find the plane-edge intersections.
      ClipPointsWithPlane(geometry, planeNormal, distances, backPoints,
                          frontPoints);

      const gfx::Point4D& normal = layerPolygon.geometry->GetNormal();
      T* data = layerPolygon.data;

      if (backPoints.Length() >= 3) {
        backLayers.emplace_back(data, std::move(backPoints), normal);
      }

      if (frontPoints.Length() >= 3) {
        frontLayers.emplace_back(data, std::move(frontPoints), normal);
      }
    }
  }

  if (!backLayers.empty()) {
    aRoot->back = new (mPool) BSPTreeNode(mListPointers);
    BuildTree(aRoot->back, backLayers);
  }

  if (!frontLayers.empty()) {
    aRoot->front = new (mPool) BSPTreeNode(mListPointers);
    BuildTree(aRoot->front, frontLayers);
  }
}

template void BSPTree<BSPTestData>::BuildTree(
    BSPTreeNode<BSPTestData>* aRoot, PolygonList<BSPTestData>& aLayers);
template void BSPTree<BSPTestData>::BuildDrawOrder(
    BSPTreeNode<BSPTestData>* aNode,
    nsTArray<BSPPolygon<BSPTestData>>& aLayers) const;

template void BSPTree<nsDisplayTransform>::BuildTree(
    BSPTreeNode<nsDisplayTransform>* aRoot,
    PolygonList<nsDisplayTransform>& aLayers);
template void BSPTree<nsDisplayTransform>::BuildDrawOrder(
    BSPTreeNode<nsDisplayTransform>* aNode,
    nsTArray<BSPPolygon<nsDisplayTransform>>& aLayers) const;

}  // namespace layers
}  // namespace mozilla

quality92%

¤ Dauer der Verarbeitung: 0.0 Sekunden (vorverarbeitet) ¤

Wurzel

Suchen

Beweissystem der NASA

Beweissystem Isabelle

NIST Cobol Testsuite

Cephes Mathematical Library

Wiener Entwicklungsmethode

Haftungshinweis

Die Informationen auf dieser Webseite wurden nach bestem Wissen sorgfältig zusammengestellt. Es wird jedoch weder Vollständigkeit, noch Richtigkeit, noch Qualität der bereit gestellten Informationen zugesichert.

Bemerkung:

Die farbliche Syntaxdarstellung ist noch experimentell.