File indexing completed on 2024-04-21 14:43:24

 /*
  * box2ddebugdraw.cpp
  * Copyright (c) 2010 Thorbjørn Lindeijer <thorbjorn@lindeijer.nl>
  * Copyright (c) 2014 Moukhlynin Ruslan <ruslan@khvmntk.ru>
  *
  * This file is part of the Box2D QML plugin.
  *
  * This software is provided 'as-is', without any express or implied warranty.
  * In no event will the authors be held liable for any damages arising from
  * the use of this software.
  *
  * Permission is granted to anyone to use this software for any purpose,
  * including commercial applications, and to alter it and redistribute it
  * freely, subject to the following restrictions:
  *
  * 1. The origin of this software must not be misrepresented; you must not
  *    claim that you wrote the original software. If you use this software in
  *    a product, an acknowledgment in the product documentation would be
  *    appreciated but is not required.
  *
  * 2. Altered source versions must be plainly marked as such, and must not be
  *    misrepresented as being the original software.
  *
  * 3. This notice may not be removed or altered from any source distribution.
  */
 
 #define CIRCLE_SEGMENTS_COUNT 32
 #define LINE_WIDTH 1
 
 #include "box2ddebugdraw.h"
 
 #include "box2dworld.h"
 
 #include <Box2D.h>
 
 #include <QPainter>
 #include <QSGNode>
 #include <QSGFlatColorMaterial>
 #include <QtCore/qmath.h>
 
 class DebugDraw : public b2Draw
 {
 public:
     DebugDraw(QSGNode *root, Box2DWorld &world);
 
     void draw();
 
     void DrawPolygon(const b2Vec2 *vertices, int32 vertexCount,
                      const b2Color &color);
     void DrawSolidPolygon(const b2Vec2 *vertices, int32 vertexCount,
                           const b2Color &color);
     void DrawCircle(const b2Vec2 &center, float32 radius,
                     const b2Color &color);
     void DrawSolidCircle(const b2Vec2 &center, float32 radius,
                          const b2Vec2 &axis, const b2Color &color);
     void DrawSegment(const b2Vec2 &p1, const b2Vec2 &p2,
                      const b2Color &color);
     void DrawTransform(const b2Transform &xf);
 
     void setAxisScale(qreal axisScale);
 
 private:
     QSGNode *mRoot;
     Box2DWorld &mWorld;
     qreal mAxisScale;
 
     QSGNode *createNode(QSGGeometry *geometry, const QColor &color, QSGNode *parent = 0);
 };
 
 DebugDraw::DebugDraw(QSGNode *root, Box2DWorld &world) :
     mRoot(root),
     mWorld(world)
 {
 }
 
 void DebugDraw::draw()
 {
     mWorld.world().SetDebugDraw(this);
     mWorld.world().DrawDebugData();
     mWorld.world().SetDebugDraw(0);
 }
 
 static QColor toQColor(const b2Color &color)
 {
     return QColor(color.r * 255,
                   color.g * 255,
                   color.b * 255,
                   color.a * 255);
 }
 
 QSGNode *DebugDraw::createNode(QSGGeometry *geometry, const QColor &color, QSGNode *parent)
 {
     QSGFlatColorMaterial *material = new QSGFlatColorMaterial;
     material->setColor(color);
 
     QSGGeometryNode *node = new QSGGeometryNode;
     node->setGeometry(geometry);
     node->setFlag(QSGNode::OwnsGeometry);
     node->setMaterial(material);
     node->setFlag(QSGNode::OwnsMaterial);
 
     if (parent)
         parent->appendChildNode(node);
     else
         mRoot->appendChildNode(node);
     return node;
 }
 
 void DebugDraw::DrawPolygon(const b2Vec2 *vertices,
                             int32 vertexCount,
                             const b2Color &color)
 {
     QSGGeometry *geometry = new QSGGeometry(QSGGeometry::defaultAttributes_Point2D(),
                                             vertexCount);
     geometry->setDrawingMode(GL_LINE_LOOP);
     geometry->setLineWidth(LINE_WIDTH);
 
     QSGGeometry::Point2D *points = geometry->vertexDataAsPoint2D();
     for (int i = 0; i < vertexCount; ++i) {
         QPointF point = mWorld.toPixels(vertices[i]);
         points[i].set(point.x(), point.y());
     }
 
     createNode(geometry, toQColor(color));
 }
 
 void DebugDraw::DrawSolidPolygon(const b2Vec2 *vertices,
                                  int32 vertexCount,
                                  const b2Color &color)
 {
     QSGGeometry *geometry = new QSGGeometry(QSGGeometry::defaultAttributes_Point2D(),
                                             vertexCount);
     geometry->setDrawingMode(GL_TRIANGLE_FAN);
     geometry->setLineWidth(LINE_WIDTH);
 
     QSGGeometry::Point2D *points = geometry->vertexDataAsPoint2D();
     for (int i = 0; i < vertexCount; ++i) {
         QPointF point = mWorld.toPixels(vertices[i]);
         points[i].set(point.x(), point.y());
     }
 
     createNode(geometry, toQColor(color));
 }
 
 void DebugDraw::DrawCircle(const b2Vec2 &center,
                            float32 radius,
                            const b2Color &color)
 {
     QSGGeometry *geometry = new QSGGeometry(QSGGeometry::defaultAttributes_Point2D(),
                                             CIRCLE_SEGMENTS_COUNT);
     geometry->setDrawingMode(GL_LINE_LOOP);
     geometry->setLineWidth(LINE_WIDTH);
 
     QPointF centerInPixels = mWorld.toPixels(center);
     qreal radiusInPixels = mWorld.toPixels(radius);
 
     QSGGeometry::Point2D *points = geometry->vertexDataAsPoint2D();
     for (int i = 0; i < CIRCLE_SEGMENTS_COUNT; ++i) {
         float theta = i * 2 * M_PI / (CIRCLE_SEGMENTS_COUNT - 2);
         points[i].set(centerInPixels.x() + radiusInPixels * qCos(theta),
                       centerInPixels.y() + radiusInPixels * qSin(theta));
     }
 
     createNode(geometry, toQColor(color));
 }
 
 void DebugDraw::DrawSolidCircle(const b2Vec2 &center, float32 radius,
                                 const b2Vec2 &axis, const b2Color &color)
 {
 
     QSGGeometry *geometry = new QSGGeometry(QSGGeometry::defaultAttributes_Point2D(),
                                             CIRCLE_SEGMENTS_COUNT);
     geometry->setDrawingMode(GL_TRIANGLE_FAN);
     geometry->setLineWidth(LINE_WIDTH);
 
     QPointF centerInPixels = mWorld.toPixels(center);
     QPointF axisInPixels = mWorld.toPixels(axis);
     qreal radiusInPixels = mWorld.toPixels(radius);
     axisInPixels.setX(centerInPixels.x() + radius * axisInPixels.x());
     axisInPixels.setY(centerInPixels.y() + radius * axisInPixels.y());
 
     QSGGeometry::Point2D *points = geometry->vertexDataAsPoint2D();
     points[0].set(centerInPixels.x(), centerInPixels.y());
     for (int i = 1; i < CIRCLE_SEGMENTS_COUNT; ++i) {
         float theta = i * 2 * M_PI / (CIRCLE_SEGMENTS_COUNT - 2);
         points[i].set(centerInPixels.x() + radiusInPixels * qCos(theta),
                       centerInPixels.y() + radiusInPixels * qSin(theta));
     }
     QSGNode * node = createNode(geometry,toQColor(color));
 
     QSGGeometry *axisGeometry = new QSGGeometry(QSGGeometry::defaultAttributes_Point2D(), 2);
     axisGeometry->setDrawingMode(GL_LINES);
     axisGeometry->setLineWidth(LINE_WIDTH);
 
     axisGeometry->vertexDataAsPoint2D()[0].set(centerInPixels.x(), centerInPixels.y());
     axisGeometry->vertexDataAsPoint2D()[1].set(axisInPixels.x(), axisInPixels.y());
     createNode(axisGeometry, qRgb(200, 64, 0), node);
 }
 
 void DebugDraw::DrawSegment(const b2Vec2 &p1,
                             const b2Vec2 &p2,
                             const b2Color &color)
 {
     QPointF p1InPixels = mWorld.toPixels(p1);
     QPointF p2InPixels = mWorld.toPixels(p2);
 
     QSGGeometry *geometry = new QSGGeometry(QSGGeometry::defaultAttributes_Point2D(), 2);
     geometry->setDrawingMode(GL_LINES);
     geometry->setLineWidth(LINE_WIDTH);
 
     geometry->vertexDataAsPoint2D()[0].set(p1InPixels.x(), p1InPixels.y());
     geometry->vertexDataAsPoint2D()[1].set(p2InPixels.x(), p2InPixels.y());
 
     createNode(geometry, toQColor(color));
 }
 
 void DebugDraw::DrawTransform(const b2Transform &xf)
 {
 
     QPointF p1 = mWorld.toPixels(xf.p);
     QPointF p2 = mWorld.toPixels(xf.q.GetXAxis());
     p2 = QPointF(p1.x() + mAxisScale * p2.x(),
                  p1.y() + mAxisScale * p2.y());
 
     QSGGeometry *geometryX = new QSGGeometry(QSGGeometry::defaultAttributes_Point2D(), 2);
     geometryX->setDrawingMode(GL_LINES);
     geometryX->setLineWidth(LINE_WIDTH);
     geometryX->vertexDataAsPoint2D()[0].set(p1.x(), p1.y());
     geometryX->vertexDataAsPoint2D()[1].set(p2.x(), p2.y());
     createNode(geometryX,Qt::blue);
 
     p2 = mWorld.toPixels(xf.q.GetYAxis());
     p2 = QPointF(p1.x() + mAxisScale * p2.x(),
                  p1.y() + mAxisScale * p2.y());
 
     QSGGeometry *geometryY = new QSGGeometry(QSGGeometry::defaultAttributes_Point2D(), 2);
     geometryY->setDrawingMode(GL_LINES);
     geometryY->setLineWidth(LINE_WIDTH);
     geometryY->vertexDataAsPoint2D()[0].set(p1.x(), p1.y());
     geometryY->vertexDataAsPoint2D()[1].set(p2.x(), p2.y());
 
     createNode(geometryY, Qt::yellow);
 }
 
 void DebugDraw::setAxisScale(qreal axisScale)
 {
     mAxisScale = axisScale;
 }
 
 Box2DDebugDraw::Box2DDebugDraw(QQuickItem *parent) :
     QQuickItem (parent),
     mWorld(0),
     mAxisScale(0.5),
     mFlags(Everything)
 {
     setFlag(QQuickItem::ItemHasContents, true);
     setWorld(Box2DWorld::defaultWorld());
 }
 
 void Box2DDebugDraw::setAxisScale(qreal axisScale)
 {
     if (mAxisScale != axisScale) {
         mAxisScale = axisScale;
         emit axisScaleChanged();
     }
 }
 
 void Box2DDebugDraw::setFlags(DebugFlag flags)
 {
     if (mFlags != flags) {
         mFlags = flags;
         emit flagsChanged();
     }
 }
 
 void Box2DDebugDraw::setWorld(Box2DWorld *world)
 {
     if (mWorld == world)
         return;
 
     if (mWorld)
         mWorld->disconnect(this);
 
     mWorld = world;
 
     if (mWorld)
         connect(mWorld, SIGNAL(stepped()), SLOT(onWorldStepped()));
 
     emit worldChanged();
 }
 
 QSGNode *Box2DDebugDraw::updatePaintNode(QSGNode *oldNode, QQuickItem::UpdatePaintNodeData *)
 {
     if (oldNode)
         delete oldNode;
 
     if (!mWorld)
         return 0;
 
     QSGTransformNode *root = new QSGTransformNode;
     DebugDraw debugDraw(root, *mWorld);
     debugDraw.SetFlags(mFlags);
     debugDraw.setAxisScale(mAxisScale);
     debugDraw.draw();
     return root;
 }
 
 void Box2DDebugDraw::onWorldStepped()
 {
     if (isVisible() && opacity() > 0)
         update();
 }