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| |
| #include "qquickturbulence_p.h" |
| #include "qquickparticlepainter_p.h"//TODO: Why was this needed again? |
| #include <cmath> |
| #include <cstdlib> |
| #include <QDebug> |
| #include <QQmlFile> |
| QT_BEGIN_NAMESPACE |
| |
| /*! |
| \qmltype Turbulence |
| \instantiates QQuickTurbulenceAffector |
| \inqmlmodule QtQuick.Particles |
| \ingroup qtquick-particles |
| \inherits Affector |
| \brief Provides fluid-like forces from a noise image. |
| |
| The Turbulence Element scales the noise source over the area it affects, |
| and uses the curl of that source to generate force vectors. |
| |
| Turbulence requires a fixed size. Unlike other affectors, a 0x0 Turbulence element |
| will affect no particles. |
| |
| The source should be relatively smooth black and white noise, such as perlin noise. |
| */ |
| /*! |
| \qmlproperty real QtQuick.Particles::Turbulence::strength |
| |
| The magnitude of the velocity vector at any point varies between zero and |
| the square root of two. It will then be multiplied by strength to get the |
| velocity per second for the particles affected by the turbulence. |
| */ |
| /*! |
| \qmlproperty url QtQuick.Particles::Turbulence::noiseSource |
| |
| The source image to generate the turbulence from. It will be scaled to the size of the element, |
| so equal or larger sizes will give better results. Tweaking this image is the only way to tweak |
| behavior such as where vortices are or how many exist. |
| |
| The source should be a relatively smooth black and white noise image, such as perlin noise. |
| A default image will be used if none is provided. |
| */ |
| |
| QQuickTurbulenceAffector::QQuickTurbulenceAffector(QQuickItem *parent) : |
| QQuickParticleAffector(parent), |
| m_strength(10), m_lastT(0), m_gridSize(0), m_field(nullptr), m_vectorField(nullptr), m_inited(false) |
| { |
| } |
| |
| void QQuickTurbulenceAffector::geometryChanged(const QRectF &, const QRectF &) |
| { |
| initializeGrid(); |
| } |
| |
| QQuickTurbulenceAffector::~QQuickTurbulenceAffector() |
| { |
| if (m_field) { |
| for (int i=0; i<m_gridSize; i++) |
| free(m_field[i]); |
| free(m_field); |
| } |
| if (m_vectorField) { |
| for (int i=0; i<m_gridSize; i++) |
| free(m_vectorField[i]); |
| free(m_vectorField); |
| } |
| } |
| |
| void QQuickTurbulenceAffector::initializeGrid() |
| { |
| if (!m_inited) |
| return; |
| |
| int arg = qMax(width(), height()); |
| if (m_gridSize != arg) { |
| if (m_field){ //deallocate and then reallocate grid |
| for (int i=0; i<m_gridSize; i++) |
| free(m_field[i]); |
| free(m_field); |
| } |
| if (m_vectorField) { |
| for (int i=0; i<m_gridSize; i++) |
| free(m_vectorField[i]); |
| free(m_vectorField); |
| } |
| m_gridSize = arg; |
| } |
| |
| m_field = (qreal**)malloc(m_gridSize * sizeof(qreal*)); |
| for (int i=0; i<m_gridSize; i++) |
| m_field[i] = (qreal*)malloc(m_gridSize * sizeof(qreal)); |
| m_vectorField = (QPointF**)malloc(m_gridSize * sizeof(QPointF*)); |
| for (int i=0; i<m_gridSize; i++) |
| m_vectorField[i] = (QPointF*)malloc(m_gridSize * sizeof(QPointF)); |
| |
| QImage image; |
| if (!m_noiseSource.isEmpty()) |
| image = QImage(QQmlFile::urlToLocalFileOrQrc(m_noiseSource)).scaled(QSize(m_gridSize, m_gridSize)); |
| if (image.isNull()) |
| image = QImage(QStringLiteral(":particleresources/noise.png")).scaled(QSize(m_gridSize, m_gridSize)); |
| |
| for (int i=0; i<m_gridSize; i++) |
| for (int j=0; j<m_gridSize; j++) |
| m_field[i][j] = qGray(image.pixel(QPoint(i,j))); |
| for (int i=0; i<m_gridSize; i++){ |
| for (int j=0; j<m_gridSize; j++){ |
| m_vectorField[i][j].setX(boundsRespectingField(i-1,j) - boundsRespectingField(i,j)); |
| m_vectorField[i][j].setY(boundsRespectingField(i,j) - boundsRespectingField(i,j-1)); |
| } |
| } |
| } |
| |
| qreal QQuickTurbulenceAffector::boundsRespectingField(int x, int y) |
| { |
| if (x < 0) |
| x = 0; |
| if (x >= m_gridSize) |
| x = m_gridSize - 1; |
| if (y < 0) |
| y = 0; |
| if (y >= m_gridSize) |
| y = m_gridSize - 1; |
| return m_field[x][y]; |
| } |
| |
| void QQuickTurbulenceAffector::ensureInit() |
| { |
| if (m_inited) |
| return; |
| m_inited = true; |
| initializeGrid(); |
| } |
| |
| void QQuickTurbulenceAffector::affectSystem(qreal dt) |
| { |
| if (!m_system || !m_enabled) |
| return; |
| ensureInit(); |
| if (!m_gridSize) |
| return; |
| |
| updateOffsets();//### Needed if an ancestor is transformed. |
| |
| QRect boundsRect(0,0,m_gridSize,m_gridSize); |
| foreach (QQuickParticleGroupData *gd, m_system->groupData){ |
| if (!activeGroup(gd->index)) |
| continue; |
| foreach (QQuickParticleData *d, gd->data){ |
| if (!shouldAffect(d)) |
| continue; |
| QPoint pos = (QPointF(d->curX(m_system), d->curY(m_system)) - m_offset).toPoint(); |
| if (!boundsRect.contains(pos,true))//Need to redo bounds checking due to quantization. |
| continue; |
| qreal fx = 0.0; |
| qreal fy = 0.0; |
| fx += m_vectorField[pos.x()][pos.y()].x() * m_strength; |
| fy += m_vectorField[pos.x()][pos.y()].y() * m_strength; |
| if (fx || fy){ |
| d->setInstantaneousVX(d->curVX(m_system)+ fx * dt, m_system); |
| d->setInstantaneousVY(d->curVY(m_system)+ fy * dt, m_system); |
| postAffect(d); |
| } |
| } |
| } |
| } |
| |
| QT_END_NAMESPACE |
| |
| #include "moc_qquickturbulence_p.cpp" |