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// Copyright (C) 2025 The Qt Company Ltd.
// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR GPL-3.0-only
// Qt-Security score:significant reason:default
#include "qcanvasconicalgradient.h"
#include "qcanvasgradient_p.h"
#include "qcanvaspainter_p.h"
#include "engine/qcpainterengine_p.h"
QT_BEGIN_NAMESPACE
/*!
\class QCanvasConicalGradient
\since 6.11
\brief QCanvasConicalGradient is a brush for conical gradient painting.
\inmodule QtCanvasPainter
Conical gradient interpolate colors between start and end points
around a point with given coordinates. The angle starts from a line
going horizontally right from the center, and proceeds clockwise.
\image qcconicalgradient-gallery.webp
{Four squares with conical gradients sweeping around a center
point, varying in color}
Here is a simple example:
\table
\row
\li \inlineimage qcconicalgradient-example.webp
{Circle with a conical gradient sweeping from yellow through blue
and back to yellow}
\li
\code
QRectF rect(20, 20, 160, 160);
QCanvasConicalGradient cg(rect.center(), 1.75 * M_PI);
cg.setColorAt(0.0, "#fdbb2d");
cg.setColorAt(0.5, "#1a2a6c");
cg.setColorAt(1.0, "#fdbb2d");
p->setFillStyle(cg);
p->beginPath();
p->ellipse(rect);
p->fill();
\endcode
\endtable
*/
#define DECONST(d) const_cast<QCanvasConicalGradientBrushPrivate *>(d)
/*!
\fn void QCanvasConicalGradient::swap(QCanvasConicalGradient &other)
\memberswap{gradient}
*/
/*!
Constructs a default conical gradient.
Gradient center position is (0, 0).
Gradient angle is 0.0.
*/
QCanvasConicalGradient::QCanvasConicalGradient()
: QCanvasConicalGradient(0.0, 0.0, 0.0)
{
}
/*!
Constructs a conical gradient.
Gradient center position is ( \a centerX, \a centerY).
Gradient start angle is \a startAngle.
*/
QCanvasConicalGradient::QCanvasConicalGradient(qreal centerX, qreal centerY, qreal startAngle)
: QCanvasGradient(QCanvasBrush::BrushType::ConicalGradient)
{
auto &conical = QCanvasGradientBrushPrivate::get(*this)->data.conical;
conical.cx = centerX;
conical.cy = centerY;
conical.angle = startAngle;
}
/*!
Constructs a conical gradient.
Gradient center position is \a center.
Gradient start angle is \a startAngle.
*/
QCanvasConicalGradient::QCanvasConicalGradient(QPointF center, qreal startAngle)
: QCanvasConicalGradient(center.x(), center.y(), startAngle)
{
}
/*!
Returns the center point of conical gradient.
\sa setCenterPosition()
*/
QPointF QCanvasConicalGradient::centerPosition() const
{
const auto &conical = QCanvasGradientBrushPrivate::get(*this)->data.conical;
return QPointF(conical.cx, conical.cy);
}
/*!
Sets the center point of conical gradient to ( \a x, \a y).
*/
void QCanvasConicalGradient::setCenterPosition(qreal x, qreal y)
{
auto *d = QCanvasGradientBrushPrivate::get(*this);
d->data.conical.cx = x;
d->data.conical.cy = y;
d->dirty |= QCanvasGradientBrushPrivate::DirtyFlag::Values;
}
/*!
\fn void QCanvasConicalGradient::setCenterPosition(QPointF center)
\overload
Sets the center point of conical gradient to \a center.
*/
/*!
Returns the start angle of conical gradient in radians.
*/
qreal QCanvasConicalGradient::startAngle() const
{
return QCanvasGradientBrushPrivate::get(*this)->data.conical.angle;
}
/*!
Sets the start angle of conical gradient to \a angle in radians.
The angle starts from a line going horizontally right from the
center, and proceeds clockwise.
*/
void QCanvasConicalGradient::setStartAngle(qreal angle)
{
auto *d = QCanvasGradientBrushPrivate::get(*this);
d->data.conical.angle = angle;
d->dirty |= QCanvasGradientBrushPrivate::DirtyFlag::Values;
}
// ***** Private *****
/*!
\internal
*/
QCPaint QCanvasConicalGradientBrushPrivate::createPaint(QCanvasPainter *painter) const
{
auto *d = this;
if (d->dirty) {
if (d->gradientStops.size() == 0) {
QColor icol = { 0, 0, 0, 0 };
QColor ocol = { 0, 0, 0, 0 };
// Note: Without stops, custom image might be used.
createConicalGradient(icol, ocol, d->imageId);
} else if (d->gradientStops.size() == 1) {
QColor c = d->gradientStops.first().color;
createConicalGradient(c, c, 0);
} else if (d->gradientStops.size() == 2) {
QColor ic = d->gradientStops.first().color;
QColor oc = d->gradientStops.last().color;
createConicalGradient(ic, oc, 0);
} else {
DECONST(d)->updateGradientTexture(painter);
QColor col = { 255, 255, 255, 255 };
createConicalGradient(col, col, d->textureId);
}
DECONST(d)->dirty = {};
}
if (d->paint.imageId > 0) {
auto *painterPriv = QCanvasPainterPrivate::get(painter);
painterPriv->markTextureIdUsed(d->paint.imageId);
}
return d->paint;
}
void QCanvasConicalGradientBrushPrivate::createConicalGradient(QColor iColor, QColor oColor,
int imageId) const
{
auto *d = this;
const auto dd = d->data.conical;
QCPaint &p = DECONST(d)->paint;
p.brushType = BrushConicalGradient;
p.transform = QTransform::fromTranslate(dd.cx, dd.cy);
// Note: p.extent and p.radius not used
// Rotating clockwise, starting from east
p.transform.rotateRadians(dd.angle + M_PI_2);
if (imageId != 0) {
// Multistop gradient
p.imageId = imageId;
p.innerColor.a = float(d->imageY);
} else {
// 2 stops gradient
p.innerColor = { iColor.redF(), iColor.greenF(), iColor.blueF(), iColor.alphaF() };
p.outerColor = { oColor.redF(), oColor.greenF(), oColor.blueF(), oColor.alphaF() };
p.imageId = 0;
}
}
#undef DECONST
QT_END_NAMESPACE