diff options
author | Edward Welbourne <edward.welbourne@qt.io> | 2017-03-22 13:18:52 +0100 |
---|---|---|
committer | Edward Welbourne <edward.welbourne@qt.io> | 2017-06-20 09:53:46 +0000 |
commit | 02b7ec05d5713aec67577cebc18e5906b5a98598 (patch) | |
tree | a8b7fe65eb276c50b5617e808ec26ddfdf065ab8 /examples/widgets/graphicsview | |
parent | 82deb0ad160459c16c77cbbea69b56387723c3a4 (diff) |
Be (somewhat more) consistent about the value of pi
Use M_PI (and friends), where possible, in favor of hand-coded
approximations of various (in)accuracies. Where that's not available
(e.g. fragment shaders), use the same value that qmath.h uses for
M_PI, for consistency. Replaced math.h with qmath.h in places that
defined a fall-back in case math.h omits it (it's not in the C++
standard, although M_PI is in POSIX); or removed this entirely where
it wasn't used.
Reworked some code to reduce the amount of arithmetic needed, in the
process; e.g. pulling common factors out of loops. Revised an
example's doc to not waste time talking about using a six-sig-fig
value for pi (which we no longer do) - it really wasn't relevant, or
anything to be proud of; nor did the doc mention its later use.
Task-number: QTBUG-58083
Change-Id: I5a31e3a2b6a823b97a43209bed61a37b9aa6c05f
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>
Diffstat (limited to 'examples/widgets/graphicsview')
-rw-r--r-- | examples/widgets/graphicsview/boxes/scene.cpp | 5 | ||||
-rw-r--r-- | examples/widgets/graphicsview/boxes/scene.h | 2 | ||||
-rw-r--r-- | examples/widgets/graphicsview/collidingmice/mouse.cpp | 7 | ||||
-rw-r--r-- | examples/widgets/graphicsview/diagramscene/arrow.cpp | 13 | ||||
-rw-r--r-- | examples/widgets/graphicsview/elasticnodes/edge.cpp | 21 |
5 files changed, 20 insertions, 28 deletions
diff --git a/examples/widgets/graphicsview/boxes/scene.cpp b/examples/widgets/graphicsview/boxes/scene.cpp index 9ac429c667..31b9553c75 100644 --- a/examples/widgets/graphicsview/boxes/scene.cpp +++ b/examples/widgets/graphicsview/boxes/scene.cpp @@ -52,7 +52,7 @@ #include "scene.h" #include <QtGui/qmatrix4x4.h> #include <QtGui/qvector3d.h> -#include <cmath> +#include <qmath.h> #include "3rdparty/fbm.h" @@ -868,11 +868,12 @@ void Scene::renderCubemaps() QVector3D center; + const float eachAngle = 2 * M_PI / m_cubemaps.size(); for (int i = m_frame % N; i < m_cubemaps.size(); i += N) { if (0 == m_cubemaps[i]) continue; - float angle = 2.0f * PI * i / m_cubemaps.size(); + float angle = i * eachAngle; center = m_trackBalls[1].rotation().rotatedVector(QVector3D(std::cos(angle), std::sin(angle), 0.0f)); diff --git a/examples/widgets/graphicsview/boxes/scene.h b/examples/widgets/graphicsview/boxes/scene.h index a2ba1d0b5a..ccb6f368cd 100644 --- a/examples/widgets/graphicsview/boxes/scene.h +++ b/examples/widgets/graphicsview/boxes/scene.h @@ -63,8 +63,6 @@ #include "glbuffers.h" #include "qtbox.h" -#define PI 3.14159265358979 - QT_BEGIN_NAMESPACE class QMatrix4x4; QT_END_NAMESPACE diff --git a/examples/widgets/graphicsview/collidingmice/mouse.cpp b/examples/widgets/graphicsview/collidingmice/mouse.cpp index cc1a15cd82..298e4aae64 100644 --- a/examples/widgets/graphicsview/collidingmice/mouse.cpp +++ b/examples/widgets/graphicsview/collidingmice/mouse.cpp @@ -53,11 +53,10 @@ #include <QGraphicsScene> #include <QPainter> #include <QStyleOption> +#include <qmath.h> -#include <cmath> - -static const double Pi = 3.14159265358979323846264338327950288419717; -static double TwoPi = 2.0 * Pi; +const qreal Pi = M_PI; +const qreal TwoPi = 2 * M_PI; static qreal normalizeAngle(qreal angle) { diff --git a/examples/widgets/graphicsview/diagramscene/arrow.cpp b/examples/widgets/graphicsview/diagramscene/arrow.cpp index ae7fa7af90..88160d9399 100644 --- a/examples/widgets/graphicsview/diagramscene/arrow.cpp +++ b/examples/widgets/graphicsview/diagramscene/arrow.cpp @@ -51,13 +51,10 @@ #include "arrow.h" -#include <cmath> - +#include <qmath.h> #include <QPen> #include <QPainter> -const qreal Pi = 3.14; - //! [0] Arrow::Arrow(DiagramItem *startItem, DiagramItem *endItem, QGraphicsItem *parent) : QGraphicsLineItem(parent) @@ -134,10 +131,10 @@ void Arrow::paint(QPainter *painter, const QStyleOptionGraphicsItem *, double angle = std::atan2(-line().dy(), line().dx()); - QPointF arrowP1 = line().p1() + QPointF(sin(angle + Pi / 3) * arrowSize, - cos(angle + Pi / 3) * arrowSize); - QPointF arrowP2 = line().p1() + QPointF(sin(angle + Pi - Pi / 3) * arrowSize, - cos(angle + Pi - Pi / 3) * arrowSize); + QPointF arrowP1 = line().p1() + QPointF(sin(angle + M_PI / 3) * arrowSize, + cos(angle + M_PI / 3) * arrowSize); + QPointF arrowP2 = line().p1() + QPointF(sin(angle + M_PI - M_PI / 3) * arrowSize, + cos(angle + M_PI - M_PI / 3) * arrowSize); arrowHead.clear(); arrowHead << line().p1() << arrowP1 << arrowP2; diff --git a/examples/widgets/graphicsview/elasticnodes/edge.cpp b/examples/widgets/graphicsview/elasticnodes/edge.cpp index d9e4c62e34..aec12b4225 100644 --- a/examples/widgets/graphicsview/elasticnodes/edge.cpp +++ b/examples/widgets/graphicsview/elasticnodes/edge.cpp @@ -51,12 +51,9 @@ #include "edge.h" #include "node.h" -#include <cmath> - +#include <qmath.h> #include <QPainter> -static const double Pi = 3.14159265358979323846264338327950288419717; - //! [0] Edge::Edge(Node *sourceNode, Node *destNode) : arrowSize(10) @@ -140,14 +137,14 @@ void Edge::paint(QPainter *painter, const QStyleOptionGraphicsItem *, QWidget *) // Draw the arrows double angle = std::atan2(-line.dy(), line.dx()); - QPointF sourceArrowP1 = sourcePoint + QPointF(sin(angle + Pi / 3) * arrowSize, - cos(angle + Pi / 3) * arrowSize); - QPointF sourceArrowP2 = sourcePoint + QPointF(sin(angle + Pi - Pi / 3) * arrowSize, - cos(angle + Pi - Pi / 3) * arrowSize); - QPointF destArrowP1 = destPoint + QPointF(sin(angle - Pi / 3) * arrowSize, - cos(angle - Pi / 3) * arrowSize); - QPointF destArrowP2 = destPoint + QPointF(sin(angle - Pi + Pi / 3) * arrowSize, - cos(angle - Pi + Pi / 3) * arrowSize); + QPointF sourceArrowP1 = sourcePoint + QPointF(sin(angle + M_PI / 3) * arrowSize, + cos(angle + M_PI / 3) * arrowSize); + QPointF sourceArrowP2 = sourcePoint + QPointF(sin(angle + M_PI - M_PI / 3) * arrowSize, + cos(angle + M_PI - M_PI / 3) * arrowSize); + QPointF destArrowP1 = destPoint + QPointF(sin(angle - M_PI / 3) * arrowSize, + cos(angle - M_PI / 3) * arrowSize); + QPointF destArrowP2 = destPoint + QPointF(sin(angle - M_PI + M_PI / 3) * arrowSize, + cos(angle - M_PI + M_PI / 3) * arrowSize); painter->setBrush(Qt::black); painter->drawPolygon(QPolygonF() << line.p1() << sourceArrowP1 << sourceArrowP2); |