Avoid unnecessary color format conversion

If a color is not the rgb format, when QColor::red() QColor::blue()
QColor::green() is used continuously to obtain the values of different
channels, three times color conversions will occur. Therefore, use
QColor::toRgb() before that to ensure that only one conversion is
performed at most. Not only rgb, the conversion of other formats is the
same.

Change-Id: Ia969e1ca6f1524ad5d7e8dec915bcbc407875c66
Reviewed-by: Shawn Rutledge <shawn.rutledge@qt.io>

2 files changed, 16 insertions, 12 deletions

diff --git a/src/plugins/scenegraph/openvg/qsgopenvghelpers.cpp b/src/plugins/scenegraph/openvg/qsgopenvghelpers.cpp
index ab5cfb48b8..a9e27b9bbf 100644
--- a/src/plugins/scenegraph/openvg/qsgopenvghelpers.cpp
+++ b/src/plugins/scenegraph/openvg/qsgopenvghelpers.cpp
@@ -334,10 +334,12 @@ void qDrawSubImage(VGImage image, const QRectF &sourceRect, const QPointF &destO
 const QVector<VGfloat> qColorToVGColor(const QColor &color, float opacity)
 {
     QVector<VGfloat> vgColor(4);
-    vgColor[0] = color.redF();
-    vgColor[1] = color.greenF();
-    vgColor[2] = color.blueF();
-    vgColor[3] = color.alphaF() * opacity;
+    float r, g, b, a;
+    color.getRgbF(&r, &g, &b, &a);
+    vgColor[0] = r;
+    vgColor[1] = g;
+    vgColor[2] = b;
+    vgColor[3] = a * opacity;
     return vgColor;
 }
 
diff --git a/src/plugins/scenegraph/openvg/qsgopenvginternalrectanglenode.cpp b/src/plugins/scenegraph/openvg/qsgopenvginternalrectanglenode.cpp
index 2c71c1610a..9cb81d05e4 100644
--- a/src/plugins/scenegraph/openvg/qsgopenvginternalrectanglenode.cpp
+++ b/src/plugins/scenegraph/openvg/qsgopenvginternalrectanglenode.cpp
@@ -87,17 +87,19 @@ static QGradientStop interpolateStop(const QGradientStop &firstStop, const QGrad
     double distance = secondStop.first - firstStop.first;
     double distanceDelta = newPos - firstStop.first;
     double modifierValue = distanceDelta / distance;
-    int redDelta = (secondStop.second.red() - firstStop.second.red()) * modifierValue;
-    int greenDelta = (secondStop.second.green() - firstStop.second.green()) * modifierValue;
-    int blueDelta = (secondStop.second.blue() - firstStop.second.blue()) * modifierValue;
-    int alphaDelta = (secondStop.second.alpha() - firstStop.second.alpha()) * modifierValue;
+    const auto firstStopRgbColor = firstStop.second.toRgb();
+    const auto secondStopRgbColor = secondStop.second.toRgb();
+    int redDelta = (secondStopRgbColor.red() - firstStopRgbColor.red()) * modifierValue;
+    int greenDelta = (secondStopRgbColor.green() - firstStopRgbColor.green()) * modifierValue;
+    int blueDelta = (secondStopRgbColor.blue() - firstStopRgbColor.blue()) * modifierValue;
+    int alphaDelta = (secondStopRgbColor.alpha() - firstStopRgbColor.alpha()) * modifierValue;
 
     QGradientStop newStop;
     newStop.first = newPos;
-    newStop.second = QColor(firstStop.second.red() + redDelta,
-                            firstStop.second.green() + greenDelta,
-                            firstStop.second.blue() + blueDelta,
-                            firstStop.second.alpha() + alphaDelta);
+    newStop.second = QColor(firstStopRgbColor.red() + redDelta,
+                            firstStopRgbColor.green() + greenDelta,
+                            firstStopRgbColor.blue() + blueDelta,
+                            firstStopRgbColor.alpha() + alphaDelta);
 
     return newStop;
 }