Use qNextPowerOfTwo instead of reimplementing it

This patch uses the new shared qNextPowerOfTwo implementation introduced in qtbase.

Change-Id: I831d056f584897a99df2ceb8c1d840764464e344
Reviewed-by: Gunnar Sletta <gunnar.sletta@jollamobile.com>

2 files changed, 6 insertions, 29 deletions

diff --git a/src/quick/scenegraph/util/qsgatlastexture.cpp b/src/quick/scenegraph/util/qsgatlastexture.cpp
index f7cf97954a..ceeaa977d7 100644
--- a/src/quick/scenegraph/util/qsgatlastexture.cpp
+++ b/src/quick/scenegraph/util/qsgatlastexture.cpp
@@ -43,6 +43,7 @@
 
 #include <QtCore/QVarLengthArray>
 #include <QtCore/QElapsedTimer>
+#include <QtCore/QtMath>
 
 #include <QtGui/QOpenGLContext>
 #include <QtGui/QGuiApplication>
@@ -67,18 +68,6 @@ static QElapsedTimer qsg_renderer_timer;
 namespace QSGAtlasTexture
 {
 
-static inline int qsg_powerOfTwo(int v)
-{
-    v--;
-    v |= v >> 1;
-    v |= v >> 2;
-    v |= v >> 4;
-    v |= v >> 8;
-    v |= v >> 16;
-    ++v;
-    return v;
-}
-
 static int qsg_envInt(const char *name, int defaultValue)
 {
     QByteArray content = qgetenv(name);
@@ -98,8 +87,8 @@ Manager::Manager()
     int max;
     gl->functions()->glGetIntegerv(GL_MAX_TEXTURE_SIZE, &max);
 
-    int w = qMin(max, qsg_envInt("QSG_ATLAS_WIDTH", qMax(512, qsg_powerOfTwo(surfaceSize.width()))));
-    int h = qMin(max, qsg_envInt("QSG_ATLAS_HEIGHT", qMax(512, qsg_powerOfTwo(surfaceSize.height()))));
+    int w = qMin(max, qsg_envInt("QSG_ATLAS_WIDTH", qMax(512U, qNextPowerOfTwo(surfaceSize.width() - 1))));
+    int h = qMin(max, qsg_envInt("QSG_ATLAS_HEIGHT", qMax(512U, qNextPowerOfTwo(surfaceSize.height() - 1))));
 
     if (surface->surfaceClass() == QSurface::Window) {
         QWindow *window = static_cast<QWindow *>(surface);
diff --git a/src/quick/scenegraph/util/qsgpainternode.cpp b/src/quick/scenegraph/util/qsgpainternode.cpp
index 8ccb9d2ffb..c9bb5daed1 100644
--- a/src/quick/scenegraph/util/qsgpainternode.cpp
+++ b/src/quick/scenegraph/util/qsgpainternode.cpp
@@ -53,19 +53,7 @@
 
 QT_BEGIN_NAMESPACE
 
-#define QT_MINIMUM_DYNAMIC_FBO_SIZE 64
-
-static inline int qt_next_power_of_two(int v)
-{
-    v--;
-    v |= v >> 1;
-    v |= v >> 2;
-    v |= v >> 4;
-    v |= v >> 8;
-    v |= v >> 16;
-    ++v;
-    return v;
-}
+#define QT_MINIMUM_DYNAMIC_FBO_SIZE 64U
 
 QSGPainterTexture::QSGPainterTexture()
     : QSGPlainTexture()
@@ -322,8 +310,8 @@ void QSGPainterNode::updateFBOSize()
     int fboWidth;
     int fboHeight;
     if (m_fastFBOResizing) {
-        fboWidth = qMax(QT_MINIMUM_DYNAMIC_FBO_SIZE, qt_next_power_of_two(m_size.width()));
-        fboHeight = qMax(QT_MINIMUM_DYNAMIC_FBO_SIZE, qt_next_power_of_two(m_size.height()));
+        fboWidth = qMax(QT_MINIMUM_DYNAMIC_FBO_SIZE, qNextPowerOfTwo(m_size.width() - 1));
+        fboHeight = qMax(QT_MINIMUM_DYNAMIC_FBO_SIZE, qNextPowerOfTwo(m_size.height() - 1));
     } else {
         QSize minimumFBOSize = m_context->sceneGraphContext()->minimumFBOSize();
         fboWidth = qMax(minimumFBOSize.width(), m_size.width());