From 5e03c4d97f72f96a8fc97aa87f24c41a043048b7 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Morten=20Johan=20S=C3=B8rvig?= <morten.sorvig@digia.com>
Date: Tue, 18 Mar 2014 13:36:10 +0100
Subject: QOpenGLWidget retina support.

Use device pixels where appropriate.

Change-Id: Ia953e6da4034eecbfccf798701ec1b850eea9d5b
Reviewed-by: Paul Olav Tvete <paul.tvete@digia.com>
---
 src/gui/painting/qplatformbackingstore.cpp         | 32 +++++++++++++++++++---
 src/widgets/kernel/qopenglwidget.cpp               |  2 +-
 .../qopenglwidget/openglwidget/openglwidget.cpp    |  9 +++---
 3 files changed, 34 insertions(+), 9 deletions(-)

diff --git a/src/gui/painting/qplatformbackingstore.cpp b/src/gui/painting/qplatformbackingstore.cpp
index 4843e93858..add3624feb 100644
--- a/src/gui/painting/qplatformbackingstore.cpp
+++ b/src/gui/painting/qplatformbackingstore.cpp
@@ -186,6 +186,28 @@ void QPlatformTextureList::clear()
 */
 
 #ifndef QT_NO_OPENGL
+
+static QRect deviceRect(const QRect &rect, QWindow *window)
+{
+    QRect deviceRect(rect.topLeft() * window->devicePixelRatio(),
+                     rect.size() * window->devicePixelRatio());
+    return deviceRect;
+}
+
+static QRegion deviceRegion(const QRegion &region, QWindow *window)
+{
+    if (!(window->devicePixelRatio() > 1))
+        return region;
+
+    QVector<QRect> rects;
+    foreach (QRect rect, region.rects())
+        rects.append(deviceRect(rect, window));
+
+    QRegion deviceRegion;
+    deviceRegion.setRects(rects.constData(), rects.count());
+    return deviceRegion;
+}
+
 /*!
     Flushes the given \a region from the specified \a window onto the
     screen, and composes it with the specified \a textures.
@@ -205,7 +227,7 @@ void QPlatformBackingStore::composeAndFlush(QWindow *window, const QRegion &regi
 
     context->makeCurrent(window);
     QOpenGLFunctions *funcs = context->functions();
-    funcs->glViewport(0, 0, window->width(), window->height());
+    funcs->glViewport(0, 0, window->width() * window->devicePixelRatio(), window->height() * window->devicePixelRatio());
 
     if (!d_ptr->blitter) {
         d_ptr->blitter = new QOpenGLTextureBlitter;
@@ -214,16 +236,18 @@ void QPlatformBackingStore::composeAndFlush(QWindow *window, const QRegion &regi
 
     d_ptr->blitter->bind();
 
-    QRect windowRect(QPoint(), window->size());
+    QRect windowRect(QPoint(), window->size() * window->devicePixelRatio());
+
     for (int i = 0; i < textures->count(); ++i) {
         GLuint textureId = textures->textureId(i);
         funcs->glBindTexture(GL_TEXTURE_2D, textureId);
 
-        QMatrix4x4 target = QOpenGLTextureBlitter::targetTransform(textures->geometry(i), windowRect);
+        QRect targetRect = deviceRect(textures->geometry(i), window);
+        QMatrix4x4 target = QOpenGLTextureBlitter::targetTransform(targetRect, windowRect);
         d_ptr->blitter->blit(textureId, target, QOpenGLTextureBlitter::OriginBottomLeft);
     }
 
-    GLuint textureId = toTexture(region);
+    GLuint textureId = toTexture(deviceRegion(region, window));
     if (!textureId)
         return;
 
diff --git a/src/widgets/kernel/qopenglwidget.cpp b/src/widgets/kernel/qopenglwidget.cpp
index e05c03d952..66aacadb28 100644
--- a/src/widgets/kernel/qopenglwidget.cpp
+++ b/src/widgets/kernel/qopenglwidget.cpp
@@ -163,7 +163,7 @@ void QOpenGLWidget::resizeEvent(QResizeEvent *)
 
     d->context.makeCurrent(d->surface());
     delete d->fbo; // recreate when resized
-    d->fbo = new QOpenGLFramebufferObject(size());
+    d->fbo = new QOpenGLFramebufferObject(size() * devicePixelRatio());
     d->fbo->bind();
     QOpenGLFunctions *funcs = d->context.functions();
     funcs->glBindTexture(GL_TEXTURE_2D, d->fbo->texture());
diff --git a/tests/manual/qopenglwidget/openglwidget/openglwidget.cpp b/tests/manual/qopenglwidget/openglwidget/openglwidget.cpp
index 5752326911..bec89b6b41 100644
--- a/tests/manual/qopenglwidget/openglwidget/openglwidget.cpp
+++ b/tests/manual/qopenglwidget/openglwidget/openglwidget.cpp
@@ -61,8 +61,8 @@
 class OpenGLWidgetPrivate
 {
 public:
-    OpenGLWidgetPrivate()
-        : m_program(0), m_frame(0)
+    OpenGLWidgetPrivate(QWidget *q)
+        : m_program(0), m_frame(0), q(q)
     {
 
     }
@@ -82,13 +82,14 @@ public:
     int m_frame;
 
     int w,h;
+    QWidget *q;
 };
 
 
 OpenGLWidget::OpenGLWidget(QWidget *parent)
     : QOpenGLWidget(parent)
 {
-    d = new OpenGLWidgetPrivate;
+    d = new OpenGLWidgetPrivate(this);
     QTimer *timer = new QTimer(this);
     connect(timer, SIGNAL(timeout()), this, SLOT(updateGL()));
     timer->start(30);
@@ -147,7 +148,7 @@ void OpenGLWidgetPrivate::initialize()
 
 void OpenGLWidgetPrivate::render()
 {
-    const qreal retinaScale = 1.0;//devicePixelRatio();
+    const qreal retinaScale = q->devicePixelRatio();
     glViewport(0, 0, width() * retinaScale, height() * retinaScale);
 
     glClearColor(0.0, 0.0, 0.0, 1.0);
-- 
cgit v1.2.3