Possible workaround for ticket #83. Adds a new toggle to the option

dialog that lets the user swap between using a QImage or a QPixmap for rendering the map. May or may not fix things. Committed so that others can try it out. git-svn-id: http://svn.osgeo.org/qgis/trunk@5567 c8812cc2-4d05-0410-92ff-de0c093fc19c
qgis · Jul 7, 2006 · 6abc64b · 6abc64b
1 parent 4dd9a2b
commit 6abc64b
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Showing 8 changed files with 137 additions and 65 deletions.
diff --git a/src/gui/qgisapp.cpp b/src/gui/qgisapp.cpp
@@ -1050,6 +1050,7 @@ void QgisApp::createOverview()
   // moved here to set anti aliasing to both map canvas and overview
   QSettings mySettings;
   mMapCanvas->enableAntiAliasing(mySettings.value("/qgis/enable_anti_aliasing",false).toBool());
+  mMapCanvas->useQImageToRender(mySettings.value("/qgis/use_qimage_to_render",false).toBool());
 }
 
 
@@ -4048,6 +4049,7 @@ void QgisApp::options()
     mAddedLayersVisible = optionsDialog->newVisible();
     QSettings mySettings;
     mMapCanvas->enableAntiAliasing(mySettings.value("/qgis/enable_anti_aliasing").toBool());
+    mMapCanvas->useQImageToRender(mySettings.value("/qgis/use_qimage_to_render").toBool());
   }
 }
 

diff --git a/src/gui/qgsmapcanvas.cpp b/src/gui/qgsmapcanvas.cpp
@@ -154,6 +154,11 @@ void QgsMapCanvas::enableAntiAliasing(bool theFlag)
     mMapOverview->enableAntiAliasing(theFlag);
 } // anti aliasing
 
+void QgsMapCanvas::useQImageToRender(bool theFlag)
+{
+  mMap->useQImageToRender(theFlag);
+}
+
 QgsMapCanvasMap* QgsMapCanvas::map()
 {
   return mMap;

diff --git a/src/gui/qgsmapcanvas.h b/src/gui/qgsmapcanvas.h
@@ -185,6 +185,9 @@ class QgsMapCanvas : public Q3CanvasView
     //! used to determine if anti-aliasing is enabled or not
     void enableAntiAliasing(bool theFlag);
 
+    //! Select which Qt class to render with
+    void useQImageToRender(bool theFlag);
+
     // following 2 methods should be moved elsewhere or changed to private
     // currently used by pan map tool
     //! Ends pan action and redraws the canvas.

diff --git a/src/gui/qgsmapcanvasmap.cpp b/src/gui/qgsmapcanvasmap.cpp
@@ -25,6 +25,7 @@ QgsMapCanvasMap::QgsMapCanvasMap(Q3Canvas *canvas, QgsMapRender* render)
   setZ(-10);
   move(0,0);
   resize(QSize(1,1));
+  mUseQImageToRender = false;
 }
 
 
@@ -42,22 +43,38 @@ void QgsMapCanvasMap::resize(QSize size)
 
 void QgsMapCanvasMap::render()
 {
-  // use temporary image for rendering
-  QImage image(size(), QImage::Format_RGB32);
+  // Rendering to a QImage gives incorrectly filled polygons in some
+  // cases (as at Qt4.1.4), but it is the only renderer that supports
+  // anti-aliasing, so we provide the means to swap between QImage and
+  // QPixmap. 
+
+  if (mUseQImageToRender)
+  {
+    // use temporary image for rendering
+    QImage image(size(), QImage::Format_RGB32);
 
-  image.fill(mBgColor.rgb());
+    image.fill(mBgColor.rgb());
 
-  QPainter paint;
-  paint.begin(&image);
+    QPainter paint;
+    paint.begin(&image);
 
-  // antialiasing
-  if (mAntiAliasing)
-    paint.setRenderHint(QPainter::Antialiasing);
+    // antialiasing
+    if (mAntiAliasing)
+      paint.setRenderHint(QPainter::Antialiasing);
 
-  mRender->render(&paint);
+    mRender->render(&paint);
 
-  paint.end();
+    paint.end();
 
-  // convert QImage to QPixmap to acheive faster drawing on screen
-  mPixmap = QPixmap::fromImage(image);
+    // convert QImage to QPixmap to acheive faster drawing on screen
+    mPixmap = QPixmap::fromImage(image);
+  }
+  else
+  {
+    mPixmap.fill(mBgColor.rgb());
+    QPainter paint;
+    paint.begin(&mPixmap);
+    mRender->render(&paint);
+    paint.end();
+  }
 }
diff --git a/src/gui/qgsmapcanvasmap.h b/src/gui/qgsmapcanvasmap.h
@@ -39,6 +39,8 @@ class QgsMapCanvasMap : public Q3CanvasRectangle
 
     void enableAntiAliasing(bool flag) { mAntiAliasing = flag; }
 
+    void useQImageToRender(bool flag) { mUseQImageToRender = flag; }
+
     QPixmap& pixmap() { return mPixmap; }
 
     //! renders map using QgsMapRender to mPixmap
@@ -61,6 +63,9 @@ class QgsMapCanvasMap : public Q3CanvasRectangle
     //! indicates whether antialiasing will be used for rendering
     bool mAntiAliasing;
 
+    //! Whether to use a QPixmap or a QImage for the rendering
+    bool mUseQImageToRender;
+
     QgsMapRender* mRender;
 
     QColor mBgColor;

diff --git a/src/gui/qgsoptions.cpp b/src/gui/qgsoptions.cpp
@@ -98,6 +98,9 @@ QgsOptions::QgsOptions(QWidget *parent, Qt::WFlags fl) :
   cmbTheme->setCurrentText(settings.readEntry("/Themes","default"));
   //set teh state of the checkboxes
   chkAntiAliasing->setChecked(settings.value("/qgis/enable_anti_aliasing",false).toBool());
+  // Slightly awkard here at the settings value is true to use QImage,
+  // but the checkbox is true to use QPixmap
+  chkUseQPixmap->setChecked(!(settings.value("/qgis/use_qimage_to_render", true).toBool()));
   chkAddedVisibility->setChecked(settings.value("/qgis/new_layers_visible",true).toBool());
   cbxHideSplash->setChecked(settings.value("/qgis/hideSplash",false).toBool());
   //set the colour for selections
@@ -154,6 +157,7 @@ void QgsOptions::saveOptions()
   settings.writeEntry("/qgis/hideSplash",cbxHideSplash->isChecked());
   settings.writeEntry("/qgis/new_layers_visible",chkAddedVisibility->isChecked());
   settings.writeEntry("/qgis/enable_anti_aliasing",chkAntiAliasing->isChecked());
+  settings.writeEntry("/qgis/use_qimage_to_render", !(chkUseQPixmap->isChecked()));
   settings.setValue("qgis/capitaliseLayerName", capitaliseCheckBox->isChecked());
 
   if(cmbTheme->currentText().length() == 0)
@@ -250,6 +254,27 @@ void QgsOptions::on_pbnSelectProjection_clicked()
   }
 
 }
+
+void QgsOptions::on_chkAntiAliasing_stateChanged()
+{
+  // We can't have the anti-aliasing turned on when QPixmap is being
+  // used (we we can. but it then doesn't do anti-aliasing, and this
+  // will confuse people).
+  if (chkAntiAliasing->isChecked())
+    chkUseQPixmap->setChecked(false);
+
+}
+
+void QgsOptions::on_chkUseQPixmap_stateChanged()
+{
+  // We can't have the anti-aliasing turned on when QPixmap is being
+  // used (we we can. but it then doesn't do anti-aliasing, and this
+  // will confuse people).
+  if (chkUseQPixmap->isChecked())
+    chkAntiAliasing->setChecked(false);
+
+}
+
 // Return state of the visibility flag for newly added layers. If
 
 bool QgsOptions::newVisible()

diff --git a/src/gui/qgsoptions.h b/src/gui/qgsoptions.h
@@ -47,6 +47,8 @@ class QgsOptions :public QDialog, private Ui::QgsOptionsBase
       //! Slot called when user chooses to change the project wide projection.
       void on_pbnSelectProjection_clicked();
       void on_btnFindBrowser_clicked();
+      void on_chkAntiAliasing_stateChanged();
+      void on_chkUseQPixmap_stateChanged();
       void saveOptions();
     //! Slot to change the theme this is handled when the user 
     // activates or highlights a theme name in the drop-down list

diff --git a/src/ui/qgsoptionsbase.ui b/src/ui/qgsoptionsbase.ui
@@ -21,15 +21,18 @@
   <property name="sizeGripEnabled" >
    <bool>true</bool>
   </property>
-  <layout class="QVBoxLayout" >
+  <layout class="QGridLayout" >
    <property name="margin" >
     <number>9</number>
    </property>
    <property name="spacing" >
     <number>6</number>
    </property>
-   <item>
+   <item row="0" column="0" >
     <widget class="QTabWidget" name="tabWidget" >
+     <property name="currentIndex" >
+      <number>1</number>
+     </property>
      <widget class="QWidget" name="tabAppearance" >
       <attribute name="title" >
        <string>&amp;Appearance</string>
@@ -227,30 +230,17 @@
       <attribute name="title" >
        <string>&amp;Rendering</string>
       </attribute>
-      <layout class="QGridLayout" >
+      <layout class="QVBoxLayout" >
        <property name="margin" >
         <number>9</number>
        </property>
        <property name="spacing" >
         <number>6</number>
        </property>
-       <item row="3" column="0" >
-        <spacer>
-         <property name="orientation" >
-          <enum>Qt::Vertical</enum>
-         </property>
-         <property name="sizeHint" >
-          <size>
-           <width>20</width>
-           <height>40</height>
-          </size>
-         </property>
-        </spacer>
-       </item>
-       <item row="2" column="0" >
-        <widget class="QGroupBox" name="groupBox_8" >
+       <item>
+        <widget class="QGroupBox" name="groupBox_5" >
          <property name="title" >
-          <string>Anti-aliasing</string>
+          <string>&amp;Update during drawing</string>
          </property>
          <layout class="QGridLayout" >
           <property name="margin" >
@@ -259,17 +249,47 @@
           <property name="spacing" >
            <number>6</number>
           </property>
+          <item row="0" column="2" >
+           <widget class="QLabel" name="textLabel2_2" >
+            <property name="text" >
+             <string>features</string>
+            </property>
+           </widget>
+          </item>
+          <item row="0" column="1" >
+           <widget class="QSpinBox" name="spinBoxUpdateThreshold" >
+            <property name="toolTip" >
+             <string>Map display will be updated (drawn) after this many features have been read from the data source</string>
+            </property>
+            <property name="maximum" >
+             <number>1000000</number>
+            </property>
+            <property name="value" >
+             <number>1000</number>
+            </property>
+           </widget>
+          </item>
           <item row="0" column="0" >
-           <widget class="QCheckBox" name="chkAntiAliasing" >
+           <widget class="QLabel" name="textLabel1_6" >
             <property name="text" >
-             <string>Make lines appear less jagged at the expense of some drawing performance</string>
+             <string>Update display after reading</string>
+            </property>
+            <property name="buddy" >
+             <cstring>spinBoxUpdateThreshold</cstring>
+            </property>
+           </widget>
+          </item>
+          <item row="1" column="0" colspan="3" >
+           <widget class="QLabel" name="textLabel3" >
+            <property name="text" >
+             <string>(Set to 0 to not update the display until all features have been read)</string>
             </property>
            </widget>
           </item>
          </layout>
         </widget>
        </item>
-       <item row="1" column="0" >
+       <item>
         <widget class="QGroupBox" name="groupBox_4" >
          <property name="title" >
           <string>Initial Visibility</string>
@@ -291,10 +311,10 @@
          </layout>
         </widget>
        </item>
-       <item row="0" column="0" >
-        <widget class="QGroupBox" name="groupBox_5" >
+       <item>
+        <widget class="QGroupBox" name="groupBox_8" >
          <property name="title" >
-          <string>&amp;Update during drawing</string>
+          <string>Rendering</string>
          </property>
          <layout class="QGridLayout" >
           <property name="margin" >
@@ -303,46 +323,39 @@
           <property name="spacing" >
            <number>6</number>
           </property>
-          <item row="0" column="2" >
-           <widget class="QLabel" name="textLabel2_2" >
-            <property name="text" >
-             <string>features</string>
-            </property>
-           </widget>
-          </item>
-          <item row="0" column="1" >
-           <widget class="QSpinBox" name="spinBoxUpdateThreshold" >
+          <item row="1" column="0" >
+           <widget class="QCheckBox" name="chkUseQPixmap" >
             <property name="toolTip" >
-             <string>Map display will be updated (drawn) after this many features have been read from the data source</string>
+             <string>&lt;html>&lt;head>&lt;meta name="qrichtext" content="1" />&lt;/head>&lt;body style=" white-space: pre-wrap; font-family:Sans Serif; font-size:9pt; font-weight:400; font-style:normal; text-decoration:none;">&lt;p style=" margin-top:0px; margin-bottom:0px; margin-left:0px; margin-right:0px; -qt-block-indent:0; text-indent:0px;">Selecting this will unselect the 'make lines less' jagged toggle&lt;/p>&lt;/body>&lt;/html></string>
             </property>
-            <property name="maximum" >
-             <number>1000000</number>
-            </property>
-            <property name="value" >
-             <number>1000</number>
-            </property>
-           </widget>
-          </item>
-          <item row="0" column="0" >
-           <widget class="QLabel" name="textLabel1_6" >
             <property name="text" >
-             <string>Update display after reading</string>
-            </property>
-            <property name="buddy" >
-             <cstring>spinBoxUpdateThreshold</cstring>
+             <string>Fix problems with incorrectly filled polygons</string>
             </property>
            </widget>
           </item>
-          <item row="1" column="0" colspan="3" >
-           <widget class="QLabel" name="textLabel3" >
+          <item row="0" column="0" >
+           <widget class="QCheckBox" name="chkAntiAliasing" >
             <property name="text" >
-             <string>(Set to 0 to not update the display until all features have been read)</string>
+             <string>Make lines appear less jagged at the expense of some drawing performance</string>
             </property>
            </widget>
           </item>
          </layout>
         </widget>
        </item>
+       <item>
+        <spacer>
+         <property name="orientation" >
+          <enum>Qt::Vertical</enum>
+         </property>
+         <property name="sizeHint" >
+          <size>
+           <width>20</width>
+           <height>40</height>
+          </size>
+         </property>
+        </spacer>
+       </item>
       </layout>
      </widget>
      <widget class="QWidget" name="tabMap" >
@@ -631,7 +644,7 @@ identifying features without zooming in very close.
      </widget>
     </widget>
    </item>
-   <item>
+   <item row="1" column="0" >
     <layout class="QHBoxLayout" >
      <property name="margin" >
       <number>0</number>