Do not recreate the VGImage if the size is unchanged

When a pixmap's contents change in QVGPixmapData, only recreate
the VGImage in the GPU if the size is different than before.
This should help reduce GPU memory fragmentation.

Task-number: QT-2504
Reviewed-by: Sarah Smith
(cherry picked from commit a8c8c2274d2d0a708786adbb357013955f99c0af)

2 files changed, 10 insertions, 33 deletions

diff --git a/src/openvg/qpixmapdata_vg.cpp b/src/openvg/qpixmapdata_vg.cpp
index af75de3..8de5e4f 100644
--- a/src/openvg/qpixmapdata_vg.cpp
+++ b/src/openvg/qpixmapdata_vg.cpp
@@ -220,7 +220,7 @@ VGImage QVGPixmapData::toVGImage()
         context = qt_vg_create_context(0);
 #endif
 
-    if (recreate) {
+    if (recreate && prevSize != QSize(w, h)) {
         if (vgImage != VG_INVALID_HANDLE) {
             vgDestroyImage(vgImage);
             vgImage = VG_INVALID_HANDLE;
@@ -229,6 +229,8 @@ VGImage QVGPixmapData::toVGImage()
             vgDestroyImage(vgImageOpacity);
             vgImageOpacity = VG_INVALID_HANDLE;
         }
+    } else if (recreate) {
+        cachedOpacity = -1.0f;  // Force opacity image to be refreshed later.
     }
 
     if (vgImage == VG_INVALID_HANDLE) {
@@ -244,6 +246,7 @@ VGImage QVGPixmapData::toVGImage()
     }
 
     recreate = false;
+    prevSize = QSize(w, h);
 
     return vgImage;
 }
@@ -251,43 +254,14 @@ VGImage QVGPixmapData::toVGImage()
 VGImage QVGPixmapData::toVGImage(qreal opacity)
 {
 #if !defined(QT_SHIVAVG)
-    if (!isValid())
+    // Force the primary VG image to be recreated if necessary.
+    if (toVGImage() == VG_INVALID_HANDLE)
         return VG_INVALID_HANDLE;
 
-#if !defined(QT_NO_EGL)
-    // Increase the reference count on the shared context.
-    if (!context)
-        context = qt_vg_create_context(0);
-#endif
-
-    if (recreate) {
-        if (vgImage != VG_INVALID_HANDLE) {
-            vgDestroyImage(vgImage);
-            vgImage = VG_INVALID_HANDLE;
-        }
-        if (vgImageOpacity != VG_INVALID_HANDLE) {
-            vgDestroyImage(vgImageOpacity);
-            vgImageOpacity = VG_INVALID_HANDLE;
-        }
-    }
-
-    if (vgImage == VG_INVALID_HANDLE) {
-        vgImage = vgCreateImage
-            (VG_sARGB_8888_PRE, w, h, VG_IMAGE_QUALITY_FASTER);
-    }
-
-    if (!source.isNull() && recreate) {
-        vgImageSubData
-            (vgImage,
-             qt_vg_imageBits(source), source.bytesPerLine(),
-             VG_sARGB_8888_PRE, 0, 0, w, h);
-    }
-
-    recreate = false;
-
     if (opacity == 1.0f)
         return vgImage;
 
+    // Create an alternative image for the selected opacity.
     if (vgImageOpacity == VG_INVALID_HANDLE || cachedOpacity != opacity) {
         if (vgImageOpacity == VG_INVALID_HANDLE) {
             vgImageOpacity = vgCreateImage
@@ -412,6 +386,7 @@ void QVGPixmapData::fromNativeType(void* pixmap, NativeType type)
             vgDestroyImage(vgImageOpacity);
             vgImageOpacity = VG_INVALID_HANDLE;
         }
+        prevSize = QSize();
 
         TInt err = 0;
 
@@ -472,6 +447,7 @@ void QVGPixmapData::fromNativeType(void* pixmap, NativeType type)
         is_null = (w <= 0 || h <= 0);
         source = QImage();
         recreate = false;
+        prevSize = QSize(w, h);
         setSerialNumber(++qt_vg_pixmap_serial);
         // release stuff
         eglDestroyImageKHR(context->display(), eglImage);
diff --git a/src/openvg/qpixmapdata_vg_p.h b/src/openvg/qpixmapdata_vg_p.h
index eea0b7d..6bb0d23 100644
--- a/src/openvg/qpixmapdata_vg_p.h
+++ b/src/openvg/qpixmapdata_vg_p.h
@@ -109,6 +109,7 @@ protected:
 #endif
 
 protected:
+    QSize prevSize;
     VGImage vgImage;
     VGImage vgImageOpacity;
     qreal cachedOpacity;