Add an image allocation pool to the OpenVG paint engine

Some OpenVG GPU's have limitations on the amount of memory
available to create VGImage's.  When the memory runs out,
vgCreateImage() will fail.

This change introduces QVGImagePool, which keeps track of all
QVGPixmapData image allocations and ejects least-recently-used
pixmaps when GPU memory is exhausted.

Task-number: QT-2554
Reviewed-by: trustme

1 files changed, 16 insertions, 1 deletions

diff --git a/src/openvg/qpixmapdata_vg_p.h b/src/openvg/qpixmapdata_vg_p.h
index c0bb098..4ff95c1 100644
--- a/src/openvg/qpixmapdata_vg_p.h
+++ b/src/openvg/qpixmapdata_vg_p.h
@@ -63,6 +63,7 @@ class RSGImage;
 QT_BEGIN_NAMESPACE
 
 class QEglContext;
+class QVGImagePool;
 
 #if !defined(QT_NO_EGL)
 class QVGPixmapData;
@@ -101,6 +102,9 @@ public:
     // Return the VGImage form for a specific opacity setting.
     virtual VGImage toVGImage(qreal opacity);
 
+    // Detach this image from the image pool.
+    virtual void detachImageFromPool();
+
     // Release the VG resources associated with this pixmap and copy
     // the pixmap's contents out of the GPU back into main memory.
     // The VG resource will be automatically recreated the next time
@@ -109,6 +113,10 @@ public:
     // process via a SgImage).
     virtual void hibernate();
 
+    // Called when the QVGImagePool wants to reclaim this pixmap's
+    // VGImage objects to reuse storage.
+    virtual void reclaimImages();
+
     QSize size() const { return QSize(w, h); }
 
 #if defined(Q_OS_SYMBIAN)
@@ -123,8 +131,13 @@ protected:
     void cleanup();
 #endif
 
-#if !defined(QT_NO_EGL)
 private:
+    QVGPixmapData *nextLRU;
+    QVGPixmapData *prevLRU;
+    bool inLRU;
+    friend class QVGImagePool;
+
+#if !defined(QT_NO_EGL)
     QVGPixmapData *next;
     QVGPixmapData *prev;
 
@@ -140,6 +153,7 @@ protected:
     qreal cachedOpacity;
     mutable QImage source;
     mutable bool recreate;
+    bool inImagePool;
 #if !defined(QT_NO_EGL)
     mutable QEglContext *context;
 #endif
@@ -148,6 +162,7 @@ protected:
     QImage::Format sourceFormat() const;
 
     void destroyImageAndContext();
+    void destroyImages();
 };
 
 QT_END_NAMESPACE