Merge remote-tracking branch 'origin/5.6' into 5.7

Conflicts:
	src/quick/items/qquickimagebase.cpp
	src/imports/layouts/plugin.cpp

Change-Id: I5f48474df4034a1347ec74795c85d369a55b6b21

1 files changed, 10 insertions, 1 deletions

diff --git a/src/quick/scenegraph/util/qsgatlastexture.cpp b/src/quick/scenegraph/util/qsgatlastexture.cpp
index 68dc813933..a93e7bbd30 100644
--- a/src/quick/scenegraph/util/qsgatlastexture.cpp
+++ b/src/quick/scenegraph/util/qsgatlastexture.cpp
@@ -127,6 +127,7 @@ Atlas::Atlas(const QSize &size)
     : m_allocator(size)
     , m_texture_id(0)
     , m_size(size)
+    , m_atlas_transient_image_threshold(0)
     , m_allocated(false)
 {
 
@@ -176,6 +177,11 @@ Atlas::Atlas(const QSize &size)
 
     m_use_bgra_fallback = qEnvironmentVariableIsSet("QSG_ATLAS_USE_BGRA_FALLBACK");
     m_debug_overlay = qEnvironmentVariableIsSet("QSG_ATLAS_OVERLAY");
+
+    // images smaller than this will retain their QImage.
+    // by default no images are retained (favoring memory)
+    // set to a very large value to retain all images (allowing quick removal from the atlas)
+    m_atlas_transient_image_threshold = qt_sg_envInt("QSG_ATLAS_TRANSIENT_IMAGE_THRESHOLD", 0);
 }
 
 Atlas::~Atlas()
@@ -398,7 +404,10 @@ void Atlas::bind(QSGTexture::Filtering filtering)
         } else {
             upload(t);
         }
-        t->releaseImage();
+        const QSize textureSize = t->textureSize();
+        if (textureSize.width() > m_atlas_transient_image_threshold ||
+                textureSize.height() > m_atlas_transient_image_threshold)
+            t->releaseImage();
 
         qCDebug(QSG_LOG_TIME_TEXTURE).nospace() << "atlastexture uploaded in: " << qsg_renderer_timer.elapsed()
                                            << "ms (" << t->textureSize().width() << "x"