Add QQuickWindow::TextureIsOpaque as option to createTextureFromImage.

Opaque textures can be a lot faster, so give this option without
forcing the user to reimplement her/his own QSGTexture class.

The old behavior was that createTextureFromImage() disregarded
TextureHasAlphaChannel and looked solely at the image's format. To
keep this behavior intact, we introduce a second opt-in flag to switch
textures from auto-detect to false, namely TextureIsOpaque.

[ChangeLog][QtQuick][QQuickWindow] Add TextureIsOpaque option to
createTextureFromImage()

Change-Id: I248db4bc5f7920864b6aa8d831ce24d23ad370ef
Reviewed-by: Laszlo Agocs <laszlo.agocs@theqtcompany.com>

1 files changed, 4 insertions, 2 deletions

diff --git a/src/quick/scenegraph/util/qsgatlastexture.cpp b/src/quick/scenegraph/util/qsgatlastexture.cpp
index 076b068f27..7a2587dacd 100644
--- a/src/quick/scenegraph/util/qsgatlastexture.cpp
+++ b/src/quick/scenegraph/util/qsgatlastexture.cpp
@@ -112,13 +112,15 @@ void Manager::invalidate()
     }
 }
 
-QSGTexture *Manager::create(const QImage &image)
+QSGTexture *Manager::create(const QImage &image, bool hasAlphaChannel)
 {
-    QSGTexture *t = 0;
+    Texture *t = 0;
     if (image.width() < m_atlas_size_limit && image.height() < m_atlas_size_limit) {
         if (!m_atlas)
             m_atlas = new Atlas(m_atlas_size);
         t = m_atlas->create(image);
+        if (!hasAlphaChannel && t->hasAlphaChannel())
+            t->setHasAlphaChannel(false);
     }
     return t;
 }