On 20 Jan 2014, at 11:54, Ola Røer Thorsen <[email protected]> wrote:
> Hi, I've got 3 questions about texture use in the Qt Quick scene graph: > > 1. > > In general it's recommended in OpenGL to use power-of-two-sized textures > whenever possible, for performance resons. Does the Qt Quick scenegraph deal > with this in any way, or is it up to the user to use properly sized images > whenever possible? > > By "deal with this", it could be that the scenegraph adds some padding to fit > an image within the closest larger power-of-two size, at the cost of wasting > some memory. The scene graph uses the images it gets in the size it gets them in. However, it does try to get them into an atlas which is power-of-two. > > 2. > > I've tried the option to visualize which images are put in a texture atlas > (QSG_ATLAS_OVERLAY). In my application, that has a lot of smaller icon images > (128x128 mostly), just about half of them are put in the atlas. Is there just > a single texture atlas implemented, or are there several of them? My > impression is that there is only one, and it gets filled up rather quickly. There is only one, but you can make it larger on your platform by changing QSG_ATLAS_WIDTH and QSG_ATLAS_HEIGHT to GL_MAX_TEXTURE_SIZE if you want a bigger one. > > 3. > > How does Qt Quick deal with trying to show an image that is larger than the > maximum texture size supported on the targeted GPU? Does it tile several > textures internally? It doesn't deal with this and the result will be a black square. > > Cheers, > Ola > > > > > > > > > _______________________________________________ > Interest mailing list > [email protected] > http://lists.qt-project.org/mailman/listinfo/interest _______________________________________________ Interest mailing list [email protected] http://lists.qt-project.org/mailman/listinfo/interest
