https://bitbucket.org/ddreaper/unity-ui-extensions/issues/57/use-of-texture-instead-of-sprite-eg-in
Refactored all primatives to use a new common base
Updated primatives (using base) to align with current Unity Image component, including:
* Using Sprites not textures (aka above issue)
* Added ILayoutElement Interface
* Added ICanvasRaycastFilter interface (experimental, can be overridden), includes basic alpha checking.
--HG--
branch : develop_5.3
e205747c13