Mobile (OpenGLES) rendering upgrades: occlusion query, anisotropic filtering, 3D text

[DP News-Robot]

Our OpenGL and OpenGLES code is now more streamlined, which allowed to “unlock” various rendering features on OpenGLES. This means we will use some features from OpenGL ES 3.0, if it is available: Occlusion Query, that is also showcased in a new demo examples/viewport_and_scenes/occlusion_query. 3D textures (example data in demo-models, look in texturing_advanced subdirectory). Using …