Basic Embedding

[Richard Kain]

I don't know if it's even supported under GL ES 2.0 required for mobile and RPi.

OpenGL ES 2's feature set is roughly analagous to OpenGL 3 for Desktop. As such, basic glsl shaders ARE supported by vanilla OpenGL ES 2. Also, the solution I came up with for using Tilengine to draw directly to an SDL2 surface seems to be working well, so the pixel data is not a concern. And I created a basic demo/proof-of-concept for running glsl shaders on the Raspberry Pi before I attempted to tie Tilengine into it. Not only can I run OpenGL shaders on the Pi, but I can also access and use the framebuffer for render-to-texture effects. I've also been building all of my trials and prototypes on the Raspberry Pi 2/3 during development. Everything I've made so far runs on the actual hardware.

Now, I don't necessarily think that the performance of this is going to be better than just using straight Tilengine. In fact, I kind of assumed that it wouldn't be faster. The point of this was to increase flexibility by adding desirable features. Keeping performance within manageable tolerances was my objective for dealing with frame-rates.

Having programmable shader support will allow for such things as color-keyed transparencies and potential integration with fore or back ground 3D rendering.