Question

I have a static library Xcode 4 project that includes a home-brewed rendering engine, and I re-use this engine in multiple apps. This engine uses OpenGL ES 2.0, and by extension, shaders. As shaders got more complicated, I moved away from storing them as NSStrings in a source file, and now store them as standalone text files with the .vert and .frag extensions.

This works fine for apps that include the rendering engine in their own source; the shaders are simply added to the app’s “Copy Bundle Resources” build phase, and loaded at runtime into NSStrings and compiled, linked, etc.

This strategy doesn’t work at all if the rendering engine that loads these shaders is in a static library project; there is no bundle into which to copy resources. I’m currently forced to have every client project of the static lib rendering engine include their own copies of the shaders in their own “Copy Bundle Resources” build phase. This is a giant pain, and defeats a large part of the convenience of making the render engine into a static lib in the first place.

I suppose this is specific instance of the more general problem of “Resources in a Static Library”. The best solution I can think of is copying the shader files’ contents into strings in a header file, which are then included in the rendering engine’s source. I may even be able to automate the conversion from .frag to .h with some “Run Scripts” build phase magic, but it seems unfortunately complicated.

Is there anything I’m missing?

Answer 1

You could try to create a framework, it seems to fit your needs. There’s an example on how to create such a framework for iOS on this page:

http://db-in.com/blog/2011/07/universal-framework-iphone-ios-2-0/

The guy that wrote the guide actually uses this technique to distribute his own iOS 3D engine project.

Edit: linked to newer version of the guide.