RubyGL -

A Complete Solution For Graphics Programming In Ruby.

Currently supports Windows and MacOSX out of the box.

gem install rubygl

Q: Why am I getting an error saying the library could not be loaded?
A: Both shared libraries are compiled as 32-bit binaries. As such, you will need a 32-bit version of ruby and the ruby devkit (to use the appropriate ffi gem) in order to run your program. If you wish to use 64-bit versions of these tools, you will have to get the appropriate SDL binary and recompile the rubygl binary.

Q: Why are my shaders not working?
A: You probably have an older version of GLSL (1.2 or earler) so your version of GLSL may not support the in and out variables (the shaders in ShaderGenerator use these). To work around this, you can change the in qualifiers in the vertex shader to attribute qualifiers and the out qualifiers to varying qualifiers. In the fragment shader change the in qualifiers to varying qualifiers and remove any out variables; you should use the built-in gl_FragColor variable to assign the output fragment color. Lastly, make sure to update the #version XXX tag for the version of GLSL your GPU can support (Ex: #version 120 if running GLSL 1.2). You can check your GLSL version by running puts RubyGL::Native::glGetString(RubyGL::Native::GL_SHADING_LANGUAGE_VERSION).

Q: Why is my program giving a segmentation fault?
A: You are most likely trying to call an OpenGL function that does not exist in your GPUs version of OpenGL. The offending function should be given to you in the stack trace. I have compiled the rubygl shared library for the latest version of OpenGL in compatibility mode to let users call any function that their version of OpenGL may support; the library will assume that any OpenGL function you are calling is valid (I should probably change this), hence the segmentation fault. Go to https://www.opengl.org/sdk/docs/man/ to see which functions are supported by each OpenGL version. You can run puts RubyGL::Native::glGetString(RubyGL::Native::GL_VERSION) to see what version of OpenGL you have.

• Not sure how to support Linux without requiring users to compile a shared library
• Windows does not guarantee that OpenGL functions loaded during context creation will be valid for other contexts
• Need to figure out how to efficiently swap these out if the user creates more than one context