gl

Overview ¶

Package gl provides a set of bindings for OpenGL ES.

The intent of this package is to provide a very simple one-to-one set of bindings, but with some small modification to be more Go-friendly, and to take advantage of some of the niceties available in Go (extra type safety, reflection, methods, color.Color, etc.). With very few exceptions, each function or method in this package corresponds directly to a single OpenGL ES function. The exceptions to this rule are noted explicitly in their documentation.

A Note on Naming ¶

Enum names are the same as their corresponding name in C, but they are in CamlCase and have the "GL" prefix removed. For example: GL_COLOR_BUFFER_BIT is ColorBufferBit. In a very small number of cases the names needed an extra prefix to disambiguate constants of different types that would otherwise have the same name. For example, GL_DELETE_STATUS is both ShaderDeleteStatus or ProgramDeleteStatus. One can be used when getting properties from shaders, and the other when getting properties from programs. This provides better type safety and is not expected to lead to any confusion. Additionally, godoc should make it trivial to find the avaliable enum values for differenc functions since they are associated with parameters via their types.

Function names are the same as their corresponding name in C but with the "gl" prefix and all size and type suffixes removed. Functions whose C equivalents operate on objects (such as buffers, shaders, programs, textures, etc.) have been converted to methods.

Method names are the same as their corresponding function names in C but with the "gl" prefix, all size and type suffixes, and the object name removed where possible. In cases where these removals results in an empty identifier (e.g., glUniform) then the object name is not removed. For example:

glShaderCompile is Shader.Compile
glGetProgram  is Program.Get
glEnableVertexAttribArray is VertexAttribArray.Enable()
glUniform is Uniform.Uniform

This should save typing in many places and be, overall, more pleasent.

It should be noted that these rules make for some non-idiomatic names. For example, getter methods have a "Get" prefix (Shader.GetInfoLog) and setter methods have no prefix (Shader.Source); Go prefers the opposite: no prefix for getters, and a "Set" prefix for setters. While annoying, this wasn't reconsiled on purpose. This package doesn't provide detailed documentation, and the ability to easily go between these names iand their C equivalents in order to find the documentation is more important than idioms (even if Go's idiom is superior ☺).

An apology ¶

I must apologize in advance for the poor godoc comments. The comments for functions and methods are straight out of the man pages and are, in most cases, completely unhelpful. On the other hand, OpenGL is fairly complex, and I am in no way qualified to write useful documentation for it. I am also not qualified to write documentation geared toward those who have never used OpenGL before, so this package's documentation assumes a user who is familiar with OpenGL from other sources. I found this tutorial helpful: http://www.arcsynthesis.org/gltut.