Creates a context from GLFW.

This relies on the GLFW shard being available. The context must be current on the calling thread when calling this method.

# Initialization and window creation code.
LibGLFW.init
window = LibGLFW.create_window(640, 480, "Gloop", nil, nil)
LibGLFW.make_context_current(window)

# Create Gloop context from GLFW.
context = Gloop::Context.from_glfw

Creates a context from SDL.

This relies on the SDL shard being available. The context must be current on the calling thread when calling this method.

# Initialization and window creation code.
SDL.init(SDL::Init::VIDEO)
window = SDL::Window.new("Gloop", 640, 480, flags: SDL::Window::Flags::OPENGL)
context = LibSDL.gl_create_context(window)
LibSDL.gl_make_current(window, context)

# Create Gloop context from SDL.
context = Gloop::Context.from_sdl

Constructs a reference to an existing context with pre-loaded functions.

The loader should be setup with OpenGL function addresses.

Constructs a reference to an existing context.

Uses a generic loader to retrieve addresses of OpenGL functions. A block must be provided that retrieves OpenGL functions. It takes a function name as an argument and returns a pointer (address) to the function. The address must correspond to the currently bound context. If the function is unavailable, a null pointer should be returned by the block.

Information for all attributes in the bound vertex array.

Information about vertex buffer and attribute binding slots.

Always references the currently bound vertex array.

See: VertexArray::Current

Retrieves an interface for the buffer binding targets for this context.

Retrieves a reference to the specified capability for this context.

Creates a buffer in this context.

See: Buffer.create

Creates multiple buffers in this context.

See: BufferList.create

Creates an empty program.

See: Program.create

Creates an empty shader of the specified type.

See: Shader.create

Creates a new texture of the specified type.

See: Texture.create

Creates a new texture of the specified type.

See: Texture.create

Creates multiple textures of the specified type.

See: Texture.create

Creates multiple textures of the specified type.

See: Texture.create

Creates a vertex array in this context.

See: VertexArray.create

Creates multiple vertex arrays in this context.

See: VertexArrayList.create

Provides access to debug functionality for this context.

Disables the specified capability for this context.

See: Capability#disable

Enables the specified capability for this context.

See: Capability#enable

Checks if the specified capability for this context is enabled.

See: Capability#enabled?

Retrieves a list of extensions for this context.

Retrieves flags that were set when the context was created (such as debugging functionality).

• OpenGL function: glGetIntegerv
• OpenGL enum: GL_CONTEXT_FLAGS
• OpenGL version: 2.0

Generates a buffer in this context.

See: Buffer.generate

Generates multiple buffer in this context.

See: BufferList.generate

Generates a new texture.

See: Texture.generate

Generates multiple textures.

See: Texture.generate

Generates a vertex array in this context.

See: VertexArray.generate

Generates multiple vertex arrays in this context.

See: VertexArrayList.generate

Provides access to OpenGL functions.

OpenGL functions can be called by using their "Crystalized" name.

context.gl.bind_buffer(target, buffer)

See: https://gitlab.com/arctic-fox/opengl.cr/-/blob/master/README.md#libgl

When compiling in debug mode or with error checking explicitly enabled (-Derror_checking), function pointers are checked prior to calling them. An error is raised if an unloaded or unavailable function is called. Additionally, glGetError is called after each method. An error is raised if the function produced an error.

In release mode or with error checking disabled, these checks are skipped. Calls to unloaded and unavailable functions can crash the program. Errors are not raised after invalid OpenGL function calls.

Retrieves the major version number of the OpenGL API supported by the current context.

For instance, if the OpenGL version is 4.6, 4 is returned.

• OpenGL function: glGetIntegerv
• OpenGL enum: GL_MAJOR_VERSION
• OpenGL version: 2.0

Retrieves the minor version number of the OpenGL API supported by the current context.

For instance, if the OpenGL version is 4.6, 6 is returned.

• OpenGL function: glGetIntegerv
• OpenGL enum: GL_MINOR_VERSION
• OpenGL version: 2.0

Retrieves the kinds of contexts supported.

• OpenGL function: glGetIntegerv
• OpenGL enum: GL_CONTEXT_PROFILE_MASK
• OpenGL version: 3.2

Retrieves the current program in use.

Returns a null-object (Object.none) if there isn't a program in use.

See: Program.current

Retrieves the current program in use.

Returns a nil if there isn't a program in use.

See: Program.current?

Releases resources held by the OpenGL implementation shader compiler.

This method hints that resources held by the compiler can be released. Additional shaders can be compiled after calling this method, and the resources will be reallocated first.

• OpenGL function: glReleaseShaderCompiler
• OpenGL version: 4.1

Retrieves a string containing the name of the renderer.

This name is typically specific to a particular configuration of a hardware platform. It does not change from release to release.

• OpenGL function: glGetString
• OpenGL enum: GL_RENDERER
• OpenGL version: 2.0

Retrieves a version or release number for the shading language (GLSL).

This usually takes the form:

MAJOR.MINOR[.RELEASE][ VENDOR]

Vendor-specific information may follow the version string. Its format depends on the implementation, but a space always separates the version number and the vendor-specific information.

• OpenGL function: glGetString
• OpenGL enum: GL_SHADING_LANGUAGE_VERSION
• OpenGL version: 2.0

Retrieves a list of supported GLSL versions for this context.

Retrieves an interface for the texture binding targets for this context.

Unbinds any existing vertex array from the context's rendering state.

See: VertexArray.unbind

References uniforms for the active program.

Uninstalls any existing program from the context's rendering state.

See: Program.uninstall

Retrieves a string containing the name of the company responsible for this GL implementation.

This name does not change from release to release.

• OpenGL function: glGetString
• OpenGL enum: GL_VENDOR
• OpenGL version: 2.0

Retrieves a version or release number.

This usually takes the form:

MAJOR.MINOR[.RELEASE][ VENDOR]

Vendor-specific information may follow the version string. Its format depends on the implementation, but a space always separates the version number and the vendor-specific information.

• OpenGL function: glGetString
• OpenGL enum: GL_VERSION
• OpenGL version: 2.0

Retrieves the currently bound vertex array.

Returns a null-object (Object.none) if there isn't a vertex array bound.

See: VertexArray.current

Retrieves the currently bound vertex array.

Returns a nil if there isn't a vertex array bound.

See: VertexArray.current?