Module Rubygame::GL
In: lib/rubygame/gl.rb

The GL module provides an interface to SDL’s OpenGL-related functions, allowing a Rubygame application to create hardware-accelerated 3D graphics with OpenGL.

Please note that Rubygame itself does not provide an interface to OpenGL functions — only functions which allow Rubygame to work together with OpenGL. You will need to use another library, for example ruby-opengl, to actually create graphics with OpenGL.

Users who wish to use Rubygame Surfaces as textures in OpenGL should see also the Surface#pixels method.

Methods

get_attrib   set_attrib   swap_buffers  

Constants

RED_SIZE = SDL::GL_RED_SIZE
GREEN_SIZE = SDL::GL_GREEN_SIZE
BLUE_SIZE = SDL::GL_BLUE_SIZE
ALPHA_SIZE = SDL::GL_ALPHA_SIZE
BUFFER_SIZE = SDL::GL_BUFFER_SIZE
DOUBLEBUFFER = SDL::GL_DOUBLEBUFFER
DEPTH_SIZE = SDL::GL_DEPTH_SIZE
STENCIL_SIZE = SDL::GL_STENCIL_SIZE
ACCUM_RED_SIZE = SDL::GL_ACCUM_RED_SIZE
ACCUM_GREEN_SIZE = SDL::GL_ACCUM_GREEN_SIZE
ACCUM_BLUE_SIZE = SDL::GL_ACCUM_BLUE_SIZE
ACCUM_ALPHA_SIZE = SDL::GL_ACCUM_ALPHA_SIZE

Public Class methods

get_attrib( attrib )

Return the value of the the SDL/OpenGL attribute identified by attrib, which should be one of the constants defined in the Rubygame::GL module. See set_attrib for a list of attribute constants.

This method is useful after using set_attrib and calling Screen#set_mode, to make sure the attribute is the expected value.

[Source]

# File lib/rubygame/gl.rb, line 45
  def self.get_attrib( attrib )
    result = SDL.GL_GetAttribute(attrib)
    if( result.nil? )
      raise Rubygame::SDLError, "GL get attribute failed: #{SDL.GetError()}"
    end
  end
set_attrib( attrib, value )

Set the SDL/OpenGL attribute attrib to value. This should be called before you call Screen#set_mode with the OPENGL flag. You may wish to use get_attrib after calling Screen#set_mode to confirm that the attribute is set to the desired value.

The full list of SDL/OpenGL attribute identifier constants (located under the Rubygame::GL module) is as follows:

RED_SIZE:Size of framebuffer red component, in bits.
GREEN_SIZE:Size of framebuffer green component, in bits.
BLUE_SIZE:Size of framebuffer blue component, in bits.
ALPHA_SIZE:Size of framebuffer alpha (opacity) component, in bits.
BUFFER_SIZE:Size of framebuffer, in bits.
DOUBLEBUFFER:Enable or disable double-buffering.
DEPTH_SIZE:Size of depth buffer, in bits.
STENCIL_SIZE:Size of stencil buffer, in bits.
ACCUM_RED_SIZE:Size of accumulation buffer red component, in bits.
ACCUM_GREEN_SIZE:Size of accumulation buffer green component, in bits.
ACCUM_BLUE_SIZE:Size of accumulation buffer blue component, in bits.
ACCUM_ALPHA_SIZE:Size of accumulation buffer alpha component, in bits.

[Source]

# File lib/rubygame/gl.rb, line 75
  def self.set_attrib( attrib, value )
    result = SDL.GL_SetAttribute( attrib, value )
    if( result == -1 )
      raise Rubygame::SDLError, "GL set attribute failed: #{SDL.GetError()}"
    end
  end
swap_buffers()

Swap the back and front buffers, for double-buffered OpenGL displays. Should be safe to use (albeit with no effect) on single-buffered OpenGL displays.

[Source]

# File lib/rubygame/gl.rb, line 88
  def self.swap_buffers
    SDL.GL_SwapBuffers()
  end

[Validate]