Module: Rubygame::GL

Defined in:
lib/rubygame/gl.rb

Overview

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.

Constant Summary collapse

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

Class Method Summary collapse

Class Method Details

.get_attrib(attrib) ⇒ Object

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.



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# 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) ⇒ Object

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.



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# 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 ⇒ Object

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.



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# File 'lib/rubygame/gl.rb', line 88

def self.swap_buffers
  SDL.GL_SwapBuffers()
end