Method: Mittsu::OpenGLState#set_blending

Defined in:
lib/mittsu/renderers/opengl/opengl_state.rb

#set_blending(blending, blend_equation = nil, blend_src = nil, blend_dst = nil, blend_equation_alpha = nil, blend_src_alpha = nil, blend_dst_alpha = nil) ⇒ Object 



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# File 'lib/mittsu/renderers/opengl/opengl_state.rb', line 55

def set_blending(blending, blend_equation = nil, blend_src = nil, blend_dst = nil, blend_equation_alpha = nil, blend_src_alpha = nil, blend_dst_alpha = nil)
  if blending != @current_blending
    case blending
    when NoBlending
      glDisable(GL_BLEND)
    when AdditiveBlending
      glEnable(GL_BLEND)
      glBlendEquation(GL_FUNC_ADD)
      glBlendFunc(GL_SRC_ALPHA, GL_ONE)
    when SubtractiveBlending
      # TODO: Find blendFuncSeparate() combination ???
      glEnable(GL_BLEND)
      glBlendEquation(GL_FUNC_ADD)
      glBlendFunc(GL_ZERO, GL_ONE_MINUS_SRC_COLOR)
    when MultiplyBlending
      # TODO: Find blendFuncSeparate() combination ???
      glEnable(GL_BLEND)
      glBlendEquation(GL_FUNC_ADD)
      glBlendFunc(GL_ZERO, GL_ONE_MINUS_SRC_COLOR)
    when CustomBlending
      glEnable(GL_BLEND)
    else
      glEnable(GL_BLEND)
      glBlendEquationSeparate(GL_FUNC_ADD, GL_FUNC_ADD)
      glBlendFuncSeparate(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA, GL_ONE, GL_ONE_MINUS_SRC_ALPHA)
    end

    @current_blending = blending
  end

  if blending == CustomBlending
    blend_equation_alpha ||= blend_equation
    blend_src_alpha ||= blend_src
    blend_dst_alpha ||= blend_dst

    if blend_equation != @current_blend_equation || blend_equation_alpha != @current_blend_equation_alpha
      glBlendEquationSeparate(GL_MITTSU_PARAMS[blend_equation], GL_MITTSU_PARAMS[blend_equation_alpha])

      @current_blend_equation = blend_equation
      @current_blend_equation_alpha = blend_equation_alpha
    end

    if blend_src != @current_blend_src || blend_dst != @current_blend_dst || blend_src_alpha != @current_blend_src_alpha || blend_dst_alpha != @current_blend_dst_alpha
      glBlendFuncSeparate(GL_MITTSU_PARAMS[blend_src], GL_MITTSU_PARAMS[blend_dst], GL_MITTSU_PARAMS[blend_src_alpha], GL_MITTSU_PARAMS[blend_dst_alpha])

      @current_blend_src = nil
      @current_blend_dst = nil
      @current_blend_src_alpha = nil
      @current_blend_dst_alpha = nil
    end
  else
    @current_blend_equation = nil
    @current_blend_src = nil
    @current_blend_dst = nil
    @current_blend_equation_alpha = nil
    @current_blend_src_alpha = nil
    @current_blend_dst_alpha = nil
  end
end