C# GraphicsDevice.GetRenderTargets方法代碼示例

 internal void ApplyState(GraphicsDevice device)
 {
   bool flag = device.GetRenderTargets().Length > 0;
   if (this.CullMode == CullMode.None)
   {
     GL.Disable(EnableCap.CullFace);
   }
   else
   {
     GL.Enable(EnableCap.CullFace);
     GL.CullFace(CullFaceMode.Back);
     if (this.CullMode == CullMode.CullClockwiseFace)
     {
       if (flag)
         GL.FrontFace(FrontFaceDirection.Cw);
       else
         GL.FrontFace(FrontFaceDirection.Ccw);
     }
     else if (flag)
       GL.FrontFace(FrontFaceDirection.Ccw);
     else
       GL.FrontFace(FrontFaceDirection.Cw);
   }
   if (this.FillMode == FillMode.Solid)
     GL.PolygonMode(MaterialFace.FrontAndBack, PolygonMode.Fill);
   else
     GL.PolygonMode(MaterialFace.FrontAndBack, PolygonMode.Line);
   if (this.ScissorTestEnable)
     GL.Enable(EnableCap.ScissorTest);
   else
     GL.Disable(EnableCap.ScissorTest);
   GL.Enable(EnableCap.PolygonOffsetFill);
   GL.PolygonOffset(this.SlopeScaleDepthBias, this.DepthBias * 1E+07f);
 }

        internal void ApplyState(GraphicsDevice device)
        {
        	// When rendering offscreen the faces change order.
            var offscreen = device.GetRenderTargets().Length > 0;

            if (CullMode == CullMode.None)
            {
                GL.Disable(EnableCap.CullFace);
                GraphicsExtensions.CheckGLError();
            }
            else
            {
                GL.Enable(EnableCap.CullFace);
                GraphicsExtensions.CheckGLError();
                GL.CullFace(CullFaceMode.Back);
                GraphicsExtensions.CheckGLError();

                if (CullMode == CullMode.CullClockwiseFace)
                {
                    if (offscreen)
                        GL.FrontFace(FrontFaceDirection.Cw);
                    else
                        GL.FrontFace(FrontFaceDirection.Ccw);
                    GraphicsExtensions.CheckGLError();
                }
                else
                {
                    if (offscreen)
                        GL.FrontFace(FrontFaceDirection.Ccw);
                    else
                        GL.FrontFace(FrontFaceDirection.Cw);
                    GraphicsExtensions.CheckGLError();
                }
            }

#if MONOMAC || WINDOWS || LINUX
			if (FillMode == FillMode.Solid) 
				GL.PolygonMode(MaterialFace.FrontAndBack, PolygonMode.Fill);
            else
				GL.PolygonMode(MaterialFace.FrontAndBack, PolygonMode.Line);
#else
            if (FillMode != FillMode.Solid)
                throw new NotImplementedException();
#endif

			if (ScissorTestEnable)
				GL.Enable(EnableCap.ScissorTest);
			else
				GL.Disable(EnableCap.ScissorTest);
            GraphicsExtensions.CheckGLError();

            // TODO: What about DepthBias, SlopeScaleDepthBias, and
            // MultiSampleAntiAlias... we're not handling these!
        }

		public virtual void Apply (GraphicsDevice graphicsDevice,
							int program, 
							EffectParameterCollection parameters,
							ConstantBuffer[] cbuffers)
		{									
			var textures = graphicsDevice.Textures;
			var samplerStates = graphicsDevice.SamplerStates;

			if (ShaderType == ShaderType.FragmentShader) {
				// Activate the textures.
				foreach (var sampler in _samplers) {
					// Set the sampler texture slot.
					//
					// TODO: This seems like it only needs to be done once!
					//
					var loc = GL.GetUniformLocation (program, sampler.name);
					GL.Uniform1 (loc, sampler.index);

					// TODO: Fix Volume samplers!
					// (are they really broken?)
					if (sampler.type == SamplerType.SamplerVolume)
						throw new NotImplementedException ();

					Texture tex = null;
					if (sampler.parameter >= 0) {
						var textureParameter = parameters [sampler.parameter];
						tex = textureParameter.Data as Texture;
					}

					if (tex == null) {
						//texutre 0 will be set in drawbatch :/
						if (sampler.index == 0)
							continue;

						//are smapler indexes always normal texture indexes?
						tex = (Texture)textures [sampler.index];
					}

					if (tex != null) {
						tex.glTextureUnit = ((TextureUnit)((int)TextureUnit.Texture0 + sampler.index));
						tex.Activate ();						
						samplerStates [sampler.index].Activate (tex.glTarget, tex.LevelCount > 1);
					}
				}
			}

			// Update and set the constants.
			for (var c = 0; c < _cbuffers.Length; c++) {
				var cb = cbuffers [_cbuffers [c]];
				cb.Apply (program, parameters);
			}

			if (ShaderType == ShaderType.VertexShader) {
				// Apply vertex shader fix:
				// The following two lines are appended to the end of vertex shaders
				// to account for rendering differences between OpenGL and DirectX:
				//
				// gl_Position.y = gl_Position.y * posFixup.y;
				// gl_Position.xy += posFixup.zw * gl_Position.ww;
				//
				// (the following paraphrased from wine, wined3d/state.c and wined3d/glsl_shader.c)
				//
				// - We need to flip along the y-axis in case of offscreen rendering.
				// - D3D coordinates refer to pixel centers while GL coordinates refer
				//   to pixel corners.
				// - D3D has a top-left filling convention. We need to maintain this
				//   even after the y-flip mentioned above.
				// In order to handle the last two points, we translate by
				// (63.0 / 128.0) / VPw and (63.0 / 128.0) / VPh. This is equivalent to
				// translating slightly less than half a pixel. We want the difference to
				// be large enough that it doesn't get lost due to rounding inside the
				// driver, but small enough to prevent it from interfering with any
				// anti-aliasing.
				//
				// OpenGL coordinates specify the center of the pixel while d3d coords specify
				// the corner. The offsets are stored in z and w in posFixup. posFixup.y contains
				// 1.0 or -1.0 to turn the rendering upside down for offscreen rendering. PosFixup.x
				// contains 1.0 to allow a mad.
	
				_posFixup [0] = 1.0f;
				_posFixup [1] = 1.0f;
				_posFixup [2] = (63.0f / 64.0f) / graphicsDevice.Viewport.Width;
				_posFixup [3] = -(63.0f / 64.0f) / graphicsDevice.Viewport.Height;
				//If we have a render target bound (rendering offscreen)
				if (graphicsDevice.GetRenderTargets ().Length > 0) {
					//flip vertically
					_posFixup [1] *= -1.0f;
					_posFixup [3] *= -1.0f;
				}
				var posFixupLoc = GL.GetUniformLocation (program, "posFixup"); // TODO: Look this up on link!
				GL.Uniform4 (posFixupLoc, 1, _posFixup);
			}
		}