C++ Context::Bind方法代码示例

	void Render(double time)
	{
		gl.Clear().ColorBuffer().DepthBuffer().StencilBuffer();
		// make the camera matrix orbiting around the origin
		// at radius of 3.5 with elevation between 15 and 90 degrees
		camera_matrix.Set(
			CamMatrixf::Orbiting(
				Vec3f(),
				5.0,
				Degrees(time * 11),
				Degrees(15 + (-SineWave(0.25+time/12.5)+1.0)*0.5*75)
			)
		);
		ModelMatrixf identity;
		// make the model transformation matrix
		ModelMatrixf model =
			ModelMatrixf::Translation(0.0f, 1.5f, 0.0) *
			ModelMatrixf::RotationZ(Degrees(time * 43))*
			ModelMatrixf::RotationY(Degrees(time * 63))*
			ModelMatrixf::RotationX(Degrees(time * 79));
		// make the reflection matrix
		auto reflection = ModelMatrixf::Reflection(false, true, false);
		//
		gl.Disable(Capability::Blend);
		gl.Disable(Capability::DepthTest);
		gl.Enable(Capability::StencilTest);
		gl.ColorMask(false, false, false, false);
		gl.StencilFunc(CompareFunction::Always, 1, 1);
		gl.StencilOp(StencilOp::Keep, StencilOp::Keep, StencilOp::Replace);

		gl.Bind(plane);
		model_matrix.Set(identity);
		gl.DrawArrays(PrimitiveType::TriangleStrip, 0, 4);

		gl.ColorMask(true, true, true, true);
		gl.Enable(Capability::DepthTest);
		gl.StencilFunc(CompareFunction::Equal, 1, 1);
		gl.StencilOp(StencilOp::Keep, StencilOp::Keep, StencilOp::Keep);

		// draw the cube using the reflection program
		model_matrix.Set(reflection * model);
		gl.Bind(cube);
		cube_instr.Draw(cube_indices);

		gl.Disable(Capability::StencilTest);

		// draw the cube using the normal object program
		model_matrix.Set(model);
		cube_instr.Draw(cube_indices);

		// blend-in the plane
		gl.Enable(Capability::Blend);
		gl.BlendEquation(BlendEquation::Max);
		gl.Bind(plane);
		model_matrix.Set(identity);
		gl.DrawArrays(PrimitiveType::TriangleStrip, 0, 4);
	}

	DrawProc(const Particles& particles)
	{
		gl.Bind(vao);

		gl.Bind(BufferTarget::ElementArray, particles.indices_d);

		gl.Bind(BufferTarget::Array, particles.positions);
		(prog|"Position").Setup<Vec3f>().Enable();

		gl.Bind(NoVertexArray());
	}

	void Render(double time)
	{
		static const Mat4f reflection(
			Vec4f( 1.0, 0.0, 0.0, 0.0),
			Vec4f( 0.0,-1.0, 0.0, 0.0),
			Vec4f( 0.0, 0.0, 1.0, 0.0),
			Vec4f( 0.0, 0.0, 0.0, 1.0)
		);

		auto camera = CamMatrixf::Orbiting(
			Vec3f(),
			GLfloat(7.0 + SineWave(time / 12.0)*2.5),
			FullCircles(time / 10.0),
			Degrees(45.0 - SineWave(time / 7.0)*35.0)
		);

		shape_prog.Use();
		shape.Bind();

		gl.Enable(Capability::CullFace);
		gl.FrontFace(make_shape.FaceWinding());

		// render into the off-screen framebuffer
		fbo.Bind(Framebuffer::Target::Draw);
		gl.Viewport(
			(width - refl_tex_side) / 2,
			(height - refl_tex_side) / 2,
			refl_tex_side, refl_tex_side
		);
		gl.Clear().ColorBuffer().DepthBuffer();

		shape_camera_matrix.Set(
			camera *
			ModelMatrixf::Translation(0.0f, -1.0f, 0.0f) *
			reflection
		);

		gl.CullFace(Face::Front);
		shape_instr.Draw(shape_indices);

		gl.Bind(Framebuffer::Target::Draw, DefaultFramebuffer());
		gl.Viewport(width, height);
		gl.Clear().ColorBuffer().DepthBuffer();

		shape_camera_matrix.Set(camera);

		gl.CullFace(Face::Back);
		shape_instr.Draw(shape_indices);

		gl.Disable(Capability::CullFace);

		// Render the plane
		plane_prog.Use();
		plane.Bind();

		plane_camera_matrix.Set(camera);
		plane_camera_position.Set(camera.Position());

		plane_instr.Draw(plane_indices);
	}

	void operator()(const Particles& particles)
	{
		gl.Enable(Capability::Blend);
		gl.Bind(vao);
		gl.Use(prog);
		gl.DrawElements(PrimitiveType::Points, particles.Count(), (GLuint*)0);
		gl.Disable(Capability::Blend);
	}

void HSWDisplay::UnloadGraphics()
{
    if(pTexture) // If initialized...
    {
        Context currentGLContext;
        currentGLContext.InitFromCurrent();
        GLContext.Bind();

        // RenderParams: No need to clear.
        if(FrameBuffer != 0)
        {
            glDeleteFramebuffers(1, &FrameBuffer);
            FrameBuffer = 0;
        }
        pTexture.Clear();
        pShaderSet.Clear();
        pVertexShader.Clear();
        pFragmentShader.Clear();
        pVB.Clear();
        if(VAO)
        {
            #ifdef OVR_OS_MAC
                if(GLVersionInfo.WholeVersion >= 302)
                    glDeleteVertexArrays(1, &VAO);
                else
                    glDeleteVertexArraysAPPLE(1, &VAO);
            #else
                glDeleteVertexArrays(1, &VAO);
            #endif
            
            VAO = 0;
            VAOInitialized = false;
        }
        // OrthoProjection: No need to clear.
        
        currentGLContext.Bind();
        GLContext.Destroy();
    }
}

	void Render(double time)
	{
		gl.Clear().ColorBuffer().DepthBuffer();
		//
		auto camera = CamMatrixf::Orbiting(
			Vec3f(),
			5.5,
			FullCircles(time / 10.0),
			Degrees(45.0 + SineWave(time / 7.0)*30.0)
		);

		// Render the plane
		plane_prog.Use();
		plane_camera_matrix.Set(camera);

		plane_model_matrix.Set(
			ModelMatrixf::Translation(0.0f, -1.1f, 0.0f)
		);

		gl.Bind(plane);
		plane_instr.Draw(plane_indices);


		// Render the shape
		shape_prog.Use();

		auto clip_plane = Planef::FromNormal(Vec3f(Data(camera.Row(2)), 3));

		shape_clip_plane.Set(clip_plane.Equation());

		shape_camera_matrix.Set(camera);

		shape_model_matrix.Set(
			ModelMatrixf::RotationX(FullCircles(time / 12.0))
		);

		gl.Bind(shape);

		gl.Enable(Capability::CullFace);
		gl.Enable(Functionality::ClipDistance, 0);

		gl.FrontFace(make_shape.FaceWinding());

		GLfloat clip_dirs[2] = {-1.0f, 1.0f};
		Face facing_dirs[2] = {Face::Front, Face::Back};

		for(int c=0; c!=2; ++c)
		{
			shape_clip_direction.Set(clip_dirs[c]);
			for(int f=0; f!=2; ++f)
			{
				Texture::CopyImage2D(
					Texture::Target::_2D,
					0,
					PixelDataInternalFormat::RGB,
					tex_side == width ? 0 : (width - tex_side) / 2,
					tex_side == height? 0 : (height- tex_side) / 2,
					tex_side, tex_side,
					0
				);
				gl.CullFace(facing_dirs[f]);
				shape_instr.Draw(shape_indices);
			}
		}

		gl.Disable(Functionality::ClipDistance, 0);
		gl.Disable(Capability::CullFace);
	}

	ReflectionExample(void)
	 : make_cube(0.5,0.5,0.5, 0.1,0.1,0.1, 3,3,3)
	 , cube_indices(make_cube.Indices())
	 , cube_instr(make_cube.Instructions())
	 , prog(make_prog())
	 , projection_matrix(prog, "ProjectionMatrix")
	 , camera_matrix(prog, "CameraMatrix")
	 , model_matrix(prog, "ModelMatrix")
	{
		gl.Use(prog);

		// bind the VAO for the cube
		gl.Bind(cube);

		// bind the VBO for the cube vertices
		gl.Bind(Buffer::Target::Array, cube_verts);
		{
			std::vector<GLfloat> data;
			GLuint n_per_vertex = make_cube.Positions(data);
			// upload the data
			Buffer::Data(Buffer::Target::Array, data);
			// setup the vertex attribs array for the vertices
			VertexArrayAttrib attr(prog, "Position");
			attr.Setup<GLfloat>(n_per_vertex);
			attr.Enable();
		}

		// bind the VBO for the cube normals
		gl.Bind(Buffer::Target::Array, cube_normals);
		{
			std::vector<GLfloat> data;
			GLuint n_per_vertex = make_cube.Normals(data);
			// upload the data
			Buffer::Data(Buffer::Target::Array, data);
			// setup the vertex attribs array for the normals
			VertexArrayAttrib attr(prog, "Normal");
			attr.Setup<GLfloat>(n_per_vertex);
			attr.Enable();
		}

		// bind the VAO for the plane
		gl.Bind(plane);

		// bind the VBO for the plane vertices
		gl.Bind(Buffer::Target::Array, plane_verts);
		{
			GLfloat data[4*3] = {
				-2.0f, 0.0f,  2.0f,
				-2.0f, 0.0f, -2.0f,
				 2.0f, 0.0f,  2.0f,
				 2.0f, 0.0f, -2.0f
			};
			// upload the data
			Buffer::Data(Buffer::Target::Array, 4*3, data);
			// setup the vertex attribs array for the vertices
			prog.Use();
			VertexArrayAttrib attr(prog, "Position");
			attr.Setup<Vec3f>();
			attr.Enable();
		}

		// bind the VBO for the cube normals
		gl.Bind(Buffer::Target::Array, plane_normals);
		{
			GLfloat data[4*3] = {
				-0.1f, 1.0f,  0.1f,
				-0.1f, 1.0f, -0.1f,
				 0.1f, 1.0f,  0.1f,
				 0.1f, 1.0f, -0.1f
			};
			// upload the data
			Buffer::Data(Buffer::Target::Array, 4*3, data);
			// setup the vertex attribs array for the normals
			prog.Use();
			VertexArrayAttrib attr(prog, "Normal");
			attr.Setup<Vec3f>();
			attr.Enable();
		}
		gl.Bind(NoVertexArray());

		Uniform<Vec3f>(prog, "LightPos").Set(1.5, 2.0, 2.5);
		//
		gl.ClearColor(0.2f, 0.2f, 0.2f, 0.0f);
		gl.ClearDepth(1.0f);
		gl.ClearStencil(0);
	}

	CubeExample(void)
	 : cube_instr(make_cube.Instructions())
	 , cube_indices(make_cube.Indices())
	 , prog(make_prog())
	 , projection_matrix(prog, "ProjectionMatrix")
	 , camera_matrix(prog, "CameraMatrix")
	 , model_matrix(prog, "ModelMatrix")
	{

		// bind the VAO for the cube
		gl.Bind(cube);

		gl.Bind(Buffer::Target::Array, verts);
		{
			std::vector<GLfloat> data;
			GLuint n_per_vertex = make_cube.Positions(data);
			Buffer::Data(Buffer::Target::Array, data);
			VertexArrayAttrib attr(prog, "Position");
			attr.Setup<GLfloat>(n_per_vertex);
			attr.Enable();
		}

		gl.Bind(Buffer::Target::Array, normals);
		{
			std::vector<GLfloat> data;
			GLuint n_per_vertex = make_cube.Normals(data);
			Buffer::Data(Buffer::Target::Array, data);
			VertexArrayAttrib attr(prog, "Normal");
			attr.Setup<GLfloat>(n_per_vertex);
			attr.Enable();
		}

		gl.Bind(Buffer::Target::Array, texcoords);
		{
			std::vector<GLfloat> data;
			GLuint n_per_vertex = make_cube.TexCoordinates(data);
			Buffer::Data(Buffer::Target::Array, data);
			VertexArrayAttrib attr(prog, "TexCoord");
			attr.Setup<GLfloat>(n_per_vertex);
			attr.Enable();
		}

		// setup the texture
		gl.Bound(Texture::Target::_2D, tex)
			.Image2D(images::LoadTexture("honeycomb"))
			.GenerateMipmap()
			.MinFilter(TextureMinFilter::LinearMipmapLinear)
			.MagFilter(TextureMagFilter::Linear)
			.WrapS(TextureWrap::MirroredRepeat)
			.WrapT(TextureWrap::MirroredRepeat)
			.Anisotropy(2);
		//
		UniformSampler(prog, "TexUnit").Set(0);
		Uniform<Vec3f>(prog, "LightPos").Set(Vec3f(1.0f, 2.0f, 3.0f));
		//
		gl.ClearColor(0.1f, 0.1f, 0.1f, 0.0f);
		gl.ClearDepth(1.0f);
		gl.Enable(Capability::DepthTest);
		gl.Enable(Capability::Blend);
		gl.BlendFunc(
			BlendFn::SrcAlpha,
			BlendFn::OneMinusSrcAlpha
		);

		gl.Enable(Capability::CullFace);
		gl.FrontFace(make_cube.FaceWinding());
	}

	CubeExample(void)
	 : cube_instr(make_cube.Instructions())
	 , cube_indices(make_cube.Indices())
	 , prog(make_prog())
	 , projection_matrix(prog, "ProjectionMatrix")
	 , camera_matrix(prog, "CameraMatrix")
	 , model_matrix(prog, "ModelMatrix")
	 , light_pos(prog, "LightPos")
	{
		gl.Bind(cube);

		gl.Bind(Buffer::Target::Array, verts);
		{
			std::vector<GLfloat> data;
			GLuint n_per_vertex = make_cube.Positions(data);
			gl.Current(Buffer::Target::Array).Data(data);
			VertexArrayAttrib attr(prog, "Position");
			attr.Setup<GLfloat>(n_per_vertex);
			attr.Enable();
		}

		gl.Bind(Buffer::Target::Array, normals);
		{
			std::vector<GLfloat> data;
			GLuint n_per_vertex = make_cube.Normals(data);
			gl.Current(Buffer::Target::Array).Data(data);
			VertexArrayAttrib attr(prog, "Normal");
			attr.Setup<GLfloat>(n_per_vertex);
			attr.Enable();
		}

		gl.Bind(Buffer::Target::Array, tangents);
		{
			std::vector<GLfloat> data;
			GLuint n_per_vertex = make_cube.Tangents(data);
			gl.Current(Buffer::Target::Array).Data(data);
			VertexArrayAttrib attr(prog, "Tangent");
			attr.Setup<GLfloat>(n_per_vertex);
			attr.Enable();
		}

		gl.Bind(Buffer::Target::Array, texcoords);
		{
			std::vector<GLfloat> data;
			GLuint n_per_vertex = make_cube.TexCoordinates(data);
			gl.Current(Buffer::Target::Array).Data(data);
			VertexArrayAttrib attr(prog, "TexCoord");
			attr.Setup<GLfloat>(n_per_vertex);
			attr.Enable();
		}

		// setup the textures
		{
			Texture::Active(0);
			UniformSampler(prog, "ColorTex").Set(0);

			gl.Bind(Texture::Target::_2D, colorTex);
			gl.Current(Texture::Target::_2D)
				.MinFilter(TextureMinFilter::LinearMipmapLinear)
				.MagFilter(TextureMagFilter::Linear)
				.WrapS(TextureWrap::Repeat)
				.WrapT(TextureWrap::Repeat)
				.Image2D(images::LoadTexture("wooden_crate"))
				.GenerateMipmap();
		}
		{
			Texture::Active(1);
			UniformSampler(prog, "NormalTex").Set(1);

			gl.Bind(Texture::Target::_2D, normalTex);
			gl.Current(Texture::Target::_2D)
				.MinFilter(TextureMinFilter::LinearMipmapLinear)
				.MagFilter(TextureMagFilter::Linear)
				.WrapS(TextureWrap::Repeat)
				.WrapT(TextureWrap::Repeat)
				.Image2D(
					images::NormalMap(
						images::LoadTexture("wooden_crate-hmap")
					)
				).GenerateMipmap();
		}
		//
		gl.ClearColor(0.1f, 0.1f, 0.1f, 0.0f);
		gl.ClearDepth(1.0f);
		gl.Enable(Capability::DepthTest);

		gl.Enable(Capability::CullFace);
		gl.FrontFace(make_cube.FaceWinding());
	}

void HSWDisplay::RenderInternal(ovrEyeType eye, const ovrTexture* eyeTexture)
{
    if(RenderEnabled && eyeTexture)
    {        
        // We need to render to the eyeTexture with the texture viewport.
        // Setup rendering to the texture.
        ovrGLTexture* eyeTextureGL = const_cast<ovrGLTexture*>(reinterpret_cast<const ovrGLTexture*>(eyeTexture));
        OVR_ASSERT(eyeTextureGL->Texture.Header.API == ovrRenderAPI_OpenGL);

        // We init a temporary Context, Bind our own context, then Bind the temporary context below before exiting.
        // It's more exensive to have a temp context copy made here instead of having it as a saved member variable,
        // but we can't have a saved member variable because the app might delete the saved member behind our back
        // or associate it with another thread, which would cause our bind of it before exiting to be a bad operation.
        Context currentGLContext; // To do: Change this to use the AutoContext class that was recently created.
        currentGLContext.InitFromCurrent();
        if(GLContext.GetIncarnation() == 0) // If not yet initialized...
            GLContext.CreateShared(currentGLContext);
        GLContext.Bind();
        #if defined(OVR_OS_MAC) // To consider: merge the following into the Bind function.
            GLContext.SetSurface(currentGLContext);
        #endif

        // Load the graphics if not loaded already.
        if (!pTexture)
            LoadGraphics();

        // Calculate ortho projection.
        GetOrthoProjection(RenderState, OrthoProjection);

        // Set the rendering to be to the eye texture.
        glBindFramebuffer(GL_FRAMEBUFFER, FrameBuffer);
        glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_TEXTURE_2D, eyeTextureGL->OGL.TexId, 0);
        glFramebufferRenderbuffer(GL_FRAMEBUFFER, GL_DEPTH_ATTACHMENT, GL_RENDERBUFFER, 0); // We aren't using depth, as we currently want this to overwrite everything.
        GLenum status = glCheckFramebufferStatus(GL_FRAMEBUFFER);
        OVR_ASSERT(status == GL_FRAMEBUFFER_COMPLETE); OVR_UNUSED(status);

        // Set up the viewport
        const GLint   x = (GLint)eyeTextureGL->Texture.Header.RenderViewport.Pos.x;
        const GLint   y = (GLint)eyeTextureGL->Texture.Header.RenderViewport.Pos.y; // Note that GL uses bottom-up coordinates.
        const GLsizei w = (GLsizei)eyeTextureGL->Texture.Header.RenderViewport.Size.w;
        const GLsizei h = (GLsizei)eyeTextureGL->Texture.Header.RenderViewport.Size.h;
        glViewport(x, y, w, h);

        // Set fixed-function render states.
        //glDepthRange(0.0,  1.0); // This is the default
        glDepthMask(GL_FALSE);
        glDisable(GL_DEPTH_TEST);
        glFrontFace(GL_CW);
        glEnable(GL_BLEND);
        glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);

        // Enable the buffer and shaders we use.
        ShaderFill fill(pShaderSet);
        if (pTexture)
            fill.SetTexture(0, pTexture);

        // Set shader uniforms.
        const float scale  = HSWDISPLAY_SCALE * ((RenderState.OurHMDInfo.HmdType == HmdType_DK1) ? 0.70f : 1.f);
        pShaderSet->SetUniform2f("Scale", scale, scale / 2.f); // X and Y scale. Y is a fixed proportion to X in order to give a certain aspect ratio.
        pShaderSet->SetUniform2f("PositionOffset", OrthoProjection[eye].GetTranslation().x, 0.0f);

        // Set vertex attributes
        if (GLVersionInfo.SupportsVAO)
        {
            OVR_ASSERT(VAO != 0);
            glBindVertexArray(VAO);
        }

        if(!VAOInitialized) // This executes for the case that VAO isn't supported.
        {
            glBindBuffer(GL_ARRAY_BUFFER, pVB->GLBuffer); // This must be called before glVertexAttribPointer is called below.

            const GLuint shaderProgram = pShaderSet->Prog;
            GLint attributeLocationArray[3];

            attributeLocationArray[0] = glGetAttribLocation(shaderProgram, "Position");
            glVertexAttribPointer(attributeLocationArray[0], sizeof(Vector3f)/sizeof(float), GL_FLOAT,         false, sizeof(HASWVertex), reinterpret_cast<char*>(offsetof(HASWVertex, Pos)));

            attributeLocationArray[1] = glGetAttribLocation(shaderProgram, "Color");
            glVertexAttribPointer(attributeLocationArray[1], sizeof(Color)/sizeof(uint8_t),  GL_UNSIGNED_BYTE,  true, sizeof(HASWVertex), reinterpret_cast<char*>(offsetof(HASWVertex, C)));  // True because we want it to convert [0,255] to [0,1] for us.

            attributeLocationArray[2] = glGetAttribLocation(shaderProgram, "TexCoord");
            glVertexAttribPointer(attributeLocationArray[2], sizeof(float[2])/sizeof(float), GL_FLOAT,         false, sizeof(HASWVertex), reinterpret_cast<char*>(offsetof(HASWVertex, U)));

            for (size_t i = 0; i < OVR_ARRAY_COUNT(attributeLocationArray); i++)
                glEnableVertexAttribArray((GLuint)i);
        }

        fill.Set(Prim_TriangleStrip);

        glDrawArrays(GL_TRIANGLE_STRIP, 0, 4);

        if (GLVersionInfo.SupportsVAO)
        {
            VAOInitialized = true;
            glBindVertexArray(0);
        }
        
        currentGLContext.Bind();
    }
//.........这里部分代码省略.........

	TorusExample(void)
	 : make_torus(1.0, 0.5, 72, 48)
	 , torus_instr(make_torus.Instructions())
	 , torus_indices(make_torus.Indices())
	 , projection_matrix(prog, "ProjectionMatrix")
	 , camera_matrix(prog, "CameraMatrix")
	 , model_matrix(prog, "ModelMatrix")
	{
		// Set the vertex shader source and compile it
		vs.Source(
			"#version 330\n"
			"uniform mat4 ProjectionMatrix, CameraMatrix, ModelMatrix;"
			"in vec4 Position;"
			"in vec3 Normal;"
			"in vec2 TexCoord;"
			"out vec3 vertNormal;"
			"out vec3 vertLight;"
			"out vec2 vertTexCoord;"
			"uniform vec3 LightPos;"
			"void main(void)"
			"{"
			"	gl_Position = ModelMatrix * Position;"
			"	vertNormal = mat3(ModelMatrix)*Normal;"
			"	vertLight = LightPos - gl_Position.xyz;"
			"	vertTexCoord = TexCoord;"
			"	gl_Position = ProjectionMatrix * CameraMatrix * gl_Position;"
			"}"
		).Compile();

		// set the fragment shader source and compile it
		fs.Source(
			"#version 330\n"
			"uniform sampler2D TexUnit;"
			"in vec3 vertNormal;"
			"in vec3 vertLight;"
			"in vec2 vertTexCoord;"
			"out vec4 fragColor;"
			"void main(void)"
			"{"
			"	float l = sqrt(length(vertLight));"
			"	float d = l > 0? dot("
			"		vertNormal, "
			"		normalize(vertLight)"
			"	) / l : 0.0;"
			"	float i = 0.2 + 3.2*max(d, 0.0);"
			"	fragColor = texture(TexUnit, vertTexCoord)*i;"
			"}"
		).Compile();

		// attach the shaders to the program
		prog.AttachShader(vs).AttachShader(fs);
		// link and use it
		prog.Link();
		gl.Use(prog);

		// bind the VAO for the torus
		gl.Bind(torus);

		// bind the VBO for the torus vertices
		gl.Bind(Buffer::Target::Array, verts);
		{
			std::vector<GLfloat> data;
			GLuint n_per_vertex = make_torus.Positions(data);
			// upload the data
			gl.Current(Buffer::Target::Array).Data(data);
			// setup the vertex attribs array for the vertices
			VertexArrayAttrib attr(prog, "Position");
			attr.Setup<GLfloat>(n_per_vertex);
			attr.Enable();
		}

		// bind the VBO for the torus normals
		gl.Bind(Buffer::Target::Array, normals);
		{
			std::vector<GLfloat> data;
			GLuint n_per_vertex = make_torus.Normals(data);
			// upload the data
			gl.Current(Buffer::Target::Array).Data(data);
			// setup the vertex attribs array for the vertices
			VertexArrayAttrib attr(prog, "Normal");
			attr.Setup<GLfloat>(n_per_vertex);
			attr.Enable();
		}

		// bind the VBO for the torus texture coordinates
		gl.Bind(Buffer::Target::Array, texcoords);
		{
			std::vector<GLfloat> data;
			GLuint n_per_vertex = make_torus.TexCoordinates(data);
			// upload the data
			gl.Current(Buffer::Target::Array).Data(data);
			// setup the vertex attribs array for the vertices
			VertexArrayAttrib attr(prog, "TexCoord");
			attr.Setup<GLfloat>(n_per_vertex);
			attr.Enable();
		}

		// setup the texture
		gl.Bind(Texture::Target::_2D, tex);
		{
//.........这里部分代码省略.........

	GlassExample(void)
	 : make_plane(Vec3f(2.0f, 0.0f, 0.0f), Vec3f(0.0f, 0.0f, -2.0f))
	 , plane_instr(make_plane.Instructions())
	 , plane_indices(make_plane.Indices())
	 , make_shape()
	 , shape_instr(make_shape.Instructions())
	 , shape_indices(make_shape.Indices())
	 , plane_vs(ObjectDesc("Plane vertex"))
	 , shape_vs(ObjectDesc("Shape vertex"))
	 , plane_fs(ObjectDesc("Plane fragment"))
	 , shape_fs(ObjectDesc("Shape fragment"))
	 , plane_proj_matrix(plane_prog)
	 , plane_camera_matrix(plane_prog)
	 , plane_model_matrix(plane_prog)
	 , shape_proj_matrix(shape_prog)
	 , shape_camera_matrix(shape_prog)
	 , shape_model_matrix(shape_prog)
	 , shape_clip_plane(shape_prog)
	 , shape_clip_direction(shape_prog)
	 , width(512)
	 , height(512)
	 , tex_side(512)
	{
		plane_vs.Source(
			"#version 140\n"
			"uniform vec3 LightPosition;"
			"uniform mat4 ProjectionMatrix, CameraMatrix, ModelMatrix;"
			"in vec4 Position;"
			"in vec2 TexCoord;"
			"out vec3 vertLightDir;"
			"out vec2 vertTexCoord;"
			"void main(void)"
			"{"
			"	gl_Position = "
			"		ModelMatrix* "
			"		Position;"
			"	vertLightDir = normalize("
			"		LightPosition - gl_Position.xyz"
			"	);"
			"	gl_Position = "
			"		ProjectionMatrix *"
			"		CameraMatrix *"
			"		gl_Position;"
			"	vertTexCoord = TexCoord;"
			"}"
		);
		plane_vs.Compile();

		plane_fs.Source(
			"#version 140\n"
			"uniform vec3 Normal;"
			"in vec3 vertLightDir;"
			"in vec2 vertTexCoord;"
			"out vec4 fragColor;"
			"void main(void)"
			"{"
			"	float checker = ("
			"		int(vertTexCoord.x*18) % 2+"
			"		int(vertTexCoord.y*18) % 2"
			"	) % 2;"
			"	vec3 color = mix("
			"		vec3(0.2, 0.4, 0.9),"
			"		vec3(0.2, 0.2, 0.7),"
			"		checker"
			"	);"
			"	float d = dot("
			"		Normal, "
			"		vertLightDir"
			"	);"
			"	float intensity = 0.5 + pow(1.4*d, 2.0);"
			"	fragColor = vec4(color*intensity, 1.0);"
			"}"
		);
		plane_fs.Compile();

		plane_prog.AttachShader(plane_vs);
		plane_prog.AttachShader(plane_fs);
		plane_prog.Link();
		plane_prog.Use();
		plane_proj_matrix.BindTo("ProjectionMatrix");
		plane_camera_matrix.BindTo("CameraMatrix");
		plane_model_matrix.BindTo("ModelMatrix");

		Vec3f lightPos(3.0f, 3.0f, 3.0f);
		Uniform<Vec3f>(plane_prog, "LightPosition").Set(lightPos);
		Uniform<Vec3f>(plane_prog, "Normal").Set(make_plane.Normal());

		gl.Bind(plane);

		gl.Bind(Buffer::Target::Array, plane_verts);
		{
			std::vector<GLfloat> data;
			GLuint n_per_vertex = make_plane.Positions(data);
			Buffer::Data(Buffer::Target::Array, data);
			VertexArrayAttrib attr(plane_prog, "Position");
			attr.Setup<GLfloat>(n_per_vertex);
			attr.Enable();
		}

		gl.Bind(Buffer::Target::Array, plane_texcoords);
//.........这里部分代码省略.........

	TorusExample(void)
	 : make_torus(1.0, 0.5, 18, 36)
	 , torus_instr(make_torus.Instructions())
	 , torus_indices(make_torus.Indices())
	 , transf_prog(make_transf_prog())
	 , face_prog(make_face_prog())
	 , frame_prog(make_frame_prog())
	 , projection_matrix(transf_prog, "ProjectionMatrix")
	 , camera_matrix(transf_prog, "CameraMatrix")
	 , model_matrix(transf_prog, "ModelMatrix")
	 , transf_time(transf_prog, "Time")
	{
		transf_prog.Use();
		torus.Bind();
		verts.Bind(Buffer::Target::Array);
		{
			std::vector<GLfloat> data;
			GLuint n_per_vertex = make_torus.Positions(data);
			Buffer::Data(Buffer::Target::Array, data);

			VertexArrayAttrib attr(transf_prog, "Position");
			attr.Setup<GLfloat>(n_per_vertex);
			attr.Enable();
		}

		normals.Bind(Buffer::Target::Array);
		{
			std::vector<GLfloat> data;
			GLuint n_per_vertex = make_torus.Normals(data);
			Buffer::Data(Buffer::Target::Array, data);

			VertexArrayAttrib attr(transf_prog, "Normal");
			attr.Setup<GLfloat>(n_per_vertex);
			attr.Enable();
		}

		texcoords.Bind(Buffer::Target::Array);
		{
			std::vector<GLfloat> data;
			GLuint n_per_vertex = make_torus.TexCoordinates(data);
			Buffer::Data(Buffer::Target::Array, data);

			VertexArrayAttrib attr(transf_prog, "TexCoord");
			attr.Setup<GLfloat>(n_per_vertex);
			attr.Enable();
		}

		face_pp.Bind();
		face_prog.Use();
		face_pp.UseStages(transf_prog).Vertex().Geometry();
		face_pp.UseStages(face_prog).Fragment();


		frame_pp.Bind();
		frame_prog.Use();
		frame_pp.UseStages(transf_prog).Vertex().Geometry();
		frame_pp.UseStages(frame_prog).Fragment();

		gl.Bind(NoProgramPipeline());
		gl.Use(NoProgram());

		gl.ClearColor(0.7f, 0.6f, 0.5f, 0.0f);
		gl.ClearDepth(1.0f);
		gl.Enable(Capability::DepthTest);
		gl.DepthFunc(CompareFn::Less);
		gl.FrontFace(make_torus.FaceWinding());
	}

    CubeExample()
      : cube_instr(make_cube.Instructions())
      , cube_indices(make_cube.Indices())
      , prog(make())
      , projection_matrix(prog, "ProjectionMatrix")
      , camera_matrix(prog, "CameraMatrix")
      , model_matrix(prog, "ModelMatrix")
      , light_pos(prog, "LightPos") {
        // bind the VAO for the cube
        gl.Bind(cube);

        gl.Bind(Buffer::Target::Array, verts);
        {
            std::vector<GLfloat> data;
            GLuint n_per_vertex = make_cube.Positions(data);
            Buffer::Data(Buffer::Target::Array, data);
            (prog | "Position").Setup<GLfloat>(n_per_vertex).Enable();
        }

        gl.Bind(Buffer::Target::Array, normals);
        {
            std::vector<GLfloat> data;
            GLuint n_per_vertex = make_cube.Normals(data);
            Buffer::Data(Buffer::Target::Array, data);
            (prog | "Normal").Setup<GLfloat>(n_per_vertex).Enable();
        }

        gl.Bind(Buffer::Target::Array, tangents);
        {
            std::vector<GLfloat> data;
            GLuint n_per_vertex = make_cube.Tangents(data);
            Buffer::Data(Buffer::Target::Array, data);
            (prog | "Tangent").Setup<GLfloat>(n_per_vertex).Enable();
        }

        gl.Bind(Buffer::Target::Array, texcoords);
        {
            std::vector<GLfloat> data;
            GLuint n_per_vertex = make_cube.TexCoordinates(data);
            Buffer::Data(Buffer::Target::Array, data);
            (prog | "TexCoord").Setup<GLfloat>(n_per_vertex).Enable();
        }

        {
            auto img = images::SphereBumpMap(512, 512, 2, 2);
            Uniform<GLsizei>(prog, "BumpTexWidth").Set(img.Width());
            Uniform<GLsizei>(prog, "BumpTexHeight").Set(img.Height());
            UniformSampler(prog, "BumpTex").Set(0);
            Texture::Active(0);

            gl.Bound(Texture::Target::_2D, bumpTex)
              .MinFilter(TextureMinFilter::LinearMipmapLinear)
              .MagFilter(TextureMagFilter::Linear)
              .WrapS(TextureWrap::Repeat)
              .WrapT(TextureWrap::Repeat)
              .Image2D(img)
              .GenerateMipmap();
        }
        //
        gl.ClearColor(0.1f, 0.1f, 0.1f, 0.0f);
        gl.ClearDepth(1.0f);
        gl.Enable(Capability::DepthTest);

        gl.Enable(Capability::CullFace);
        gl.FrontFace(make_cube.FaceWinding());
    }