void Render(double time)
	{
		gl.ClearDepth(0.0f);
		gl.Clear().DepthBuffer();

		auto camera =
			CamMatrixf::Orbiting(
				objects.BoundingSphere().Center(),
				objects.BoundingSphere().Radius()*2.8,
				FullCircles(time / 19.0),
				Degrees(SineWave(time / 17.0) * 90)
			);



		depth_prog.Use();
		gl.DepthFunc(CompareFn::Greater);
		gl.CullFace(Face::Front);
		depth_prog.camera_matrix.Set(camera);
		depth_prog.model_matrix.Set(Mat4f());
		objects.Draw();

		Texture::CopyImage2D(
			Texture::Target::Rectangle,
			0,
			PixelDataInternalFormat::DepthComponent,
			0, 0,
			width,
			height,
			0
		);

		gl.ClearDepth(1.0f);
		gl.Clear().ColorBuffer().DepthBuffer();

		draw_prog.Use();
		gl.DepthFunc(CompareFn::Less);
		gl.CullFace(Face::Back);
		draw_prog.camera_matrix.Set(camera);
		draw_prog.model_matrix.Set(Mat4f());

		objects.Draw();
	}
示例#2
0
	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());
	}
示例#3
0
	SketchExample(void)
	 : transf_prog()
	 , sketch_prog()
	 , plane(
		transf_prog,
		shapes::Plane(
			Vec3f(0, 0, 0),
			Vec3f(9, 0, 0),
			Vec3f(0, 0,-9),
			9, 9
		)
	), torus(transf_prog, shapes::WickerTorus())
	 , sketch_tex_layers(8)
	 , shadow_tex_side(1024)
	{

		NoProgram().Use();

		shadow_pp.Bind();
		shadow_pp.UseStages(transf_prog).Vertex();
		shadow_pp.UseStages(shadow_prog).Fragment();

		sketch_pp.Bind();
		sketch_pp.UseStages(transf_prog).Vertex();
		sketch_pp.UseStages(sketch_prog).Fragment();

		line_pp.Bind();
		line_pp.UseStages(transf_prog).Vertex();
		line_pp.UseStages(line_prog).Geometry().Fragment();

		Texture::Active(0);
		sketch_prog.sketch_tex.Set(0);
		{
			auto bound_tex = gl.Bound(Texture::Target::_3D, sketch_texture);

			for(GLuint i=0; i<sketch_tex_layers; ++i)
			{
				auto image = images::BrushedMetalUByte(
					512, 512,
					64 + i*128,
					-(2+i*4), +(2+i*4),
					64, 256-i*4
				);
				if(i == 0)
				{
					bound_tex.Image3D(
						0,
						PixelDataInternalFormat::RGB,
						image.Width(),
						image.Height(),
						sketch_tex_layers,
						0,
						image.Format(),
						image.Type(),
						nullptr
					);
				}
				bound_tex.SubImage3D(
					0,
					0, 0, i,
					image.Width(),
					image.Height(),
					1,
					image.Format(),
					image.Type(),
					image.RawData()
				);
			}
			bound_tex.GenerateMipmap();
			bound_tex.MinFilter(TextureMinFilter::LinearMipmapLinear);
			bound_tex.MagFilter(TextureMagFilter::Linear);
			bound_tex.WrapS(TextureWrap::Repeat);
			bound_tex.WrapT(TextureWrap::Repeat);
			bound_tex.WrapR(TextureWrap::ClampToEdge);
		}

		Texture::Active(1);
		sketch_prog.shadow_tex.Set(1);

		gl.Bound(Texture::Target::_2D, shadow_tex)
			.MinFilter(TextureMinFilter::Linear)
			.MagFilter(TextureMagFilter::Linear)
			.WrapS(TextureWrap::ClampToEdge)
			.WrapT(TextureWrap::ClampToEdge)
			.CompareMode(TextureCompareMode::CompareRefToTexture)
			.Image2D(
				0,
				PixelDataInternalFormat::DepthComponent32,
				shadow_tex_side, shadow_tex_side,
				0,
				PixelDataFormat::DepthComponent,
				PixelDataType::Float,
				nullptr
			);

		gl.Bound(Framebuffer::Target::Draw, frame_shadow_fbo)
			.AttachTexture(
				FramebufferAttachment::Depth,
				shadow_tex,
				0
			);

		gl.ClearDepth(1.0f);
		gl.Enable(Capability::DepthTest);
		gl.Enable(Capability::CullFace);

		gl.DepthFunc(CompareFn::LEqual);
		gl.BlendFunc(BlendFn::SrcAlpha, BlendFn::OneMinusSrcAlpha);

		gl.PolygonOffset(1.0, 1.0);
		gl.LineWidth(1.5);

	}
示例#4
0
	TorusExample(void)
	 : make_torus(1.0, 0.5, 18, 36)
	 , torus_instr(make_torus.Instructions())
	 , torus_indices(make_torus.Indices())
	 , vs(ObjectDesc("Vertex"))
	 , gs(ObjectDesc("Geometry"))
	 , face_fs(ObjectDesc("Face fragment"))
	 , frame_fs(ObjectDesc("Frame fragment"))
	 , transf_prog(ObjectDesc("Transformation"))
	 , face_prog(ObjectDesc("Face"))
	 , frame_prog(ObjectDesc("Frame"))
	 , projection_matrix(transf_prog, "ProjectionMatrix")
	 , camera_matrix(transf_prog, "CameraMatrix")
	 , model_matrix(transf_prog, "ModelMatrix")
	 , transf_time(transf_prog, "Time")
	{
		vs.Source(
			"#version 330\n"
			"uniform mat4 ModelMatrix;"
			"in vec4 Position;"
			"in vec3 Normal;"
			"in vec2 TexCoord;"
			"out gl_PerVertex {"
			"	vec4 gl_Position;"
			"};"
			"out vec3 vertNormal;"
			"out vec2 vertTexCoord;"
			"void main(void)"
			"{"
			"	gl_Position = ModelMatrix * Position;"
			"	vertNormal = (ModelMatrix*vec4(Normal,0.0)).xyz;"
			"	vertTexCoord = TexCoord;"
			"}"
		);
		vs.Compile();

		gs.Source(
			"#version 330\n"
			"layout(triangles) in;"
			"layout(triangle_strip, max_vertices = 15) out;"
			"uniform mat4 CameraMatrix, ProjectionMatrix;"
			"uniform vec3 LightPos;"
			"uniform float Time;"
			"in gl_PerVertex {"
			"	vec4 gl_Position;"
			"} gl_in[];"
			"in vec3 vertNormal[];"
			"in vec2 vertTexCoord[];"
			"out gl_PerVertex {"
			"	vec4 gl_Position;"
			"};"
			"out vec3 geomNormal;"
			"out vec3 geomLight;"
			"out float geomGlow;"
			"flat out int geomTop;"
			"void main(void)"
			"{"
			"	vec3 FaceNormal = normalize("
			"		vertNormal[0]+"
			"		vertNormal[1]+"
			"		vertNormal[2] "
			"	);"
			"	vec2 FaceCoord = 0.33333 * ("
			"		vertTexCoord[0]+"
			"		vertTexCoord[1]+"
			"		vertTexCoord[2] "
			"	);"
			"	float Offs = (sin((FaceCoord.s + Time/10.0)* 3.14 * 2.0 * 10)*0.5 + 0.5)*0.4;"
			"	Offs *= cos(FaceCoord.t * 3.1415 * 2.0)*0.5 + 0.51;"

			"	vec3 pos[3], norm[3];"
			"	for(int i=0; i!=3; ++i)"
			"		pos[i] = gl_in[i].gl_Position.xyz;"
			"	for(int i=0; i!=3; ++i)"
			"		norm[i] = cross("
			"			FaceNormal, "
			"			normalize(pos[(i+1)%3] - pos[i])"
			"		);"
			"	vec3 pofs = FaceNormal * Offs;"

			"	geomTop = 0;"
			"	for(int i=0; i!=3; ++i)"
			"	{"
			"		geomNormal = norm[i];"
			"		for(int j=0; j!=2; ++j)"
			"		{"
			"			vec3 tpos = pos[(i+j)%3];"
			"			geomLight = LightPos-tpos;"
			"			geomGlow = 1.0;"
			"			gl_Position = "
			"				ProjectionMatrix *"
			"				CameraMatrix *"
			"				vec4(tpos, 1.0);"
			"			EmitVertex();"
			"			geomGlow = 0.7;"
			"			geomLight = LightPos-tpos+pofs;"
			"			gl_Position = "
			"				ProjectionMatrix *"
			"				CameraMatrix *"
			"				vec4(tpos + pofs, 1.0);"
			"			EmitVertex();"
			"		}"
			"		EndPrimitive();"
			"	}"

			"	geomGlow = 0.0;"
			"	geomTop = 1;"
			"	for(int i=0; i!=3; ++i)"
			"	{"
			"		geomLight = LightPos - (pos[i]+pofs);"
			"		geomNormal = vertNormal[i];"
			"		gl_Position = "
			"			ProjectionMatrix *"
			"			CameraMatrix *"
			"			vec4(pos[i] + pofs, 1.0);"
			"		EmitVertex();"
			"	}"
			"	EndPrimitive();"
			"}"
		);
		gs.Compile();

		transf_prog.AttachShader(vs);
		transf_prog.AttachShader(gs);
		transf_prog.MakeSeparable();
		transf_prog.Link();
		transf_prog.Use();

		ProgramUniform<Vec3f>(transf_prog, "LightPos").Set(4, 4, -8);

		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);

			VertexAttribArray attr(transf_prog, "Position");
			attr.Setup(n_per_vertex, DataType::Float);
			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);

			VertexAttribArray attr(transf_prog, "Normal");
			attr.Setup(n_per_vertex, DataType::Float);
			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);

			VertexAttribArray attr(transf_prog, "TexCoord");
			attr.Setup(n_per_vertex, DataType::Float);
			attr.Enable();
		}

		face_fs.Source(
			"#version 330\n"
			"in vec3 geomNormal;"
			"in vec3 geomLight;"
			"in float geomGlow;"
			"flat in int geomTop;"
			"uniform vec3 TopColor, SideColor;"
			"const vec3 LightColor = vec3(1.0, 1.0, 1.0);"
			"out vec4 fragColor;"
			"void main(void)"
			"{"
			"	float d = max(dot("
			"		normalize(geomLight),"
			"		normalize(geomNormal)"
			"	), 0.0);"
			"	vec3 color;"
			"	if(geomTop != 0)"
			"	{"
			"		color = TopColor * d +"
			"			LightColor * pow(d, 8.0);"
			"	}"
			"	else"
			"	{"
			"		color = SideColor * geomGlow +"
			"			LightColor *"
			"			pow(d, 2.0) * 0.2;"
			"	}"
			"	fragColor = vec4(color, 1.0);"
			"}"
		);
		face_fs.Compile();

		face_prog.AttachShader(face_fs);
		face_prog.MakeSeparable();
		face_prog.Link();

		ProgramUniform<Vec3f>(face_prog, "TopColor").Set(0.2f, 0.2f, 0.2f);
		ProgramUniform<Vec3f>(face_prog, "SideColor").Set(0.9f, 0.9f, 0.2f);

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


		frame_fs.Source(
			"#version 330\n"
			"out vec4 fragColor;"
			"void main(void)"
			"{"
			"	fragColor = vec4(0.2, 0.1, 0.0, 1.0);"
			"}"
		);
		frame_fs.Compile();

		frame_prog.AttachShader(frame_fs);
		frame_prog.MakeSeparable();
		frame_prog.Link();

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

		ProgramPipeline::Unbind();
		Program::UseNone();

		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());
	}
示例#5
0
	DOFExample(const ExampleParams& params)
	 : face_instr(make_cube.Instructions())
	 , edge_instr(make_cube.EdgeInstructions())
	 , face_indices(make_cube.Indices())
	 , edge_indices(make_cube.EdgeIndices())
	 , cube_matrices(MakeCubeMatrices(100, 10.0))
	 , viewport_width(dof_prog, "ViewportWidth")
	 , viewport_height(dof_prog, "ViewportHeight")
	 , projection_matrix(main_prog, "ProjectionMatrix")
	 , camera_matrix(main_prog, "CameraMatrix")
	 , model_matrix(main_prog, "ModelMatrix")
	 , ambient_color(main_prog, "AmbientColor")
	 , diffuse_color(main_prog, "DiffuseColor")
	 , focus_depth(dof_prog, "FocusDepth")
	 , color_tex(Texture::Target::Rectangle)
	 , depth_tex(Texture::Target::Rectangle)
	 , width(800)
	 , height(600)
	{
		main_vs.Source(
			"#version 330\n"
			"uniform mat4 ProjectionMatrix, CameraMatrix, ModelMatrix;"
			"uniform vec3 LightPos;"
			"in vec4 Position;"
			"in vec3 Normal;"
			"out vec3 vertLightDir;"
			"out vec3 vertNormal;"
			"void main(void)"
			"{"
			"	gl_Position = ModelMatrix * Position;"
			"	vertLightDir = normalize(LightPos - gl_Position.xyz);"
			"	vertNormal = normalize(mat3(ModelMatrix)*Normal);"
			"	gl_Position = ProjectionMatrix * CameraMatrix * gl_Position;"
			"}"
		);
		// compile it
		main_vs.Compile();

		// set the fragment shader source
		main_fs.Source(
			"#version 330\n"
			"uniform vec3 AmbientColor, DiffuseColor;"
			"in vec3 vertLightDir;"
			"in vec3 vertNormal;"
			"out vec4 fragColor;"
			"void main(void)"
			"{"
			"	float d = max(dot(vertLightDir,vertNormal),0.0);"
			"	float e = sin("
			"		10.0*vertLightDir.x + "
			"		20.0*vertLightDir.y + "
			"		25.0*vertLightDir.z   "
			"	)*0.9;"
			"	fragColor = vec4("
			"		mix(AmbientColor, DiffuseColor, d+e),"
			"		1.0"
			"	);"
			"}"
		);
		// compile it
		main_fs.Compile();

		// attach the shaders to the program
		main_prog.AttachShader(main_vs);
		main_prog.AttachShader(main_fs);
		// link and use it
		main_prog.Link();
		main_prog.Use();

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

		// bind the VBO for the cube vertices
		positions.Bind(Buffer::Target::Array);
		{
			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
			VertexAttribArray attr(main_prog, "Position");
			attr.Setup<GLfloat>(n_per_vertex);
			attr.Enable();
		}

		// bind the VBO for the cube normals
		normals.Bind(Buffer::Target::Array);
		{
			std::vector<GLfloat> data;
			GLuint n_per_vertex = make_cube.Normals(data);
			Buffer::Data(Buffer::Target::Array, data);
			VertexAttribArray attr(main_prog, "Normal");
			attr.Setup<GLfloat>(n_per_vertex);
			attr.Enable();
		}

		Uniform<Vec3f>(main_prog, "LightPos").Set(30.0, 50.0, 20.0);

		dof_vs.Source(
			"#version 330\n"
			"uniform uint ViewportWidth, ViewportHeight;"
			"in vec4 Position;"
			"out vec2 vertTexCoord;"
			"void main(void)"
			"{"
			"	gl_Position = Position;"
			"	vertTexCoord = vec2("
			"		(Position.x*0.5 + 0.5)*ViewportWidth,"
			"		(Position.y*0.5 + 0.5)*ViewportHeight"
			"	);"
			"}"
		);
		dof_vs.Compile();

		dof_fs.Source(
			"#version 330\n"
			"uniform sampler2DRect ColorTex;"
			"uniform sampler2DRect DepthTex;"
			"uniform float FocusDepth;"
			"uniform uint SampleMult;"
			"in vec2 vertTexCoord;"
			"out vec4 fragColor;"
			"const float strength = 16.0;"
			"void main(void)"
			"{"
			"	float fragDepth = texture(DepthTex, vertTexCoord).r;"
			"	vec3 color = texture(ColorTex, vertTexCoord).rgb;"
			"	float of = abs(fragDepth - FocusDepth);"
			"	int nsam = int(of*SampleMult);"
			"	float inv_nsam = 1.0 / (1.0 + nsam);"
			"	float astep = (3.14151*4.0)/nsam;"
			"	for(int i=0; i!=nsam; ++i)"
			"	{"
			"		float a = i*astep;"
			"		float d = sqrt(i*inv_nsam);"
			"		float sx = cos(a)*of*strength*d;"
			"		float sy = sin(a)*of*strength*d;"
			"		vec2 samTexCoord = vertTexCoord + vec2(sx, sy) + noise2(vec2(sx, sy));"
			"		color += texture(ColorTex, samTexCoord).rgb;"
			"	}"
			"	fragColor = vec4(color * inv_nsam , 1.0);"
			"}"
		);
		dof_fs.Compile();

		dof_prog.AttachShader(dof_vs);
		dof_prog.AttachShader(dof_fs);
		dof_prog.Link();
		dof_prog.Use();

		GLuint sample_mult = params.HighQuality()?512:128;
		Uniform<GLuint>(dof_prog, "SampleMult") = sample_mult;

		// bind the VAO for the screen
		screen.Bind();

		corners.Bind(Buffer::Target::Array);
		{
			GLfloat screen_verts[8] = {
				-1.0f, -1.0f,
				-1.0f,  1.0f,
				 1.0f, -1.0f,
				 1.0f,  1.0f
			};
			Buffer::Data(Buffer::Target::Array, 8, screen_verts);
			VertexAttribArray attr(dof_prog, "Position");
			attr.Setup<Vec2f>();
			attr.Enable();
		}

		Texture::Active(0);
		UniformSampler(dof_prog, "ColorTex").Set(0);
		{
			auto bound_tex = Bind(color_tex, Texture::Target::Rectangle);
			bound_tex.MinFilter(TextureMinFilter::Linear);
			bound_tex.MagFilter(TextureMagFilter::Linear);
			bound_tex.WrapS(TextureWrap::ClampToEdge);
			bound_tex.WrapT(TextureWrap::ClampToEdge);
			bound_tex.Image2D(
				0,
				PixelDataInternalFormat::RGB,
				width, height,
				0,
				PixelDataFormat::RGB,
				PixelDataType::UnsignedByte,
				nullptr
			);
		}

		Texture::Active(1);
		UniformSampler(dof_prog, "DepthTex").Set(1);
		{
			auto bound_tex = Bind(depth_tex, Texture::Target::Rectangle);
			bound_tex.MinFilter(TextureMinFilter::Linear);
			bound_tex.MagFilter(TextureMagFilter::Linear);
			bound_tex.WrapS(TextureWrap::ClampToEdge);
			bound_tex.WrapT(TextureWrap::ClampToEdge);
			bound_tex.Image2D(
				0,
				PixelDataInternalFormat::DepthComponent,
				width, height,
				0,
				PixelDataFormat::DepthComponent,
				PixelDataType::Float,
				nullptr
			);
		}

		{
			auto bound_fbo = Bind(
				fbo,
				Framebuffer::Target::Draw
			);
			bound_fbo.AttachTexture(
				FramebufferAttachment::Color,
				color_tex,
				0
			);
			bound_fbo.AttachTexture(
				FramebufferAttachment::Depth,
				depth_tex,
				0
			);
		}

		//
		gl.ClearColor(0.9f, 0.9f, 0.9f, 0.0f);
		gl.ClearDepth(1.0f);
		gl.Enable(Capability::DepthTest);
		gl.DepthFunc(CompareFn::LEqual);
		gl.Enable(Capability::LineSmooth);
		gl.BlendFunc(BlendFn::SrcAlpha, BlendFn::OneMinusSrcAlpha);
	}
示例#6
0
	TorusExample(void)
	 : make_torus(1.0, 0.5, 12, 12)
	 , torus_instr(make_torus.Instructions())
	 , torus_indices(make_torus.Indices())
	 , projection_matrix(prog, "ProjectionMatrix")
	 , camera_matrix(prog, "CameraMatrix")
	 , model_matrix(prog, "ModelMatrix")
	 , light_pos_cam(prog, "LightPosCam")
	 , front_color(prog, "FrontColor")
	 , back_color(prog, "BackColor")
	{
		vs.Source(
			"#version 330\n"
			"uniform mat4 ModelMatrix, CameraMatrix;"
			"in vec4 Position;"
			"void main(void)"
			"{"
			"	gl_Position = CameraMatrix *"
			"		ModelMatrix * Position;"
			"}"
		);
		vs.Compile();

		gs.Source(
			"#version 330\n"
			"layout(triangles) in;"
			"layout(triangle_strip, max_vertices = 8) out;"
			"uniform mat4 ProjectionMatrix;"
			"uniform vec4 LightPosCam;"
			"out vec3 geomLightDir;"
			"out float geomOpacity;"
			"void main(void)"
			"{"
			"	vec4 c = vec4(("
			"		gl_in[0].gl_Position.xyz+"
			"		gl_in[1].gl_Position.xyz+"
			"		gl_in[2].gl_Position.xyz "
			"	) * 0.333333, 1.0);"
			"	for(int v = 0; v != 4; ++v)"
			"	{"
			"		vec4 b = gl_in[v%3].gl_Position;"
			"		vec4 a = vec4("
			"			b.xyz + (c.xyz - b.xyz)*0.3,"
			"			1.0"
			"		);"

			"		gl_Position = ProjectionMatrix * a;"
			"		geomLightDir = (LightPosCam - a).xyz;"
			"		geomOpacity = 1.0;"
			"		EmitVertex();"
			"		gl_Position = ProjectionMatrix * b;"
			"		geomLightDir = (LightPosCam - b).xyz;"
			"		geomOpacity = 0.0;"
			"		EmitVertex();"
			"	}"
			"	EndPrimitive();"
			"}"
		);
		gs.Compile();

		fs.Source(
			"#version 330\n"
			"in vec3 geomLightDir;"
			"in float geomOpacity;"
			"uniform vec3 FrontColor, BackColor;"
			"out vec4 fragColor;"
			"void main(void)"
			"{"
			"	float l = length(geomLightDir);"
			"	vec3 color = gl_FrontFacing?"
			"		FrontColor:"
			"		BackColor;"
			"	fragColor = vec4(color*(4.0/l), geomOpacity);"
			"}"
		);
		fs.Compile();

		prog.AttachShader(vs);
		prog.AttachShader(gs);
		prog.AttachShader(fs);
		prog.Link();

		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);

			prog.Use();
			VertexAttribArray attr(prog, "Position");
			attr.Setup(n_per_vertex, DataType::Float);
			attr.Enable();
		}

		gl.ClearColor(0.8f, 0.7f, 0.6f, 0.0f);
		gl.ClearDepth(1.0f);
		gl.Enable(Capability::DepthTest);
		gl.DepthFunc(CompareFn::LEqual);
		gl.FrontFace(make_torus.FaceWinding());
	}