/// <summary>
/// 创建相关资源
/// </summary>
/// <param name="gd"></param>
/// <param name="factory"></param>
public void CreateDeviceResources(GraphicsDevice gd, ResourceFactory factory)
{
List <Vector3> positions = new List <Vector3>();
//记录其indices
// List<ushort> indics = new List<ushort>();
//填充顶点跟索引
//详细流程，如果是投影坐标，将其转换成wgs84的经纬度坐标，再使用参考系计算出其真实的地理坐标
foreach (var coord in _feature.Geometry.Coordinates)
{
//将其转换成弧度制,自动贴地
positions.Add(_shape.ToVector3(new Geodetic3D(MathExtension.ToRadius(coord.X), MathExtension.ToRadius(coord.Y))));
}
//三角网化
var indices = EarClippingOnEllipsoid.Triangulate(positions);
//三角细分,细分精度为1度
_mesh = TriangleMeshSubdivision.Compute(positions, indices.ToArray(), Math.PI / 180);
_vertexBuffer = factory.CreateBuffer(new BufferDescription((uint)(12 * _mesh.Positions.Count()), BufferUsage.VertexBuffer));
gd.UpdateBuffer(_vertexBuffer, 0, _mesh.Positions);
_indexBuffer = factory.CreateBuffer(new BufferDescription((uint)(sizeof(ushort) * _mesh.Indices.Length), BufferUsage.IndexBuffer));
gd.UpdateBuffer(_indexBuffer, 0, _mesh.Indices);
ShaderSetDescription shaderSet = new ShaderSetDescription(
new[]
{
new VertexLayoutDescription(
new VertexElementDescription("Position", VertexElementSemantic.Position, VertexElementFormat.Float3))
},
new[]
{
ResourceHelper.LoadEmbbedShader(ShaderStages.Vertex, "GlobeVS.spv", gd),
ResourceHelper.LoadEmbbedShader(ShaderStages.Fragment, "GlobeFS.spv", gd)
});
_pipeline = factory.CreateGraphicsPipeline(new GraphicsPipelineDescription(
BlendStateDescription.SingleOverrideBlend,
DepthStencilStateDescription.DepthOnlyLessEqual,
RasterizerStateDescription.Default,
PrimitiveTopology.TriangleList,
shaderSet,
//共享View和prj的buffer
new ResourceLayout[] { ShareResource.ProjectionResourceLoyout },
gd.MainSwapchain.Framebuffer.OutputDescription));
_cl = factory.CreateCommandList();
}
public Polygon(Context context, Ellipsoid globeShape, IEnumerable <Vector3D> positions)
{
Verify.ThrowIfNull(context);
Verify.ThrowIfNull(globeShape);
//
// Pipeline Stage 1a: Clean up - Remove duplicate positions
//
List <Vector3D> cleanPositions = (List <Vector3D>)SimplePolygonAlgorithms.Cleanup(positions);
//
// Pipeline Stage 1b: Clean up - Swap winding order
//
EllipsoidTangentPlane plane = new EllipsoidTangentPlane(globeShape, cleanPositions);
ICollection <Vector2D> positionsOnPlane = plane.ComputePositionsOnPlane(cleanPositions);
if (SimplePolygonAlgorithms.ComputeWindingOrder(positionsOnPlane) == PolygonWindingOrder.Clockwise)
{
cleanPositions.Reverse();
//((List<Vector2D>)positionsOnPlane).Reverse();
}
//
// Pipeline Stage 2: Triangulate
//
IndicesUnsignedInt indices = EarClippingOnEllipsoid.Triangulate(cleanPositions);
//IndicesInt32 indices = EarClipping.Triangulate(positionsOnPlane);
//
// Pipeline Stage 3: Subdivide
//
TriangleMeshSubdivisionResult result = TriangleMeshSubdivision.Compute(cleanPositions, indices, Trig.ToRadians(1));
//
// Pipeline Stage 4: Set height
//
VertexAttributeDoubleVector3 positionsAttribute = new VertexAttributeDoubleVector3(
"position", (result.Indices.Values.Count / 3) + 2);
foreach (Vector3D position in result.Positions)
{
positionsAttribute.Values.Add(globeShape.ScaleToGeocentricSurface(position));
}
Mesh mesh = new Mesh();
mesh.PrimitiveType = PrimitiveType.Triangles;
mesh.FrontFaceWindingOrder = WindingOrder.Counterclockwise;
mesh.Attributes.Add(positionsAttribute);
mesh.Indices = result.Indices;
ShaderProgram sp = Device.CreateShaderProgram(
EmbeddedResources.GetText("OpenGlobe.Scene.Renderables.Polygon.Shaders.PolygonVS.glsl"),
EmbeddedResources.GetText("OpenGlobe.Scene.Renderables.Polygon.Shaders.PolygonFS.glsl"));
((Uniform <Vector3F>)sp.Uniforms["u_globeOneOverRadiiSquared"]).Value = globeShape.OneOverRadiiSquared.ToVector3F();
_colorUniform = (Uniform <Vector4F>)sp.Uniforms["u_color"];
_drawState = new DrawState();
_drawState.RenderState.Blending.Enabled = true;
_drawState.RenderState.Blending.SourceRGBFactor = SourceBlendingFactor.SourceAlpha;
_drawState.RenderState.Blending.SourceAlphaFactor = SourceBlendingFactor.SourceAlpha;
_drawState.RenderState.Blending.DestinationRGBFactor = DestinationBlendingFactor.OneMinusSourceAlpha;
_drawState.RenderState.Blending.DestinationAlphaFactor = DestinationBlendingFactor.OneMinusSourceAlpha;
_drawState.ShaderProgram = sp;
_meshBuffers = Device.CreateMeshBuffers(mesh, _drawState.ShaderProgram.VertexAttributes, BufferHint.StaticDraw);
_primitiveType = mesh.PrimitiveType;
Color = Color.White;
}