public void WindingOrderOnEllipsoid()
{
IList <Vector3D> positions = new List <Vector3D>();
positions.Add(Ellipsoid.UnitSphere.ToVector3D(Trig.ToRadians(new Geodetic3D(0, 0))));
positions.Add(Ellipsoid.UnitSphere.ToVector3D(Trig.ToRadians(new Geodetic3D(1, 0))));
positions.Add(Ellipsoid.UnitSphere.ToVector3D(Trig.ToRadians(new Geodetic3D(1, 1))));
EllipsoidTangentPlane plane = new EllipsoidTangentPlane(Ellipsoid.UnitSphere, positions);
ICollection <Vector2D> positionsOnPlane = plane.ComputePositionsOnPlane(positions);
Assert.AreEqual(PolygonWindingOrder.Counterclockwise, SimplePolygonAlgorithms.ComputeWindingOrder(positionsOnPlane));
}
public void WindingOrderOnEllipsoid2()
{
IList<Vector3D> positions = new List<Vector3D>();
positions.Add(Ellipsoid.UnitSphere.ToVector3D(Trig.ToRadians(new Geodetic3D(1, 1))));
positions.Add(Ellipsoid.UnitSphere.ToVector3D(Trig.ToRadians(new Geodetic3D(1, 0))));
positions.Add(Ellipsoid.UnitSphere.ToVector3D(Trig.ToRadians(new Geodetic3D(0, 0))));
EllipsoidTangentPlane plane = new EllipsoidTangentPlane(Ellipsoid.UnitSphere, positions);
ICollection<Vector2D> positionsOnPlane = plane.ComputePositionsOnPlane(positions);
Assert.AreEqual(PolygonWindingOrder.Clockwise, SimplePolygonAlgorithms.ComputeWindingOrder(positionsOnPlane));
}
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;
}
