void EnsureMesh(ICanvasResourceCreator resourceCreator)
{
if (gradientMesh != null)
{
return;
}
CanvasGradientMeshPatch[] patchArray = new CanvasGradientMeshPatch[patchPoints.Count];
for (int i = 0; i < patchPoints.Count; ++i)
{
CanvasGradientMeshPatch patch;
var points = patchPoints[i];
var colors = new Vector4[] { Color00.Color, Color03.Color, Color30.Color, Color33.Color };
var edges = new CanvasGradientMeshPatchEdge[] { Edge00To03, Edge03To33, Edge33To30, Edge30To00 };
if (patchPoints[i].Length == 12)
{
patch = CanvasGradientMesh.CreateCoonsPatch(points, colors, edges);
}
else
{
Debug.Assert(patchPoints[i].Length == 16);
patch = CanvasGradientMesh.CreateTensorPatch(points, colors, edges);
}
patchArray[i] = patch;
}
// Gradient meshes are allowed to be zero-sized, so there is no need to
// account for zero here.
gradientMesh = new CanvasGradientMesh(resourceCreator, patchArray);
}
void DrawControlLines(CanvasDrawingSession drawingSession)
{
CanvasGradientMeshPatch[] patches = gradientMesh.Patches;
for (int i = 0; i < patchPoints.Count; ++i)
{
var pointArray = patchPoints[i];
foreach (Vector2 point in pointArray)
{
drawingSession.FillCircle(point, 7, Colors.White);
}
CanvasGradientMeshPatch patch = patches[i];
bool showInterior = patchPoints[i].Length == 16;
DrawBezier(drawingSession, patch.Point00, patch.Point01, patch.Point02, patch.Point03);
DrawBezier(drawingSession, patch.Point03, patch.Point13, patch.Point23, patch.Point33);
DrawBezier(drawingSession, patch.Point00, patch.Point10, patch.Point20, patch.Point30);
DrawBezier(drawingSession, patch.Point30, patch.Point31, patch.Point32, patch.Point33);
if (showInterior)
{
DrawBezier(drawingSession, patch.Point10, patch.Point11, patch.Point12, patch.Point13);
DrawBezier(drawingSession, patch.Point20, patch.Point21, patch.Point22, patch.Point23);
DrawBezier(drawingSession, patch.Point01, patch.Point11, patch.Point21, patch.Point31);
DrawBezier(drawingSession, patch.Point02, patch.Point12, patch.Point22, patch.Point32);
}
drawingSession.DrawLine(patch.Point00, patch.Point01, Colors.White);
drawingSession.DrawLine(patch.Point02, patch.Point03, Colors.White);
drawingSession.DrawLine(patch.Point03, patch.Point13, Colors.White);
drawingSession.DrawLine(patch.Point23, patch.Point33, Colors.White);
drawingSession.DrawLine(patch.Point33, patch.Point32, Colors.White);
drawingSession.DrawLine(patch.Point31, patch.Point30, Colors.White);
drawingSession.DrawLine(patch.Point30, patch.Point20, Colors.White);
drawingSession.DrawLine(patch.Point10, patch.Point00, Colors.White);
if (showInterior)
{
drawingSession.DrawLine(patch.Point01, patch.Point11, Colors.White);
drawingSession.DrawLine(patch.Point21, patch.Point31, Colors.White);
drawingSession.DrawLine(patch.Point02, patch.Point12, Colors.White);
drawingSession.DrawLine(patch.Point22, patch.Point32, Colors.White);
drawingSession.DrawLine(patch.Point10, patch.Point11, Colors.White);
drawingSession.DrawLine(patch.Point12, patch.Point13, Colors.White);
drawingSession.DrawLine(patch.Point20, patch.Point21, Colors.White);
drawingSession.DrawLine(patch.Point22, patch.Point23, Colors.White);
}
}
}