private void DrawPathCContent(SKCanvas canvas)
{
canvas.Save();
GetPathA((float)Width, (float)Height);
_region.SetRect(ToSKRectI(canvas.LocalClipBounds));
ClipRegion(_region, _pathA);
ClipRegion(_region, GetPathC(), SKRegionOperation.ReverseDifference);
canvas.ClipRegion(_region);
canvas.DrawColor(SKColors.Green);
canvas.Restore();
}
void DisplayClipOp(SKCanvas canvas, SKRect rect, SKRegionOperation regionOp)
{
float textSize = textPaint.TextSize;
canvas.DrawText(regionOp.ToString(), rect.MidX, rect.Top + textSize, textPaint);
rect.Top += textSize;
float radius = 0.9f * Math.Min(rect.Width / 3, rect.Height / 2);
float xCenter = rect.MidX;
float yCenter = rect.MidY;
SKRectI recti = new SKRectI((int)rect.Left, (int)rect.Top,
(int)rect.Right, (int)rect.Bottom);
using (SKRegion wholeRectRegion = new SKRegion())
{
wholeRectRegion.SetRect(recti);
using (SKRegion region1 = new SKRegion(wholeRectRegion))
using (SKRegion region2 = new SKRegion(wholeRectRegion))
{
using (SKPath path1 = new SKPath())
{
path1.AddCircle(xCenter - radius / 2, yCenter, radius);
region1.SetPath(path1);
}
using (SKPath path2 = new SKPath())
{
path2.AddCircle(xCenter + radius / 2, yCenter, radius);
region2.SetPath(path2);
}
region1.Op(region2, regionOp);
canvas.Save();
canvas.ClipRegion(region1);
canvas.DrawPaint(fillPaint);
canvas.Restore();
}
}
}
void OnCanvasViewPaintSurface(object sender, SKPaintSurfaceEventArgs args)
{
SKImageInfo info = args.Info;
SKSurface surface = args.Surface;
SKCanvas canvas = surface.Canvas;
canvas.Clear();
float xCenter = info.Width / 2;
float yCenter = info.Height / 2;
float radius = 0.24f * Math.Min(info.Width, info.Height);
using (SKRegion wholeScreenRegion = new SKRegion())
{
wholeScreenRegion.SetRect(new SKRectI(0, 0, info.Width, info.Height));
using (SKRegion leftRegion = new SKRegion(wholeScreenRegion))
using (SKRegion rightRegion = new SKRegion(wholeScreenRegion))
using (SKRegion topRegion = new SKRegion(wholeScreenRegion))
using (SKRegion bottomRegion = new SKRegion(wholeScreenRegion))
{
using (SKPath circlePath = new SKPath())
{
// Make basic circle path
circlePath.AddCircle(xCenter, yCenter, radius);
// Left leaf
circlePath.Transform(SKMatrix.MakeTranslation(-radius, 0));
leftRegion.SetPath(circlePath);
// Right leaf
circlePath.Transform(SKMatrix.MakeTranslation(2 * radius, 0));
rightRegion.SetPath(circlePath);
// Make union of right with left
leftRegion.Op(rightRegion, SKRegionOperation.Union);
// Top leaf
circlePath.Transform(SKMatrix.MakeTranslation(-radius, -radius));
topRegion.SetPath(circlePath);
// Combine with bottom leaf
circlePath.Transform(SKMatrix.MakeTranslation(0, 2 * radius));
bottomRegion.SetPath(circlePath);
// Make union of top with bottom
bottomRegion.Op(topRegion, SKRegionOperation.Union);
// Exclusive-OR left and right with top and bottom
leftRegion.Op(bottomRegion, SKRegionOperation.XOR);
// Set that as clip region
canvas.ClipRegion(leftRegion);
// Set transform for drawing lines from center
canvas.Translate(xCenter, yCenter);
// Draw 360 lines
for (double angle = 0; angle < 360; angle++)
{
float x = 2 * radius * (float)Math.Cos(Math.PI * angle / 180);
float y = 2 * radius * (float)Math.Sin(Math.PI * angle / 180);
using (SKPaint strokePaint = new SKPaint())
{
strokePaint.Color = SKColors.Green;
strokePaint.StrokeWidth = 2;
canvas.DrawLine(0, 0, x, y, strokePaint);
}
}
}
}
}
}
