private void OnPaintingShapes(object sender, SKPaintSurfaceEventArgs e)
{
var surface = e.Surface;
var canvas = surface.Canvas;
// clear the surface
canvas.Clear(SKColors.White);
// get the radius of the screen
var radius = Math.Min(e.Info.Width / 2f, e.Info.Height / 2f);
// create the paint for a star
var starPaint = new SKPaint
{
IsAntialias = true,
Color = SKColors.Gold
};
// draw the star
canvas.DrawStar(e.Info.Width / 2f, e.Info.Height / 2f, radius * 0.4f, radius * 0.2f, 5, starPaint);
// create the paint for the pie
var piePaint = new SKPaint
{
IsAntialias = true,
Color = SKColors.Green
};
// calculate the pie
var piePath = SKGeometry.CreatePiePath(sectors, radius * 0.9f, radius * 0.5f, 6f);
// draw the pie
canvas.Translate(e.Info.Width / 2f, e.Info.Height / 2f);
canvas.DrawPath(piePath, piePaint);
}
public static void DrawStar(this SKCanvas canvas, float cx, float cy, float outerRadius, float innerRadius, int points, SKPaint paint)
{
var path = SKGeometry.CreateRegularStarPath(outerRadius, innerRadius, points);
path.Offset(cx, cy);
canvas.DrawPath(path, paint);
}
public static void DrawSquare(this SKCanvas canvas, float cx, float cy, float side, SKPaint paint)
{
var path = SKGeometry.CreateSquarePath(side);
path.Offset(cx, cy);
canvas.DrawPath(path, paint);
}
public static void DrawRegularPolygon(this SKCanvas canvas, float cx, float cy, float radius, int points, SKPaint paint)
{
var path = SKGeometry.CreateRegularPolygonPath(radius, points);
path.Offset(cx, cy);
canvas.DrawPath(path, paint);
}
public static void DrawTriangle(this SKCanvas canvas, float cx, float cy, float radius, SKPaint paint)
{
var path = SKGeometry.CreateTrianglePath(radius);
path.Offset(cx, cy);
canvas.DrawPath(path, paint);
}
public static void DrawRect(this SKCanvas canvas, float cx, float cy, float width, float height, SKPaint paint)
{
var path = SKGeometry.CreateRectanglePath(width, height);
path.Offset(cx, cy);
canvas.DrawPath(path, paint);
}
public void PerimeterCalculation()
{
var points = new[]
{
new SKPoint(10, 10),
new SKPoint(10, 40),
new SKPoint(50, 40),
};
var perimeter = SKGeometry.Perimeter(points);
Assert.AreEqual(120f, perimeter);
}
public void TriangleAreaCalculation()
{
var points = new[]
{
new SKPoint(10, 10),
new SKPoint(10, 20),
new SKPoint(20, 20),
};
var area = SKGeometry.Area(points);
Assert.AreEqual(50f, area);
}
public void CreateInterpolationReturnsOriginals()
{
var path1 = new SKPath();
var path2 = new SKPath();
var interpolated = SKGeometry.CreateInterpolation(path1, path2, -1);
Assert.AreEqual(path1, interpolated);
interpolated = SKGeometry.CreateInterpolation(path1, path2, 0);
Assert.AreEqual(path1, interpolated);
interpolated = SKGeometry.CreateInterpolation(path1, path2, 0.5f);
Assert.AreNotEqual(path1, interpolated);
Assert.AreNotEqual(path2, interpolated);
interpolated = SKGeometry.CreateInterpolation(path1, path2, 1);
Assert.AreEqual(path2, interpolated);
interpolated = SKGeometry.CreateInterpolation(path1, path2, 2);
Assert.AreEqual(path2, interpolated);
}
public void GeometryGeneratesRectPath()
{
var rectPath = SKGeometry.CreateTrianglePath(100);
Assert.AreEqual(3, rectPath.PointCount);
}
public void DistanceCalculation()
{
var dist = SKGeometry.Distance(new SKPoint(10, 10), new SKPoint(10, 40));
Assert.AreEqual(30f, dist);
}
protected override void OnDraw(SKCanvas canvas, SKPaint paint, float size)
{
using var star = SKGeometry.CreateRegularStarPath(size, size / 2, Points);
canvas.DrawPath(star, paint);
}
