void DrawArc(SKCanvas canvas, SKPaint paint, double startAngleInDegrees, double endAngleInDegrees)
{
// find center and radius
var centerx = (float)Bounds.Width / 2;
var centery = (float)Bounds.Height / 2;
var radius = Bounds.Width < Bounds.Height ? (float)Bounds.Width / 2 : (float)Bounds.Height / 2;
var w = 0.558f;
// convert degrees to radians
var startAngleRadians = startAngleInDegrees * Math.PI / 180;
var endAngleRadians = endAngleInDegrees * Math.PI / 180;
// find x,y coordinates for start and end points
var startx = centerx + radius * (float)Math.Cos(startAngleRadians);
var starty = centery + radius * (float)Math.Sin(startAngleRadians);
var startPoint = new SKPoint(startx, starty);
var endx = centerx + radius * (float)Math.Cos(endAngleRadians);
var endy = centery + radius * (float)Math.Sin(endAngleRadians);
var endPoint = new SKPoint(endx, endy);
// find linear distance & midpoint between start and end points
var linearDistance = Math.Sqrt(Math.Pow(endy - starty, 2) / Math.Pow(endx - startx, 2));
var midx = (startx + endx) / 2;
var midy = (starty + endy) / 2;
var midPoint = new SKPoint(midx, midy);
// rotate end point 45 degrees counterclockwise around midpoint to find Conic function anchor
var anchorPoint = RotatePoint(endPoint, midPoint, 45);
// build path
var path = new SKPath();
//path.MoveTo (startx, starty);
//path.ConicTo (anchorPoint.X, anchorPoint.Y, endx, endy, w);
path.MoveTo(centerx, centery - radius);
path.ConicTo(centerx + radius, centery - radius, centerx + radius, centery, w);
path.ConicTo(centerx + radius, centery + radius, centerx, centery + radius, w);
path.ConicTo(centerx - radius, centery + radius, centerx - radius, centery, w);
//path.ConicTo (centerx - radius, centery - radius, centerx, centery - radius, w);
//canvas.DrawPoints (SKPointMode.Points, new SKPoint [] { }, paint);
canvas.DrawPath(path, paint);
}
void OnCanvasViewPaintSurface(object sender, SKPaintSurfaceEventArgs args)
{
SKImageInfo info = args.Info;
SKSurface surface = args.Surface;
SKCanvas canvas = surface.Canvas;
canvas.Clear();
// Draw path with conic curve
using (SKPath path = new SKPath())
{
path.MoveTo(touchPoints[0].Center);
path.ConicTo(touchPoints[1].Center,
touchPoints[2].Center,
(float)weightSlider.Value);
canvas.DrawPath(path, strokePaint);
}
// Draw tangent lines
canvas.DrawLine(touchPoints[0].Center.X,
touchPoints[0].Center.Y,
touchPoints[1].Center.X,
touchPoints[1].Center.Y, dottedStrokePaint);
canvas.DrawLine(touchPoints[1].Center.X,
touchPoints[1].Center.Y,
touchPoints[2].Center.X,
touchPoints[2].Center.Y, dottedStrokePaint);
foreach (TouchPoint touchPoint in touchPoints)
{
touchPoint.Paint(canvas);
}
}
internal static void AddConic(IToolContext context, ConicShape conic, double dx, double dy, SKPath geometry)
{
geometry.MoveTo(ToSKPoint(conic.StartPoint, dx, dy));
geometry.ConicTo(
ToSKPoint(conic.Point1, dx, dy),
ToSKPoint(conic.Point2, dx, dy),
(float)conic.Weight);
}
/// <summary>
/// Draws layout entities.
/// </summary>
/// <param name="State">Current drawing state.</param>
/// <param name="PathState">Current path state.</param>
/// <param name="Path">Path being generated.</param>
public override void Draw(DrawingState State, PathState PathState, SKPath Path)
{
if (this.defined)
{
this.P0 = Path.LastPoint;
this.P1 = PathState.Add(this.xCoordinate, this.yCoordinate);
this.P2 = PathState.Add(this.xCoordinate2, this.yCoordinate2);
Path.ConicTo(this.P1, this.P2, this.weight);
}
}
/// <summary>
/// Draws layout entities.
/// </summary>
/// <param name="State">Current drawing state.</param>
/// <param name="PathState">Current path state.</param>
/// <param name="Path">Path being generated.</param>
public virtual void Draw(DrawingState State, PathState PathState, SKPath Path)
{
if (this.defined)
{
this.P0 = Path.LastPoint;
this.P1 = new SKPoint(this.xCoordinate, this.yCoordinate);
this.P2 = new SKPoint(this.xCoordinate2, this.yCoordinate2);
PathState.Set(this.xCoordinate, this.yCoordinate);
PathState.Set(this.xCoordinate2, this.yCoordinate2);
Path.ConicTo(this.P1, this.P2, this.weight);
}
}
private static SKPath CreatePath(float curveStart, float curveEnd, float width)
{
SKPath path = new SKPath();
SKPoint point0 = new SKPoint(0, curveStart);
SKPoint point1 = new SKPoint(width / 2, curveEnd);
SKPoint point2 = new SKPoint(width, curveStart);
path.MoveTo(0, 0);
path.LineTo(point0);
path.ConicTo(point1, point2, (float).5);
path.LineTo(width, 0);
path.LineTo(0, 0);
path.Close();
return(path);
}
void OnCanvasViewPaintSurface(object sender, SKPaintSurfaceEventArgs args)
{
SKImageInfo info = args.Info;
SKSurface surface = args.Surface;
SKCanvas canvas = surface.Canvas;
canvas.Clear();
// Translate to center
canvas.Translate(info.Width / 2, info.Height / 2);
// Draw the circle
float radius = Math.Min(info.Width, info.Height) / 4;
canvas.DrawCircle(0, 0, radius, blackStroke);
// Get the value of the Slider
float angle = (float)angleSlider.Value;
// Calculate sin and cosine for half that angle
float sin = (float)Math.Sin(Math.PI * angle / 180 / 2);
float cos = (float)Math.Cos(Math.PI * angle / 180 / 2);
// Find the points and weight
SKPoint point0 = new SKPoint(-radius * sin, radius * cos);
SKPoint point1 = new SKPoint(0, radius / cos);
SKPoint point2 = new SKPoint(radius * sin, radius * cos);
float weight = cos;
// Draw the points
canvas.DrawCircle(point0.X, point0.Y, 10, blackFill);
canvas.DrawCircle(point1.X, point1.Y, 10, blackFill);
canvas.DrawCircle(point2.X, point2.Y, 10, blackFill);
// Draw the tangent lines
canvas.DrawLine(point0.X, point0.Y, point1.X, point1.Y, dottedStroke);
canvas.DrawLine(point2.X, point2.Y, point1.X, point1.Y, dottedStroke);
// Draw the conic
using (SKPath path = new SKPath())
{
path.MoveTo(point0);
path.ConicTo(point1, point2, weight);
canvas.DrawPath(path, redStroke);
}
}
void OnCanvasViewPaintSurface(object sender, SKPaintSurfaceEventArgs args)
{
SKImageInfo info = args.Info;
SKSurface surface = args.Surface;
SKCanvas canvas = surface.Canvas;
float densityMultiplier = args.Info.Height / (float)SkiaCanvas.Height;
float pixelHeight = currentHeaderHeight * densityMultiplier;
float pullPoint = minHeaderHeight * densityMultiplier;
canvas.Clear();
SKPath path = new SKPath();
SKPoint point0 = new SKPoint(0, pixelHeight);
SKPoint point1 = new SKPoint(args.Info.Width / 2, pullPoint);
SKPoint point2 = new SKPoint(args.Info.Width, pixelHeight);
path.MoveTo(0, 0);
path.LineTo(point0);
path.ConicTo(point1, point2, (float)weightSlider.Value);
path.LineTo(args.Info.Width, 0);
path.LineTo(0, 0);
path.Close();
canvas.ClipPath(path, antialias: true);
using (SKPaint paint = new SKPaint())
{
// Create bitmap tiling
paint.Shader = SKShader.CreateBitmap(resourceBitmap,
SKShaderTileMode.Repeat,
SKShaderTileMode.Repeat);
// Draw background
canvas.DrawRect(info.Rect, paint);
}
//SKRect dest = new SKRect(0, 0, info.Width, info.Height);
//canvas.DrawBitmap(resourceBitmap, dest, BitmapStretch.AspectFill, BitmapAlignment.Start, BitmapAlignment.Start);
}
protected override void OnPaintSurface(SKPaintSurfaceEventArgs e)
{
base.OnPaintSurface(e);
SKRect skRect = new SKRect(e.Info.Rect.Left, e.Info.Rect.Top, e.Info.Rect.Right, e.Info.Rect.Bottom);
SKSurface surface = e.Surface;
SKCanvas canvas = surface.Canvas;
canvas.Clear(myBackgroundColor);
SKPaint paint = new SKPaint
{
Style = SKPaintStyle.Fill,
TextSize = 28,
StrokeWidth = ChartWidth,
IsAntialias = true
};
SKPaint paintAxis = new SKPaint
{
Style = SKPaintStyle.Fill,
TextSize = 14,
StrokeWidth = LineWidth,
IsAntialias = true,
Color = myColorText
};
SKPaint paintLinesAxis = new SKPaint
{
Style = SKPaintStyle.Fill,
TextSize = 14,
StrokeWidth = LineWidth,
IsAntialias = true,
Color = myColorAxis,
StrokeCap = SKStrokeCap.Round,
PathEffect = SKPathEffect.CreateDash(new[] { 2f, 6f }, 0)
};
//paint.Style = SKPaintStyle.Stroke;
paint.Color = myColorAxis;
// title
//SKPoint ptTitle=new SKPoint(leftMargin,topMargin);
//canvas.DrawText(myTitle, ptTitle, paint);
using (var paintTitle = new SKPaint())
{
paintTitle.TextSize = 24.0f;
paintTitle.IsAntialias = true;
paintTitle.Color = myColorTitle;
paintTitle.IsStroke = true;
paintTitle.StrokeWidth = 1;
paintTitle.TextAlign = SKTextAlign.Center;
canvas.DrawText(myTitle, e.Info.Width / 2f, topMargin, paintTitle);
}
//Y Axis
SKPoint ptAxis = new SKPoint(leftMargin + 2, topMargin);
canvas.DrawText(myTitleY, ptAxis, paintAxis);
// Y Axis
ptAxis = new SKPoint(skRect.Right - rightMargin, skRect.Bottom - bottomMargin);
canvas.DrawText(myTitleX, ptAxis, paintAxis);
// draw axis
SKPoint pt1 = new SKPoint(skRect.Left + leftMargin, skRect.Bottom - bottomMargin);
SKPoint pt2 = new SKPoint(skRect.Right - rightMargin, skRect.Bottom - bottomMargin);
canvas.DrawLine(pt1, pt2, paintAxis);
pt1 = new SKPoint(skRect.Left + leftMargin, skRect.Bottom - bottomMargin);
pt2 = new SKPoint(skRect.Left + leftMargin, skRect.Top - topMargin);
canvas.DrawLine(pt1, pt2, paintAxis);
List <SKPoint> pointList = new List <SKPoint>();
if (timeSeries.Count > 0)
{
float onex = (skRect.Width - leftMargin - rightMargin) / timeSeries.Count;
float oney = (skRect.Height - topMargin - bottomMargin) / timeSeries.Max;
for (float st = 0; st < this.timeSeries.Max; st += stepY)
{
ptAxis = new SKPoint(skRect.Left + leftMargin + 4, skRect.Bottom - bottomMargin - st * oney);
if (st > 0)
{
SKPoint ptLine = new SKPoint(skRect.Right - rightMargin, skRect.Bottom - bottomMargin - st * oney);
canvas.DrawLine(ptAxis, ptLine, paintLinesAxis);
}
canvas.DrawText(st.ToString("0"), ptAxis, paintAxis);
}
int index = 0;
foreach (TimeValue val in timeSeries)
{
float x = index * onex;
float y = oney * val.Value;
SKPoint pt = new SKPoint(leftMargin + x, skRect.Bottom - bottomMargin - y);
pointList.Add(pt);
index++;
}
SKPoint[] points = pointList.ToArray();
paint.Style = SKPaintStyle.Stroke;
paint.Color = myColorLine;
if (pointList.Count > 0)
{
SKPoint origin = new SKPoint(skRect.Left + leftMargin, skRect.Bottom - bottomMargin);
var path = new SKPath();
path.MoveTo(points.First().X, origin.Y);
path.LineTo(points.First());
var last = points.Length;
TimeValue lastMonth = null;
for (int i = 0; i < last; i++)
{
SKPoint pt = points[i];
TimeValue tval = timeSeries[i];
if (lastMonth == null || tval.DateTime.Month != lastMonth.DateTime.Month)
{
lastMonth = tval;
ptAxis = new SKPoint(pt.X, skRect.Bottom - (bottomMargin / 2));
canvas.DrawText(lastMonth.DateTime.ToString("MM/yy"), ptAxis, paintAxis);
}
if (i == 0)
{
path.LineTo(pt);
}
else
{
SKPoint pt0 = points[i - 1];
path.ConicTo(pt0, pt, Math.Abs(pt.X - pt0.X));
}
}
canvas.DrawPath(path, paint);
}
}
}
public void ConicTo(float controlX, float controlY, float x, float y, float w) => _path.ConicTo(controlX, controlY, x, y, w);
protected override void OnDrawSample(SKCanvas canvas, int width, int height)
{
canvas.Clear(SKColors.White);
canvas.Scale(2);
var points = new[]
{
new SKPoint(10, 10),
new SKPoint(50, 20),
new SKPoint(100, 150)
};
using (SKPaint paint = new SKPaint())
using (SKPaint textPaint = new SKPaint())
{
paint.Style = SKPaintStyle.Stroke;
paint.StrokeWidth = 5;
paint.IsAntialias = true;
paint.StrokeCap = SKStrokeCap.Round;
textPaint.IsAntialias = true;
using (SKPath path = new SKPath())
{
// create a conic path
path.MoveTo(points[0]);
path.ConicTo(points[1], points[2], 10);
// draw the conic-based path
paint.Color = SampleMedia.Colors.XamarinDarkBlue;
canvas.DrawPath(path, paint);
// get the quads from the conic points
SKPoint[] pts;
var quads = SKPath.ConvertConicToQuads(points[0], points[1], points[2], 10, out pts, 2);
// move the points on a bit
for (int i = 0; i < pts.Length; i++)
{
pts[i].Offset(120, 0);
}
// draw the quad-based path
using (var quadsPath = new SKPath())
{
quadsPath.MoveTo(pts[0].X, pts[0].Y);
for (int i = 0; i < quads; i++)
{
var idx = i * 2;
quadsPath.CubicTo(
pts[idx].X, pts[idx].Y,
pts[idx + 1].X, pts[idx + 1].Y,
pts[idx + 2].X, pts[idx + 2].Y);
}
paint.Color = SampleMedia.Colors.XamarinPurple;
canvas.DrawPath(quadsPath, paint);
}
// move the points on a bit
for (int i = 0; i < pts.Length; i++)
{
pts[i].Offset(120, 0);
}
// draw the dots
paint.Color = SampleMedia.Colors.XamarinGreen;
canvas.DrawPoints(SKPointMode.Points, pts, paint);
}
}
}
internal static void AddFigure(IToolContext context, IList <IBaseShape> shapes, bool isClosed, double dx, double dy, SKPath geometry)
{
bool isFirstShape = true;
foreach (var shape in shapes)
{
switch (shape)
{
case LineShape line:
{
if (isFirstShape)
{
geometry.MoveTo(ToSKPoint(line.StartPoint, dx, dy));
isFirstShape = false;
}
geometry.LineTo(ToSKPoint(line.Point, dx, dy));
}
break;
case CubicBezierShape cubicBezier:
{
if (isFirstShape)
{
geometry.MoveTo(ToSKPoint(cubicBezier.StartPoint, dx, dy));
isFirstShape = false;
}
geometry.CubicTo(
ToSKPoint(cubicBezier.Point1, dx, dy),
ToSKPoint(cubicBezier.Point2, dx, dy),
ToSKPoint(cubicBezier.Point3, dx, dy));
}
break;
case QuadraticBezierShape quadraticBezier:
{
if (isFirstShape)
{
geometry.MoveTo(ToSKPoint(quadraticBezier.StartPoint, dx, dy));
isFirstShape = false;
}
geometry.QuadTo(
ToSKPoint(quadraticBezier.Point1, dx, dy),
ToSKPoint(quadraticBezier.Point2, dx, dy));
}
break;
case ConicShape conic:
{
if (isFirstShape)
{
geometry.MoveTo(ToSKPoint(conic.StartPoint, dx, dy));
isFirstShape = false;
}
geometry.ConicTo(
ToSKPoint(conic.Point1, dx, dy),
ToSKPoint(conic.Point2, dx, dy),
(float)conic.Weight);
}
break;
}
}
if (!isFirstShape && isClosed)
{
geometry.Close();
}
}
