private Paint CreateLinearPaint(ILinearGradient gradient, DrawContext context)
{
var rect = context.RenderRect;
var line = new LinearGradientGeometry();
line.CalculateOffsets(gradient, (int)context.RenderRect.Width, (int)context.RenderRect.Height);
line.CalculateGeometry(gradient, rect);
var renderStops = GetRenderStops(gradient);
var start = line.Start;
var end = line.End;
if (gradient.IsRepeating)
{
var firstOffset = renderStops.FirstOrDefault()?.Offset ?? 0;
var lastOffset = renderStops.LastOrDefault()?.Offset ?? 1;
start = line.GetColorPointAt(firstOffset);
end = line.GetColorPointAt(lastOffset);
foreach (var stop in renderStops)
{
stop.Offset = line.ScaleWithBias(stop.Offset, firstOffset, lastOffset, 0, 1);
}
}
// Convert pixels to proportional
var startPoint = new Point(start.X / rect.Width, start.Y / rect.Height);
var endPoint = new Point(end.X / rect.Width, end.Y / rect.Height);
return(new LinearGradientPaintEx(renderStops, startPoint, endPoint, gradient.IsRepeating));
}
public SKShader CreateShader(ILinearGradient gradient, DrawContext context)
{
var rect = context.RenderRect;
var line = new LinearGradientGeometry();
line.CalculateOffsets(gradient, context.RenderRect.Width, context.RenderRect.Height);
line.CalculateGeometry(gradient, rect.ToRectF());
var renderStops = GetRenderStops(gradient);
var colors = renderStops.Select(x => x.Color.ToSKColor()).ToArray();
var colorPos = renderStops.Select(x => x.RenderOffset).ToArray();
var startPoint = line.Start;
var endPoint = line.End;
if (gradient.IsRepeating)
{
var firstOffset = renderStops.FirstOrDefault()?.RenderOffset ?? 0;
var lastOffset = renderStops.LastOrDefault()?.RenderOffset ?? 1;
startPoint = line.GetColorPointAt(firstOffset);
endPoint = line.GetColorPointAt(lastOffset);
for (var i = 0; i < colorPos.Length; i++)
{
colorPos[i] = line.ScaleWithBias(colorPos[i], firstOffset, lastOffset, 0, 1);
}
}
var shader = SKShader.CreateLinearGradient(
startPoint.ToSKPoint(),
endPoint.ToSKPoint(),
colors,
colorPos,
gradient.IsRepeating ? SKShaderTileMode.Repeat : SKShaderTileMode.Clamp);
return(shader);
}
