/// <summary>See <c>WpfExtensions</c> for details.</summary>
public static void DrawRectangle(DrawingContext dc, Rect rect, Paint paint, CornerRadius corners, CornerStyle cornerStyle, BorderSide borderSide, bool snapToPixel) {
// get brush and stroke resources
if (paint == null) return;
var fill = paint.Fill;
var strokes = paint.GetStrokePens().ToArray();
var hasFill = (fill != null);
var hasStroke = (strokes.Length > 0 && borderSide != BorderSide.None);
if (!hasFill && !hasStroke) return;
// compute the drawing rectangle with offset for pixel snapping
// (assumptions: the box itself is pixel snapped, all strokes have same thickness, and the thickness is a whole number)
var halfThickness = Math.Round(hasStroke ? strokes[0].Thickness : 0.0) / 2;
if (snapToPixel && hasStroke) {
rect = new Rect(rect.X + halfThickness, rect.Y + halfThickness, (rect.Width - 2 * halfThickness).Max(0), (rect.Height - 2 * halfThickness).Max(0));
}
// select drawing function based on the corners complexity
DrawingFunction fillFunc = null;
if (corners.IsZero()) {
fillFunc = _drawSimpleRectangle;
} else if (corners.IsUniform()) {
fillFunc = _drawRoundedRectangle;
} else {
fillFunc = _drawComplexRectangle;
}
// draw the border
if (hasStroke) {
if (paint.IsA<QuadPaint>()) {
rect = _drawSide(dc, rect, null, strokes[0], corners, cornerStyle, BorderSide.Left);
rect = _drawSide(dc, rect, null, strokes[1], corners, cornerStyle, BorderSide.Top);
rect = _drawSide(dc, rect, null, strokes[2], corners, cornerStyle, BorderSide.Right);
rect = _drawSide(dc, rect, null, strokes[3], corners, cornerStyle, BorderSide.Bottom);
corners = _inflateCorners(corners, strokes[3]);
} else {
var strokeFunc = (borderSide == BorderSide.All ? fillFunc : _drawSide);
foreach (var stroke in strokes) {
rect = strokeFunc(dc, rect, null, stroke, corners, cornerStyle, borderSide);
corners = _inflateCorners(corners, stroke);
}
}
}
// draw the background
if (hasFill) {
if (snapToPixel) {
rect = _deflateRect(rect, -halfThickness);
}
if (paint.FillMode == BrushMappingMode.Absolute) {
fill = _mapAbsoluteFill(fill, rect);
}
fillFunc(dc, rect, fill, null, corners, cornerStyle, borderSide);
}
}
private static CornerRadius _inflateCorners(CornerRadius corners, Pen stroke) {
if (stroke == null || stroke.Thickness.IsZero() || corners.IsZero()) return corners;
var thickness = stroke.Thickness;
return new CornerRadius(
(corners.TopLeft - thickness).Max(0),
(corners.TopRight - thickness).Max(0),
(corners.BottomRight - thickness).Max(0),
(corners.BottomLeft - thickness).Max(0)
);
}
