コード例 #1
0
        public UGRadialGradientBrush(IUGContext context, Vector2 center, float radius, IEnumerable <UGGradientStop> gradientStops, UGEdgeBehavior edgeBehavior)
        {
            Center       = center;
            Radius       = radius;
            EdgeBehavior = edgeBehavior;
            Stops        = gradientStops.ToArray();

            if (Stops.Length < 2)
            {
                throw new ArgumentException(nameof(gradientStops));
            }

            unsafe
            {
                var baseFunction = CGFunctionsHelper.GetCGFunction(EdgeBehavior);
                CGFunction.CGFunctionEvaluate function = (data, outData) => baseFunction(Stops, data, outData);
                var domain = new nfloat[] { 0, edgeBehavior != UGEdgeBehavior.Clamp ? 1.5F : 1 };
                _function = new CGFunction(domain, new nfloat[] { 0, 1, 0, 1, 0, 1, 0, 1 }, function);
            }

            var cgCenter = Center.ToCGPoint();
            var cgRadius = EdgeBehavior != UGEdgeBehavior.Clamp ? 1.5F * Radius : Radius;

            using (var colorSpace = CGColorSpace.CreateSrgb())
            {
                _native = CGShading.CreateRadial(colorSpace, cgCenter, 0F, cgCenter, cgRadius, _function, true, true);
            }
        }
コード例 #2
0
			public unsafe override void Draw (RectangleF rect)
			{
				var start = new PointF (rect.Left, rect.Bottom);
				var end = new PointF (rect.Left, rect.Top);

				var domain = new nfloat[] {0f, 1f};
				var range = new nfloat[] {0f, 1f, 0f, 1f};
				using (var context = UIGraphics.GetCurrentContext ())
				using (var rgb = CGColorSpace.CreateDeviceGray())
				using (var shadingFunction = new CGFunction(domain, range, Shading))
				using (var shading = CGShading.CreateAxial (rgb, start, end, shadingFunction, true, false))
				{
					context.DrawShading (shading);
				}

				base.Draw (rect);
			}
コード例 #3
0
        // http://developer.apple.com/library/mac/#documentation/GraphicsImaging/Conceptual/drawingwithquartz2d/dq_shadings/dq_shadings.html#//apple_ref/doc/uid/TP30001066-CH207-BBCECJBF
        internal override void Setup(Graphics graphics, bool fill)
        {
            CGContext context = graphics.context;

            // if fill is false then we are being called from a Pen stroke so
            // we need to setup a transparency layer
            // http://developer.apple.com/library/mac/#documentation/GraphicsImaging/Conceptual/drawingwithquartz2d/dq_shadings/dq_shadings.html#//apple_ref/doc/uid/TP30001066-CH207-BBCECJBF
            if (!fill)
            {
                context.BeginTransparencyLayer();
                hasTransparencyLayer = true;
                // Make sure we set a color here so that the gradient shows up
                graphics.lastBrushColor = Color.Black;
                return;
            }

            // if this is the same as the last that was set and no changes have been made
            // then return.
            if (graphics.LastBrush != this || changed)
            {
                setupShadingColors();
            }

            CGSize gradientRegionCg = context.GetClipBoundingBox().Size;
            SizeF  gradientRegion   = new SizeF((float)gradientRegionCg.Width, (float)gradientRegionCg.Height);
//			SizeF gradientRegionPath = context.GetPathBoundingBox().Size;
            PointF sp = startPoint;
            PointF ep = endPoint;

            PointF[] points = { sp, ep };

            // Transform the start and end points using the brush's transformation matrix
            gradientTransform.TransformPoints(points);

            sp = points[0];
            ep = points[1];

            var cgf = CyclicGradientFunction(gradientRegion,
                                             ref sp, ref ep);

            var     colorSpace = CGColorSpace.CreateDeviceRGB();
            CGPoint cgsp = new CGPoint(sp.X, sp.Y), cgep = new CGPoint(ep.X, ep.Y);
            var     shading = CGShading.CreateAxial(colorSpace, cgsp, cgep, cgf, false, false);

            colorSpace.Dispose();

            context.SaveState();

            // if path is empty here then we are being called from a Pen stroke so
            // we set the blend mode for strokes and clip the path for fills
            if (!context.IsPathEmpty())
            {
                context.Clip();
            }
            else
            {
                context.SetBlendMode(CGBlendMode.SourceIn);
            }

            context.DrawShading(shading);
            context.RestoreState();

            // If we are in a Transparency layer then we need to end the transparency
            if (hasTransparencyLayer)
            {
                context.EndTransparencyLayer();
            }

            cgf.Dispose();
            shading.Dispose();
            shading = null;

            changed = false;

            graphics.LastBrush = this;
            // We will reset the last pen so that it can be setup again
            // so that we do not loose the settings after stroking the gradient
            // not sure where the setting are being reset so this may be a hack
            // and things are just not being restored correctly.
            graphics.LastPen = null;
            // I am setting this to be used for Text coloring in DrawString
            graphics.lastBrushColor = colors[0];
        }
コード例 #4
0
 internal UGRadialGradientBrush(CGShading native)
 => _native = native;