Clear() public method

public Clear ( ) : void
return void
Beispiel #1
0
        private static SKBitmap CreateLabelAsBitmap(LabelStyle style, string text, SKPaint paint)
        {
            var rect = new SKRect();
            paint.MeasureText(text, ref rect);

            var backRect = new SKRect(0, 0, rect.Width + 6, rect.Height + 6);

            var bitmap = new SKBitmap((int)backRect.Width, (int)backRect.Height);

            using (var target = new SKCanvas(bitmap))
            {
                target.Clear();

                DrawBackground(style, backRect, target);
                target.DrawText(text, -rect.Left + 3, -rect.Top +3, paint);
                return bitmap;
            }
        }
		public static void DilateImageFilter(SKCanvas canvas, int width, int height)
		{
			canvas.Clear(SKColors.White);

			var assembly = typeof(Demos).GetTypeInfo().Assembly;
			var imageName = assembly.GetName().Name + ".baboon.png";

			// load the image from the embedded resource stream
			using (var resource = assembly.GetManifestResourceStream(imageName))
			using (var stream = new SKManagedStream(resource))
			using (var bitmap = SKBitmap.Decode(stream))
			using (var filter = SKImageFilter.CreateDilate(5, 5))
			using (var paint = new SKPaint())
			{
				paint.ImageFilter = filter;

				canvas.DrawBitmap(bitmap, SKRect.Create(width, height), paint);
			}
		}
		public static void ColorTableColorFilter(SKCanvas canvas, int width, int height)
		{
			canvas.Clear(SKColors.White);

			var assembly = typeof(Demos).GetTypeInfo().Assembly;
			var imageName = assembly.GetName().Name + ".baboon.png";

			var ct = new byte[256];
			for (int i = 0; i < 256; ++i)
			{
				var x = (i - 96) * 255 / 64;
				ct[i] = x < 0 ? (byte)0 : x > 255 ? (byte)255 : (byte)x;
			}

			// load the image from the embedded resource stream
			using (var resource = assembly.GetManifestResourceStream(imageName))
			using (var stream = new SKManagedStream(resource))
			using (var bitmap = SKBitmap.Decode(stream))
			using (var cf = SKColorFilter.CreateTable(null, ct, ct, ct))
			using (var paint = new SKPaint())
			{
				paint.ColorFilter = cf;

				canvas.DrawBitmap(bitmap, SKRect.Create(width, height), paint);
			}
		}
		public static void ColorMatrixColorFilter(SKCanvas canvas, int width, int height)
		{
			canvas.Clear(SKColors.White);

			var assembly = typeof(Demos).GetTypeInfo().Assembly;
			var imageName = assembly.GetName().Name + ".baboon.png";

			// load the image from the embedded resource stream
			using (var resource = assembly.GetManifestResourceStream(imageName))
			using (var stream = new SKManagedStream(resource))
			using (var bitmap = SKBitmap.Decode(stream))
			{
				var f = new Action<SKRect, float[]>((rect, colorMatrix) =>
				{
					using (var cf = SKColorFilter.CreateColorMatrix(colorMatrix))
					using (var paint = new SKPaint())
					{
						paint.ColorFilter = cf;

						canvas.DrawBitmap(bitmap, rect, paint);
					}
				});

				var colorMatrix1 = new float[20] {
					0f, 1f, 0f, 0f, 0f,
					0f, 0f, 1f, 0f, 0f,
					1f, 0f, 0f, 0f, 0f,
					0f, 0f, 0f, 1f, 0f
				};
				var grayscale = new float[20] {
					0.21f, 0.72f, 0.07f, 0.0f, 0.0f,
					0.21f, 0.72f, 0.07f, 0.0f, 0.0f,
					0.21f, 0.72f, 0.07f, 0.0f, 0.0f,
					0.0f,  0.0f,  0.0f,  1.0f, 0.0f
				};
				var colorMatrix3 = new float[20] {
					-1f,  1f,  1f, 0f, 0f,
					 1f, -1f,  1f, 0f, 0f,
					 1f,  1f, -1f, 0f, 0f,
					 0f,  0f,  0f, 1f, 0f
				};
				var colorMatrix4 = new float[20] {
					0.0f, 0.5f, 0.5f, 0f, 0f,
					0.5f, 0.0f, 0.5f, 0f, 0f,
					0.5f, 0.5f, 0.0f, 0f, 0f,
					0.0f, 0.0f, 0.0f, 1f, 0f
				};
				var highContrast = new float[20] {
					4.0f, 0.0f, 0.0f, 0.0f, -4.0f * 255f / (4.0f - 1f),
					0.0f, 4.0f, 0.0f, 0.0f, -4.0f * 255f / (4.0f - 1f),
					0.0f, 0.0f, 4.0f, 0.0f, -4.0f * 255f / (4.0f - 1f),
					0.0f, 0.0f, 0.0f, 1.0f, 0.0f
				};
				var colorMatrix6 = new float[20] {
					0f, 0f, 1f, 0f, 0f,
					1f, 0f, 0f, 0f, 0f,
					0f, 1f, 0f, 0f, 0f,
					0f, 0f, 0f, 1f, 0f
				};
				var sepia = new float[20] {
					0.393f, 0.769f, 0.189f, 0.0f, 0.0f,
					0.349f, 0.686f, 0.168f, 0.0f, 0.0f,
					0.272f, 0.534f, 0.131f, 0.0f, 0.0f,
					0.0f,   0.0f,   0.0f,   1.0f, 0.0f
				};
				var inverter = new float[20] {
					-1f,  0f,  0f, 0f, 255f,
					0f, -1f,  0f, 0f, 255f,
					0f,  0f, -1f, 0f, 255f,
					0f,  0f,  0f, 1f, 0f
				};

				var matices = new[] {
					colorMatrix1, grayscale, highContrast, sepia,
					colorMatrix3, colorMatrix4, colorMatrix6, inverter
				};

				var cols = width < height ? 2 : 4;
				var rows = (matices.Length - 1) / cols + 1;
				var w = (float)width / cols;
				var h = (float)height / rows;

				for (int y = 0; y < rows; y++)
				{
					for (int x = 0; x < cols; x++)
					{
						f(SKRect.Create(x * w, y * h, w, h), matices[y * cols + x]);
					}
				}
			}
		}
		public static void TurbulencePerlinNoiseShader(SKCanvas canvas, int width, int height)
		{
			canvas.Clear(SKColors.White);

			using (var shader = SKShader.CreatePerlinNoiseTurbulence(0.05f, 0.05f, 4, 0.0f))
			using (var paint = new SKPaint())
			{
				paint.Shader = shader;
				canvas.DrawPaint(paint);
			}
		}
Beispiel #6
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		public static void BitmapDecoder(SKCanvas canvas, int width, int height)
		{
			var assembly = typeof(Demos).GetTypeInfo().Assembly;
			var imageName = assembly.GetName().Name + ".color-wheel.png";

			canvas.Clear(SKColors.White);

			// load the embedded resource stream
			using (var resource = assembly.GetManifestResourceStream(imageName))
			using (var stream = new SKManagedStream(resource))
			using (var codec = SKCodec.Create(stream))
			using (var paint = new SKPaint())
			using (var tf = SKTypeface.FromFamilyName("Arial"))
			{
				var info = codec.Info;

				paint.IsAntialias = true;
				paint.TextSize = 14;
				paint.Typeface = tf;
				paint.Color = SKColors.Black;

				// decode the image
				using (var bitmap = new SKBitmap(info.Width, info.Height, info.ColorType, info.IsOpaque ? SKAlphaType.Opaque : SKAlphaType.Premul))
				{
					IntPtr length;
					var result = codec.GetPixels(bitmap.Info, bitmap.GetPixels(out length));
					if (result == SKCodecResult.Success || result == SKCodecResult.IncompleteInput)
					{
						var x = 25;
						var y = 25;

						canvas.DrawBitmap(bitmap, x, y);
						x += bitmap.Info.Width + 25;
						y += 14;

						canvas.DrawText(string.Format("Result: {0}", result), x, y, paint);
						y += 20;

						canvas.DrawText(string.Format("Size: {0}px x {1}px", bitmap.Width, bitmap.Height), x, y, paint);
						y += 20;

						canvas.DrawText(string.Format("Pixels: {0} @ {1}b/px", bitmap.Pixels.Length, bitmap.BytesPerPixel), x, y, paint);
					}
				}
			}
		}
 public void Clear(Color color)
 => _canvas.Clear(color.ToSkia());
Beispiel #8
0
        public static void ColorMatrixColorFilter(SKCanvas canvas, int width, int height)
        {
            canvas.Clear(SKColors.White);

            var assembly  = typeof(Demos).GetTypeInfo().Assembly;
            var imageName = assembly.GetName().Name + ".baboon.png";

            // load the image from the embedded resource stream
            using (var resource = assembly.GetManifestResourceStream(imageName))
                using (var stream = new SKManagedStream(resource))
                    using (var bitmap = SKBitmap.Decode(stream))
                    {
                        var f = new Action <SKRect, float[]>((rect, colorMatrix) =>
                        {
                            using (var cf = SKColorFilter.CreateColorMatrix(colorMatrix))
                                using (var paint = new SKPaint())
                                {
                                    paint.ColorFilter = cf;

                                    canvas.DrawBitmap(bitmap, rect, paint);
                                }
                        });

                        var colorMatrix1 = new float[20] {
                            0f, 1f, 0f, 0f, 0f,
                            0f, 0f, 1f, 0f, 0f,
                            1f, 0f, 0f, 0f, 0f,
                            0f, 0f, 0f, 1f, 0f
                        };
                        var grayscale = new float[20] {
                            0.21f, 0.72f, 0.07f, 0.0f, 0.0f,
                            0.21f, 0.72f, 0.07f, 0.0f, 0.0f,
                            0.21f, 0.72f, 0.07f, 0.0f, 0.0f,
                            0.0f, 0.0f, 0.0f, 1.0f, 0.0f
                        };
                        var colorMatrix3 = new float[20] {
                            -1f, 1f, 1f, 0f, 0f,
                            1f, -1f, 1f, 0f, 0f,
                            1f, 1f, -1f, 0f, 0f,
                            0f, 0f, 0f, 1f, 0f
                        };
                        var colorMatrix4 = new float[20] {
                            0.0f, 0.5f, 0.5f, 0f, 0f,
                            0.5f, 0.0f, 0.5f, 0f, 0f,
                            0.5f, 0.5f, 0.0f, 0f, 0f,
                            0.0f, 0.0f, 0.0f, 1f, 0f
                        };
                        var highContrast = new float[20] {
                            4.0f, 0.0f, 0.0f, 0.0f, -4.0f * 255f / (4.0f - 1f),
                            0.0f, 4.0f, 0.0f, 0.0f, -4.0f * 255f / (4.0f - 1f),
                            0.0f, 0.0f, 4.0f, 0.0f, -4.0f * 255f / (4.0f - 1f),
                            0.0f, 0.0f, 0.0f, 1.0f, 0.0f
                        };
                        var colorMatrix6 = new float[20] {
                            0f, 0f, 1f, 0f, 0f,
                            1f, 0f, 0f, 0f, 0f,
                            0f, 1f, 0f, 0f, 0f,
                            0f, 0f, 0f, 1f, 0f
                        };
                        var sepia = new float[20] {
                            0.393f, 0.769f, 0.189f, 0.0f, 0.0f,
                            0.349f, 0.686f, 0.168f, 0.0f, 0.0f,
                            0.272f, 0.534f, 0.131f, 0.0f, 0.0f,
                            0.0f, 0.0f, 0.0f, 1.0f, 0.0f
                        };
                        var inverter = new float[20] {
                            -1f, 0f, 0f, 0f, 255f,
                            0f, -1f, 0f, 0f, 255f,
                            0f, 0f, -1f, 0f, 255f,
                            0f, 0f, 0f, 1f, 0f
                        };

                        var matices = new[] {
                            colorMatrix1, grayscale, highContrast, sepia,
                            colorMatrix3, colorMatrix4, colorMatrix6, inverter
                        };

                        var cols = width < height ? 2 : 4;
                        var rows = (matices.Length - 1) / cols + 1;
                        var w    = (float)width / cols;
                        var h    = (float)height / rows;

                        for (int y = 0; y < rows; y++)
                        {
                            for (int x = 0; x < cols; x++)
                            {
                                f(SKRect.Create(x * w, y * h, w, h), matices[y * cols + x]);
                            }
                        }
                    }
        }
		public static void Xfermode (SKCanvas canvas, int width, int height)
		{
			var modes = Enum.GetValues (typeof(SKXferMode)).Cast<SKXferMode> ().ToArray ();

			var cols = width < height ? 3 : 5;
			var rows = (modes.Length - 1) / cols + 1;

			var w = (float)width / cols;
			var h = (float)height / rows;
			var rect = SKRect.Create (w, h);
			var srcPoints = new[] {
				new SKPoint (0.0f, 0.0f),
				new SKPoint (w, 0.0f)
			};
			var srcColors = new [] {
				SKColors.Magenta.WithAlpha (0),
				SKColors.Magenta
			};
			var dstPoints = new [] {
				new SKPoint (0.0f, 0.0f),
				new SKPoint (0.0f, h)
			};
			var dstColors = new [] {
				SKColors.Cyan.WithAlpha (0),
				SKColors.Cyan
			};

			using (var text = new SKPaint ())
			using (var stroke = new SKPaint ())
			using (var src = new SKPaint ())
			using (var dst = new SKPaint ())
			using (var srcShader = SKShader.CreateLinearGradient (srcPoints [0], srcPoints [1], srcColors, null, SKShaderTileMode.Clamp))
			using (var dstShader = SKShader.CreateLinearGradient (dstPoints [0], dstPoints [1], dstColors, null, SKShaderTileMode.Clamp)) {
				text.TextSize = 12.0f;
				text.IsAntialias = true;
				text.TextAlign = SKTextAlign.Center;
				stroke.IsStroke = true;
				src.Shader = srcShader;
				dst.Shader = dstShader;

				canvas.Clear (SKColors.White);

				for (var i = 0; i < modes.Length; ++i) {
					using (new SKAutoCanvasRestore (canvas, true)) {
						canvas.Translate (w * (i / rows), h * (i % rows));

						canvas.ClipRect (rect);
						canvas.DrawColor (SKColors.LightGray);

						canvas.SaveLayer (null);
						canvas.Clear (SKColors.Transparent);
						canvas.DrawPaint (dst);

						src.XferMode = modes [i];
						canvas.DrawPaint (src);
						canvas.DrawRect (rect, stroke);

						var desc = modes [i].ToString ();
						canvas.DrawText (desc, w / 2f, h / 2f, text);
					}
				}
			}
		}
		public static void CustomFonts (SKCanvas canvas, int width, int height)
		{
			string text = "\u03A3 and \u0750";

			using (var paint = new SKPaint ()) {
				canvas.Clear (SKColors.White);
				paint.IsAntialias = true;

				using (var tf = SKTypeface.FromFile (CustomFontPath)) {
					paint.Color = XamGreen;
					paint.TextSize = 40;
					paint.Typeface = tf;

					canvas.DrawText (text, 50, 50, paint);
				}

				using (var stream = new SKFileStream (CustomFontPath))
				using (var tf = SKTypeface.FromStream (stream)) {
					paint.Color = XamDkBlue;
					paint.TextSize = 40;
					paint.Typeface = tf;

					canvas.DrawText (text, 50, 100, paint);
				}

				var assembly = typeof(Demos).GetTypeInfo ().Assembly;
				var fontName = assembly.GetName ().Name + ".embedded-font.ttf";

				using (var resource = assembly.GetManifestResourceStream (fontName))
				using (var memory = new MemoryStream ()) {
					resource.CopyTo (memory);
					var bytes = memory.ToArray ();
					using (var stream = new SKMemoryStream (bytes))
					using (var tf = SKTypeface.FromStream (stream)) {
						paint.Color = XamLtBlue;
						paint.TextSize = 40;
						paint.Typeface = tf;

						canvas.DrawText (text, 50, 150, paint);
					}
				}

				using (var resource = assembly.GetManifestResourceStream (fontName))
				using (var stream = new SKManagedStream (resource))
				using (var tf = SKTypeface.FromStream (stream)) {
					paint.Color = XamPurple;
					paint.TextSize = 40;
					paint.Typeface = tf;

					canvas.DrawText (text, 50, 200, paint);
				}
			}
		}
		public static void ManageDrawMatrix (SKCanvas canvas, int width, int height)
		{
			var size = ((float)height > width ? width : height) * 0.5f;
			var center = new SKPoint ((width - size) / 2f, (height - size) / 2f);

			// draw these at specific locations
			var leftRect = SKRect.Create (center.X - size / 2f, center.Y, size, size);
			var rightRect = SKRect.Create (center.X + size / 2f, center.Y, size, size);

			// draw this at the current location / transformation
			var rotatedRect = SKRect.Create (0f, 0f, size, size);

			using (var paint = new SKPaint ()) {
				paint.IsAntialias = true;
				canvas.Clear (XamPurple);

				// draw
				paint.Color = XamDkBlue;
				canvas.DrawRect (leftRect, paint);

				// save
				canvas.Save();

				// transform
				canvas.Translate (width / 2f, center.Y);
				canvas.RotateDegrees (45);

				// draw
				paint.Color = XamGreen;
				canvas.DrawRect (rotatedRect, paint);

				// undo transform / restore
				canvas.Restore();

				// draw
				paint.Color = XamLtBlue;
				canvas.DrawRect (rightRect, paint);
			}
		}
		public static void FilledHeptagram (SKCanvas canvas, int width, int height)
		{
			var size = ((float)height > width ? width : height) * 0.75f;
			var R = 0.45f * size;
			var TAU = 6.2831853f;

			using (var path = new SKPath ()) {
				path.MoveTo (R, 0.0f);
				for (int i = 1; i < 7; ++i) {
					var theta = 3f * i * TAU / 7f;
					path.LineTo (R * (float)Math.Cos (theta), R * (float)Math.Sin (theta));
				}
				path.Close ();

				using (var paint = new SKPaint ()) {
					paint.IsAntialias = true;
					canvas.Clear (SKColors.White);
					canvas.Translate (width / 2f, height / 2f);
					canvas.DrawPath (path, paint);
				}
			}
		}
Beispiel #13
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		public static void PathEffects (SKCanvas canvas, int width, int height)
		{
			canvas.Clear (SKColors.White);

			var step = height / 4;

			using (var paint = new SKPaint ())
			using (var effect = SKPathEffect.CreateDash (new [] { 15f, 5f }, 0)) {
				paint.IsStroke = true;
				paint.StrokeWidth = 4;
				paint.PathEffect = effect;
				canvas.DrawLine (10, step, width - 10 - 10, step, paint);
			}

			using (var paint = new SKPaint ())
			using (var effect = SKPathEffect.CreateDiscrete (10, 10)) {
				paint.IsStroke = true;
				paint.StrokeWidth = 4;
				paint.PathEffect = effect;
				canvas.DrawLine (10, step * 2, width - 10 - 10, step * 2, paint);
			}

			using (var paint = new SKPaint ())
			using (var dashEffect = SKPathEffect.CreateDash (new [] { 15f, 5f }, 0))
			using (var discreteEffect = SKPathEffect.CreateDiscrete (10, 10))
			using (var effect = SKPathEffect.CreateCompose (dashEffect, discreteEffect)) {
				paint.IsStroke = true;
				paint.StrokeWidth = 4;
				paint.PathEffect = effect;
				canvas.DrawLine (10, step * 3, width - 10 - 10, step * 3, paint);
			}

		}
Beispiel #14
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		public static void CreatePdfSample (SKCanvas canvas, int width, int height)
		{
			canvas.Clear(SKColors.White);

			using (var paint = new SKPaint ()) {
				paint.TextSize = 24.0f;
				paint.IsAntialias = true;
				paint.Color = new SKColor (0x9C, 0xAF, 0xB7);
				paint.StrokeWidth = 3;
				paint.TextAlign = SKTextAlign.Center;

				canvas.DrawText ("tap to open", width / 2f, 100f, paint);
			}

			using (var stream = new SKFileWStream (Path.Combine (WorkingDirectory, "document.pdf")))
			using (var document = SKDocument.CreatePdf (stream))
			using (var pdfCanvas = document.BeginPage (width, height))
			using (var paint = new SKPaint ()) {
				paint.TextSize = 64.0f;
				paint.IsAntialias = true;
				paint.Color = new SKColor (0x9C, 0xAF, 0xB7);
				paint.IsStroke = true;
				paint.StrokeWidth = 3;
				paint.TextAlign = SKTextAlign.Center;

				pdfCanvas.DrawText ("...PDF...", width / 2f, 100f, paint);
				document.EndPage ();
				document.Close ();
			}
		}
		public static void ChainedImageFilter(SKCanvas canvas, int width, int height)
		{
			canvas.Clear(SKColors.White);

			var assembly = typeof(Demos).GetTypeInfo().Assembly;
			var imageName = assembly.GetName().Name + ".baboon.png";

			var size = width > height ? height : width;
			var small = size / 5;

			// load the image from the embedded resource stream
			using (var resource = assembly.GetManifestResourceStream(imageName))
			using (var stream = new SKManagedStream(resource))
			using (var bitmap = SKBitmap.Decode(stream))
			using (var filterMag = SKImageFilter.CreateMagnifier(SKRect.Create(small*2, small*2, small*3, small*3), small))
			using (var filterBlur = SKImageFilter.CreateBlur(5, 5, filterMag))
			using (var paint = new SKPaint())
			{
				paint.ImageFilter = filterBlur;

				canvas.DrawBitmap(bitmap, SKRect.Create(width, height), paint);
			}
		}
Beispiel #16
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        public static void Xfermode(SKCanvas canvas, int width, int height)
        {
            var modes = Enum.GetValues(typeof(SKXferMode)).Cast <SKXferMode> ().ToArray();

            var cols = width < height ? 3 : 5;
            var rows = (modes.Length - 1) / cols + 1;

            var w         = (float)width / cols;
            var h         = (float)height / rows;
            var rect      = SKRect.Create(w, h);
            var srcPoints = new[] {
                new SKPoint(0.0f, 0.0f),
                new SKPoint(w, 0.0f)
            };
            var srcColors = new [] {
                SKColors.Magenta.WithAlpha(0),
                SKColors.Magenta
            };
            var dstPoints = new [] {
                new SKPoint(0.0f, 0.0f),
                new SKPoint(0.0f, h)
            };
            var dstColors = new [] {
                SKColors.Cyan.WithAlpha(0),
                SKColors.Cyan
            };

            using (var text = new SKPaint())
                using (var stroke = new SKPaint())
                    using (var src = new SKPaint())
                        using (var dst = new SKPaint())
                            using (var srcShader = SKShader.CreateLinearGradient(srcPoints [0], srcPoints [1], srcColors, null, SKShaderTileMode.Clamp))
                                using (var dstShader = SKShader.CreateLinearGradient(dstPoints [0], dstPoints [1], dstColors, null, SKShaderTileMode.Clamp)) {
                                    text.TextSize    = 12.0f;
                                    text.IsAntialias = true;
                                    text.TextAlign   = SKTextAlign.Center;
                                    stroke.IsStroke  = true;
                                    src.Shader       = srcShader;
                                    dst.Shader       = dstShader;

                                    canvas.Clear(SKColors.White);

                                    for (var i = 0; i < modes.Length; ++i)
                                    {
                                        using (new SKAutoCanvasRestore(canvas, true)) {
                                            canvas.Translate(w * (i / rows), h * (i % rows));

                                            canvas.ClipRect(rect);
                                            canvas.DrawColor(SKColors.LightGray);

                                            canvas.SaveLayer(null);
                                            canvas.Clear(SKColors.Transparent);
                                            canvas.DrawPaint(dst);

                                            src.XferMode = modes [i];
                                            canvas.DrawPaint(src);
                                            canvas.DrawRect(rect, stroke);

                                            var desc = modes [i].ToString();
                                            canvas.DrawText(desc, w / 2f, h / 2f, text);
                                        }
                                    }
                                }
        }
		public static void BitmapShader (SKCanvas canvas, int width, int height)
		{
			var assembly = typeof(Demos).GetTypeInfo ().Assembly;
			var imageName = assembly.GetName ().Name + ".color-wheel.png";

			// load the image from the embedded resource stream
			using (var resource = assembly.GetManifestResourceStream (imageName))
			using (var stream = new SKManagedStream(resource)) 
			using (var source = SKBitmap.Decode (stream)) {
				// create the shader and paint
				//SkMatrix matrix;
				//matrix.setScale(0.75f, 0.75f);
				//matrix.preRotate(30.0f);
				var matrix = SKMatrix.MakeRotation (30.0f);
				using (var shader = SKShader.CreateBitmap (source, SKShaderTileMode.Repeat, SKShaderTileMode.Repeat, matrix))
				using (var paint = new SKPaint ()) {
					paint.IsAntialias = true;
					paint.Shader = shader;

					// tile the bitmap
					canvas.Clear (SKColors.White);
					canvas.DrawPaint (paint);
				}
			}
		}
		public static void BitmapShaderManipulated (SKCanvas canvas, int width, int height)
		{
			var assembly = typeof(Demos).GetTypeInfo ().Assembly;
			var imageName = assembly.GetName ().Name + ".color-wheel.png";

			// load the image from the embedded resource stream
			using (var resource = assembly.GetManifestResourceStream (imageName))
			using (var stream = new SKManagedStream(resource))
			using (var source = SKBitmap.Decode (stream)) {
				// invert the pixels
				var pixels = source.Pixels;
				for (int i = 0; i < pixels.Length; i++) {
					pixels[i] = new SKColor (
						(byte)(255 - pixels [i].Red), 
						(byte)(255 - pixels [i].Green), 
						(byte)(255 - pixels [i].Blue), 
						pixels [i].Alpha);
				}
				source.Pixels = pixels;

				using (var shader = SKShader.CreateBitmap (source, SKShaderTileMode.Repeat, SKShaderTileMode.Repeat))
				using (var paint = new SKPaint ()) {
					paint.IsAntialias = true;
					paint.Shader = shader;

					// tile the bitmap
					canvas.Clear (SKColors.White);
					canvas.DrawPaint (paint);
				}
			}
		}
		public static void BitmapDecoder(SKCanvas canvas, int width, int height)
		{
			var assembly = typeof(Demos).GetTypeInfo().Assembly;
			var imageName = assembly.GetName().Name + ".color-wheel.png";

			canvas.Clear(SKColors.White);

			// load the embedded resource stream
			using (var resource = assembly.GetManifestResourceStream(imageName))
			using (var stream = new SKManagedStream(resource))
			using (var decoder = new SKImageDecoder(stream))
			using (var paint = new SKPaint())
			using (var tf = SKTypeface.FromFamilyName("Arial"))
			{
				paint.IsAntialias = true;
				paint.TextSize = 14;
				paint.Typeface = tf;
				paint.Color = SKColors.Black;

				// read / set decoder settings
				decoder.DitherImage = true;
				decoder.PreferQualityOverSpeed = true;
				decoder.SampleSize = 2;

				// decode the image
				using (var bitmap = new SKBitmap())
				{
					var result = decoder.Decode(stream, bitmap);
					if (result != SKImageDecoderResult.Failure)
					{
						var info = bitmap.Info;
						var x = 25;
						var y = 25;

						canvas.DrawBitmap(bitmap, x, y);
						x += info.Width + 25;
						y += 14;

						canvas.DrawText(string.Format("Result: {0}", result), x, y, paint);
						y += 20;

						canvas.DrawText(string.Format("Size: {0}px x {1}px", bitmap.Width, bitmap.Height), x, y, paint);
						y += 20;

						canvas.DrawText(string.Format("Pixels: {0} @ {1}b/px", bitmap.Pixels.Length, bitmap.BytesPerPixel), x, y, paint);
					}
				}
			}
		}
 public DrawingContextImpl(SKCanvas canvas)
 {
     Canvas = canvas;
     Canvas.Clear();
 }
Beispiel #21
0
		public static void BitmapLattice (SKCanvas canvas, int width, int height)
		{
			canvas.Clear (SKColors.White);

			var assembly = typeof (Demos).GetTypeInfo ().Assembly;
			var imageName = assembly.GetName ().Name + ".nine-patch.png";

			// load the image from the embedded resource stream
			using (var resource = assembly.GetManifestResourceStream (imageName))
			using (var stream = new SKManagedStream (resource))
			using (var bitmap = SKBitmap.Decode (stream))
			{
				var patchCenter = new SKRectI (33, 33, 256 - 33, 256 - 33);

				// 2x3 for portrait, or 3x2 for landscape
				var land = width > height;
				var min = land ? Math.Min (width / 3f, height / 2f) : Math.Min (width / 2f, height / 3f);
				var wide = SKRect.Inflate (SKRect.Create (0, land ? min : (min * 2f), min * 2f, min), -6, -6);
				var tall = SKRect.Inflate (SKRect.Create (land ? (min * 2f) : min, 0, min, min * 2f), -6, -6);
				var square = SKRect.Inflate (SKRect.Create (0, 0, min, min), -6, -6);
				var text = SKRect.Create (land ? min : 0, land ? 0 : min, min, min / 5f);
				text.Offset (text.Width / 2f, text.Height * 1.5f);
				text.Right = text.Left;

				// draw the bitmaps
				canvas.DrawBitmapNinePatch (bitmap, patchCenter, square);
				canvas.DrawBitmapNinePatch (bitmap, patchCenter, tall);
				canvas.DrawBitmapNinePatch (bitmap, patchCenter, wide);

				// describe what we see
				using (var paint = new SKPaint ())
				{
					paint.TextAlign = SKTextAlign.Center;
					paint.TextSize = text.Height * 0.75f;

					canvas.DrawText ("The corners", text.Left, text.Top, paint);
					text.Offset (0, text.Height);
					canvas.DrawText ("should always", text.Left, text.Top, paint);
					text.Offset (0, text.Height);
					canvas.DrawText ("be square", text.Left, text.Top, paint);
				}
			}
		}