PixiEditor/PixiEditorTests/ModelsTests/DataHoldersTests/SurfaceTests.cs

using PixiEditor.Models.DataHolders;
using SkiaSharp;
using Xunit;

namespace PixiEditorTests.ModelsTests.DataHoldersTests
{
    public class SurfaceTests
    {
        SKColor redColor = new SKColor(254, 2, 3);
        SKColor greenColor = new SKColor(6, 224, 3);
        SKPaint redPaint;
        SKPaint greenPaint;

        public SurfaceTests()
        {
            redPaint = new SKPaint()
            {
                Color = redColor,
            };
            greenPaint = new SKPaint()
            {
                Color = greenColor,
            };
        }

        [Fact]
        public void TestSurfaceSRGBPixelManipulation()
        {
            using Surface surface = new Surface(128, 200);
            surface.SkiaSurface.Canvas.Clear(SKColors.Red);
            surface.SkiaSurface.Canvas.DrawRect(new SKRect(10, 10, 70, 70), redPaint);
            surface.SetSRGBPixel(73, 21, greenColor);
            Assert.Equal(redColor, surface.GetSRGBPixel(14, 14));
            Assert.Equal(greenColor, surface.GetSRGBPixel(73, 21));
        }

        [Fact]
        public void TestSurfacePbgraBytes()
        {
            byte[] bytes = new byte[]
            {
                123, 121, 141, 255,  014, 010, 007, 255,
                042, 022, 055, 128,  024, 020, 021, 128,
                040, 010, 055, 064,  042, 022, 005, 064,
                005, 009, 001, 032,  001, 011, 016, 032,
            };
            using Surface surface = new Surface(2, 4, bytes);
            Assert.Equal(new SKColor(141, 121, 123, 255), surface.GetSRGBPixel(0, 0));
            Assert.Equal(new SKColor(110, 44, 84, 128), surface.GetSRGBPixel(0, 1));
            var newBytes = surface.ToByteArray();
            Assert.Equal(bytes, newBytes);
        }

        [Fact]
        public void TestCloneSurface()
        {
            using Surface original = new Surface(30, 40);
            original.SkiaSurface.Canvas.Clear(redColor);
            original.SkiaSurface.Canvas.DrawRect(5, 5, 10, 10, greenPaint);
            using Surface clone = new Surface(original);
            Assert.NotSame(original.SkiaSurface, clone.SkiaSurface);
            Assert.NotSame(original.SkiaSurface.Canvas, clone.SkiaSurface.Canvas);
            Assert.Equal(redColor, clone.GetSRGBPixel(3, 3));
            Assert.Equal(greenColor, clone.GetSRGBPixel(6, 6));
        }

        [Fact]
        public void TestSurfaceNearestNeighborResize()
        {
            using Surface original = new Surface(30, 40);
            original.SkiaSurface.Canvas.Clear(redColor);
            original.SkiaSurface.Canvas.DrawRect(5, 5, 20, 20, greenPaint);
            using Surface resized = original.ResizeNearestNeighbor(10, 10);
            Assert.Equal(10, resized.Width);
            Assert.Equal(10, resized.Height);
            Assert.Equal(redColor, resized.GetSRGBPixel(0, 0));
            Assert.Equal(redColor, resized.GetSRGBPixel(9, 9));
            Assert.Equal(greenColor, resized.GetSRGBPixel(5, 5));
        }

        [Fact]
        public void TestSurfaceToWriteableBitmap()
        {
            using Surface original = new Surface(30, 40);
            original.SkiaSurface.Canvas.Clear(redColor);
            original.SkiaSurface.Canvas.DrawRect(5, 5, 20, 20, greenPaint);
            var bitmap = original.ToWriteableBitmap();
            byte[] pixels = new byte[30 * 40 * 4];
            bitmap.CopyPixels(pixels, 30 * 4, 0);
            Assert.Equal(redColor, new SKColor(pixels[2], pixels[1], pixels[0], pixels[3]));
            int offset = (30 * 5 + 5) * 4;
            Assert.Equal(greenColor, new SKColor(pixels[2 + offset], pixels[1 + offset], pixels[0 + offset], pixels[3 + offset]));
        }

        [Fact]
        public void TestSurfaceFromWriteableBitmap()
        {
            using Surface original = new Surface(30, 30);
            original.SkiaSurface.Canvas.Clear(SKColors.Transparent);
            original.SkiaSurface.Canvas.DrawRect(5, 5, 20, 20, redPaint);
            original.SkiaSurface.Canvas.DrawRect(10, 10, 20, 20, greenPaint);
            using Surface fromWriteable = new Surface(original.ToWriteableBitmap());
            Assert.Equal(original.GetSRGBPixel(0, 0), fromWriteable.GetSRGBPixel(0, 0));
            Assert.Equal(original.GetSRGBPixel(6, 6), fromWriteable.GetSRGBPixel(6, 6));
            Assert.Equal(original.GetSRGBPixel(15, 15), fromWriteable.GetSRGBPixel(15, 15));
        }
    }
}