Merge pull request #59 from andy840119/fix-masking-issue

Implement masking container.

osu.Framework.Font.Tests/Visual/Containers/MaskingContainerTestScene.cs

@@ -0,0 +1,60 @@
+// Copyright (c) andy840119 <[email protected]>. Licensed under the MIT Licence.
+// See the LICENCE file in the repository root for full licence text.
+
+using NUnit.Framework;
+using osu.Framework.Graphics;
+using osu.Framework.Graphics.Containers;
+using osu.Framework.Graphics.Shapes;
+using osuTK;
+using osuTK.Graphics;
+
+namespace osu.Framework.Font.Tests.Visual.Containers
+{
+    public class MaskingContainerTestScene : BackgroundGridTestSample
+    {
+        private readonly MaskingContainer<Drawable> maskingContainer;
+
+        public MaskingContainerTestScene()
+        {
+            Child = maskingContainer = new MaskingContainer<Drawable>
+            {
+                Anchor = Anchor.Centre,
+                Origin = Anchor.Centre,
+                Size = new Vector2(200),
+                Children = new Drawable[]
+                {
+                    new Box
+                    {
+                        Anchor = Anchor.Centre,
+                        Origin = Anchor.Centre,
+                        Size = new Vector2(250),
+                        Colour = Colour4.Red
+                    },
+                    new DraggableCircle
+                    {
+                        Anchor = Anchor.Centre,
+                        Origin = Anchor.Centre,
+                        Colour = Color4.Blue,
+                        Size = new Vector2(100)
+                    }
+                }
+            };
+        }
+
+        [TestCase(Edges.None)]
+        [TestCase(Edges.Left)]
+        [TestCase(Edges.Right)]
+        [TestCase(Edges.Top)]
+        [TestCase(Edges.Bottom)]
+        [TestCase(Edges.Vertical)]
+        [TestCase(Edges.Horizontal)]
+        [TestCase(Edges.Left | Edges.Top)]
+        public void TestMasking(Edges edges)
+        {
+            AddStep("apply masking", () =>
+            {
+                maskingContainer.MaskingEdges = edges;
+            });
+        }
+    }
+}

osu.Framework.Font/Graphics/Containers/MaskingContainer.cs

@@ -0,0 +1,107 @@
+// Copyright (c) andy840119 <[email protected]>. Licensed under the MIT Licence.
+// See the LICENCE file in the repository root for full licence text.
+
+using System;
+using osu.Framework.Graphics.OpenGL;
+using osu.Framework.Graphics.OpenGL.Vertices;
+using osu.Framework.Graphics.Primitives;
+
+namespace osu.Framework.Graphics.Containers
+{
+    /// <summary>
+    /// It's a container that only masking target direction.
+    /// </summary>
+    /// <typeparam name="T"></typeparam>
+    public class MaskingContainer<T> : Container<T> where T : Drawable
+    {
+        /// <summary>
+        /// If enabled, only the portion of children that falls within this <see cref="Container"/>'s
+        /// shape is drawn to the screen.
+        /// </summary>
+        public new bool Masking
+        {
+            get => throw new InvalidOperationException("Should not get masking in here.");
+            set => throw new InvalidOperationException("Should not assign masking in here.");
+        }
+
+        private Edges maskingEdges = Edges.None;
+
+        public Edges MaskingEdges
+        {
+            get => maskingEdges;
+            set
+            {
+                if (maskingEdges == value)
+                    return;
+
+                maskingEdges = value;
+                Invalidate(Invalidation.DrawNode);
+            }
+        }
+
+        protected override DrawNode CreateDrawNode()
+            => new MaskingCompositeDrawableDrawNode(this);
+
+        protected class MaskingCompositeDrawableDrawNode : CompositeDrawableDrawNode
+        {
+            protected new MaskingContainer<T> Source => (MaskingContainer<T>)base.Source;
+
+            /// <summary>
+            /// Information about how masking of children should be carried out.
+            /// </summary>
+            private MaskingInfo? maskingInfo;
+
+            public MaskingCompositeDrawableDrawNode(CompositeDrawable source)
+                : base(source)
+            {
+            }
+
+            public override void ApplyState()
+            {
+                base.ApplyState();
+
+                maskingInfo = Source.MaskingEdges == Edges.None
+                    ? (MaskingInfo?)null
+                    : new MaskingInfo
+                    {
+                        ScreenSpaceAABB = generateMasking(Source.ScreenSpaceDrawQuad.AABB, Source.MaskingEdges),
+                    };
+            }
+
+            private static RectangleI generateMasking(RectangleI source, Edges edges)
+            {
+                return source.Inflate(getExtendSize(Edges.Left), getExtendSize(Edges.Right), getExtendSize(Edges.Top), getExtendSize(Edges.Bottom));
+
+                int getExtendSize(Edges flag)
+                {
+                    const int extend_size = 1000;
+                    return edges.HasFlag(flag) ? 0 : extend_size;
+                }
+            }
+
+            public override void Draw(Action<TexturedVertex2D> vertexAction)
+            {
+                // will not working if not adding masking info into here.
+                if (maskingInfo != null)
+                    GLWrapper.PushMaskingInfo(maskingInfo.Value);
+
+                base.Draw(vertexAction);
+
+                if (maskingInfo != null)
+                    GLWrapper.PopMaskingInfo();
+            }
+
+            protected override void DrawChildrenOpaqueInteriors(DepthValue depthValue, Action<TexturedVertex2D> vertexAction)
+            {
+                // will have black border if not adding masking info into here.
+                if (maskingInfo != null)
+                    GLWrapper.PushMaskingInfo(maskingInfo.Value);
+
+                base.DrawChildrenOpaqueInteriors(depthValue, vertexAction);
+
+                if (maskingInfo != null)
+                    GLWrapper.PopMaskingInfo();
+            }
+        }
+    }
+}

osu.Framework.Font/Graphics/Sprites/KaraokeSpriteText.cs

@@ -20,10 +20,10 @@ public class KaraokeSpriteText : KaraokeSpriteText<LyricSpriteText>
 
     public partial class KaraokeSpriteText<T> : CompositeDrawable, IMultiShaderBufferedDrawable, IHasRuby, IHasRomaji where T : LyricSpriteText, new()
     {
-        private readonly Container frontLyricTextContainer;
+        private readonly MaskingContainer<T> frontLyricTextContainer;
         private readonly T frontLyricText;
 
-        private readonly Container backLyricTextContainer;
+        private readonly MaskingContainer<T> backLyricTextContainer;
         private readonly T backLyricText;
 
         public IShader TextureShader { get; private set; }
@@ -34,23 +34,22 @@ public KaraokeSpriteText()
             AutoSizeAxes = Axes.Both;
             InternalChildren = new Drawable[]
             {
-                backLyricTextContainer = new Container
+                backLyricTextContainer = new MaskingContainer<T>
                 {
                     AutoSizeAxes = Axes.Y,
                     Anchor = Anchor.CentreRight,
                     Origin = Anchor.CentreRight,
-                    Masking = true,
+                    MaskingEdges = Edges.Left,
                     Child = backLyricText = new T
                     {
                         Anchor = Anchor.CentreRight,
                         Origin = Anchor.CentreRight,
                     }
                 },
-                frontLyricTextContainer = new Container
+                frontLyricTextContainer = new MaskingContainer<T>
                 {
                     AutoSizeAxes = Axes.Y,
-
-                    Masking = true,
+                    MaskingEdges = Edges.Right,
                     Child = frontLyricText = new T(),
                 }
             };