Use SSBOs for bindless masking

osu.Framework.Tests/Visual/Graphics/TestSceneScissor.cs

@@ -0,0 +1,94 @@
+// Copyright (c) ppy Pty Ltd <contact@ppy.sh>. Licensed under the MIT Licence.
+// See the LICENCE file in the repository root for full licence text.
+
+using osu.Framework.Graphics;
+using osu.Framework.Graphics.Containers;
+using osu.Framework.Graphics.Shapes;
+using osu.Framework.Graphics.Sprites;
+using osuTK;
+using osuTK.Graphics;
+
+namespace osu.Framework.Tests.Visual.Graphics
+{
+    public partial class TestSceneScissor : FrameworkTestScene
+    {
+        public TestSceneScissor()
+        {
+            Children = new Drawable[]
+            {
+                new Container
+                {
+                    Anchor = Anchor.Centre,
+                    Origin = Anchor.Centre,
+                    RelativeSizeAxes = Axes.Both,
+                    Size = new Vector2(0.5f),
+                    Masking = true,
+                    Child = new Container
+                    {
+                        Anchor = Anchor.Centre,
+                        Origin = Anchor.Centre,
+                        RelativeSizeAxes = Axes.Both,
+                        Size = new Vector2(2),
+                        Masking = true,
+                        Child = new Box
+                        {
+                            RelativeSizeAxes = Axes.Both
+                        },
+                    }
+                },
+                new Container
+                {
+                    Name = "Overlays",
+                    RelativeSizeAxes = Axes.Both,
+                    Masking = true,
+                    BorderColour = Color4.Red,
+                    BorderThickness = 4,
+                    Children = new Drawable[]
+                    {
+                        new Box
+                        {
+                            RelativeSizeAxes = Axes.Both,
+                            Alpha = 0,
+                            AlwaysPresent = true,
+                        },
+                        new SpriteText
+                        {
+                            Anchor = Anchor.TopCentre,
+                            Origin = Anchor.TopCentre,
+                            Text = "Invisible Area",
+                            Colour = Color4.Red,
+                            Font = FontUsage.Default.With(size: 36)
+                        },
+                        new Container
+                        {
+                            Anchor = Anchor.Centre,
+                            Origin = Anchor.Centre,
+                            RelativeSizeAxes = Axes.Both,
+                            Size = new Vector2(0.5f),
+                            Masking = true,
+                            BorderColour = Color4.Green,
+                            BorderThickness = 4,
+                            Children = new Drawable[]
+                            {
+                                new Box
+                                {
+                                    RelativeSizeAxes = Axes.Both,
+                                    Alpha = 0,
+                                    AlwaysPresent = true
+                                },
+                                new SpriteText
+                                {
+                                    Anchor = Anchor.TopCentre,
+                                    Origin = Anchor.TopCentre,
+                                    Text = "Visible Area",
+                                    Colour = Color4.Green,
+                                    Font = FontUsage.Default.With(size: 36)
+                                }
+                            }
+                        }
+                    }
+                }
+            };
+        }
+    }
+}

osu.Framework/Graphics/Audio/WaveformGraph.cs

@@ -336,7 +336,7 @@ public override void Draw(IRenderer renderer)
                 // We're dealing with a _large_ number of points, so we need to optimise the quadToDraw * drawInfo.Matrix multiplications below
                 // for points that are going to be masked out anyway. This allows for higher resolution graphs at larger scales with virtually no performance loss.
                 // Since the points are generated in the local coordinate space, we need to convert the screen space masking quad coordinates into the local coordinate space
-                RectangleF localMaskingRectangle = (Quad.FromRectangle(renderer.CurrentMaskingInfo.ScreenSpaceAABB) * DrawInfo.MatrixInverse).AABBFloat;
+                RectangleF localMaskingRectangle = (Quad.FromRectangle(renderer.CurrentMaskingInfo.ScreenSpaceScissorArea) * DrawInfo.MatrixInverse).AABBFloat;
 
                 float separation = drawSize.X / (points.Count - 1);
 

osu.Framework/Graphics/BufferedDrawNode.cs

@@ -35,6 +35,7 @@ public class BufferedDrawNode : TexturedShaderDrawNode
         protected RectangleF DrawRectangle { get; private set; }
 
         private Color4 backgroundColour;
+        private RectangleF localDrawRectangle;
         private RectangleF screenSpaceDrawRectangle;
         private Vector2 frameBufferScale;
         private Vector2 frameBufferSize;
@@ -52,6 +53,7 @@ public override void ApplyState()
             base.ApplyState();
 
             backgroundColour = Source.BackgroundColour;
+            localDrawRectangle = ((Drawable)Source).DrawRectangle;
             screenSpaceDrawRectangle = Source.ScreenSpaceDrawQuad.AABBFloat;
             DrawColourInfo = Source.FrameBufferDrawColour ?? new DrawColourInfo(Color4.White, base.DrawColourInfo.Blending);
             frameBufferScale = Source.FrameBufferScale;
@@ -155,32 +157,25 @@ protected IDisposable BindFrameBuffer(IFrameBuffer frameBuffer)
 
         private IDisposable establishFrameBufferViewport(IRenderer renderer)
         {
-            // Disable masking for generating the frame buffer since masking will be re-applied
-            // when actually drawing later on anyways. This allows more information to be captured
-            // in the frame buffer and helps with cached buffers being re-used.
-            RectangleI screenSpaceMaskingRect = new RectangleI((int)Math.Floor(screenSpaceDrawRectangle.X), (int)Math.Floor(screenSpaceDrawRectangle.Y), (int)frameBufferSize.X + 1,
-                (int)frameBufferSize.Y + 1);
-
             renderer.PushMaskingInfo(new MaskingInfo
             {
-                ScreenSpaceAABB = screenSpaceMaskingRect,
-                MaskingRect = screenSpaceDrawRectangle,
-                ToMaskingSpace = Matrix3.Identity,
+                ScreenSpaceScissorArea = screenSpaceDrawRectangle,
+                MaskingArea = localDrawRectangle,
+                ToMaskingSpace = DrawInfo.MatrixInverse,
+                ToScissorSpace = Matrix3.Identity,
                 BlendRange = 1,
                 AlphaExponent = 1,
             }, true);
 
             // Match viewport to FrameBuffer such that we don't draw unnecessary pixels.
             renderer.PushViewport(new RectangleI(0, 0, (int)frameBufferSize.X, (int)frameBufferSize.Y));
             renderer.PushScissor(new RectangleI(0, 0, (int)frameBufferSize.X, (int)frameBufferSize.Y));
-            renderer.PushScissorOffset(screenSpaceMaskingRect.Location);
 
             return new ValueInvokeOnDisposal<(BufferedDrawNode node, IRenderer renderer)>((this, renderer), tup => tup.node.returnViewport(tup.renderer));
         }
 
         private void returnViewport(IRenderer renderer)
         {
-            renderer.PopScissorOffset();
             renderer.PopViewport();
             renderer.PopScissor();
             renderer.PopMaskingInfo();

osu.Framework/Graphics/Containers/BufferedContainer.cs

@@ -266,7 +266,7 @@ public BufferedContainer(RenderBufferFormat[] formats = null, bool pixelSnapping
         private void load(ShaderManager shaders)
         {
             TextureShader = shaders.Load(VertexShaderDescriptor.TEXTURE_2, FragmentShaderDescriptor.TEXTURE);
-            blurShader = shaders.Load(VertexShaderDescriptor.TEXTURE_2, FragmentShaderDescriptor.BLUR);
+            blurShader = shaders.Load(VertexShaderDescriptor.TEXTURE_2_NO_MASKING, FragmentShaderDescriptor.BLUR);
         }
 
         protected override DrawNode CreateDrawNode() => new BufferedContainerDrawNode(this, sharedData);

osu.Framework/Graphics/Containers/CompositeDrawable_DrawNode.cs

@@ -43,7 +43,7 @@ protected class CompositeDrawableDrawNode : DrawNode, ICompositeDrawNode
             private MaskingInfo? maskingInfo;
 
             /// <summary>
-            /// The screen-space version of <see cref="MaskingInfo.MaskingRect"/>.
+            /// The screen-space version of <see cref="MaskingInfo.MaskingArea"/>.
             /// Used as cache of screen-space masking quads computed in previous frames.
             /// Assign null to reset.
             /// </summary>
@@ -92,10 +92,11 @@ public override void ApplyState()
                     ? null
                     : new MaskingInfo
                     {
-                        ScreenSpaceAABB = Source.ScreenSpaceDrawQuad.AABB,
-                        MaskingRect = Source.DrawRectangle.Normalize(),
+                        ScreenSpaceScissorArea = Source.ScreenSpaceDrawQuad.AABB,
+                        MaskingArea = Source.DrawRectangle.Normalize(),
                         ConservativeScreenSpaceQuad = Quad.FromRectangle(shrunkDrawRectangle) * DrawInfo.Matrix,
                         ToMaskingSpace = DrawInfo.MatrixInverse,
+                        ToScissorSpace = Matrix3.Identity,
                         CornerRadius = Source.effectiveCornerRadius,
                         CornerExponent = Source.CornerExponent,
                         BorderThickness = Source.BorderThickness,
@@ -121,13 +122,13 @@ private void drawEdgeEffect(IRenderer renderer)
                 if (maskingInfo == null || edgeEffect.Type == EdgeEffectType.None || edgeEffect.Radius <= 0.0f || edgeEffect.Colour.Alpha <= 0)
                     return;
 
-                RectangleF effectRect = maskingInfo.Value.MaskingRect.Inflate(edgeEffect.Radius).Offset(edgeEffect.Offset);
+                RectangleF effectRect = maskingInfo.Value.MaskingArea.Inflate(edgeEffect.Radius).Offset(edgeEffect.Offset);
 
                 screenSpaceMaskingQuad ??= Quad.FromRectangle(effectRect) * DrawInfo.Matrix;
 
                 MaskingInfo edgeEffectMaskingInfo = maskingInfo.Value;
-                edgeEffectMaskingInfo.MaskingRect = effectRect;
-                edgeEffectMaskingInfo.ScreenSpaceAABB = screenSpaceMaskingQuad.Value.AABB;
+                edgeEffectMaskingInfo.MaskingArea = effectRect;
+                edgeEffectMaskingInfo.ScreenSpaceScissorArea = screenSpaceMaskingQuad.Value.AABB;
                 edgeEffectMaskingInfo.CornerRadius = maskingInfo.Value.CornerRadius + edgeEffect.Radius + edgeEffect.Roundness;
                 edgeEffectMaskingInfo.BorderThickness = 0;
                 // HACK HACK HACK. We abuse blend range to give us the linear alpha gradient of

osu.Framework/Graphics/OpenGL/GLRenderer.cs

@@ -283,6 +283,7 @@ public void DrawVertices(PrimitiveType type, int vertexStart, int verticesCount)
             var glShader = (GLShader)Shader!;
 
             glShader.BindUniformBlock("g_GlobalUniforms", GlobalUniformBuffer!);
+            glShader.BindUniformBlock("g_MaskingBuffer", ShaderMaskingStack!.CurrentBuffer);
 
             int currentUniformBinding = 0;
             int currentStorageBinding = 0;

osu.Framework/Graphics/OpenGL/Shaders/GLShaderPart.cs

@@ -5,6 +5,7 @@
 using System.Collections.Generic;
 using System.Globalization;
 using System.IO;
+using System.Linq;
 using System.Text.RegularExpressions;
 using osu.Framework.Graphics.Rendering;
 using osu.Framework.Graphics.Shaders;
@@ -43,11 +44,26 @@ public GLShaderPart(GLRenderer renderer, string name, byte[]? data, ShaderType t
             // Load the shader files.
             shaderCodes.Add(loadFile(data, true));
 
+            // Find the minimum uniform/buffer binding set across all shader codes. This will be a negative number (see sh_GlobalUniforms.h).
+            int minSet = 0;
+
+            foreach (string code in shaderCodes)
+            {
+                minSet = Math.Min(minSet, uniform_pattern.Matches(code)
+                                                         .Where(m => m.Success)
+                                                         .Select(m => int.Parse(m.Groups[2].Value, CultureInfo.InvariantCulture))
+                                                         .DefaultIfEmpty(0).Min());
+            }
+
             // Increment the binding set of all uniform blocks.
             // After this transformation, the g_GlobalUniforms block is placed in set 0 and all other user blocks begin from 1.
             // The difference in implementation here (compared to above) is intentional, as uniform blocks must be consistent between the shader stages, so they can't be easily appended.
             for (int i = 0; i < shaderCodes.Count; i++)
-                shaderCodes[i] = uniform_pattern.Replace(shaderCodes[i], match => $"{match.Groups[1].Value}set = {int.Parse(match.Groups[2].Value, CultureInfo.InvariantCulture) + 1}{match.Groups[3].Value}");
+            {
+                shaderCodes[i] = uniform_pattern.Replace(
+                    shaderCodes[i],
+                    match => $"{match.Groups[1].Value}set = {int.Parse(match.Groups[2].Value, CultureInfo.InvariantCulture) + Math.Abs(minSet)}{match.Groups[3].Value}");
+            }
         }
 
         private string loadFile(byte[]? bytes, bool mainFile)

osu.Framework/Graphics/Rendering/Dummy/DummyRenderer.cs

@@ -29,6 +29,7 @@ public sealed class DummyRenderer : IRenderer
         public bool IsUvOriginTopLeft => true;
         public bool IsClipSpaceYInverted => true;
         public ref readonly MaskingInfo CurrentMaskingInfo => ref maskingInfo;
+        public int CurrentMaskingIndex => 0;
         private readonly MaskingInfo maskingInfo;
 
         public RectangleI Viewport => RectangleI.Empty;

osu.Framework/Graphics/Rendering/FlushBatchSource.cs

@@ -12,7 +12,6 @@ public enum FlushBatchSource
         SetBlendMask,
         SetDepthInfo,
         SetFrameBuffer,
-        SetMasking,
         SetProjection,
         SetScissor,
         SetShader,

osu.Framework/Graphics/Rendering/GlobalUniformData.cs

@@ -16,23 +16,9 @@ public record struct GlobalUniformData
         public UniformBool IsUvOriginTopLeft;
 
         public UniformMatrix4 ProjMatrix;
-        public UniformMatrix3 ToMaskingSpace;
-        public UniformBool IsMasking;
-        public UniformFloat CornerRadius;
-        public UniformFloat CornerExponent;
-        private readonly UniformPadding4 pad2;
 
-        public UniformVector4 MaskingRect;
-        public UniformFloat BorderThickness;
-        private readonly UniformPadding12 pad3;
-
-        public UniformMatrix4 BorderColour;
-        public UniformFloat MaskingBlendRange;
-        public UniformFloat AlphaExponent;
-        public UniformVector2 EdgeOffset;
-        public UniformBool DiscardInner;
-        public UniformFloat InnerCornerRadius;
         public UniformInt WrapModeS;
         public UniformInt WrapModeT;
+        private readonly UniformPadding8 pad1;
     }
 }

osu.Framework/Graphics/Rendering/IRenderer.cs

@@ -98,6 +98,8 @@ public interface IRenderer
         /// </summary>
         ref readonly MaskingInfo CurrentMaskingInfo { get; }
 
+        int CurrentMaskingIndex { get; }
+
         /// <summary>
         /// The current viewport.
         /// </summary>
@@ -276,17 +278,6 @@ public interface IRenderer
         /// </summary>
         void PopScissor();
 
-        /// <summary>
-        /// Applies a new scissor offset to the scissor rectangle.
-        /// </summary>
-        /// <param name="offset">The scissor offset.</param>
-        void PushScissorOffset(Vector2I offset);
-
-        /// <summary>
-        /// Restores the last scissor offset.
-        /// </summary>
-        void PopScissorOffset();
-
         /// <summary>
         /// Applies a new projection matrix.
         /// </summary>

osu.Framework/Graphics/Rendering/MaskingInfo.cs

@@ -10,18 +10,34 @@ namespace osu.Framework.Graphics.Rendering
 {
     public struct MaskingInfo : IEquatable<MaskingInfo>
     {
-        public RectangleI ScreenSpaceAABB;
-        public RectangleF MaskingRect;
+        /// <summary>
+        /// A rectangle that defines the scissor area in screen-space coordinates.
+        /// </summary>
+        public RectangleI ScreenSpaceScissorArea;
+
+        /// <summary>
+        /// A rectangle that defines the masking area in the local-space (i.e. <see cref="Drawable.DrawRectangle"/>) of the masking container.
+        /// </summary>
+        public RectangleF MaskingArea;
 
+        /// <summary>
+        /// A quad representing the internal "safe" (without borders, corners, and AA smoothening) area of the masking container.
+        /// </summary>
+        /// <remarks>
+        /// This is used to clip drawn polygons during the front-to-back pass such that only areas guaranteed to be visible are drawn.
+        /// </remarks>
         public Quad ConservativeScreenSpaceQuad;
 
         /// <summary>
-        /// This matrix transforms screen space coordinates to masking space (likely the parent
-        /// space of the container doing the masking).
-        /// It is used by a shader to determine which pixels to discard.
+        /// A matrix that converts from vertex coordinates to the space of <see cref="MaskingArea"/>.
         /// </summary>
         public Matrix3 ToMaskingSpace;
 
+        /// <summary>
+        /// A matrix that converts from vertex coordinates to the space of <see cref="ScreenSpaceScissorArea"/>.
+        /// </summary>
+        public Matrix3 ToScissorSpace;
+
         public float CornerRadius;
         public float CornerExponent;
 
@@ -39,10 +55,11 @@ public struct MaskingInfo : IEquatable<MaskingInfo>
         public readonly bool Equals(MaskingInfo other) => this == other;
 
         public static bool operator ==(in MaskingInfo left, in MaskingInfo right) =>
-            left.ScreenSpaceAABB == right.ScreenSpaceAABB &&
-            left.MaskingRect == right.MaskingRect &&
+            left.ScreenSpaceScissorArea == right.ScreenSpaceScissorArea &&
+            left.MaskingArea == right.MaskingArea &&
             left.ConservativeScreenSpaceQuad.Equals(right.ConservativeScreenSpaceQuad) &&
             left.ToMaskingSpace == right.ToMaskingSpace &&
+            left.ToScissorSpace == right.ToScissorSpace &&
             left.CornerRadius == right.CornerRadius &&
             left.CornerExponent == right.CornerExponent &&
             left.BorderThickness == right.BorderThickness &&