Add area sampling scaler to allow for super-sampled anti-aliasing. (#7304)

* Add area sampling scaler to allow for super-sampled anti-aliasing.

* Area scaling filter doesn't have a scaling level.

* Add further clarification to the tooltip on how to achieve supersampling.

* ShaderHelper: Merge the two CompileProgram functions.

* Convert tabs to spaces in area scaling shaders

* Fixup Vulkan and OpenGL project files.

* AreaScaling: Replace texture() by texelFetch() and use integer vectors.

No functional difference, but it cleans up the code a bit.

* AreaScaling: Delete unused sharpening level member.

Also rename _scale to _sharpeningLevel for clarity and consistency.

* AreaScaling: Delete unused scaleX/scaleY uniforms.

* AreaScaling: Force the alpha to 1 when storing the pixel.

* AreaScaling: Remove left-over sharpening buffer.

1 files changed, 106 insertions, 0 deletions

diff --git a/src/Ryujinx.Graphics.OpenGL/Effects/AreaScalingFilter.cs b/src/Ryujinx.Graphics.OpenGL/Effects/AreaScalingFilter.cs
new file mode 100644
index 00000000..9b19f2f2
--- /dev/null
+++ b/src/Ryujinx.Graphics.OpenGL/Effects/AreaScalingFilter.cs
@@ -0,0 +1,106 @@
+using OpenTK.Graphics.OpenGL;
+using Ryujinx.Common;
+using Ryujinx.Graphics.GAL;
+using Ryujinx.Graphics.OpenGL.Image;
+using System;
+using static Ryujinx.Graphics.OpenGL.Effects.ShaderHelper;
+
+namespace Ryujinx.Graphics.OpenGL.Effects
+{
+    internal class AreaScalingFilter : IScalingFilter
+    {
+        private readonly OpenGLRenderer _renderer;
+        private int _inputUniform;
+        private int _outputUniform;
+        private int _srcX0Uniform;
+        private int _srcX1Uniform;
+        private int _srcY0Uniform;
+        private int _scalingShaderProgram;
+        private int _srcY1Uniform;
+        private int _dstX0Uniform;
+        private int _dstX1Uniform;
+        private int _dstY0Uniform;
+        private int _dstY1Uniform;
+
+        public float Level { get; set; }
+
+        public AreaScalingFilter(OpenGLRenderer renderer)
+        {
+            Initialize();
+
+            _renderer = renderer;
+        }
+
+        public void Dispose()
+        {
+            if (_scalingShaderProgram != 0)
+            {
+                GL.DeleteProgram(_scalingShaderProgram);
+            }
+        }
+
+        private void Initialize()
+        {
+            var scalingShader = EmbeddedResources.ReadAllText("Ryujinx.Graphics.OpenGL/Effects/Shaders/area_scaling.glsl");
+
+            _scalingShaderProgram = CompileProgram(scalingShader, ShaderType.ComputeShader);
+
+            _inputUniform = GL.GetUniformLocation(_scalingShaderProgram, "Source");
+            _outputUniform = GL.GetUniformLocation(_scalingShaderProgram, "imgOutput");
+
+            _srcX0Uniform = GL.GetUniformLocation(_scalingShaderProgram, "srcX0");
+            _srcX1Uniform = GL.GetUniformLocation(_scalingShaderProgram, "srcX1");
+            _srcY0Uniform = GL.GetUniformLocation(_scalingShaderProgram, "srcY0");
+            _srcY1Uniform = GL.GetUniformLocation(_scalingShaderProgram, "srcY1");
+            _dstX0Uniform = GL.GetUniformLocation(_scalingShaderProgram, "dstX0");
+            _dstX1Uniform = GL.GetUniformLocation(_scalingShaderProgram, "dstX1");
+            _dstY0Uniform = GL.GetUniformLocation(_scalingShaderProgram, "dstY0");
+            _dstY1Uniform = GL.GetUniformLocation(_scalingShaderProgram, "dstY1");
+        }
+
+        public void Run(
+            TextureView view,
+            TextureView destinationTexture,
+            int width,
+            int height,
+            Extents2D source,
+            Extents2D destination)
+        {
+            int previousProgram = GL.GetInteger(GetPName.CurrentProgram);
+            int previousUnit = GL.GetInteger(GetPName.ActiveTexture);
+            GL.ActiveTexture(TextureUnit.Texture0);
+            int previousTextureBinding = GL.GetInteger(GetPName.TextureBinding2D);
+
+            GL.BindImageTexture(0, destinationTexture.Handle, 0, false, 0, TextureAccess.ReadWrite, SizedInternalFormat.Rgba8);
+
+            int threadGroupWorkRegionDim = 16;
+            int dispatchX = (width + (threadGroupWorkRegionDim - 1)) / threadGroupWorkRegionDim;
+            int dispatchY = (height + (threadGroupWorkRegionDim - 1)) / threadGroupWorkRegionDim;
+
+            // Scaling pass
+            GL.UseProgram(_scalingShaderProgram);
+            view.Bind(0);
+            GL.Uniform1(_inputUniform, 0);
+            GL.Uniform1(_outputUniform, 0);
+            GL.Uniform1(_srcX0Uniform, (float)source.X1);
+            GL.Uniform1(_srcX1Uniform, (float)source.X2);
+            GL.Uniform1(_srcY0Uniform, (float)source.Y1);
+            GL.Uniform1(_srcY1Uniform, (float)source.Y2);
+            GL.Uniform1(_dstX0Uniform, (float)destination.X1);
+            GL.Uniform1(_dstX1Uniform, (float)destination.X2);
+            GL.Uniform1(_dstY0Uniform, (float)destination.Y1);
+            GL.Uniform1(_dstY1Uniform, (float)destination.Y2);
+            GL.DispatchCompute(dispatchX, dispatchY, 1);
+
+            GL.UseProgram(previousProgram);
+            GL.MemoryBarrier(MemoryBarrierFlags.ShaderImageAccessBarrierBit);
+
+            (_renderer.Pipeline as Pipeline).RestoreImages1And2();
+
+            GL.ActiveTexture(TextureUnit.Texture0);
+            GL.BindTexture(TextureTarget.Texture2D, previousTextureBinding);
+
+            GL.ActiveTexture((TextureUnit)previousUnit);
+        }
+    }
+}