Implement Zero-Configuration Resolution Scaling (#1365)

* Initial implementation of Render Target Scaling

Works with most games I have. No GUI option right now, it is hardcoded.

Missing handling for texelFetch operation.

* Realtime Configuration, refactoring.

* texelFetch scaling on fragment shader (WIP)

* Improve Shader-Side changes.

* Fix potential crash when no color/depth bound

* Workaround random uses of textures in compute.

This was blacklisting textures in a few games despite causing no bugs. Will eventually add full support so this doesn't break anything.

* Fix scales oscillating when changing between non-native scales.

* Scaled textures on compute, cleanup, lazier uniform update.

* Cleanup.

* Fix stupidity

* Address Thog Feedback.

* Cover most of GDK's feedback (two comments remain)

* Fix bad rename

* Move IsDepthStencil to FormatExtensions, add docs.

* Fix default config, square texture detection.

* Three final fixes:

- Nearest copy when texture is integer format.
- Texture2D -> Texture3D copy correctly blacklists the texture before trying an unscaled copy (caused driver error)
- Discount small textures.

* Remove scale threshold.

Not needed right now - we'll see if we run into problems.

* All CPU modification blacklists scale.

* Fix comment.

1 files changed, 28 insertions, 1 deletions

diff --git a/Ryujinx.Graphics.Shader/CodeGen/Glsl/Instructions/InstGenMemory.cs b/Ryujinx.Graphics.Shader/CodeGen/Glsl/Instructions/InstGenMemory.cs
index d05c77df..b951798d 100644
--- a/Ryujinx.Graphics.Shader/CodeGen/Glsl/Instructions/InstGenMemory.cs
+++ b/Ryujinx.Graphics.Shader/CodeGen/Glsl/Instructions/InstGenMemory.cs
@@ -390,7 +390,34 @@ namespace Ryujinx.Graphics.Shader.CodeGen.Glsl.Instructions
                 }
             }
 
-            Append(AssemblePVector(pCount));
+            string ApplyScaling(string vector)
+            {
+                if (intCoords)
+                {
+                    int index = context.FindTextureDescriptorIndex(texOp);
+
+                    if ((context.Config.Stage == ShaderStage.Fragment || context.Config.Stage == ShaderStage.Compute) &&
+                        (texOp.Flags & TextureFlags.Bindless) == 0 &&
+                        texOp.Type != SamplerType.Indexed &&
+                        pCount == 2)
+                    {
+                        return "Helper_TexelFetchScale(" + vector + ", " + index + ")";
+                    }
+                    else
+                    {
+                        // Resolution scaling cannot be applied to this texture right now.
+                        // Flag so that we know to blacklist scaling on related textures when binding them.
+
+                        TextureDescriptor descriptor = context.TextureDescriptors[index];
+                        descriptor.Flags |= TextureUsageFlags.ResScaleUnsupported;
+                        context.TextureDescriptors[index] = descriptor;
+                    }
+                }
+
+                return vector;
+            }
+
+            Append(ApplyScaling(AssemblePVector(pCount)));
 
             string AssembleDerivativesVector(int count)
             {