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.

2 files changed, 18 insertions, 0 deletions

diff --git a/Ryujinx.Graphics.Shader/CodeGen/Glsl/HelperFunctions/TexelFetchScale_cp.glsl b/Ryujinx.Graphics.Shader/CodeGen/Glsl/HelperFunctions/TexelFetchScale_cp.glsl
new file mode 100644
index 00000000..381566d3
--- /dev/null
+++ b/Ryujinx.Graphics.Shader/CodeGen/Glsl/HelperFunctions/TexelFetchScale_cp.glsl
@@ -0,0 +1,7 @@
+ivec2 Helper_TexelFetchScale(ivec2 inputVec, int samplerIndex) {
+    float scale = cp_renderScale[samplerIndex];
+    if (scale == 1.0) {
+        return inputVec;
+    }
+    return ivec2(vec2(inputVec) * scale);
+}
\ No newline at end of file
diff --git a/Ryujinx.Graphics.Shader/CodeGen/Glsl/HelperFunctions/TexelFetchScale_fp.glsl b/Ryujinx.Graphics.Shader/CodeGen/Glsl/HelperFunctions/TexelFetchScale_fp.glsl
new file mode 100644
index 00000000..4efaa65a
--- /dev/null
+++ b/Ryujinx.Graphics.Shader/CodeGen/Glsl/HelperFunctions/TexelFetchScale_fp.glsl
@@ -0,0 +1,11 @@
+ivec2 Helper_TexelFetchScale(ivec2 inputVec, int samplerIndex) {
+    float scale = fp_renderScale[1 + samplerIndex];
+    if (scale == 1.0) {
+        return inputVec;
+    }
+    if (scale < 0.0) { // If less than 0, try interpolate between texels by using the screen position.
+        return ivec2(vec2(inputVec) * (-scale) + mod(gl_FragCoord.xy, -scale));
+    } else {
+        return ivec2(vec2(inputVec) * scale);
+    }
+}
\ No newline at end of file