Shader Recomnpiler: implement textuzreGrad 3D emulation constant propagation

1 files changed, 7 insertions, 1 deletions

diff --git a/src/shader_recompiler/backend/glsl/emit_glsl_image.cpp b/src/shader_recompiler/backend/glsl/emit_glsl_image.cpp
index 418505475..3ad668a47 100644
--- a/src/shader_recompiler/backend/glsl/emit_glsl_image.cpp
+++ b/src/shader_recompiler/backend/glsl/emit_glsl_image.cpp
@@ -548,7 +548,7 @@ void EmitImageGradient(EmitContext& ctx, IR::Inst& inst, const IR::Value& index,
     if (sparse_inst) {
         throw NotImplementedException("EmitImageGradient Sparse");
     }
-    if (!offset.IsEmpty()) {
+    if (!offset.IsEmpty() && info.num_derivates <= 2) {
         throw NotImplementedException("EmitImageGradient offset");
     }
     const auto texture{Texture(ctx, info, index)};
@@ -556,6 +556,12 @@ void EmitImageGradient(EmitContext& ctx, IR::Inst& inst, const IR::Value& index,
     const bool multi_component{info.num_derivates > 1 || info.has_lod_clamp};
     const auto derivatives_vec{ctx.var_alloc.Consume(derivatives)};
     if (multi_component) {
+        if (info.num_derivates >= 3) {
+            const auto offset_vec{ctx.var_alloc.Consume(offset)};
+            ctx.Add("{}=textureGrad({},{},vec3({}.xz, {}.x),vec3({}.yz, {}.y));", texel, texture,
+                    coords, derivatives_vec, offset_vec, derivatives_vec, offset_vec);
+            return;
+        }
         ctx.Add("{}=textureGrad({},{},vec2({}.xz),vec2({}.yz));", texel, texture, coords,
                 derivatives_vec, derivatives_vec);
     } else {