1 files changed, 34 insertions, 2 deletions

diff --git a/src/video_core/renderer_opengl/gl_shader_decompiler.cpp b/src/video_core/renderer_opengl/gl_shader_decompiler.cpp
index e890cfe57..cbf501cc7 100644
--- a/src/video_core/renderer_opengl/gl_shader_decompiler.cpp
+++ b/src/video_core/renderer_opengl/gl_shader_decompiler.cpp
@@ -1280,13 +1280,13 @@ private:
                 header.ps.IsColorComponentOutputEnabled(render_target, 1) ||
                 header.ps.IsColorComponentOutputEnabled(render_target, 2) ||
                 header.ps.IsColorComponentOutputEnabled(render_target, 3)) {
-                shader.AddLine(fmt::format("if ({} < alpha_testing_ref) discard;",
+                shader.AddLine(fmt::format("if (AlphaFunc({}, alpha_testing_ref, alpha_testing_func)) discard;",
                                            regs.GetRegisterAsFloat(current_reg)));
                 current_reg += 4;
             }
         }
         --shader.scope;
-        shader.AddLine("}");
+        shader.AddLine('}');
 
         // Write the color outputs using the data in the shader registers, disabled
         // rendertargets/components are skipped in the register assignment.
@@ -3505,6 +3505,38 @@ private:
             declarations.AddLine("bool " + pred + " = false;");
         }
         declarations.AddNewLine();
+        GenerateFunctionDeclarations();
+    }
+
+    void GenerateFunctionDeclarations() {
+        if (stage == Maxwell3D::Regs::ShaderStage::Fragment) {
+            declarations.AddLine("bool AlphaFunc(in float value, in float ref, in uint func) {");
+            declarations.scope++;
+            declarations.AddLine("switch (func) {");
+            declarations.scope++;
+            declarations.AddLine("case 1:");
+            declarations.AddLine("return false;");
+            declarations.AddLine("case 2:");
+            declarations.AddLine("return value < ref;");
+            declarations.AddLine("case 3:");
+            declarations.AddLine("return value == ref;");
+            declarations.AddLine("case 4:");
+            declarations.AddLine("return value <= ref;");
+            declarations.AddLine("case 5:");
+            declarations.AddLine("return value > ref;");
+            declarations.AddLine("case 6:");
+            declarations.AddLine("return value != ref;");
+            declarations.AddLine("case 7:");
+            declarations.AddLine("return value >= ref;");
+            declarations.AddLine("case 8:");
+            declarations.AddLine("return true;");
+            declarations.AddLine("default:");
+            declarations.AddLine("return false;");
+            declarations.scope--;
+            declarations.AddLine('}');
+            declarations.scope--;
+            declarations.AddLine('}');
+        }
     }
 
 private: