From 0663d29795d9af0ab615c8080db119958a0666c0 Mon Sep 17 00:00:00 2001
From: riperiperi <rhy3756547@hotmail.com>
Date: Mon, 23 Mar 2020 14:13:01 +0000
Subject: [PATCH] Index constant buffer vec4s using ternary expressions.

---
 .../CodeGen/Glsl/OperandManager.cs            | 21 +++++++++++++++++--
 1 file changed, 19 insertions(+), 2 deletions(-)

diff --git a/Ryujinx.Graphics.Shader/CodeGen/Glsl/OperandManager.cs b/Ryujinx.Graphics.Shader/CodeGen/Glsl/OperandManager.cs
index 4c9d5b5507..f734580b4e 100644
--- a/Ryujinx.Graphics.Shader/CodeGen/Glsl/OperandManager.cs
+++ b/Ryujinx.Graphics.Shader/CodeGen/Glsl/OperandManager.cs
@@ -114,6 +114,24 @@ namespace Ryujinx.Graphics.Shader.CodeGen.Glsl
             return ubName + "." + GetSwizzleMask(offset & 3);
         }
 
+        private static string GetVec4Indexed(string vectorName, string indexExpr)
+        {
+            bool canIndexVec4 = false;
+            if (canIndexVec4)
+            {
+                return $"{vectorName}[{indexExpr}]";
+            } 
+            else
+            {
+                string result = $"{vectorName}.x";
+                for (int i = 1; i < 4; i++)
+                {
+                    result = $"(({indexExpr}) == {i}) ? ({vectorName}.{GetSwizzleMask(i)}) : ({result})";
+                }
+                return $"({result})";
+            }
+        }
+
         public static string GetConstantBufferName(IAstNode slot, string offsetExpr, ShaderStage stage)
         {
             // Non-constant slots are not supported.
@@ -124,9 +142,8 @@ namespace Ryujinx.Graphics.Shader.CodeGen.Glsl
             string ubName = GetUbName(stage, operand.Value);
 
             string index0 = "[" + offsetExpr + " >> 2]";
-            string index1 = "[" + offsetExpr + " & 3]";
 
-            return ubName + index0 + index1;
+            return GetVec4Indexed(ubName + index0, offsetExpr + " & 3");
         }
 
         public static string GetOutAttributeName(AstOperand attr, ShaderStage stage)