Some small shader related fixes (#258)

* Some small shader related fixes

* Address PR feedback

3 files changed, 36 insertions, 9 deletions

diff --git a/Ryujinx.Graphics/Gal/IGalShader.cs b/Ryujinx.Graphics/Gal/IGalShader.cs
index 06f3fac9..9adaceaf 100644
--- a/Ryujinx.Graphics/Gal/IGalShader.cs
+++ b/Ryujinx.Graphics/Gal/IGalShader.cs
@@ -18,6 +18,8 @@ namespace Ryujinx.Graphics.Gal
 
         void Bind(long Key);
 
+        void Unbind(GalShaderType Type);
+
         void BindProgram();
     }
 }
\ No newline at end of file
diff --git a/Ryujinx.Graphics/Gal/OpenGL/OGLShader.cs b/Ryujinx.Graphics/Gal/OpenGL/OGLShader.cs
index 3c5c874e..c55a758b 100644
--- a/Ryujinx.Graphics/Gal/OpenGL/OGLShader.cs
+++ b/Ryujinx.Graphics/Gal/OpenGL/OGLShader.cs
@@ -203,6 +203,18 @@ namespace Ryujinx.Graphics.Gal.OpenGL
             }
         }
 
+        public void Unbind(GalShaderType Type)
+        {
+            switch (Type)
+            {
+                case GalShaderType.Vertex:         Current.Vertex         = null; break;
+                case GalShaderType.TessControl:    Current.TessControl    = null; break;
+                case GalShaderType.TessEvaluation: Current.TessEvaluation = null; break;
+                case GalShaderType.Geometry:       Current.Geometry       = null; break;
+                case GalShaderType.Fragment:       Current.Fragment       = null; break;
+            }
+        }
+
         public void BindProgram()
         {
             if (Current.Vertex   == null ||
diff --git a/Ryujinx.Graphics/Gal/Shader/GlslDecompiler.cs b/Ryujinx.Graphics/Gal/Shader/GlslDecompiler.cs
index f3075a50..575fb72f 100644
--- a/Ryujinx.Graphics/Gal/Shader/GlslDecompiler.cs
+++ b/Ryujinx.Graphics/Gal/Shader/GlslDecompiler.cs
@@ -216,7 +216,7 @@ namespace Ryujinx.Graphics.Gal.Shader
 
         private void PrintDeclOutAttributes()
         {
-            if (Decl.ShaderType == GalShaderType.Vertex)
+            if (Decl.ShaderType != GalShaderType.Fragment)
             {
                 SB.AppendLine("layout (location = " + GlslDecl.PositionOutAttrLocation + ") out vec4 " + GlslDecl.PositionOutAttrName + ";");
             }
@@ -337,7 +337,10 @@ namespace Ryujinx.Graphics.Gal.Shader
             if (Decl.ShaderType == GalShaderType.Vertex)
             {
                 SB.AppendLine(IdentationStr + "gl_Position.xy *= " + GlslDecl.FlipUniformName + ";");
+            }
 
+            if (Decl.ShaderType != GalShaderType.Fragment)
+            {
                 SB.AppendLine(IdentationStr + GlslDecl.PositionOutAttrName + " = gl_Position;");
                 SB.AppendLine(IdentationStr + GlslDecl.PositionOutAttrName + ".w = 1;");
             }
@@ -598,9 +601,6 @@ namespace Ryujinx.Graphics.Gal.Shader
         {
             switch (Op.Inst)
             {
-                case ShaderIrInst.Frcp:
-                    return true;
-
                 case ShaderIrInst.Ipa:
                 case ShaderIrInst.Texq:
                 case ShaderIrInst.Texs:
@@ -608,8 +608,7 @@ namespace Ryujinx.Graphics.Gal.Shader
                     return false;
             }
 
-            return Op.OperandB != null ||
-                   Op.OperandC != null;
+            return true;
         }
 
         private string GetName(ShaderIrOperCbuf Cbuf)
@@ -711,13 +710,13 @@ namespace Ryujinx.Graphics.Gal.Shader
             }
             else
             {
-                return Imm.Value.ToString(CultureInfo.InvariantCulture);
+                return GetIntConst(Imm.Value);
             }
         }
 
         private string GetValue(ShaderIrOperImmf Immf)
         {
-            return Immf.Value.ToString(CultureInfo.InvariantCulture);
+            return GetFloatConst(Immf.Value);
         }
 
         private string GetName(ShaderIrOperPred Pred)
@@ -1047,7 +1046,7 @@ namespace Ryujinx.Graphics.Gal.Shader
 
                             if (!float.IsNaN(Value) && !float.IsInfinity(Value))
                             {
-                                return Value.ToString(CultureInfo.InvariantCulture);
+                                return GetFloatConst(Value);
                             }
                         }
                         break;
@@ -1064,6 +1063,20 @@ namespace Ryujinx.Graphics.Gal.Shader
             return Expr;
         }
 
+        private static string GetIntConst(int Value)
+        {
+            string Expr = Value.ToString(CultureInfo.InvariantCulture);
+
+            return Value < 0 ? "(" + Expr + ")" : Expr;
+        }
+
+        private static string GetFloatConst(float Value)
+        {
+            string Expr = Value.ToString(CultureInfo.InvariantCulture);
+
+            return Value < 0 ? "(" + Expr + ")" : Expr;
+        }
+
         private static OperType GetDstNodeType(ShaderIrNode Node)
         {
             //Special case instructions with the result type different