Implement BGRA texture support (#1418)

* Implement BGRA texture support

* Missing AppendLine

* Remove empty lines

* Address PR feedback

5 files changed, 54 insertions, 11 deletions

diff --git a/Ryujinx.Graphics.Shader/CodeGen/Glsl/Declarations.cs b/Ryujinx.Graphics.Shader/CodeGen/Glsl/Declarations.cs
index efd30143..40e277e0 100644
--- a/Ryujinx.Graphics.Shader/CodeGen/Glsl/Declarations.cs
+++ b/Ryujinx.Graphics.Shader/CodeGen/Glsl/Declarations.cs
@@ -139,6 +139,12 @@ namespace Ryujinx.Graphics.Shader.CodeGen.Glsl
 
             if (context.Config.Stage == ShaderStage.Fragment || context.Config.Stage == ShaderStage.Compute)
             {
+                if (context.Config.Stage == ShaderStage.Fragment)
+                {
+                    context.AppendLine($"uniform bool {DefaultNames.IsBgraName}[8];");
+                    context.AppendLine();
+                }
+
                 if (DeclareRenderScale(context))
                 {
                     context.AppendLine();
diff --git a/Ryujinx.Graphics.Shader/CodeGen/Glsl/DefaultNames.cs b/Ryujinx.Graphics.Shader/CodeGen/Glsl/DefaultNames.cs
index 4da38b2d..d1cf4636 100644
--- a/Ryujinx.Graphics.Shader/CodeGen/Glsl/DefaultNames.cs
+++ b/Ryujinx.Graphics.Shader/CodeGen/Glsl/DefaultNames.cs
@@ -23,5 +23,7 @@ namespace Ryujinx.Graphics.Shader.CodeGen.Glsl
         public const string SharedMemoryName = "shared_mem";
 
         public const string UndefinedName = "undef";
+
+        public const string IsBgraName = "is_bgra";
     }
 }
\ No newline at end of file
diff --git a/Ryujinx.Graphics.Shader/CodeGen/Glsl/OperandManager.cs b/Ryujinx.Graphics.Shader/CodeGen/Glsl/OperandManager.cs
index 8801fc11..4ae9a00a 100644
--- a/Ryujinx.Graphics.Shader/CodeGen/Glsl/OperandManager.cs
+++ b/Ryujinx.Graphics.Shader/CodeGen/Glsl/OperandManager.cs
@@ -64,6 +64,16 @@ namespace Ryujinx.Graphics.Shader.CodeGen.Glsl
             { AttributeConsts.GtMask,              new BuiltInAttribute("unpackUint2x32(gl_SubGroupGtMaskARB).x", VariableType.U32) },
             { AttributeConsts.LeMask,              new BuiltInAttribute("unpackUint2x32(gl_SubGroupLeMaskARB).x", VariableType.U32) },
             { AttributeConsts.LtMask,              new BuiltInAttribute("unpackUint2x32(gl_SubGroupLtMaskARB).x", VariableType.U32) },
+
+            // Support uniforms.
+            { AttributeConsts.FragmentOutputIsBgraBase + 0,  new BuiltInAttribute($"{DefaultNames.IsBgraName}[0]",  VariableType.Bool) },
+            { AttributeConsts.FragmentOutputIsBgraBase + 4,  new BuiltInAttribute($"{DefaultNames.IsBgraName}[1]",  VariableType.Bool) },
+            { AttributeConsts.FragmentOutputIsBgraBase + 8,  new BuiltInAttribute($"{DefaultNames.IsBgraName}[2]",  VariableType.Bool) },
+            { AttributeConsts.FragmentOutputIsBgraBase + 12, new BuiltInAttribute($"{DefaultNames.IsBgraName}[3]",  VariableType.Bool) },
+            { AttributeConsts.FragmentOutputIsBgraBase + 16, new BuiltInAttribute($"{DefaultNames.IsBgraName}[4]",  VariableType.Bool) },
+            { AttributeConsts.FragmentOutputIsBgraBase + 20, new BuiltInAttribute($"{DefaultNames.IsBgraName}[5]",  VariableType.Bool) },
+            { AttributeConsts.FragmentOutputIsBgraBase + 24, new BuiltInAttribute($"{DefaultNames.IsBgraName}[6]",  VariableType.Bool) },
+            { AttributeConsts.FragmentOutputIsBgraBase + 28, new BuiltInAttribute($"{DefaultNames.IsBgraName}[7]",  VariableType.Bool) }
         };
 
         private Dictionary<AstOperand, string> _locals;
@@ -149,8 +159,7 @@ namespace Ryujinx.Graphics.Shader.CodeGen.Glsl
 
             char swzMask = GetSwizzleMask((value >> 2) & 3);
 
-            if (value >= AttributeConsts.UserAttributeBase &&
-                value <  AttributeConsts.UserAttributeEnd)
+            if (value >= AttributeConsts.UserAttributeBase && value < AttributeConsts.UserAttributeEnd)
             {
                 value -= AttributeConsts.UserAttributeBase;
 
@@ -169,8 +178,7 @@ namespace Ryujinx.Graphics.Shader.CodeGen.Glsl
             }
             else
             {
-                if (value >= AttributeConsts.FragmentOutputColorBase &&
-                    value <  AttributeConsts.FragmentOutputColorEnd)
+                if (value >= AttributeConsts.FragmentOutputColorBase && value < AttributeConsts.FragmentOutputColorEnd)
                 {
                     value -= AttributeConsts.FragmentOutputColorBase;
 
diff --git a/Ryujinx.Graphics.Shader/Translation/AttributeConsts.cs b/Ryujinx.Graphics.Shader/Translation/AttributeConsts.cs
index 8ff37429..c194b5c2 100644
--- a/Ryujinx.Graphics.Shader/Translation/AttributeConsts.cs
+++ b/Ryujinx.Graphics.Shader/Translation/AttributeConsts.cs
@@ -35,6 +35,9 @@ namespace Ryujinx.Graphics.Shader.Translation
         public const int FragmentOutputColorBase = 0x1000010;
         public const int FragmentOutputColorEnd  = FragmentOutputColorBase + 8 * 16;
 
+        public const int FragmentOutputIsBgraBase = 0x1000100;
+        public const int FragmentOutputIsBgraEnd  = FragmentOutputIsBgraBase + 8 * 4;
+
         public const int ThreadIdX = 0x2000000;
         public const int ThreadIdY = 0x2000004;
         public const int ThreadIdZ = 0x2000008;
diff --git a/Ryujinx.Graphics.Shader/Translation/EmitterContext.cs b/Ryujinx.Graphics.Shader/Translation/EmitterContext.cs
index 39532a64..9b26fa4a 100644
--- a/Ryujinx.Graphics.Shader/Translation/EmitterContext.cs
+++ b/Ryujinx.Graphics.Shader/Translation/EmitterContext.cs
@@ -115,22 +115,46 @@ namespace Ryujinx.Graphics.Shader.Translation
 
                 int regIndex = 0;
 
-                for (int attachment = 0; attachment < 8; attachment++)
+                for (int rtIndex = 0; rtIndex < 8; rtIndex++)
                 {
-                    OmapTarget target = Config.OmapTargets[attachment];
+                    OmapTarget target = Config.OmapTargets[rtIndex];
 
                     for (int component = 0; component < 4; component++)
                     {
-                        if (target.ComponentEnabled(component))
+                        if (!target.ComponentEnabled(component))
                         {
-                            Operand dest = Attribute(AttributeConsts.FragmentOutputColorBase + attachment * 16 + component * 4);
+                            continue;
+                        }
+
+                        int fragmentOutputColorAttr = AttributeConsts.FragmentOutputColorBase + rtIndex * 16;
+
+                        Operand src = Register(regIndex, RegisterType.Gpr);
+
+                        // Perform B <-> R swap if needed, for BGRA formats (not supported on OpenGL).
+                        if (component == 0 || component == 2)
+                        {
+                            Operand isBgra = Attribute(AttributeConsts.FragmentOutputIsBgraBase + rtIndex * 4);
+
+                            Operand lblIsBgra = Label();
+                            Operand lblEnd    = Label();
 
-                            Operand src = Register(regIndex, RegisterType.Gpr);
+                            this.BranchIfTrue(lblIsBgra, isBgra);
 
-                            this.Copy(dest, src);
+                            this.Copy(Attribute(fragmentOutputColorAttr + component * 4), src);
+                            this.Branch(lblEnd);
 
-                            regIndex++;
+                            MarkLabel(lblIsBgra);
+
+                            this.Copy(Attribute(fragmentOutputColorAttr + (2 - component) * 4), src);
+
+                            MarkLabel(lblEnd);
                         }
+                        else
+                        {
+                            this.Copy(Attribute(fragmentOutputColorAttr + component * 4), src);
+                        }
+
+                        regIndex++;
                     }
                 }
             }