diff --git a/Ryujinx.Graphics.GAL/VertexAttribDescriptor.cs b/Ryujinx.Graphics.GAL/VertexAttribDescriptor.cs
index 34daff57..1547658e 100644
--- a/Ryujinx.Graphics.GAL/VertexAttribDescriptor.cs
+++ b/Ryujinx.Graphics.GAL/VertexAttribDescriptor.cs
@@ -5,12 +5,15 @@ namespace Ryujinx.Graphics.GAL
public int BufferIndex { get; }
public int Offset { get; }
+ public bool IsZero { get; }
+
public Format Format { get; }
- public VertexAttribDescriptor(int bufferIndex, int offset, Format format)
+ public VertexAttribDescriptor(int bufferIndex, int offset, bool isZero, Format format)
{
BufferIndex = bufferIndex;
Offset = offset;
+ IsZero = isZero;
Format = format;
}
}
diff --git a/Ryujinx.Graphics.Gpu/Engine/Methods.cs b/Ryujinx.Graphics.Gpu/Engine/Methods.cs
index 0b30e61d..18720440 100644
--- a/Ryujinx.Graphics.Gpu/Engine/Methods.cs
+++ b/Ryujinx.Graphics.Gpu/Engine/Methods.cs
@@ -532,6 +532,7 @@ namespace Ryujinx.Graphics.Gpu.Engine
vertexAttribs[index] = new VertexAttribDescriptor(
vertexAttrib.UnpackBufferIndex(),
vertexAttrib.UnpackOffset(),
+ vertexAttrib.UnpackIsConstant(),
format);
}
diff --git a/Ryujinx.Graphics.Gpu/State/VertexAttribState.cs b/Ryujinx.Graphics.Gpu/State/VertexAttribState.cs
index 897da797..c22b1ca9 100644
--- a/Ryujinx.Graphics.Gpu/State/VertexAttribState.cs
+++ b/Ryujinx.Graphics.Gpu/State/VertexAttribState.cs
@@ -16,6 +16,15 @@ namespace Ryujinx.Graphics.Gpu.State
return (int)(Attribute & 0x1f);
}
+ ///
+ /// Unpacks the attribute constant flag.
+ ///
+ /// True if the attribute is constant, false otherwise
+ public bool UnpackIsConstant()
+ {
+ return (Attribute & 0x40) != 0;
+ }
+
///
/// Unpacks the offset, in bytes, of the attribute on the vertex buffer.
///
diff --git a/Ryujinx.Graphics.OpenGL/VertexArray.cs b/Ryujinx.Graphics.OpenGL/VertexArray.cs
index 721a90f0..43d200a4 100644
--- a/Ryujinx.Graphics.OpenGL/VertexArray.cs
+++ b/Ryujinx.Graphics.OpenGL/VertexArray.cs
@@ -58,8 +58,17 @@ namespace Ryujinx.Graphics.OpenGL
{
FormatInfo fmtInfo = FormatTable.GetFormatInfo(attrib.Format);
- GL.EnableVertexAttribArray(attribIndex);
-
+ if (attrib.IsZero)
+ {
+ // Disabling the attribute causes the shader to read a constant value.
+ // The value is configurable, but by default is a vector of (0, 0, 0, 1).
+ GL.DisableVertexAttribArray(attribIndex);
+ }
+ else
+ {
+ GL.EnableVertexAttribArray(attribIndex);
+ }
+
int offset = attrib.Offset;
int size = fmtInfo.Components;
@@ -117,7 +126,7 @@ namespace Ryujinx.Graphics.OpenGL
continue;
}
- if (_needsAttribsUpdate)
+ if (_needsAttribsUpdate && !attrib.IsZero)
{
GL.EnableVertexAttribArray(attribIndex);
}