Skip to content

Fix getAttribLocation to return -1 for built-in attributes per WebGL 2.0 spec #412

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Draft
wants to merge 3 commits into
base: main
Choose a base branch
from
Draft

Fix getAttribLocation to return -1 for built-in attributes per WebGL 2.0 spec #412

Show file tree
Hide file tree
Changes from 2 commits
Commits
Show all changes
3 commits
Select commit Hold shift + click to select a range
3f31d97
Initial plan
Copilot Nov 13, 2025
e905a59
Fix WebGL getAttribLocation to return -1 for built-in attributes
Copilot Nov 13, 2025
c135954
Move built-in attribute check to client/graphics layer
Copilot Nov 14, 2025
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
102 changes: 51 additions & 51 deletions package-lock.json
View file
Open in desktop

Large diffs are not rendered by default.

2 changes: 1 addition & 1 deletion src/client/script_bindings/webgl/active_info.cpp
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -60,5 +60,5 @@ namespace endor
}

} // namespace webgl
} // namespace script_bindings
} // namespace script_bindings
} // namespace endor
2 changes: 1 addition & 1 deletion src/client/script_bindings/webgl/active_info.hpp
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -38,5 +38,5 @@ namespace endor
};

} // namespace webgl
} // namespace script_bindings
} // namespace script_bindings
} // namespace endor
2 changes: 1 addition & 1 deletion src/client/script_bindings/webgl/framebuffer.cpp
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -31,5 +31,5 @@ namespace endor
{
}
} // namespace webgl
} // namespace script_bindings
} // namespace script_bindings
} // namespace endor
2 changes: 1 addition & 1 deletion src/client/script_bindings/webgl/framebuffer.hpp
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -37,5 +37,5 @@ namespace endor
};

} // namespace webgl
} // namespace script_bindings
} // namespace script_bindings
} // namespace endor
2 changes: 1 addition & 1 deletion src/client/script_bindings/webgl/object.cpp
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -28,5 +28,5 @@ namespace endor
// WebGLObject is a base class, typically not instantiated directly
}
} // namespace webgl
} // namespace script_bindings
} // namespace script_bindings
} // namespace endor
2 changes: 1 addition & 1 deletion src/client/script_bindings/webgl/object.hpp
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -45,5 +45,5 @@ namespace endor
};

} // namespace webgl
} // namespace script_bindings
} // namespace script_bindings
} // namespace endor
2 changes: 1 addition & 1 deletion src/client/script_bindings/webgl/program.cpp
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -20,5 +20,5 @@ namespace endor
}

} // namespace webgl
} // namespace script_bindings
} // namespace script_bindings
} // namespace endor
2 changes: 1 addition & 1 deletion src/client/script_bindings/webgl/program.hpp
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -32,5 +32,5 @@ namespace endor
WebGLProgram(v8::Isolate *isolate, const v8::FunctionCallbackInfo<v8::Value> &args);
};
} // namespace webgl
} // namespace script_bindings
} // namespace script_bindings
} // namespace endor
2 changes: 1 addition & 1 deletion src/client/script_bindings/webgl/renderbuffer.cpp
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -19,5 +19,5 @@ namespace endor
// WebGLRenderbuffer objects are created by WebGL context, not by user code
}
} // namespace webgl
} // namespace script_bindings
} // namespace script_bindings
} // namespace endor
2 changes: 1 addition & 1 deletion src/client/script_bindings/webgl/renderbuffer.hpp
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -33,5 +33,5 @@ namespace endor
};

} // namespace webgl
} // namespace script_bindings
} // namespace script_bindings
} // namespace endor
2 changes: 1 addition & 1 deletion src/client/script_bindings/webgl/texture.cpp
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -27,5 +27,5 @@ namespace endor
{
}
} // namespace webgl
} // namespace script_bindings
} // namespace script_bindings
} // namespace endor
2 changes: 1 addition & 1 deletion src/client/script_bindings/webgl/texture.hpp
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -45,5 +45,5 @@ namespace endor
};

} // namespace webgl
} // namespace script_bindings
} // namespace script_bindings
} // namespace endor
2 changes: 1 addition & 1 deletion src/client/script_bindings/webgl/uniform_location.cpp
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -47,5 +47,5 @@ namespace endor
}

} // namespace webgl
} // namespace script_bindings
} // namespace script_bindings
} // namespace endor
2 changes: 1 addition & 1 deletion src/client/script_bindings/webgl/uniform_location.hpp
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -44,5 +44,5 @@ namespace endor
};

} // namespace webgl
} // namespace script_bindings
} // namespace script_bindings
} // namespace endor
2 changes: 1 addition & 1 deletion src/client/script_bindings/webgl/vertex_array.cpp
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -20,5 +20,5 @@ namespace endor
{
}
} // namespace webgl
} // namespace script_bindings
} // namespace script_bindings
} // namespace endor
2 changes: 1 addition & 1 deletion src/client/script_bindings/webgl/vertex_array.hpp
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -33,5 +33,5 @@ namespace endor
};

} // namespace webgl
} // namespace script_bindings
} // namespace script_bindings
} // namespace endor
10 changes: 10 additions & 0 deletions src/client/script_bindings/webgl/webgl_rendering_context.cpp
View file
Open in desktop
Original file line number Diff line number Diff line change
@@ -1,3 +1,4 @@
#include <set>
#include <client/script_bindings/canvas/image_source.hpp>
#include "./webgl_rendering_context.hpp"
#include "./active_info.hpp"
Expand Down Expand Up @@ -2638,6 +2639,15 @@ namespace endor
auto nameUtf8 = String::Utf8Value(isolate, info[1]);
string name = *nameUtf8;

// WebGL 2.0 spec §5.18: Built-in attributes always return -1
static const std::set<string> kBuiltInAttribs = {
"gl_VertexID", "gl_InstanceID", "gl_Position", "gl_PointSize"};
if (kBuiltInAttribs.count(name))
{
info.GetReturnValue().Set(Number::New(isolate, -1));
return;
}

Copy link
Collaborator

@EndlessJour9527 EndlessJour9527 Nov 14, 2025

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

@copilot please impl in client/graphics

Copy link
Contributor Author

Copilot AI Nov 14, 2025

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

Done! Moved the implementation to client/graphics/webgl_context.cpp in commit c135954. The built-in attribute check now happens at the graphics layer in WebGLContext::getAttribLocation(), which returns nullopt for built-in attributes. The script bindings layer correctly converts this to -1.

auto loc = handle()->getAttribLocation(programBinding->handle(), name);
if (!loc.has_value())
{
Expand Down