Problem

Calling context.getParameter() for various buffer and framebuffer-related enums (including COPY_READ_BUFFER_BINDING, COPY_WRITE_BUFFER_BINDING, DRAW_FRAMEBUFFER_BINDING, READ_FRAMEBUFFER_BINDING, PIXEL_PACK_BUFFER_BINDING, PIXEL_UNPACK_BUFFER_BINDING, UNIFORM_BUFFER_BINDING, VERTEX_ARRAY_BINDING, SAMPLER_BINDING, TRANSFORM_FEEDBACK_BINDING, TRANSFORM_FEEDBACK_BUFFER_BINDING, TEXTURE_BINDING_2D_ARRAY, TEXTURE_BINDING_3D) incorrectly returns undefined instead of the expected default value (usually null or an actual object per WebGL2 spec). This causes compliance failures with the WebGL 2.0 conformance suite.

Notable FAIL cases

• context.getParameter(context.COPY_READ_BUFFER_BINDING)
• context.getParameter(context.COPY_WRITE_BUFFER_BINDING)
• context.getParameter(context.DRAW_FRAMEBUFFER_BINDING)
• context.getParameter(context.READ_FRAMEBUFFER_BINDING)
• context.getParameter(context.PIXEL_PACK_BUFFER_BINDING)
• context.getParameter(context.PIXEL_UNPACK_BUFFER_BINDING)
• context.getParameter(context.UNIFORM_BUFFER_BINDING)
• context.getParameter(context.VERTEX_ARRAY_BINDING)
• context.getParameter(context.SAMPLER_BINDING)
• context.getParameter(context.TRANSFORM_FEEDBACK_BINDING)
• context.getParameter(context.TRANSFORM_FEEDBACK_BUFFER_BINDING)
• context.getParameter(context.TEXTURE_BINDING_2D_ARRAY)
• context.getParameter(context.TEXTURE_BINDING_3D)

Expected behavior

According to the WebGL2 specification, these parameters must return null or a valid WebGL* object, never undefined.

Steps to reproduce

1. Create a WebGL2 context
2. Call context.getParameter(param) for each of the above enums
3. Observe returned value is undefined

Impact

• Fails conformance tests
• Breaks compatibility with standard WebGL2 applications

References

• WebGL2 spec section 5.14.3
• Chromium implementation example

Suggested Actions

• Audit the implementation of getParameter() for all buffer, framebuffer, and object bindings in the WebGL2 context
• Ensure correct default return value according to the spec
• Add regression tests for these cases

Category: WebGL2 object/buffer binding compliance