Auto merge of #25789 - szeged:mmatyas__webgl_fns_clearbuffer, r=jdm

Add support for WebGL2 clear buffer operations

Adds support for the following WebGL2 methods:

- `clearBufferfv`
- `clearBufferiv`
- `clearBufferuiv`
- `clearBufferfi`

See: https://www.khronos.org/registry/webgl/specs/latest/2.0/#3.7.11

<!-- Please describe your changes on the following line: -->

cc @jdm @zakorgy

Note: While the code itself doesn't depend on any other PRs, some of the tests do require WebGL2 framebuffer/renderbuffer support (#25785).

---
<!-- Thank you for contributing to Servo! Please replace each `[ ]` by `[X]` when the step is complete, and replace `___` with appropriate data: -->
- [x] `./mach build -d` does not report any errors
- [x] `./mach test-tidy` does not report any errors
- [x] There are tests for these changes

<!-- Also, please make sure that "Allow edits from maintainers" checkbox is checked, so that we can help you if you get stuck somewhere along the way.-->

<!-- Pull requests that do not address these steps are welcome, but they will require additional verification as part of the review process. -->

1 files changed, 12 insertions, 0 deletions

diff --git a/components/canvas/webgl_thread.rs b/components/canvas/webgl_thread.rs
index 186ac043b38..079928c9d57 100644
--- a/components/canvas/webgl_thread.rs
+++ b/components/canvas/webgl_thread.rs
@@ -1956,6 +1956,18 @@ impl WebGLImpl {
                 offset as isize,
                 size as isize,
             ),
+            WebGLCommand::ClearBufferfv(buffer, draw_buffer, ref value) => {
+                gl.clear_buffer_fv(buffer, draw_buffer, value)
+            },
+            WebGLCommand::ClearBufferiv(buffer, draw_buffer, ref value) => {
+                gl.clear_buffer_iv(buffer, draw_buffer, value)
+            },
+            WebGLCommand::ClearBufferuiv(buffer, draw_buffer, ref value) => {
+                gl.clear_buffer_uiv(buffer, draw_buffer, value)
+            },
+            WebGLCommand::ClearBufferfi(buffer, draw_buffer, depth, stencil) => {
+                gl.clear_buffer_fi(buffer, draw_buffer, depth, stencil)
+            },
         }
 
         // If debug asertions are enabled, then check the error state.