Auto merge of #25229 - mmatyas:webgl_fns_ubo, r=jdm

Add initial support for WebGL2 uniform buffer functions

This *work-in-progress* patch adds initial support for the following WebGL2 calls:

- `bindBufferBase`
- `bindBufferRange`
- `getUniformIndices`
- `getUniformBlockIndex`
- `getActiveUniforms`
- `getActiveUniformBlockParameter`
- `getActiveUniformBlockName`
- `uniformBlockBinding`

See: https://www.khronos.org/registry/webgl/specs/latest/2.0/#3.7.16

However, indexed uniforms and `getIndexedParameter`, which would be used by some of the functions (and transform feedback) is still missing. Also this patch depends on:

- https://github.com/servo/sparkle/pull/16
- https://github.com/servo/servo/issues/25034

(required for both building and running the tests).

cc @jdm @zakorgy @imiklos

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- [x] `./mach test-tidy` does not report any errors
- [ ] These changes fix #___ (GitHub issue number if applicable)

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1 files changed, 39 insertions, 1 deletions

diff --git a/components/canvas/webgl_limits.rs b/components/canvas/webgl_limits.rs
index d910be71d99..1a08dfea945 100644
--- a/components/canvas/webgl_limits.rs
+++ b/components/canvas/webgl_limits.rs
@@ -65,14 +65,24 @@ impl GLLimitsDetect for GLLimits {
         };
 
         let (
+            max_uniform_block_size,
             max_uniform_buffer_bindings,
             min_program_texel_offset,
             max_program_texel_offset,
             max_transform_feedback_separate_attribs,
             max_draw_buffers,
             max_color_attachments,
+            max_combined_uniform_blocks,
+            max_combined_vertex_uniform_components,
+            max_combined_fragment_uniform_components,
+            max_vertex_uniform_blocks,
+            max_vertex_uniform_components,
+            max_fragment_uniform_blocks,
+            max_fragment_uniform_components,
+            uniform_buffer_offset_alignment,
         );
         if webgl_version == WebGLVersion::WebGL2 {
+            max_uniform_block_size = gl.get_integer(gl::MAX_UNIFORM_BLOCK_SIZE);
             max_uniform_buffer_bindings = gl.get_integer(gl::MAX_UNIFORM_BUFFER_BINDINGS);
             min_program_texel_offset = gl.get_integer(gl::MIN_PROGRAM_TEXEL_OFFSET);
             max_program_texel_offset = gl.get_integer(gl::MAX_PROGRAM_TEXEL_OFFSET);
@@ -81,14 +91,33 @@ impl GLLimitsDetect for GLLimits {
             max_color_attachments = gl.get_integer(gl::MAX_COLOR_ATTACHMENTS);
             max_draw_buffers = gl
                 .get_integer(gl::MAX_DRAW_BUFFERS)
-                .min(max_color_attachments)
+                .min(max_color_attachments);
+            max_combined_uniform_blocks = gl.get_integer(gl::MAX_COMBINED_UNIFORM_BLOCKS);
+            max_combined_vertex_uniform_components =
+                gl.get_integer(gl::MAX_COMBINED_VERTEX_UNIFORM_COMPONENTS);
+            max_combined_fragment_uniform_components =
+                gl.get_integer(gl::MAX_COMBINED_FRAGMENT_UNIFORM_COMPONENTS);
+            max_vertex_uniform_blocks = gl.get_integer(gl::MAX_VERTEX_UNIFORM_BLOCKS);
+            max_vertex_uniform_components = gl.get_integer(gl::MAX_VERTEX_UNIFORM_COMPONENTS);
+            max_fragment_uniform_blocks = gl.get_integer(gl::MAX_FRAGMENT_UNIFORM_BLOCKS);
+            max_fragment_uniform_components = gl.get_integer(gl::MAX_FRAGMENT_UNIFORM_COMPONENTS);
+            uniform_buffer_offset_alignment = gl.get_integer(gl::UNIFORM_BUFFER_OFFSET_ALIGNMENT);
         } else {
+            max_uniform_block_size = 0;
             max_uniform_buffer_bindings = 0;
             min_program_texel_offset = 0;
             max_program_texel_offset = 0;
             max_transform_feedback_separate_attribs = 0;
             max_color_attachments = 1;
             max_draw_buffers = 1;
+            max_combined_uniform_blocks = 0;
+            max_combined_vertex_uniform_components = 0;
+            max_combined_fragment_uniform_components = 0;
+            max_vertex_uniform_blocks = 0;
+            max_vertex_uniform_components = 0;
+            max_fragment_uniform_blocks = 0;
+            max_fragment_uniform_components = 0;
+            uniform_buffer_offset_alignment = 0;
         }
 
         GLLimits {
@@ -111,6 +140,15 @@ impl GLLimitsDetect for GLLimits {
             max_program_texel_offset,
             max_color_attachments,
             max_draw_buffers,
+            max_uniform_block_size,
+            max_combined_uniform_blocks,
+            max_combined_vertex_uniform_components,
+            max_combined_fragment_uniform_components,
+            max_vertex_uniform_blocks,
+            max_vertex_uniform_components,
+            max_fragment_uniform_blocks,
+            max_fragment_uniform_components,
+            uniform_buffer_offset_alignment,
         }
     }
 }