Add support for WebGL2 read and draw buffer settings

Adds support for the `ReadBuffer` and `DrawBuffers`
WebGL2 calls and the related parameter getters.

See:

- https://www.khronos.org/registry/webgl/specs/latest/2.0/#3.7.2
- https://www.khronos.org/registry/webgl/specs/latest/2.0/#3.7.4
- https://www.khronos.org/registry/webgl/specs/latest/2.0/#3.7.11

17 files changed, 315 insertions, 51 deletions

diff --git a/components/canvas/webgl_thread.rs b/components/canvas/webgl_thread.rs
index 3ab38995e8d..ff627d121ad 100644
--- a/components/canvas/webgl_thread.rs
+++ b/components/canvas/webgl_thread.rs
@@ -2024,6 +2024,8 @@ impl WebGLImpl {
                     attach(attachment)
                 }
             },
+            WebGLCommand::ReadBuffer(buffer) => gl.read_buffer(buffer),
+            WebGLCommand::DrawBuffers(ref buffers) => gl.draw_buffers(buffers),
         }
 
         // If debug asertions are enabled, then check the error state.
diff --git a/components/canvas_traits/webgl.rs b/components/canvas_traits/webgl.rs
index 3b943200d71..d5be8822ee9 100644
--- a/components/canvas_traits/webgl.rs
+++ b/components/canvas_traits/webgl.rs
@@ -546,6 +546,8 @@ pub enum WebGLCommand {
     InvalidateFramebuffer(u32, Vec<u32>),
     InvalidateSubFramebuffer(u32, Vec<u32>, i32, i32, i32, i32),
     FramebufferTextureLayer(u32, u32, Option<WebGLTextureId>, i32, i32),
+    ReadBuffer(u32),
+    DrawBuffers(Vec<u32>),
 }
 
 macro_rules! nonzero_type {
diff --git a/components/script/dom/webgl2renderingcontext.rs b/components/script/dom/webgl2renderingcontext.rs
index dabcd4cf54e..c0c3aab5ad6 100644
--- a/components/script/dom/webgl2renderingcontext.rs
+++ b/components/script/dom/webgl2renderingcontext.rs
@@ -96,6 +96,8 @@ pub struct WebGL2RenderingContext {
     texture_pack_skip_pixels: Cell<usize>,
     texture_pack_skip_rows: Cell<usize>,
     enable_rasterizer_discard: Cell<bool>,
+    default_fb_readbuffer: Cell<u32>,
+    default_fb_drawbuffer: Cell<u32>,
 }
 
 fn typedarray_elem_size(typeid: Type) -> usize {
@@ -162,6 +164,8 @@ impl WebGL2RenderingContext {
             texture_pack_skip_pixels: Cell::new(0),
             texture_pack_skip_rows: Cell::new(0),
             enable_rasterizer_discard: Cell::new(false),
+            default_fb_readbuffer: Cell::new(constants::BACK),
+            default_fb_drawbuffer: Cell::new(constants::BACK),
         })
     }
 
@@ -344,6 +348,11 @@ impl WebGL2RenderingContext {
             return self.base.webgl_error(InvalidOperation);
         }
 
+        let fb_slot = self.base.get_draw_framebuffer_slot();
+        if fb_slot.get().is_none() && self.default_fb_readbuffer.get() == constants::NONE {
+            return self.base.webgl_error(InvalidOperation);
+        }
+
         let dst_byte_offset = {
             let dst_elem_size = typedarray_elem_size(dst.get_array_type());
             dst_elem_offset as usize * dst_elem_size
@@ -800,6 +809,26 @@ impl WebGL2RenderingContextMethods for WebGL2RenderingContext {
                     &self.base.get_read_framebuffer_slot().get()
                 );
             },
+            constants::READ_BUFFER => {
+                let buffer = match self.base.get_read_framebuffer_slot().get() {
+                    Some(fb) => fb.read_buffer(),
+                    None => self.default_fb_readbuffer.get(),
+                };
+                return UInt32Value(buffer);
+            },
+            constants::DRAW_BUFFER0..=constants::DRAW_BUFFER15 => {
+                let buffer = match self.base.get_read_framebuffer_slot().get() {
+                    Some(fb) => {
+                        let idx = parameter - constants::DRAW_BUFFER0;
+                        fb.draw_buffer_i(idx as usize)
+                    },
+                    None if parameter == constants::DRAW_BUFFER0 => {
+                        self.default_fb_readbuffer.get()
+                    },
+                    None => constants::NONE,
+                };
+                return UInt32Value(buffer);
+            },
             _ => {},
         }
 
@@ -3811,6 +3840,46 @@ impl WebGL2RenderingContextMethods for WebGL2RenderingContext {
         self.base
             .renderbuffer_storage(target, samples, internal_format, width, height)
     }
+
+    /// https://www.khronos.org/registry/webgl/specs/latest/2.0/#3.7.4
+    fn ReadBuffer(&self, src: u32) {
+        match src {
+            constants::BACK | constants::NONE => {},
+            _ if self.base.valid_color_attachment_enum(src) => {},
+            _ => return self.base.webgl_error(InvalidEnum),
+        }
+
+        if let Some(fb) = self.base.get_read_framebuffer_slot().get() {
+            handle_potential_webgl_error!(self.base, fb.set_read_buffer(src), return)
+        } else {
+            match src {
+                constants::NONE | constants::BACK => {},
+                _ => return self.base.webgl_error(InvalidOperation),
+            }
+
+            self.default_fb_readbuffer.set(src);
+            self.base.send_command(WebGLCommand::ReadBuffer(src));
+        }
+    }
+
+    /// https://www.khronos.org/registry/webgl/specs/latest/2.0/#3.7.11
+    fn DrawBuffers(&self, buffers: Vec<u32>) {
+        if let Some(fb) = self.base.get_draw_framebuffer_slot().get() {
+            handle_potential_webgl_error!(self.base, fb.set_draw_buffers(buffers), return)
+        } else {
+            if buffers.len() != 1 {
+                return self.base.webgl_error(InvalidOperation);
+            }
+
+            match buffers[0] {
+                constants::NONE | constants::BACK => {},
+                _ => return self.base.webgl_error(InvalidOperation),
+            }
+
+            self.default_fb_drawbuffer.set(buffers[0]);
+            self.base.send_command(WebGLCommand::DrawBuffers(buffers));
+        }
+    }
 }
 
 impl LayoutCanvasWebGLRenderingContextHelpers for LayoutDom<WebGL2RenderingContext> {
diff --git a/components/script/dom/webglframebuffer.rs b/components/script/dom/webglframebuffer.rs
index 2d6fcf9122d..f3f6e939f4f 100644
--- a/components/script/dom/webglframebuffer.rs
+++ b/components/script/dom/webglframebuffer.rs
@@ -101,6 +101,8 @@ pub struct WebGLFramebuffer {
     depth: DomRefCell<Option<WebGLFramebufferAttachment>>,
     stencil: DomRefCell<Option<WebGLFramebufferAttachment>>,
     depthstencil: DomRefCell<Option<WebGLFramebufferAttachment>>,
+    color_read_buffer: DomRefCell<u32>,
+    color_draw_buffers: DomRefCell<Vec<u32>>,
     is_initialized: Cell<bool>,
     // Framebuffers for XR keep a reference to the XR session.
     // https://github.com/immersive-web/webxr/issues/856
@@ -121,6 +123,8 @@ impl WebGLFramebuffer {
             depth: DomRefCell::new(None),
             stencil: DomRefCell::new(None),
             depthstencil: DomRefCell::new(None),
+            color_read_buffer: DomRefCell::new(constants::COLOR_ATTACHMENT0),
+            color_draw_buffers: DomRefCell::new(vec![constants::COLOR_ATTACHMENT0]),
             is_initialized: Cell::new(false),
             xr_session: Default::default(),
         }
@@ -914,6 +918,55 @@ impl WebGLFramebuffer {
         });
     }
 
+    pub fn set_read_buffer(&self, buffer: u32) -> WebGLResult<()> {
+        let context = self.upcast::<WebGLObject>().context();
+
+        match buffer {
+            constants::NONE => {},
+            _ if context.valid_color_attachment_enum(buffer) => {},
+            _ => return Err(WebGLError::InvalidOperation),
+        };
+
+        *self.color_read_buffer.borrow_mut() = buffer;
+        context.send_command(WebGLCommand::ReadBuffer(buffer));
+        Ok(())
+    }
+
+    pub fn set_draw_buffers(&self, buffers: Vec<u32>) -> WebGLResult<()> {
+        let context = self.upcast::<WebGLObject>().context();
+
+        if buffers.len() > context.limits().max_draw_buffers as usize {
+            return Err(WebGLError::InvalidValue);
+        }
+
+        let enums_valid = buffers
+            .iter()
+            .all(|&val| val == constants::NONE || context.valid_color_attachment_enum(val));
+        if !enums_valid {
+            return Err(WebGLError::InvalidEnum);
+        }
+
+        let values_valid = buffers.iter().enumerate().all(|(i, &val)| {
+            val == constants::NONE || val == (constants::COLOR_ATTACHMENT0 + i as u32)
+        });
+        if !values_valid {
+            return Err(WebGLError::InvalidOperation);
+        }
+
+        *self.color_draw_buffers.borrow_mut() = buffers.clone();
+        context.send_command(WebGLCommand::DrawBuffers(buffers));
+        Ok(())
+    }
+
+    pub fn read_buffer(&self) -> u32 {
+        *self.color_read_buffer.borrow()
+    }
+
+    pub fn draw_buffer_i(&self, index: usize) -> u32 {
+        let buffers = &*self.color_draw_buffers.borrow();
+        *buffers.get(index).unwrap_or(&constants::NONE)
+    }
+
     pub fn target(&self) -> Option<u32> {
         self.target.get()
     }
diff --git a/components/script/dom/webglrenderingcontext.rs b/components/script/dom/webglrenderingcontext.rs
index 9f30edac79c..25e5bf4baa1 100644
--- a/components/script/dom/webglrenderingcontext.rs
+++ b/components/script/dom/webglrenderingcontext.rs
@@ -1510,6 +1510,11 @@ impl WebGLRenderingContext {
 
         // FIXME: https://github.com/servo/servo/issues/13710
     }
+
+    pub fn valid_color_attachment_enum(&self, attachment: u32) -> bool {
+        let last_slot = constants::COLOR_ATTACHMENT0 + self.limits().max_color_attachments - 1;
+        constants::COLOR_ATTACHMENT0 <= attachment && attachment <= last_slot
+    }
 }
 
 #[cfg(not(feature = "webgl_backtrace"))]
diff --git a/components/script/dom/webidls/WebGL2RenderingContext.webidl b/components/script/dom/webidls/WebGL2RenderingContext.webidl
index c08bcb044b8..dca86da39fe 100644
--- a/components/script/dom/webidls/WebGL2RenderingContext.webidl
+++ b/components/script/dom/webidls/WebGL2RenderingContext.webidl
@@ -313,7 +313,7 @@ interface mixin WebGL2RenderingContextBase
   void invalidateFramebuffer(GLenum target, sequence<GLenum> attachments);
   void invalidateSubFramebuffer(GLenum target, sequence<GLenum> attachments,
                                 GLint x, GLint y, GLsizei width, GLsizei height);
-  // void readBuffer(GLenum src);
+  void readBuffer(GLenum src);
 
   /* Renderbuffer objects */
   any getInternalformatParameter(GLenum target, GLenum internalformat, GLenum pname);
@@ -475,7 +475,7 @@ interface mixin WebGL2RenderingContextBase
                   /*[AllowShared]*/ ArrayBufferView dstData, GLuint dstOffset);
 
   /* Multiple Render Targets */
-  // void drawBuffers(sequence<GLenum> buffers);
+  void drawBuffers(sequence<GLenum> buffers);
 
   void clearBufferfv(GLenum buffer, GLint drawbuffer, Float32List values,
                      optional GLuint srcOffset = 0);
diff --git a/tests/wpt/webgl/meta/conformance2/context/methods-2.html.ini b/tests/wpt/webgl/meta/conformance2/context/methods-2.html.ini
index ace9681c8eb..100b5866388 100644
--- a/tests/wpt/webgl/meta/conformance2/context/methods-2.html.ini
+++ b/tests/wpt/webgl/meta/conformance2/context/methods-2.html.ini
@@ -1,52 +1,46 @@
 [methods-2.html]
-  [WebGL test #2: Property either does not exist or is not a function: readBuffer]
-    expected: FAIL
-
   [WebGL test #1: Property either does not exist or is not a function: blitFramebuffer]
     expected: FAIL
 
-  [WebGL test #11: Property either does not exist or is not a function: vertexAttribI4iv]
-    expected: FAIL
-
-  [WebGL test #8: Property either does not exist or is not a function: compressedTexImage3D]
+  [WebGL test #7: Property either does not exist or is not a function: compressedTexImage3D]
     expected: FAIL
 
-  [WebGL test #13: Property either does not exist or is not a function: vertexAttribI4uiv]
+  [WebGL test #4: Property either does not exist or is not a function: texStorage3D]
     expected: FAIL
 
-  [WebGL test #16: Property either does not exist or is not a function: drawBuffers]
+  [WebGL test #11: Property either does not exist or is not a function: vertexAttribI4ui]
     expected: FAIL
 
-  [WebGL test #3: Property either does not exist or is not a function: texImage3D]
+  [WebGL test #2: Property either does not exist or is not a function: texImage3D]
     expected: FAIL
 
-  [WebGL test #10: Property either does not exist or is not a function: vertexAttribI4i]
+  [WebGL test #12: Property either does not exist or is not a function: vertexAttribI4uiv]
     expected: FAIL
 
-  [WebGL test #9: Property either does not exist or is not a function: compressedTexSubImage3D]
+  [WebGL test #3: Property either does not exist or is not a function: texStorage2D]
     expected: FAIL
 
-  [WebGL test #12: Property either does not exist or is not a function: vertexAttribI4ui]
+  [WebGL test #8: Property either does not exist or is not a function: compressedTexSubImage3D]
     expected: FAIL
 
   [WebGL test #0: Property either does not exist or is not a function: isContextLost]
     expected: FAIL
 
-  [WebGL test #7: Property either does not exist or is not a function: copyTexSubImage3D]
+  [WebGL test #9: Property either does not exist or is not a function: vertexAttribI4i]
     expected: FAIL
 
-  [WebGL test #14: Property either does not exist or is not a function: vertexAttribIPointer]
+  [WebGL test #13: Property either does not exist or is not a function: vertexAttribIPointer]
     expected: FAIL
 
-  [WebGL test #4: Property either does not exist or is not a function: texStorage2D]
+  [WebGL test #14: Property either does not exist or is not a function: drawRangeElements]
     expected: FAIL
 
-  [WebGL test #15: Property either does not exist or is not a function: drawRangeElements]
+  [WebGL test #5: Property either does not exist or is not a function: texSubImage3D]
     expected: FAIL
 
-  [WebGL test #6: Property either does not exist or is not a function: texSubImage3D]
+  [WebGL test #10: Property either does not exist or is not a function: vertexAttribI4iv]
     expected: FAIL
 
-  [WebGL test #5: Property either does not exist or is not a function: texStorage3D]
+  [WebGL test #6: Property either does not exist or is not a function: copyTexSubImage3D]
     expected: FAIL
 
diff --git a/tests/wpt/webgl/meta/conformance2/renderbuffers/readbuffer.html.ini b/tests/wpt/webgl/meta/conformance2/renderbuffers/readbuffer.html.ini
index 5d2bfb385a5..232dfdd8524 100644
--- a/tests/wpt/webgl/meta/conformance2/renderbuffers/readbuffer.html.ini
+++ b/tests/wpt/webgl/meta/conformance2/renderbuffers/readbuffer.html.ini
@@ -1,5 +1,5 @@
 [readbuffer.html]
-  expected: ERROR
+  expected: TIMEOUT
   [WebGL test #3: gl.getParameter(gl.READ_BUFFER) should be 1029 (of type number). Was null (of type object).]
     expected: FAIL
 
diff --git a/tests/wpt/webgl/meta/conformance2/rendering/blitframebuffer-srgb-and-linear-drawbuffers.html.ini b/tests/wpt/webgl/meta/conformance2/rendering/blitframebuffer-srgb-and-linear-drawbuffers.html.ini
index 615333948ac..6e960398105 100644
--- a/tests/wpt/webgl/meta/conformance2/rendering/blitframebuffer-srgb-and-linear-drawbuffers.html.ini
+++ b/tests/wpt/webgl/meta/conformance2/rendering/blitframebuffer-srgb-and-linear-drawbuffers.html.ini
@@ -1,8 +1,109 @@
 [blitframebuffer-srgb-and-linear-drawbuffers.html]
-  expected: ERROR
+  [WebGL test #10: getError expected: NO_ERROR. Was INVALID_ENUM : setup read framebuffer should succeed]
+    expected: FAIL
+
+  [WebGL test #31: getError expected: NO_ERROR. Was INVALID_ENUM : setup read framebuffer should succeed]
+    expected: FAIL
+
+  [WebGL test #7: getError expected: NO_ERROR. Was INVALID_ENUM : setup read framebuffer should succeed]
+    expected: FAIL
+
+  [WebGL test #35: getError expected: NO_ERROR. Was INVALID_ENUM : setup draw framebuffer should succeed]
+    expected: FAIL
+
+  [WebGL test #3: Framebuffer incomplete when setup draw framebuffer.]
+    expected: FAIL
+
+  [WebGL test #4: getError expected: NO_ERROR. Was INVALID_ENUM : setup read framebuffer should succeed]
+    expected: FAIL
+
   [WebGL test #1: getError expected: NO_ERROR. Was INVALID_ENUM : setup read framebuffer should succeed]
     expected: FAIL
 
-  [WebGL test #2: successfullyParsed should be true (of type boolean). Was undefined (of type undefined).]
+  [WebGL test #21: Framebuffer incomplete when setup draw framebuffer.]
+    expected: FAIL
+
+  [WebGL test #14: getError expected: NO_ERROR. Was INVALID_ENUM : setup draw framebuffer should succeed]
+    expected: FAIL
+
+  [WebGL test #30: Framebuffer incomplete when setup draw framebuffer.]
+    expected: FAIL
+
+  [WebGL test #6: Framebuffer incomplete when setup draw framebuffer.]
+    expected: FAIL
+
+  [WebGL test #11: getError expected: NO_ERROR. Was INVALID_ENUM : setup draw framebuffer should succeed]
+    expected: FAIL
+
+  [WebGL test #9: Framebuffer incomplete when setup draw framebuffer.]
+    expected: FAIL
+
+  [WebGL test #2: getError expected: NO_ERROR. Was INVALID_ENUM : setup draw framebuffer should succeed]
+    expected: FAIL
+
+  [WebGL test #22: getError expected: NO_ERROR. Was INVALID_ENUM : setup read framebuffer should succeed]
+    expected: FAIL
+
+  [WebGL test #20: getError expected: NO_ERROR. Was INVALID_ENUM : setup draw framebuffer should succeed]
+    expected: FAIL
+
+  [WebGL test #27: Framebuffer incomplete when setup draw framebuffer.]
+    expected: FAIL
+
+  [WebGL test #13: getError expected: NO_ERROR. Was INVALID_ENUM : setup read framebuffer should succeed]
+    expected: FAIL
+
+  [WebGL test #12: Framebuffer incomplete when setup draw framebuffer.]
+    expected: FAIL
+
+  [WebGL test #19: getError expected: NO_ERROR. Was INVALID_ENUM : setup read framebuffer should succeed]
+    expected: FAIL
+
+  [WebGL test #34: getError expected: NO_ERROR. Was INVALID_ENUM : setup read framebuffer should succeed]
+    expected: FAIL
+
+  [WebGL test #24: Framebuffer incomplete when setup draw framebuffer.]
+    expected: FAIL
+
+  [WebGL test #25: getError expected: NO_ERROR. Was INVALID_ENUM : setup read framebuffer should succeed]
+    expected: FAIL
+
+  [WebGL test #17: getError expected: NO_ERROR. Was INVALID_ENUM : setup draw framebuffer should succeed]
+    expected: FAIL
+
+  [WebGL test #16: getError expected: NO_ERROR. Was INVALID_ENUM : setup read framebuffer should succeed]
+    expected: FAIL
+
+  [WebGL test #15: Framebuffer incomplete when setup draw framebuffer.]
+    expected: FAIL
+
+  [WebGL test #18: Framebuffer incomplete when setup draw framebuffer.]
+    expected: FAIL
+
+  [WebGL test #33: Framebuffer incomplete when setup draw framebuffer.]
+    expected: FAIL
+
+  [WebGL test #28: getError expected: NO_ERROR. Was INVALID_ENUM : setup read framebuffer should succeed]
+    expected: FAIL
+
+  [WebGL test #8: getError expected: NO_ERROR. Was INVALID_ENUM : setup draw framebuffer should succeed]
+    expected: FAIL
+
+  [WebGL test #26: getError expected: NO_ERROR. Was INVALID_ENUM : setup draw framebuffer should succeed]
+    expected: FAIL
+
+  [WebGL test #32: getError expected: NO_ERROR. Was INVALID_ENUM : setup draw framebuffer should succeed]
+    expected: FAIL
+
+  [WebGL test #23: getError expected: NO_ERROR. Was INVALID_ENUM : setup draw framebuffer should succeed]
+    expected: FAIL
+
+  [WebGL test #36: Framebuffer incomplete when setup draw framebuffer.]
+    expected: FAIL
+
+  [WebGL test #5: getError expected: NO_ERROR. Was INVALID_ENUM : setup draw framebuffer should succeed]
+    expected: FAIL
+
+  [WebGL test #29: getError expected: NO_ERROR. Was INVALID_ENUM : setup draw framebuffer should succeed]
     expected: FAIL
 
diff --git a/tests/wpt/webgl/meta/conformance2/rendering/clear-func-buffer-type-match.html.ini b/tests/wpt/webgl/meta/conformance2/rendering/clear-func-buffer-type-match.html.ini
index b711ea2d3c7..eae2c252214 100644
--- a/tests/wpt/webgl/meta/conformance2/rendering/clear-func-buffer-type-match.html.ini
+++ b/tests/wpt/webgl/meta/conformance2/rendering/clear-func-buffer-type-match.html.ini
@@ -1,5 +1,5 @@
 [clear-func-buffer-type-match.html]
-  expected: ERROR
+  expected: TIMEOUT
   [WebGL test #1: successfullyParsed should be true (of type boolean). Was undefined (of type undefined).]
     expected: FAIL
 
diff --git a/tests/wpt/webgl/meta/conformance2/rendering/draw-buffers.html.ini b/tests/wpt/webgl/meta/conformance2/rendering/draw-buffers.html.ini
index f5a106b6c71..9c96659618a 100644
--- a/tests/wpt/webgl/meta/conformance2/rendering/draw-buffers.html.ini
+++ b/tests/wpt/webgl/meta/conformance2/rendering/draw-buffers.html.ini
@@ -1,5 +1,43 @@
 [draw-buffers.html]
-  expected: ERROR
-  [WebGL test #5: successfullyParsed should be true (of type boolean). Was undefined (of type undefined).]
+  [WebGL test #44: attachment 7 should be 0,255,0,255\nat (0, 0) expected: 0,255,0,255 was 0,0,0,0]
+    expected: FAIL
+
+  [WebGL test #49: attachment 4 should be 0,255,0,255\nat (0, 0) expected: 0,255,0,255 was 0,0,0,0]
+    expected: FAIL
+
+  [WebGL test #43: attachment 6 should be 0,255,0,255\nat (0, 0) expected: 0,255,0,255 was 0,0,0,0]
+    expected: FAIL
+
+  [WebGL test #38: attachment 1 should be 0,255,0,255\nat (0, 0) expected: 0,255,0,255 was 0,0,0,0]
+    expected: FAIL
+
+  [WebGL test #51: attachment 6 should be 0,255,0,255\nat (0, 0) expected: 0,255,0,255 was 0,0,0,0]
+    expected: FAIL
+
+  [WebGL test #50: attachment 5 should be 0,255,0,255\nat (0, 0) expected: 0,255,0,255 was 0,0,0,0]
+    expected: FAIL
+
+  [WebGL test #48: attachment 3 should be 0,255,0,255\nat (0, 0) expected: 0,255,0,255 was 0,0,0,0]
+    expected: FAIL
+
+  [WebGL test #42: attachment 5 should be 0,255,0,255\nat (0, 0) expected: 0,255,0,255 was 0,0,0,0]
+    expected: FAIL
+
+  [WebGL test #40: attachment 3 should be 0,255,0,255\nat (0, 0) expected: 0,255,0,255 was 0,0,0,0]
+    expected: FAIL
+
+  [WebGL test #39: attachment 2 should be 0,255,0,255\nat (0, 0) expected: 0,255,0,255 was 0,0,0,0]
+    expected: FAIL
+
+  [WebGL test #46: attachment 1 should be 0,255,0,255\nat (0, 0) expected: 0,255,0,255 was 0,0,0,0]
+    expected: FAIL
+
+  [WebGL test #47: attachment 2 should be 0,255,0,255\nat (0, 0) expected: 0,255,0,255 was 0,0,0,0]
+    expected: FAIL
+
+  [WebGL test #52: attachment 7 should be 0,255,0,255\nat (0, 0) expected: 0,255,0,255 was 0,0,0,0]
+    expected: FAIL
+
+  [WebGL test #41: attachment 4 should be 0,255,0,255\nat (0, 0) expected: 0,255,0,255 was 0,0,0,0]
     expected: FAIL
 
diff --git a/tests/wpt/webgl/meta/conformance2/rendering/framebuffer-completeness-unaffected.html.ini b/tests/wpt/webgl/meta/conformance2/rendering/framebuffer-completeness-unaffected.html.ini
deleted file mode 100644
index 31e5e1e855c..00000000000
--- a/tests/wpt/webgl/meta/conformance2/rendering/framebuffer-completeness-unaffected.html.ini
+++ /dev/null
@@ -1,5 +0,0 @@
-[framebuffer-completeness-unaffected.html]
-  expected: ERROR
-  [WebGL test #2: successfullyParsed should be true (of type boolean). Was undefined (of type undefined).]
-    expected: FAIL
-
diff --git a/tests/wpt/webgl/meta/conformance2/rendering/fs-color-type-mismatch-color-buffer-type.html.ini b/tests/wpt/webgl/meta/conformance2/rendering/fs-color-type-mismatch-color-buffer-type.html.ini
index 861cb782158..a63bce3601f 100644
--- a/tests/wpt/webgl/meta/conformance2/rendering/fs-color-type-mismatch-color-buffer-type.html.ini
+++ b/tests/wpt/webgl/meta/conformance2/rendering/fs-color-type-mismatch-color-buffer-type.html.ini
@@ -1,5 +1,5 @@
 [fs-color-type-mismatch-color-buffer-type.html]
-  expected: ERROR
+  expected: TIMEOUT
   [WebGL test #2: successfullyParsed should be true (of type boolean). Was undefined (of type undefined).]
     expected: FAIL
 
diff --git a/tests/wpt/webgl/meta/conformance2/rendering/read-draw-when-missing-image.html.ini b/tests/wpt/webgl/meta/conformance2/rendering/read-draw-when-missing-image.html.ini
index 511d437a930..47ce7fd0715 100644
--- a/tests/wpt/webgl/meta/conformance2/rendering/read-draw-when-missing-image.html.ini
+++ b/tests/wpt/webgl/meta/conformance2/rendering/read-draw-when-missing-image.html.ini
@@ -1,8 +1,17 @@
 [read-draw-when-missing-image.html]
   expected: ERROR
+  [WebGL test #3: getError expected: INVALID_OPERATION. Was INVALID_FRAMEBUFFER_OPERATION : Should generate INVALID_OPERATION when reading from a color buffer without image.]
+    expected: FAIL
+
   [WebGL test #1: Framebuffer incomplete.]
     expected: FAIL
 
-  [WebGL test #2: successfullyParsed should be true (of type boolean). Was undefined (of type undefined).]
+  [WebGL test #4: getError expected: INVALID_OPERATION. Was INVALID_ENUM : Should generate INVALID_OPERATION when reading from a color buffer without image.]
+    expected: FAIL
+
+  [WebGL test #2: getError expected: INVALID_OPERATION. Was INVALID_ENUM : Should generate INVALID_OPERATION when reading from a color buffer without image.]
+    expected: FAIL
+
+  [WebGL test #5: successfullyParsed should be true (of type boolean). Was undefined (of type undefined).]
     expected: FAIL
 
diff --git a/tests/wpt/webgl/meta/conformance2/rendering/rendering-sampling-feedback-loop.html.ini b/tests/wpt/webgl/meta/conformance2/rendering/rendering-sampling-feedback-loop.html.ini
index 9a29f0113d0..d9d3b521cb1 100644
--- a/tests/wpt/webgl/meta/conformance2/rendering/rendering-sampling-feedback-loop.html.ini
+++ b/tests/wpt/webgl/meta/conformance2/rendering/rendering-sampling-feedback-loop.html.ini
@@ -1,5 +1,7 @@
 [rendering-sampling-feedback-loop.html]
-  expected: ERROR
-  [WebGL test #2: successfullyParsed should be true (of type boolean). Was undefined (of type undefined).]
+  [WebGL test #2: getError expected: INVALID_OPERATION. Was NO_ERROR : Rendering to a texture where it samples from should geneates INVALID_OPERATION. Otherwise, it should be NO_ERROR]
+    expected: FAIL
+
+  [WebGL test #3: getError expected: INVALID_OPERATION. Was NO_ERROR : Rendering to a texture where it samples from should geneates INVALID_OPERATION. Otherwise, it should be NO_ERROR]
     expected: FAIL
 
diff --git a/tests/wpt/webgl/meta/conformance2/state/gl-get-calls.html.ini b/tests/wpt/webgl/meta/conformance2/state/gl-get-calls.html.ini
index 37ba9d9f5dc..2b3a626bd9c 100644
--- a/tests/wpt/webgl/meta/conformance2/state/gl-get-calls.html.ini
+++ b/tests/wpt/webgl/meta/conformance2/state/gl-get-calls.html.ini
@@ -1,7 +1,4 @@
 [gl-get-calls.html]
-  [WebGL test #13: context.getParameter(context.READ_BUFFER) should be 1029 (of type number). Was null (of type object).]
-    expected: FAIL
-
   [WebGL test #47: context.getParameter(context.MAX_FRAGMENT_INPUT_COMPONENTS) should be >= 60. Was null (of type object).]
     expected: FAIL
 
@@ -23,9 +20,6 @@
   [WebGL test #56: context.getParameter(context.MAX_PROGRAM_TEXEL_OFFSET) is not an instance of Number]
     expected: FAIL
 
-  [WebGL test #4: context.getParameter(context.DRAW_BUFFER0) should be 1029 (of type number). Was null (of type object).]
-    expected: FAIL
-
   [WebGL test #45: context.getParameter(context.MAX_ELEMENTS_INDICES) is not an instance of Number]
     expected: FAIL
 
diff --git a/tests/wpt/webgl/meta/conformance2/state/gl-object-get-calls.html.ini b/tests/wpt/webgl/meta/conformance2/state/gl-object-get-calls.html.ini
index 4a27c171b93..a9ee7d9ac81 100644
--- a/tests/wpt/webgl/meta/conformance2/state/gl-object-get-calls.html.ini
+++ b/tests/wpt/webgl/meta/conformance2/state/gl-object-get-calls.html.ini
@@ -24,6 +24,9 @@
   [WebGL test #21: gl.getBufferParameter(gl.UNIFORM_BUFFER, gl.BUFFER_SIZE) should be 16 (of type number). Was null (of type object).]
     expected: FAIL
 
+  [WebGL test #3: gl.getBufferParameter(gl.ELEMENT_ARRAY_BUFFER, gl.BUFFER_SIZE) should be 16 (of type number). Was null (of type object).]
+    expected: FAIL
+
   [WebGL test #15: gl.getBufferParameter(gl.PIXEL_UNPACK_BUFFER, gl.BUFFER_SIZE) should be 16 (of type number). Was null (of type object).]
     expected: FAIL
 
@@ -45,9 +48,15 @@
   [WebGL test #6: gl.getBufferParameter(gl.COPY_READ_BUFFER, gl.BUFFER_SIZE) should be 16 (of type number). Was null (of type object).]
     expected: FAIL
 
+  [WebGL test #4: gl.getBufferParameter(gl.ELEMENT_ARRAY_BUFFER, gl.BUFFER_USAGE) should be 35048 (of type number). Was null (of type object).]
+    expected: FAIL
+
   [WebGL test #203: gl.getTexParameter(gl.TEXTURE_2D, gl.TEXTURE_IMMUTABLE_LEVELS) should be 0 (of type number). Was null (of type object).]
     expected: FAIL
 
+  [WebGL test #5: getBufferParameter did not generate INVALID_ENUM for invalid parameter enum: NO_ERROR]
+    expected: FAIL
+
   [WebGL test #22: gl.getBufferParameter(gl.UNIFORM_BUFFER, gl.BUFFER_USAGE) should be 35048 (of type number). Was null (of type object).]
     expected: FAIL
 
@@ -87,12 +96,3 @@
   [WebGL test #274: successfullyParsed should be true (of type boolean). Was undefined (of type undefined).]
     expected: FAIL
 
-  [WebGL test #3: gl.getBufferParameter(gl.ELEMENT_ARRAY_BUFFER, gl.BUFFER_SIZE) should be 16 (of type number). Was null (of type object).]
-    expected: FAIL
-
-  [WebGL test #4: gl.getBufferParameter(gl.ELEMENT_ARRAY_BUFFER, gl.BUFFER_USAGE) should be 35048 (of type number). Was null (of type object).]
-    expected: FAIL
-
-  [WebGL test #5: getBufferParameter did not generate INVALID_ENUM for invalid parameter enum: NO_ERROR]
-    expected: FAIL
-