Auto merge of #25785 - szeged:mmatyas__webgl_fns_framebuf_getattrparam, r=jdm

Add support for WebGL2 getFramebufferAttachmentParameter

Implements the WebGL2 variant of `getFramebufferAttachmentParameter` and the related parameter checks.

See: https://www.khronos.org/registry/webgl/specs/latest/2.0/#3.7.4

<!-- Please describe your changes on the following line: -->
Depends on #25784

cc @jdm @zakorgy

---
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- [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

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3 files changed, 182 insertions, 99 deletions

diff --git a/components/script/dom/webgl2renderingcontext.rs b/components/script/dom/webgl2renderingcontext.rs
index 4c69efdcb55..dfce0f043ab 100644
--- a/components/script/dom/webgl2renderingcontext.rs
+++ b/components/script/dom/webgl2renderingcontext.rs
@@ -21,7 +21,7 @@ use crate::dom::htmlcanvaselement::HTMLCanvasElement;
 use crate::dom::htmliframeelement::HTMLIFrameElement;
 use crate::dom::webglactiveinfo::WebGLActiveInfo;
 use crate::dom::webglbuffer::WebGLBuffer;
-use crate::dom::webglframebuffer::WebGLFramebuffer;
+use crate::dom::webglframebuffer::{WebGLFramebuffer, WebGLFramebufferAttachmentRoot};
 use crate::dom::webglprogram::WebGLProgram;
 use crate::dom::webglquery::WebGLQuery;
 use crate::dom::webglrenderbuffer::WebGLRenderbuffer;
@@ -406,6 +406,157 @@ impl WebGL2RenderingContext {
         self.base
             .uniform_vec_section::<u32>(vec, offset, length, uniform_size, uniform_location)
     }
+
+    #[allow(unsafe_code)]
+    fn get_default_fb_attachment_param(&self, attachment: u32, pname: u32) -> WebGLResult<JSVal> {
+        match attachment {
+            constants::BACK | constants::DEPTH | constants::STENCIL => {},
+            _ => return Err(InvalidEnum),
+        }
+
+        if pname == constants::FRAMEBUFFER_ATTACHMENT_OBJECT_NAME {
+            return Ok(NullValue());
+        }
+
+        let attrs = self
+            .GetContextAttributes()
+            .unwrap_or_else(WebGLContextAttributes::empty);
+
+        let intval = match pname {
+            constants::FRAMEBUFFER_ATTACHMENT_OBJECT_TYPE => match attachment {
+                constants::DEPTH if !attrs.depth => constants::NONE as _,
+                constants::STENCIL if !attrs.stencil => constants::NONE as _,
+                _ => constants::FRAMEBUFFER_DEFAULT as _,
+            },
+            constants::FRAMEBUFFER_ATTACHMENT_RED_SIZE |
+            constants::FRAMEBUFFER_ATTACHMENT_GREEN_SIZE |
+            constants::FRAMEBUFFER_ATTACHMENT_BLUE_SIZE => match attachment {
+                constants::BACK => 8,
+                _ => 0,
+            },
+            constants::FRAMEBUFFER_ATTACHMENT_ALPHA_SIZE => match attachment {
+                constants::BACK if attrs.alpha => 8,
+                constants::BACK => return Err(InvalidOperation),
+                _ => 0,
+            },
+            constants::FRAMEBUFFER_ATTACHMENT_DEPTH_SIZE => match attachment {
+                constants::DEPTH if attrs.depth => 24,
+                constants::DEPTH => return Err(InvalidOperation),
+                _ => 0,
+            },
+            constants::FRAMEBUFFER_ATTACHMENT_STENCIL_SIZE => match attachment {
+                constants::STENCIL if attrs.stencil => 8,
+                constants::STENCIL => return Err(InvalidOperation),
+                _ => 0,
+            },
+            constants::FRAMEBUFFER_ATTACHMENT_COMPONENT_TYPE => match attachment {
+                constants::DEPTH if attrs.depth => constants::UNSIGNED_NORMALIZED as _,
+                constants::STENCIL if attrs.stencil => constants::UNSIGNED_INT as _,
+                constants::DEPTH => return Err(InvalidOperation),
+                constants::STENCIL => return Err(InvalidOperation),
+                _ => constants::UNSIGNED_NORMALIZED as _,
+            },
+            constants::FRAMEBUFFER_ATTACHMENT_COLOR_ENCODING => match attachment {
+                constants::DEPTH if !attrs.depth => return Err(InvalidOperation),
+                constants::STENCIL if !attrs.stencil => return Err(InvalidOperation),
+                _ => constants::LINEAR as _,
+            },
+            _ => return Err(InvalidEnum),
+        };
+        Ok(Int32Value(intval))
+    }
+
+    #[allow(unsafe_code)]
+    fn get_specific_fb_attachment_param(
+        &self,
+        cx: JSContext,
+        fb: &WebGLFramebuffer,
+        target: u32,
+        attachment: u32,
+        pname: u32,
+    ) -> WebGLResult<JSVal> {
+        use crate::dom::webglframebuffer::WebGLFramebufferAttachmentRoot::{Renderbuffer, Texture};
+
+        match attachment {
+            constants::DEPTH_ATTACHMENT | constants::STENCIL_ATTACHMENT => {},
+            constants::DEPTH_STENCIL_ATTACHMENT => {
+                if pname == constants::FRAMEBUFFER_ATTACHMENT_COMPONENT_TYPE {
+                    return Err(InvalidOperation);
+                }
+
+                let a = fb.attachment(constants::DEPTH_ATTACHMENT);
+                let b = fb.attachment(constants::STENCIL_ATTACHMENT);
+                match (a, b) {
+                    (Some(Renderbuffer(ref a)), Some(Renderbuffer(ref b))) if a.id() == b.id() => {
+                    },
+                    (Some(Texture(ref a)), Some(Texture(ref b))) if a.id() == b.id() => {},
+                    _ => return Err(InvalidOperation),
+                }
+            },
+            constants::COLOR_ATTACHMENT0..=constants::COLOR_ATTACHMENT15 => {
+                let last_slot =
+                    constants::COLOR_ATTACHMENT0 + self.base.limits().max_color_attachments - 1;
+                if last_slot < attachment {
+                    return Err(InvalidEnum);
+                }
+            },
+            _ => return Err(InvalidEnum),
+        }
+
+        let attachment = match attachment {
+            constants::DEPTH_STENCIL_ATTACHMENT => constants::DEPTH_ATTACHMENT,
+            _ => attachment,
+        };
+
+        if pname == constants::FRAMEBUFFER_ATTACHMENT_OBJECT_NAME {
+            rooted!(in(*cx) let mut rval = NullValue());
+            match fb.attachment(attachment) {
+                Some(Renderbuffer(rb)) => unsafe {
+                    rb.to_jsval(*cx, rval.handle_mut());
+                },
+                Some(Texture(texture)) => unsafe {
+                    texture.to_jsval(*cx, rval.handle_mut());
+                },
+                _ => {},
+            }
+            return Ok(rval.get());
+        }
+
+        match pname {
+            constants::FRAMEBUFFER_ATTACHMENT_OBJECT_TYPE => {},
+            _ => match fb.attachment(attachment) {
+                Some(webgl_attachment) => match pname {
+                    constants::FRAMEBUFFER_ATTACHMENT_RED_SIZE |
+                    constants::FRAMEBUFFER_ATTACHMENT_GREEN_SIZE |
+                    constants::FRAMEBUFFER_ATTACHMENT_BLUE_SIZE |
+                    constants::FRAMEBUFFER_ATTACHMENT_ALPHA_SIZE |
+                    constants::FRAMEBUFFER_ATTACHMENT_DEPTH_SIZE |
+                    constants::FRAMEBUFFER_ATTACHMENT_STENCIL_SIZE |
+                    constants::FRAMEBUFFER_ATTACHMENT_COMPONENT_TYPE |
+                    constants::FRAMEBUFFER_ATTACHMENT_COLOR_ENCODING => {},
+                    _ => match webgl_attachment {
+                        WebGLFramebufferAttachmentRoot::Renderbuffer(_) => return Err(InvalidEnum),
+                        WebGLFramebufferAttachmentRoot::Texture(_) => match pname {
+                            constants::FRAMEBUFFER_ATTACHMENT_TEXTURE_LEVEL |
+                            constants::FRAMEBUFFER_ATTACHMENT_TEXTURE_CUBE_MAP_FACE |
+                            constants::FRAMEBUFFER_ATTACHMENT_TEXTURE_LAYER => {},
+                            _ => return Err(InvalidEnum),
+                        },
+                    },
+                },
+                None => return Err(InvalidOperation),
+            },
+        }
+
+        let (sender, receiver) = webgl_channel().unwrap();
+        self.base
+            .send_command(WebGLCommand::GetFramebufferAttachmentParameter(
+                target, attachment, pname, sender,
+            ));
+
+        let retval = receiver.recv().unwrap();
+        Ok(Int32Value(retval))
+    }
 }
 
 impl WebGL2RenderingContextMethods for WebGL2RenderingContext {
@@ -586,8 +737,33 @@ impl WebGL2RenderingContextMethods for WebGL2RenderingContext {
         attachment: u32,
         pname: u32,
     ) -> JSVal {
-        self.base
-            .GetFramebufferAttachmentParameter(cx, target, attachment, pname)
+        let fb_slot = match target {
+            constants::FRAMEBUFFER | constants::DRAW_FRAMEBUFFER => {
+                self.base.get_draw_framebuffer_slot()
+            },
+            constants::READ_FRAMEBUFFER => &self.base.get_read_framebuffer_slot(),
+            _ => {
+                self.base.webgl_error(InvalidEnum);
+                return NullValue();
+            },
+        };
+
+        if let Some(fb) = fb_slot.get() {
+            // A selected framebuffer is bound to the target
+            handle_potential_webgl_error!(self.base, fb.validate_transparent(), return NullValue());
+            handle_potential_webgl_error!(
+                self.base,
+                self.get_specific_fb_attachment_param(cx, &fb, target, attachment, pname),
+                return NullValue()
+            )
+        } else {
+            // The default framebuffer is bound to the target
+            handle_potential_webgl_error!(
+                self.base,
+                self.get_default_fb_attachment_param(attachment, pname),
+                return NullValue()
+            )
+        }
     }
 
     /// https://www.khronos.org/registry/webgl/specs/latest/1.0/#5.14.7
diff --git a/tests/wpt/webgl/meta/conformance2/renderbuffers/framebuffer-object-attachment.html.ini b/tests/wpt/webgl/meta/conformance2/renderbuffers/framebuffer-object-attachment.html.ini
index 3b4f43532af..29e24af8116 100644
--- a/tests/wpt/webgl/meta/conformance2/renderbuffers/framebuffer-object-attachment.html.ini
+++ b/tests/wpt/webgl/meta/conformance2/renderbuffers/framebuffer-object-attachment.html.ini
@@ -1,43 +1,13 @@
 [framebuffer-object-attachment.html]
-  [WebGL test #13: checkFramebufferStatus expects [FRAMEBUFFER_COMPLETE\], was FRAMEBUFFER_INCOMPLETE_ATTACHMENT]
-    expected: FAIL
-
-  [WebGL test #20: checkFramebufferStatus expects [FRAMEBUFFER_COMPLETE\], was FRAMEBUFFER_INCOMPLETE_ATTACHMENT]
-    expected: FAIL
-
-  [WebGL test #30: getError expected: NO_ERROR. Was INVALID_ENUM : ]
-    expected: FAIL
-
-  [WebGL test #21: checkFramebufferStatus expects [FRAMEBUFFER_COMPLETE\], was FRAMEBUFFER_UNSUPPORTED]
-    expected: FAIL
-
-  [WebGL test #25: checkFramebufferStatus expects [FRAMEBUFFER_COMPLETE\], was FRAMEBUFFER_UNSUPPORTED]
-    expected: FAIL
-
-  [WebGL test #23: checkFramebufferStatus expects [FRAMEBUFFER_COMPLETE\], was FRAMEBUFFER_UNSUPPORTED]
-    expected: FAIL
-
-  [WebGL test #24: checkFramebufferStatus expects [FRAMEBUFFER_COMPLETE\], was FRAMEBUFFER_UNSUPPORTED]
-    expected: FAIL
-
-  [WebGL test #22: checkFramebufferStatus expects [FRAMEBUFFER_COMPLETE\], was FRAMEBUFFER_UNSUPPORTED]
-    expected: FAIL
-
-  [WebGL test #14: getError expected: NO_ERROR. Was INVALID_ENUM : ]
-    expected: FAIL
-
-  [WebGL test #16: gl.getParameter(gl.RED_BITS) + gl.getParameter(gl.GREEN_BITS) + gl.getParameter(gl.BLUE_BITS) + gl.getParameter(gl.ALPHA_BITS) >= 16 should be true. Was false.]
-    expected: FAIL
-
-  [WebGL test #59: getError expected: NO_ERROR. Was INVALID_ENUM : Query should not generate error]
-    expected: FAIL
-
   [WebGL test #13: gl.getParameter(gl.RED_BITS) + gl.getParameter(gl.GREEN_BITS) + gl.getParameter(gl.BLUE_BITS) + gl.getParameter(gl.ALPHA_BITS) >= 16 should be true. Was false.]
     expected: FAIL
 
   [WebGL test #10: checkFramebufferStatus expects [FRAMEBUFFER_COMPLETE\], was FRAMEBUFFER_INCOMPLETE_ATTACHMENT]
     expected: FAIL
 
+  [WebGL test #20: checkFramebufferStatus expects [FRAMEBUFFER_COMPLETE\], was FRAMEBUFFER_INCOMPLETE_ATTACHMENT]
+    expected: FAIL
+
   [WebGL test #21: checkFramebufferStatus expects [FRAMEBUFFER_COMPLETE\], was FRAMEBUFFER_INCOMPLETE_ATTACHMENT]
     expected: FAIL
 
@@ -53,9 +23,6 @@
   [WebGL test #19: checkFramebufferStatus expects [FRAMEBUFFER_COMPLETE\], was FRAMEBUFFER_INCOMPLETE_ATTACHMENT]
     expected: FAIL
 
-  [WebGL test #56: getError expected: NO_ERROR. Was INVALID_ENUM : Query should not generate error]
-    expected: FAIL
-
   [WebGL test #22: checkFramebufferStatus expects [FRAMEBUFFER_COMPLETE\], was FRAMEBUFFER_INCOMPLETE_ATTACHMENT]
     expected: FAIL
 
diff --git a/tests/wpt/webgl/meta/conformance2/renderbuffers/framebuffer-test.html.ini b/tests/wpt/webgl/meta/conformance2/renderbuffers/framebuffer-test.html.ini
index 1b898b12be0..9361819dbfb 100644
--- a/tests/wpt/webgl/meta/conformance2/renderbuffers/framebuffer-test.html.ini
+++ b/tests/wpt/webgl/meta/conformance2/renderbuffers/framebuffer-test.html.ini
@@ -2,63 +2,3 @@
   [WebGL test #38: getError expected: INVALID_OPERATION. Was INVALID_ENUM : getFramebufferAttachmentParameter(FRAMEBUFFER_ATTACHMENT_COLOR_ENCODING) on read framebuffer with no attachment.]
     expected: FAIL
 
-  [WebGL test #1: getError expected: INVALID_ENUM. Was INVALID_OPERATION : getFramebufferAttachmentParameter(COLOR_ATTACHMENT0) on the default framebuffer.]
-    expected: FAIL
-
-  [WebGL test #33: getError expected: NO_ERROR. Was INVALID_ENUM : getFramebufferAttachmentParameter(FRAMEBUFFER_ATTACHMENT_COLOR_ENCODING) on read/draw framebuffer.]
-    expected: FAIL
-
-  [WebGL test #42: getError expected: NO_ERROR. Was INVALID_ENUM : getFramebufferAttachmentParameter(FRAMEBUFFER_ATTACHMENT_COLOR_ENCODING) on read/draw framebuffer.]
-    expected: FAIL
-
-  [WebGL test #51: getError expected: INVALID_OPERATION. Was INVALID_ENUM : getFramebufferAttachmentParameter(FRAMEBUFFER_ATTACHMENT_DEPTH_SIZE) on read framebuffer without depth attachment.]
-    expected: FAIL
-
-  [WebGL test #40: getError expected: INVALID_OPERATION. Was INVALID_ENUM : getFramebufferAttachmentParameter(FRAMEBUFFER_ATTACHMENT_COLOR_ENCODING) on draw framebuffer with no attachment.]
-    expected: FAIL
-
-  [WebGL test #46: getError expected: NO_ERROR. Was INVALID_ENUM : getFramebufferAttachmentParameter(FRAMEBUFFER_ATTACHMENT_COLOR_ENCODING) on read/draw framebuffer.]
-    expected: FAIL
-
-  [WebGL test #54: getError expected: INVALID_OPERATION. Was INVALID_ENUM : getFramebufferAttachmentParameter(FRAMEBUFFER_ATTACHMENT_RED_SIZE) on read framebuffer with no attachment.]
-    expected: FAIL
-
-  [WebGL test #20: getError expected: INVALID_OPERATION. Was INVALID_ENUM : getFramebufferAttachmentParameter(GL_FRAMEBUFFER_ATTACHMENT_COLOR_ENCODING) with no attachment.]
-    expected: FAIL
-
-  [WebGL test #53: getError expected: INVALID_OPERATION. Was INVALID_ENUM : getFramebufferAttachmentParameter(FRAMEBUFFER_ATTACHMENT_RED_SIZE) on draw framebuffer without color attachment.]
-    expected: FAIL
-
-  [WebGL test #37: gl.getFramebufferAttachmentParameter(gl.DRAW_FRAMEBUFFER, gl.COLOR_ATTACHMENT0, gl.FRAMEBUFFER_ATTACHMENT_BLUE_SIZE) should be 0 (of type number). Was null (of type object).]
-    expected: FAIL
-
-  [WebGL test #2: getError expected: NO_ERROR. Was INVALID_OPERATION : getFramebufferAttachmentParameter(BACK) on the default framebuffer.]
-    expected: FAIL
-
-  [WebGL test #56: getError expected: INVALID_OPERATION. Was INVALID_ENUM : getFramebufferAttachmentParameter(FRAMEBUFFER_ATTACHMENT_DEPTH_SIZE) on draw framebuffer with no attachment.]
-    expected: FAIL
-
-  [WebGL test #15: getError expected: NO_ERROR. Was INVALID_ENUM : getFramebufferAttachmentParameter(FRAMEBUFFER_ATTACHMENT_OBJECT_TYPE) with no attachment.]
-    expected: FAIL
-
-  [WebGL test #29: getError expected: NO_ERROR. Was INVALID_ENUM : getFramebufferAttachmentParameter(FRAMEBUFFER_ATTACHMENT_COLOR_ENCODING) on read/draw framebuffer.]
-    expected: FAIL
-
-  [WebGL test #43: getError expected: INVALID_OPERATION. Was INVALID_ENUM : getFramebufferAttachmentParameter(FRAMEBUFFER_ATTACHMENT_COLOR_ENCODING) on read/draw framebuffer with no attachment.]
-    expected: FAIL
-
-  [WebGL test #34: getError expected: INVALID_OPERATION. Was INVALID_ENUM : getFramebufferAttachmentParameter(FRAMEBUFFER_ATTACHMENT_COLOR_ENCODING) on read/draw framebuffer with no attachment.]
-    expected: FAIL
-
-  [WebGL test #47: getError expected: INVALID_OPERATION. Was INVALID_ENUM : getFramebufferAttachmentParameter(FRAMEBUFFER_ATTACHMENT_COLOR_ENCODING) on read/draw framebuffer with no attachment.]
-    expected: FAIL
-
-  [WebGL test #39: getError expected: NO_ERROR. Was INVALID_ENUM : getFramebufferAttachmentParameter(FRAMEBUFFER_ATTACHMENT_COLOR_ENCODING) on draw framebuffer.]
-    expected: FAIL
-
-  [WebGL test #9: getError expected: NO_ERROR. Was INVALID_ENUM : getFramebufferAttachmentParameter(READ_FRAMEBUFFER).]
-    expected: FAIL
-
-  [WebGL test #30: getError expected: INVALID_OPERATION. Was INVALID_ENUM : getFramebufferAttachmentParameter(FRAMEBUFFER_ATTACHMENT_COLOR_ENCODING) on read/draw framebuffer with no attachment.]
-    expected: FAIL
-