Add support for some more WebGL2 renderbuffer functions

Adds support for the following WebGL2 calls:

- `RenderbufferStorageMultisample`
- `GetInternalFormativ`

See: https://www.khronos.org/registry/webgl/specs/latest/2.0/#3.7.5

components/canvas/webgl_thread.rs

@@ -13,6 +13,7 @@ use canvas_traits::webgl::DOMToTextureCommand;
 use canvas_traits::webgl::GLContextAttributes;
 use canvas_traits::webgl::GLLimits;
 use canvas_traits::webgl::GlType;
+use canvas_traits::webgl::InternalFormatIntVec;
 use canvas_traits::webgl::ProgramLinkInfo;
 use canvas_traits::webgl::SwapChainId;
 use canvas_traits::webgl::TexDataType;
@@ -1211,6 +1212,13 @@ impl WebGLImpl {
             WebGLCommand::RenderbufferStorage(target, format, width, height) => {
                 gl.renderbuffer_storage(target, format, width, height)
             },
+            WebGLCommand::RenderbufferStorageMultisample(
+                target,
+                samples,
+                format,
+                width,
+                height,
+            ) => gl.renderbuffer_storage_multisample(target, samples, format, width, height),
             WebGLCommand::SampleCoverage(value, invert) => gl.sample_coverage(value, invert),
             WebGLCommand::Scissor(x, y, width, height) => {
                 // FIXME(nox): Kinda unfortunate that some u32 values could
@@ -1666,6 +1674,29 @@ impl WebGLImpl {
                     .send(gl.get_tex_parameter_iv(target, param as u32))
                     .unwrap();
             },
+            WebGLCommand::GetInternalFormatIntVec(target, internal_format, param, ref sender) => {
+                match param {
+                    InternalFormatIntVec::Samples => {
+                        let mut count = [0; 1];
+                        gl.get_internal_format_iv(
+                            target,
+                            internal_format,
+                            gl::NUM_SAMPLE_COUNTS,
+                            &mut count,
+                        );
+                        assert!(count[0] >= 0);
+
+                        let mut values = vec![0; count[0] as usize];
+                        gl.get_internal_format_iv(
+                            target,
+                            internal_format,
+                            param as u32,
+                            &mut values,
+                        );
+                        sender.send(values).unwrap()
+                    },
+                }
+            },
             WebGLCommand::TexParameteri(target, param, value) => {
                 gl.tex_parameter_i(target, param as u32, value)
             },

components/canvas_traits/webgl.rs

@@ -330,6 +330,7 @@ pub enum WebGLCommand {
     TransformFeedbackVaryings(WebGLProgramId, Vec<String>, u32),
     PolygonOffset(f32, f32),
     RenderbufferStorage(u32, u32, i32, i32),
+    RenderbufferStorageMultisample(u32, i32, u32, i32, i32),
     ReadPixels(Rect<u32>, u32, u32, IpcBytesSender),
     ReadPixelsPP(Rect<i32>, u32, u32, usize),
     SampleCoverage(f32, bool),
@@ -458,6 +459,7 @@ pub enum WebGLCommand {
     GetCurrentVertexAttrib(u32, WebGLSender<[f32; 4]>),
     GetTexParameterFloat(u32, TexParameterFloat, WebGLSender<f32>),
     GetTexParameterInt(u32, TexParameterInt, WebGLSender<i32>),
+    GetInternalFormatIntVec(u32, u32, InternalFormatIntVec, WebGLSender<Vec<i32>>),
     TexParameteri(u32, u32, i32),
     TexParameterf(u32, u32, f32),
     DrawArrays {
@@ -913,6 +915,14 @@ parameters! {
     }
 }
 
+parameters! {
+    InternalFormatParameter {
+        IntVec(InternalFormatIntVec {
+            Samples = gl::SAMPLES,
+        }),
+    }
+}
+
 #[macro_export]
 macro_rules! gl_enums {
     ($(pub enum $name:ident { $($variant:ident = $mod:ident::$constant:ident,)+ })*) => {

components/script/dom/webgl2renderingcontext.rs

@@ -42,7 +42,8 @@ use crate::js::conversions::ToJSValConvertible;
 use crate::script_runtime::JSContext;
 use canvas_traits::webgl::WebGLError::*;
 use canvas_traits::webgl::{
-    webgl_channel, GLContextAttributes, WebGLCommand, WebGLResult, WebGLVersion,
+    webgl_channel, GLContextAttributes, InternalFormatParameter, WebGLCommand, WebGLResult,
+    WebGLVersion,
 };
 use dom_struct::dom_struct;
 use euclid::default::{Point2D, Rect, Size2D};
@@ -51,7 +52,7 @@ use js::jsapi::{JSObject, Type};
 use js::jsval::{BooleanValue, DoubleValue, Int32Value, UInt32Value};
 use js::jsval::{JSVal, NullValue, ObjectValue, UndefinedValue};
 use js::rust::CustomAutoRooterGuard;
-use js::typedarray::{ArrayBufferView, CreateWith, Float32, Uint32, Uint32Array};
+use js::typedarray::{ArrayBufferView, CreateWith, Float32, Int32Array, Uint32, Uint32Array};
 use script_layout_interface::HTMLCanvasDataSource;
 use std::cell::Cell;
 use std::cmp;
@@ -3753,6 +3754,60 @@ impl WebGL2RenderingContextMethods for WebGL2RenderingContext {
             None => self.base.webgl_error(InvalidOperation),
         }
     }
+
+    /// https://www.khronos.org/registry/webgl/specs/latest/2.0/#3.7.5
+    #[allow(unsafe_code)]
+    fn GetInternalformatParameter(
+        &self,
+        cx: JSContext,
+        target: u32,
+        internal_format: u32,
+        pname: u32,
+    ) -> JSVal {
+        if target != constants::RENDERBUFFER {
+            self.base.webgl_error(InvalidEnum);
+            return NullValue();
+        }
+
+        match handle_potential_webgl_error!(
+            self.base,
+            InternalFormatParameter::from_u32(pname),
+            return NullValue()
+        ) {
+            InternalFormatParameter::IntVec(param) => unsafe {
+                let (sender, receiver) = webgl_channel().unwrap();
+                self.base
+                    .send_command(WebGLCommand::GetInternalFormatIntVec(
+                        target,
+                        internal_format,
+                        param,
+                        sender,
+                    ));
+
+                rooted!(in(*cx) let mut rval = ptr::null_mut::<JSObject>());
+                let _ = Int32Array::create(
+                    *cx,
+                    CreateWith::Slice(&receiver.recv().unwrap()),
+                    rval.handle_mut(),
+                )
+                .unwrap();
+                ObjectValue(rval.get())
+            },
+        }
+    }
+
+    /// https://www.khronos.org/registry/webgl/specs/latest/2.0/#3.7.5
+    fn RenderbufferStorageMultisample(
+        &self,
+        target: u32,
+        samples: i32,
+        internal_format: u32,
+        width: i32,
+        height: i32,
+    ) {
+        self.base
+            .renderbuffer_storage(target, samples, internal_format, width, height)
+    }
 }
 
 impl LayoutCanvasWebGLRenderingContextHelpers for LayoutDom<WebGL2RenderingContext> {

components/script/dom/webglrenderbuffer.rs

@@ -14,7 +14,8 @@ use crate::dom::webglframebuffer::WebGLFramebuffer;
 use crate::dom::webglobject::WebGLObject;
 use crate::dom::webglrenderingcontext::WebGLRenderingContext;
 use canvas_traits::webgl::{
-    webgl_channel, GlType, WebGLCommand, WebGLError, WebGLRenderbufferId, WebGLResult, WebGLVersion,
+    webgl_channel, GlType, InternalFormatIntVec, WebGLCommand, WebGLError, WebGLRenderbufferId,
+    WebGLResult, WebGLVersion,
 };
 use dom_struct::dom_struct;
 use std::cell::Cell;
@@ -133,11 +134,13 @@ impl WebGLRenderbuffer {
     pub fn storage(
         &self,
         api_type: GlType,
+        sample_count: i32,
         internal_format: u32,
         width: i32,
         height: i32,
     ) -> WebGLResult<()> {
         let is_gles = api_type == GlType::Gles;
+        let webgl_version = self.upcast().context().webgl_version();
 
         // Validate the internal_format, and save it for completeness
         // validation.
@@ -173,7 +176,7 @@ impl WebGLRenderbuffer {
             constants::DEPTH_COMPONENT24 |
             constants::DEPTH_COMPONENT32F |
             constants::DEPTH24_STENCIL8 |
-            constants::DEPTH32F_STENCIL8 => match self.upcast().context().webgl_version() {
+            constants::DEPTH32F_STENCIL8 => match webgl_version {
                 WebGLVersion::WebGL1 => return Err(WebGLError::InvalidEnum),
                 _ => internal_format,
             },
@@ -221,24 +224,47 @@ impl WebGLRenderbuffer {
             _ => return Err(WebGLError::InvalidEnum),
         };
 
+        if webgl_version != WebGLVersion::WebGL1 {
+            let (sender, receiver) = webgl_channel().unwrap();
+            self.upcast::<WebGLObject>().context().send_command(
+                WebGLCommand::GetInternalFormatIntVec(
+                    constants::RENDERBUFFER,
+                    internal_format,
+                    InternalFormatIntVec::Samples,
+                    sender,
+                ),
+            );
+            let samples = receiver.recv().unwrap();
+            if sample_count < 0 || sample_count as usize > samples.len() {
+                return Err(WebGLError::InvalidOperation);
+            }
+        }
+
         self.internal_format.set(Some(internal_format));
         self.is_initialized.set(false);
 
         if let Some(fb) = self.attached_framebuffer.get() {
             fb.update_status();
         }
 
-        self.upcast::<WebGLObject>()
-            .context()
-            .send_command(WebGLCommand::RenderbufferStorage(
+        let command = match sample_count {
+            0 => WebGLCommand::RenderbufferStorage(
                 constants::RENDERBUFFER,
                 actual_format,
                 width,
                 height,
-            ));
+            ),
+            _ => WebGLCommand::RenderbufferStorageMultisample(
+                constants::RENDERBUFFER,
+                sample_count,
+                actual_format,
+                width,
+                height,
+            ),
+        };
+        self.upcast::<WebGLObject>().context().send_command(command);
 
         self.size.set(Some((width, height)));
-
         Ok(())
     }
 

components/script/dom/webglrenderingcontext.rs

@@ -1476,6 +1476,40 @@ impl WebGLRenderingContext {
         }
         slot.set(framebuffer);
     }
+
+    pub fn renderbuffer_storage(
+        &self,
+        target: u32,
+        samples: i32,
+        internal_format: u32,
+        width: i32,
+        height: i32,
+    ) {
+        if target != constants::RENDERBUFFER {
+            return self.webgl_error(InvalidEnum);
+        }
+
+        let max = self.limits.max_renderbuffer_size;
+
+        if samples < 0 || width < 0 || width as u32 > max || height < 0 || height as u32 > max {
+            return self.webgl_error(InvalidValue);
+        }
+
+        let rb = handle_potential_webgl_error!(
+            self,
+            self.bound_renderbuffer.get().ok_or(InvalidOperation),
+            return
+        );
+        handle_potential_webgl_error!(
+            self,
+            rb.storage(self.api_type, samples, internal_format, width, height)
+        );
+        if let Some(fb) = self.bound_draw_framebuffer.get() {
+            fb.invalidate_renderbuffer(&*rb);
+        }
+
+        // FIXME: https://github.com/servo/servo/issues/13710
+    }
 }
 
 #[cfg(not(feature = "webgl_backtrace"))]
@@ -4336,30 +4370,7 @@ impl WebGLRenderingContextMethods for WebGLRenderingContext {
 
     // https://www.khronos.org/registry/webgl/specs/latest/1.0/#5.14.7
     fn RenderbufferStorage(&self, target: u32, internal_format: u32, width: i32, height: i32) {
-        if target != constants::RENDERBUFFER {
-            return self.webgl_error(InvalidEnum);
-        }
-
-        let max = self.limits.max_renderbuffer_size;
-
-        if width < 0 || width as u32 > max || height < 0 || height as u32 > max {
-            return self.webgl_error(InvalidValue);
-        }
-
-        let rb = handle_potential_webgl_error!(
-            self,
-            self.bound_renderbuffer.get().ok_or(InvalidOperation),
-            return
-        );
-        handle_potential_webgl_error!(
-            self,
-            rb.storage(self.api_type, internal_format, width, height)
-        );
-        if let Some(fb) = self.bound_draw_framebuffer.get() {
-            fb.invalidate_renderbuffer(&*rb);
-        }
-
-        // FIXME: https://github.com/servo/servo/issues/13710
+        self.renderbuffer_storage(target, 0, internal_format, width, height)
     }
 
     // https://www.khronos.org/registry/webgl/specs/latest/1.0/#5.14.6

components/script/dom/webidls/WebGL2RenderingContext.webidl

@@ -316,9 +316,9 @@ interface mixin WebGL2RenderingContextBase
   // void readBuffer(GLenum src);
 
   /* Renderbuffer objects */
-  // any getInternalformatParameter(GLenum target, GLenum internalformat, GLenum pname);
-  // void renderbufferStorageMultisample(GLenum target, GLsizei samples, GLenum internalformat,
-  //                                     GLsizei width, GLsizei height);
+  any getInternalformatParameter(GLenum target, GLenum internalformat, GLenum pname);
+  void renderbufferStorageMultisample(GLenum target, GLsizei samples, GLenum internalformat,
+                                      GLsizei width, GLsizei height);
 
   /* Texture objects */
   // void texStorage2D(GLenum target, GLsizei levels, GLenum internalformat, GLsizei width,