Auto merge of #20216 - servo:mozangle, r=emilio

Switch from servo/angle to the mozangle crate

https://github.com/servo/mozangle

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components/script/dom/webglprogram.rs

@@ -31,6 +31,46 @@ pub struct WebGLProgram {
     renderer: WebGLMsgSender,
 }
 
+/// ANGLE adds a `_u` prefix to variable names:
+///
+/// https://chromium.googlesource.com/angle/angle/+/855d964bd0d05f6b2cb303f625506cf53d37e94f
+///
+/// To avoid hard-coding this we would need to use the `sh::GetAttributes` and `sh::GetUniforms`
+/// API to look up the `x.name` and `x.mappedName` members,
+/// then build a data structure for bi-directional lookup (so either linear scan or two hashmaps).
+/// Even then, this would probably only support plain variable names like "foo".
+/// Strings passed to e.g. `GetUniformLocation` can be expressions like "foo[0].bar",
+/// with the mapping for that "bar" name in yet another part of ANGLE’s API.
+const ANGLE_NAME_PREFIX: &'static str = "_u";
+
+fn to_name_in_compiled_shader(s: &str) -> String {
+    map_dot_separated(s, |s, mapped| {
+        mapped.push_str(ANGLE_NAME_PREFIX);
+        mapped.push_str(s);
+    })
+}
+
+fn from_name_in_compiled_shader(s: &str) -> String {
+    map_dot_separated(s, |s, mapped| {
+        mapped.push_str(if s.starts_with(ANGLE_NAME_PREFIX) {
+            &s[ANGLE_NAME_PREFIX.len()..]
+        } else {
+            s
+        })
+    })
+}
+
+fn map_dot_separated<F: Fn(&str, &mut String)>(s: &str, f: F) -> String {
+    let mut iter = s.split('.');
+    let mut mapped = String::new();
+    f(iter.next().unwrap(), &mut mapped);
+    for s in iter {
+        mapped.push('.');
+        f(s, &mut mapped);
+    }
+    mapped
+}
+
 impl WebGLProgram {
     fn new_inherited(renderer: WebGLMsgSender,
                      id: WebGLProgramId)
@@ -213,8 +253,10 @@ impl WebGLProgram {
             return Err(WebGLError::InvalidOperation);
         }
 
+        let name = to_name_in_compiled_shader(&name);
+
         self.renderer
-            .send(WebGLCommand::BindAttribLocation(self.id, index, String::from(name)))
+            .send(WebGLCommand::BindAttribLocation(self.id, index, name))
             .unwrap();
         Ok(())
     }
@@ -228,8 +270,10 @@ impl WebGLProgram {
             .send(WebGLCommand::GetActiveUniform(self.id, index, sender))
             .unwrap();
 
-        receiver.recv().unwrap().map(|(size, ty, name)|
-            WebGLActiveInfo::new(self.global().as_window(), size, ty, DOMString::from(name)))
+        receiver.recv().unwrap().map(|(size, ty, name)| {
+            let name = DOMString::from(from_name_in_compiled_shader(&name));
+            WebGLActiveInfo::new(self.global().as_window(), size, ty, name)
+        })
     }
 
     /// glGetActiveAttrib
@@ -242,8 +286,10 @@ impl WebGLProgram {
             .send(WebGLCommand::GetActiveAttrib(self.id, index, sender))
             .unwrap();
 
-        receiver.recv().unwrap().map(|(size, ty, name)|
-            WebGLActiveInfo::new(self.global().as_window(), size, ty, DOMString::from(name)))
+        receiver.recv().unwrap().map(|(size, ty, name)| {
+            let name = DOMString::from(from_name_in_compiled_shader(&name));
+            WebGLActiveInfo::new(self.global().as_window(), size, ty, name)
+        })
     }
 
     /// glGetAttribLocation
@@ -264,9 +310,11 @@ impl WebGLProgram {
             return Ok(None);
         }
 
+        let name = to_name_in_compiled_shader(&name);
+
         let (sender, receiver) = webgl_channel().unwrap();
         self.renderer
-            .send(WebGLCommand::GetAttribLocation(self.id, String::from(name), sender))
+            .send(WebGLCommand::GetAttribLocation(self.id, name, sender))
             .unwrap();
         Ok(receiver.recv().unwrap())
     }
@@ -285,9 +333,11 @@ impl WebGLProgram {
             return Ok(None);
         }
 
+        let name = to_name_in_compiled_shader(&name);
+
         let (sender, receiver) = webgl_channel().unwrap();
         self.renderer
-            .send(WebGLCommand::GetUniformLocation(self.id, String::from(name), sender))
+            .send(WebGLCommand::GetUniformLocation(self.id, name, sender))
             .unwrap();
         Ok(receiver.recv().unwrap())
     }

components/script/dom/webglshader.rs

@@ -3,7 +3,6 @@
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 
 // https://www.khronos.org/registry/webgl/specs/latest/1.0/webgl.idl
-use angle::hl::{BuiltInResources, Output, ShaderValidator};
 use canvas_traits::webgl::{WebGLSLVersion, WebGLVersion};
 use canvas_traits::webgl::{webgl_channel, WebGLCommand, WebGLMsgSender, WebGLParameter, WebGLResult, WebGLShaderId};
 use dom::bindings::cell::DomRefCell;
@@ -16,6 +15,7 @@ use dom::webgl_extensions::ext::oesstandardderivatives::OESStandardDerivatives;
 use dom::webglobject::WebGLObject;
 use dom::window::Window;
 use dom_struct::dom_struct;
+use mozangle::shaders::{BuiltInResources, Output, ShaderValidator};
 use std::cell::Cell;
 use std::sync::{ONCE_INIT, Once};
 
@@ -47,7 +47,7 @@ impl WebGLShader {
                      id: WebGLShaderId,
                      shader_type: u32)
                      -> WebGLShader {
-        GLSLANG_INITIALIZATION.call_once(|| ::angle::hl::initialize().unwrap());
+        GLSLANG_INITIALIZATION.call_once(|| ::mozangle::shaders::initialize().unwrap());
         WebGLShader {
             webgl_object: WebGLObject::new_inherited(),
             id: id,