Auto merge of #10215 - ConnorGBrewster:webgl_finish, r=emilio

WebGL: Finish, Flush, DetachShader, GenerateMipmap

Implements #10212 and #10213

r? @emilio

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---
This change is [<img src="https://reviewable.io/review_button.svg" height="35" align="absmiddle" alt="Reviewable"/>](https://reviewable.io/reviews/servo/servo/10215)
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6 files changed, 321 insertions, 9 deletions

diff --git a/components/script/dom/macros.rs b/components/script/dom/macros.rs
index 57966e37ae6..d3c157cf134 100644
--- a/components/script/dom/macros.rs
+++ b/components/script/dom/macros.rs
@@ -266,6 +266,14 @@ macro_rules! make_nonzero_dimension_setter(
 /// For use on non-jsmanaged types
 /// Use #[derive(JSTraceable)] on JS managed types
 macro_rules! no_jsmanaged_fields(
+    ([$ty:ident; $count:expr]) => (
+        impl $crate::dom::bindings::trace::JSTraceable for [$ty; $count] {
+            #[inline]
+            fn trace(&self, _: *mut ::js::jsapi::JSTracer) {
+                // Do nothing
+            }
+        }
+    );
     ($($ty:ident),+) => (
         $(
             impl $crate::dom::bindings::trace::JSTraceable for $ty {
diff --git a/components/script/dom/webglprogram.rs b/components/script/dom/webglprogram.rs
index 338a1e8d46b..378039b03eb 100644
--- a/components/script/dom/webglprogram.rs
+++ b/components/script/dom/webglprogram.rs
@@ -94,7 +94,10 @@ impl WebGLProgram {
         let shader_slot = match shader.gl_type() {
             constants::FRAGMENT_SHADER => &self.fragment_shader,
             constants::VERTEX_SHADER => &self.vertex_shader,
-            _ => return Err(WebGLError::InvalidOperation),
+            _ => {
+                error!("detachShader: Unexpected shader type");
+                return Err(WebGLError::InvalidValue);
+            }
         };
 
         // TODO(emilio): Differentiate between same shader already assigned and other previous
@@ -110,6 +113,32 @@ impl WebGLProgram {
         Ok(())
     }
 
+    /// glDetachShader
+    pub fn detach_shader(&self, shader: &WebGLShader) -> WebGLResult<()> {
+        let shader_slot = match shader.gl_type() {
+            constants::FRAGMENT_SHADER => &self.fragment_shader,
+            constants::VERTEX_SHADER => &self.vertex_shader,
+            _ => {
+                error!("detachShader: Unexpected shader type");
+                return Err(WebGLError::InvalidValue);
+            }
+        };
+
+        match shader_slot.get() {
+            Some(ref attached_shader) if attached_shader.id() != shader.id() =>
+                return Err(WebGLError::InvalidOperation),
+            None =>
+                return Err(WebGLError::InvalidOperation),
+            _ => {}
+        }
+
+        shader_slot.set(None);
+
+        self.renderer.send(CanvasMsg::WebGL(WebGLCommand::DetachShader(self.id, shader.id()))).unwrap();
+
+        Ok(())
+    }
+
     /// glBindAttribLocation
     pub fn bind_attrib_location(&self, index: u32, name: DOMString) -> WebGLResult<()> {
         if name.len() > MAX_UNIFORM_AND_ATTRIBUTE_LEN {
diff --git a/components/script/dom/webglrenderingcontext.rs b/components/script/dom/webglrenderingcontext.rs
index e614b7afc6f..d08a9456624 100644
--- a/components/script/dom/webglrenderingcontext.rs
+++ b/components/script/dom/webglrenderingcontext.rs
@@ -181,6 +181,22 @@ impl WebGLRenderingContextMethods for WebGLRenderingContext {
         Root::from_ref(&*self.canvas)
     }
 
+    // https://www.khronos.org/registry/webgl/specs/latest/1.0/#5.14.11
+    fn Flush(&self) {
+        self.ipc_renderer
+            .send(CanvasMsg::WebGL(WebGLCommand::Flush))
+            .unwrap();
+    }
+
+    // https://www.khronos.org/registry/webgl/specs/latest/1.0/#5.14.11
+    fn Finish(&self) {
+        let (sender, receiver) = ipc::channel().unwrap();
+        self.ipc_renderer
+            .send(CanvasMsg::WebGL(WebGLCommand::Finish(sender)))
+            .unwrap();
+        receiver.recv().unwrap()
+    }
+
     // https://www.khronos.org/registry/webgl/specs/latest/1.0/#5.14.1
     fn DrawingBufferWidth(&self) -> i32 {
         let (sender, receiver) = ipc::channel().unwrap();
@@ -332,6 +348,15 @@ impl WebGLRenderingContextMethods for WebGLRenderingContext {
     }
 
     // https://www.khronos.org/registry/webgl/specs/latest/1.0/#5.14.9
+    fn DetachShader(&self, program: Option<&WebGLProgram>, shader: Option<&WebGLShader>) {
+        if let Some(program) = program {
+            if let Some(shader) = shader {
+                handle_potential_webgl_error!(self, program.detach_shader(shader));
+            }
+        }
+    }
+
+    // https://www.khronos.org/registry/webgl/specs/latest/1.0/#5.14.9
     fn BindAttribLocation(&self, program: Option<&WebGLProgram>,
                           index: u32, name: DOMString) {
         if let Some(program) = program {
@@ -414,6 +439,21 @@ impl WebGLRenderingContextMethods for WebGLRenderingContext {
         }
     }
 
+    // https://www.khronos.org/registry/webgl/specs/latest/1.0/#5.14.8
+    fn GenerateMipmap(&self, target: u32) {
+        let slot = match target {
+            constants::TEXTURE_2D => &self.bound_texture_2d,
+            constants::TEXTURE_CUBE_MAP => &self.bound_texture_cube_map,
+
+            _ => return self.webgl_error(InvalidEnum),
+        };
+
+        match slot.get() {
+            Some(texture) => handle_potential_webgl_error!(self, texture.generate_mipmap()),
+            None => self.webgl_error(InvalidOperation)
+        }
+    }
+
     #[allow(unsafe_code)]
     // https://www.khronos.org/registry/webgl/specs/latest/1.0/#5.14.5
     fn BufferData(&self, _cx: *mut JSContext, target: u32, data: Option<*mut JSObject>, usage: u32) {
@@ -950,6 +990,25 @@ impl WebGLRenderingContextMethods for WebGLRenderingContext {
     }
 
     // https://www.khronos.org/registry/webgl/specs/latest/1.0/#5.14.10
+    fn Uniform1i(&self,
+                  uniform: Option<&WebGLUniformLocation>,
+                  val: i32) {
+        let uniform = match uniform {
+            Some(uniform) => uniform,
+            None => return,
+        };
+
+        match self.current_program.get() {
+            Some(ref program) if program.id() == uniform.program_id() => {},
+            _ => return self.webgl_error(InvalidOperation),
+        };
+
+        self.ipc_renderer
+            .send(CanvasMsg::WebGL(WebGLCommand::Uniform1i(uniform.id(), val)))
+            .unwrap()
+    }
+
+    // https://www.khronos.org/registry/webgl/specs/latest/1.0/#5.14.10
     fn Uniform1fv(&self,
                   uniform: Option<&WebGLUniformLocation>,
                   data: Vec<f32>) {
@@ -1107,7 +1166,7 @@ impl WebGLRenderingContextMethods for WebGLRenderingContext {
                   internal_format: u32,
                   format: u32,
                   data_type: u32,
-                  source: Option<ImageDataOrHTMLImageElementOrHTMLCanvasElementOrHTMLVideoElement >) {
+                  source: Option<ImageDataOrHTMLImageElementOrHTMLCanvasElementOrHTMLVideoElement>) {
         let texture = match target {
             constants::TEXTURE_2D => self.bound_texture_2d.get(),
             constants::TEXTURE_CUBE_MAP => self.bound_texture_cube_map.get(),
@@ -1169,11 +1228,22 @@ impl WebGLRenderingContextMethods for WebGLRenderingContext {
                 => unimplemented!(),
         };
 
+        if size.width < 0 || size.height < 0 || level < 0 {
+            self.webgl_error(WebGLError::InvalidOperation);
+        }
+
         // TODO(emilio): Invert axis, convert colorspace, premultiply alpha if requested
         let msg = WebGLCommand::TexImage2D(target, level, internal_format as i32,
                                              size.width, size.height,
                                              format, data_type, pixels);
 
+        // depth is always 1 when coming from html elements
+        handle_potential_webgl_error!(self, texture.unwrap().initialize(size.width as u32,
+                                                                        size.height as u32,
+                                                                        1,
+                                                                        internal_format,
+                                                                        level as u32));
+
         self.ipc_renderer
             .send(CanvasMsg::WebGL(msg))
             .unwrap()
diff --git a/components/script/dom/webglshader.rs b/components/script/dom/webglshader.rs
index 03c39b698b0..804dc3cdcf8 100644
--- a/components/script/dom/webglshader.rs
+++ b/components/script/dom/webglshader.rs
@@ -99,7 +99,7 @@ impl WebGLShader {
             let validator = ShaderValidator::for_webgl(self.gl_type,
                                                        SHADER_OUTPUT_FORMAT,
                                                        &BuiltInResources::default()).unwrap();
-            match validator.compile_and_translate(&[source.as_bytes()]) {
+            match validator.compile_and_translate(&[source]) {
                 Ok(translated_source) => {
                     // NOTE: At this point we should be pretty sure that the compilation in the paint thread
                     // will succeed.
diff --git a/components/script/dom/webgltexture.rs b/components/script/dom/webgltexture.rs
index e40938d84f1..5bb7d5ff734 100644
--- a/components/script/dom/webgltexture.rs
+++ b/components/script/dom/webgltexture.rs
@@ -4,6 +4,7 @@
 
 // https://www.khronos.org/registry/webgl/specs/latest/1.0/webgl.idl
 use canvas_traits::CanvasMsg;
+use dom::bindings::cell::DOMRefCell;
 use dom::bindings::codegen::Bindings::WebGLRenderingContextBinding::WebGLRenderingContextConstants as constants;
 use dom::bindings::codegen::Bindings::WebGLTextureBinding;
 use dom::bindings::global::GlobalRef;
@@ -12,6 +13,7 @@ use dom::bindings::reflector::reflect_dom_object;
 use dom::webglobject::WebGLObject;
 use ipc_channel::ipc::{self, IpcSender};
 use std::cell::Cell;
+use std::cmp;
 use webrender_traits::{WebGLCommand, WebGLError, WebGLResult};
 
 pub enum TexParameterValue {
@@ -19,6 +21,11 @@ pub enum TexParameterValue {
     Int(i32),
 }
 
+const MAX_LEVEL_COUNT: usize = 31;
+const MAX_FACE_COUNT: usize = 6;
+
+no_jsmanaged_fields!([ImageInfo; MAX_LEVEL_COUNT * MAX_FACE_COUNT]);
+
 #[dom_struct]
 pub struct WebGLTexture {
     webgl_object: WebGLObject,
@@ -26,6 +33,13 @@ pub struct WebGLTexture {
     /// The target to which this texture was bound the first time
     target: Cell<Option<u32>>,
     is_deleted: Cell<bool>,
+    is_initialized: Cell<bool>,
+    /// Stores information about mipmap levels and cubemap faces.
+    #[ignore_heap_size_of = "Arrays are cumbersome"]
+    image_info_array: DOMRefCell<[ImageInfo; MAX_LEVEL_COUNT * MAX_FACE_COUNT]>,
+    /// Face count can only be 1 or 6
+    face_count: Cell<u8>,
+    base_mipmap_level: u32,
     #[ignore_heap_size_of = "Defined in ipc-channel"]
     renderer: IpcSender<CanvasMsg>,
 }
@@ -37,6 +51,10 @@ impl WebGLTexture {
             id: id,
             target: Cell::new(None),
             is_deleted: Cell::new(false),
+            is_initialized: Cell::new(false),
+            face_count: Cell::new(0),
+            base_mipmap_level: 0,
+            image_info_array: DOMRefCell::new([ImageInfo::new(); MAX_LEVEL_COUNT * MAX_FACE_COUNT]),
             renderer: renderer,
         }
     }
@@ -63,11 +81,22 @@ impl WebGLTexture {
 
     // NB: Only valid texture targets come here
     pub fn bind(&self, target: u32) -> WebGLResult<()> {
+        if self.is_deleted.get() {
+            return Err(WebGLError::InvalidOperation);
+        }
+
         if let Some(previous_target) = self.target.get() {
             if target != previous_target {
                 return Err(WebGLError::InvalidOperation);
             }
         } else {
+            // This is the first time binding
+            let face_count = match target {
+                constants::TEXTURE_2D => 1,
+                constants::TEXTURE_CUBE_MAP => 6,
+                _ => return Err(WebGLError::InvalidOperation)
+            };
+            self.face_count.set(face_count);
             self.target.set(Some(target));
         }
 
@@ -76,6 +105,58 @@ impl WebGLTexture {
         Ok(())
     }
 
+    pub fn initialize(&self, width: u32, height: u32, depth: u32, internal_format: u32, level: u32) -> WebGLResult<()> {
+        let image_info = ImageInfo {
+            width: width,
+            height: height,
+            depth: depth,
+            internal_format: Some(internal_format),
+            is_initialized: true,
+        };
+        self.set_image_infos_at_level(level, image_info);
+
+        self.is_initialized.set(true);
+
+        Ok(())
+    }
+
+    pub fn generate_mipmap(&self) -> WebGLResult<()> {
+        let target = match self.target.get() {
+            Some(target) => target,
+            None => {
+                error!("Cannot generate mipmap on texture that has no target!");
+                return Err(WebGLError::InvalidOperation);
+            }
+        };
+
+        let base_image_info = self.base_image_info().unwrap();
+
+        if !base_image_info.is_initialized() {
+            return Err(WebGLError::InvalidOperation);
+        }
+
+        if target == constants::TEXTURE_CUBE_MAP && !self.is_cube_complete() {
+            return Err(WebGLError::InvalidOperation);
+        }
+
+        if !base_image_info.is_power_of_two() {
+            return Err(WebGLError::InvalidOperation);
+        }
+
+        if base_image_info.is_compressed_format() {
+            return Err(WebGLError::InvalidOperation);
+        }
+
+        self.renderer.send(CanvasMsg::WebGL(WebGLCommand::GenerateMipmap(target))).unwrap();
+
+        if self.base_mipmap_level + base_image_info.get_max_mimap_levels() == 0 {
+            return Err(WebGLError::InvalidOperation);
+        }
+
+        let last_level = self.base_mipmap_level + base_image_info.get_max_mimap_levels() - 1;
+        self.populate_mip_chain(self.base_mipmap_level, last_level)
+    }
+
     pub fn delete(&self) {
         if !self.is_deleted.get() {
             self.is_deleted.set(true);
@@ -145,6 +226,84 @@ impl WebGLTexture {
             _ => Err(WebGLError::InvalidEnum),
         }
     }
+
+    pub fn populate_mip_chain(&self, first_level: u32, last_level: u32) -> WebGLResult<()> {
+        let base_image_info = self.image_info_at_face(0, first_level);
+        if !base_image_info.is_initialized() {
+            return Err(WebGLError::InvalidOperation);
+        }
+
+        let mut ref_width = base_image_info.width;
+        let mut ref_height = base_image_info.height;
+
+        if ref_width == 0 || ref_height == 0 {
+            return Err(WebGLError::InvalidOperation);
+        }
+
+        for level in (first_level + 1)..last_level {
+            if ref_width == 1 && ref_height == 1 {
+                break;
+            }
+
+            ref_width = cmp::max(1, ref_width / 2);
+            ref_height = cmp::max(1, ref_height / 2);
+
+            let image_info = ImageInfo {
+                width: ref_width,
+                height: ref_height,
+                depth: 0,
+                internal_format: base_image_info.internal_format,
+                is_initialized: base_image_info.is_initialized(),
+            };
+
+            self.set_image_infos_at_level(level, image_info);
+        }
+        Ok(())
+    }
+
+    fn is_cube_complete(&self) -> bool {
+        let image_info = self.base_image_info().unwrap();
+        if !image_info.is_defined() {
+            return false;
+        }
+
+        let ref_width = image_info.width;
+        let ref_format = image_info.internal_format;
+
+        for face in 0..self.face_count.get() {
+            let current_image_info = self.image_info_at_face(face, self.base_mipmap_level);
+            if !current_image_info.is_defined() {
+                return false;
+            }
+
+            // Compares height with width to enforce square dimensions
+            if current_image_info.internal_format != ref_format ||
+               current_image_info.width != ref_width ||
+               current_image_info.height != ref_width {
+                return false;
+            }
+        }
+
+        true
+    }
+
+    fn image_info_at_face(&self, face: u8, level: u32) -> ImageInfo {
+        let pos = (level * self.face_count.get() as u32) + face as u32;
+        self.image_info_array.borrow()[pos as usize]
+    }
+
+    fn set_image_infos_at_level(&self, level: u32, image_info: ImageInfo) {
+        for face in 0..self.face_count.get() {
+            let pos = (level * self.face_count.get() as u32) + face as u32;
+            self.image_info_array.borrow_mut()[pos as usize] = image_info;
+        }
+    }
+
+    fn base_image_info(&self) -> Option<ImageInfo> {
+        assert!((self.base_mipmap_level as usize) < MAX_LEVEL_COUNT);
+
+        Some(self.image_info_at_face(0, self.base_mipmap_level))
+    }
 }
 
 impl Drop for WebGLTexture {
@@ -152,3 +311,50 @@ impl Drop for WebGLTexture {
         self.delete();
     }
 }
+
+#[derive(Clone, Copy, PartialEq, Debug, JSTraceable, HeapSizeOf)]
+struct ImageInfo {
+    width: u32,
+    height: u32,
+    depth: u32,
+    internal_format: Option<u32>,
+    is_initialized: bool,
+}
+
+impl ImageInfo {
+    fn new() -> ImageInfo {
+        ImageInfo {
+            width: 0,
+            height: 0,
+            depth: 0,
+            internal_format: None,
+            is_initialized: false,
+        }
+    }
+
+    fn is_power_of_two(&self) -> bool {
+        self.width.is_power_of_two() && self.height.is_power_of_two() && self.depth.is_power_of_two()
+    }
+
+    fn is_initialized(&self) -> bool {
+        self.is_initialized
+    }
+
+    fn is_defined(&self) -> bool {
+        !self.internal_format.is_none()
+    }
+
+    fn get_max_mimap_levels(&self) -> u32 {
+        let largest = cmp::max(cmp::max(self.width, self.height), self.depth);
+        if largest == 0 {
+            return 0;
+        }
+        // FloorLog2(largest) + 1
+        (largest as f64).log2() as u32 + 1
+    }
+
+    fn is_compressed_format(&self) -> bool {
+        // TODO: Once Servo supports compressed formats, check for them here
+        false
+    }
+}
diff --git a/components/script/dom/webidls/WebGLRenderingContext.webidl b/components/script/dom/webidls/WebGLRenderingContext.webidl
index ea49e38d4bd..39e13835c29 100644
--- a/components/script/dom/webidls/WebGLRenderingContext.webidl
+++ b/components/script/dom/webidls/WebGLRenderingContext.webidl
@@ -548,7 +548,7 @@ interface WebGLRenderingContextBase
     void depthFunc(GLenum func);
     void depthMask(GLboolean flag);
     void depthRange(GLclampf zNear, GLclampf zFar);
-    //void detachShader(WebGLProgram? program, WebGLShader? shader);
+    void detachShader(WebGLProgram? program, WebGLShader? shader);
     void disable(GLenum cap);
     //void disableVertexAttribArray(GLuint index);
     void drawArrays(GLenum mode, GLint first, GLsizei count);
@@ -556,8 +556,8 @@ interface WebGLRenderingContextBase
 
     void enable(GLenum cap);
     void enableVertexAttribArray(GLuint index);
-    //void finish();
-    //void flush();
+    void finish();
+    void flush();
     //void framebufferRenderbuffer(GLenum target, GLenum attachment,
     //                             GLenum renderbuffertarget,
     //                             WebGLRenderbuffer? renderbuffer);
@@ -565,7 +565,7 @@ interface WebGLRenderingContextBase
     //                          WebGLTexture? texture, GLint level);
     void frontFace(GLenum mode);
 
-    //void generateMipmap(GLenum target);
+    void generateMipmap(GLenum target);
 
     //WebGLActiveInfo? getActiveAttrib(WebGLProgram? program, GLuint index);
     //WebGLActiveInfo? getActiveUniform(WebGLProgram? program, GLuint index);
@@ -647,7 +647,7 @@ interface WebGLRenderingContextBase
     void uniform1f(WebGLUniformLocation? location, GLfloat x);
     //void uniform1fv(WebGLUniformLocation? location, Float32Array v);
     void uniform1fv(WebGLUniformLocation? location, sequence<GLfloat> v);
-    //void uniform1i(WebGLUniformLocation? location, GLint x);
+    void uniform1i(WebGLUniformLocation? location, GLint x);
     //void uniform1iv(WebGLUniformLocation? location, Int32Array v);
     //void uniform1iv(WebGLUniformLocation? location, sequence<long> v);
     //void uniform2f(WebGLUniformLocation? location, GLfloat x, GLfloat y);
@@ -717,4 +717,3 @@ interface WebGLRenderingContext
 {
 };
 WebGLRenderingContext implements WebGLRenderingContextBase;
-