Auto merge of #21701 - servo:webgl, r=jdm

Yet another batch of arbitrary improvements to our WebGL stuff

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components/canvas/canvas_data.rs

@@ -11,7 +11,7 @@ use azure::azure_hl::SurfacePattern;
 use canvas_traits::canvas::*;
 use cssparser::RGBA;
 use euclid::{Transform2D, Point2D, Vector2D, Rect, Size2D};
-use ipc_channel::ipc::IpcSender;
+use ipc_channel::ipc::{IpcBytesSender, IpcSender};
 use num_traits::ToPrimitive;
 use serde_bytes::ByteBuf;
 use std::mem;
@@ -456,13 +456,9 @@ impl<'a> CanvasData<'a> {
         &self,
         dest_rect: Rect<i32>,
         canvas_size: Size2D<f64>,
-        chan: IpcSender<ByteBuf>,
+        sender: IpcBytesSender,
     ) {
-        let mut dest_data = self.read_pixels(dest_rect, canvas_size);
-
-        // bgra -> rgba
-        byte_swap(&mut dest_data);
-        chan.send(dest_data.into()).unwrap();
+        sender.send(&self.read_pixels(dest_rect, canvas_size)).unwrap();
     }
 
     // https://html.spec.whatwg.org/multipage/#dom-context-2d-putimagedata

components/canvas_traits/canvas.rs

@@ -4,7 +4,7 @@
 
 use cssparser::RGBA;
 use euclid::{Transform2D, Point2D, Vector2D, Rect, Size2D};
-use ipc_channel::ipc::IpcSender;
+use ipc_channel::ipc::{IpcBytesSender, IpcSender};
 use serde_bytes::ByteBuf;
 use std::default::Default;
 use std::str::FromStr;
@@ -51,7 +51,7 @@ pub enum Canvas2dMsg {
     Fill,
     FillText(String, f64, f64, Option<f64>),
     FillRect(Rect<f32>),
-    GetImageData(Rect<i32>, Size2D<f64>, IpcSender<ByteBuf>),
+    GetImageData(Rect<i32>, Size2D<f64>, IpcBytesSender),
     IsPointInPath(f64, f64, FillRule, IpcSender<bool>),
     LineTo(Point2D<f32>),
     MoveTo(Point2D<f32>),

components/script/dom/canvasrenderingcontext2d.rs

@@ -32,7 +32,7 @@ use dom::imagedata::ImageData;
 use dom::node::{Node, NodeDamage, window_from_node};
 use dom_struct::dom_struct;
 use euclid::{Transform2D, Point2D, Vector2D, Rect, Size2D, vec2};
-use ipc_channel::ipc::IpcSender;
+use ipc_channel::ipc::{self, IpcSender};
 use net_traits::image::base::PixelFormat;
 use net_traits::image_cache::CanRequestImages;
 use net_traits::image_cache::ImageCache;
@@ -41,7 +41,7 @@ use net_traits::image_cache::ImageResponse;
 use net_traits::image_cache::ImageState;
 use net_traits::image_cache::UsePlaceholder;
 use num_traits::ToPrimitive;
-use profile_traits::ipc;
+use profile_traits::ipc as profiled_ipc;
 use script_traits::ScriptMsg;
 use servo_url::ServoUrl;
 use std::{cmp, fmt, mem};
@@ -130,7 +130,7 @@ impl CanvasRenderingContext2D {
                          size: Size2D<i32>)
                          -> CanvasRenderingContext2D {
         debug!("Creating new canvas rendering context.");
-        let (sender, receiver) = ipc::channel(global.time_profiler_chan().clone()).unwrap();
+        let (sender, receiver) = profiled_ipc::channel(global.time_profiler_chan().clone()).unwrap();
         let script_to_constellation_chan = global.script_to_constellation_chan();
         debug!("Asking constellation to create new canvas thread.");
         script_to_constellation_chan.send(ScriptMsg::CreateCanvasPaintThread(size, sender)).unwrap();
@@ -790,7 +790,7 @@ impl CanvasRenderingContext2DMethods for CanvasRenderingContext2D {
             CanvasFillRule::Nonzero => FillRule::Nonzero,
             CanvasFillRule::Evenodd => FillRule::Evenodd,
         };
-        let (sender, receiver) = ipc::channel::<bool>(self.global().time_profiler_chan().clone()).unwrap();
+        let (sender, receiver) = profiled_ipc::channel::<bool>(self.global().time_profiler_chan().clone()).unwrap();
         self.send_canvas_2d_msg(Canvas2dMsg::IsPointInPath(x, y, fill_rule, sender));
         receiver.recv().unwrap()
     }
@@ -1107,7 +1107,7 @@ impl CanvasRenderingContext2DMethods for CanvasRenderingContext2D {
         let sh = cmp::max(1, sh.to_u32().unwrap());
         let sw = cmp::max(1, sw.to_u32().unwrap());
 
-        let (sender, receiver) = ipc::channel(self.global().time_profiler_chan().clone()).unwrap();
+        let (sender, receiver) = ipc::bytes_channel().unwrap();
         let dest_rect = Rect::new(Point2D::new(sx.to_i32().unwrap(), sy.to_i32().unwrap()),
                                   Size2D::new(sw as i32, sh as i32));
         let canvas_size = self.canvas.as_ref().map(|c| c.get_size()).unwrap_or(Size2D::zero());
@@ -1115,12 +1115,12 @@ impl CanvasRenderingContext2DMethods for CanvasRenderingContext2D {
         self.send_canvas_2d_msg(Canvas2dMsg::GetImageData(dest_rect, canvas_size, sender));
         let mut data = receiver.recv().unwrap();
 
-        // Un-premultiply alpha
+        // Byte swap and unmultiply alpha.
         for chunk in data.chunks_mut(4) {
-            let alpha = chunk[3] as usize;
-            chunk[0] = UNPREMULTIPLY_TABLE[256 * alpha + chunk[0] as usize];
-            chunk[1] = UNPREMULTIPLY_TABLE[256 * alpha + chunk[1] as usize];
-            chunk[2] = UNPREMULTIPLY_TABLE[256 * alpha + chunk[2] as usize];
+            let (b, g, r, a) = (chunk[0], chunk[1], chunk[2], chunk[3]);
+            chunk[0] = UNPREMULTIPLY_TABLE[256 * (a as usize) + r as usize];
+            chunk[1] = UNPREMULTIPLY_TABLE[256 * (a as usize) + g as usize];
+            chunk[2] = UNPREMULTIPLY_TABLE[256 * (a as usize) + b as usize];
         }
 
         ImageData::new(&self.global(), sw, sh, Some(data.to_vec()))

components/script/dom/webglrenderingcontext.rs

@@ -1752,22 +1752,6 @@ impl WebGLRenderingContextMethods for WebGLRenderingContext {
             Err(_) => return,
         };
 
-        let image_info = texture.image_info_for_target(&target, level);
-
-        // The color buffer components can be dropped during the conversion to
-        // the internal_format, but new components cannot be added.
-        //
-        // Note that this only applies if we're copying to an already
-        // initialized texture.
-        //
-        // GL_INVALID_OPERATION is generated if the color buffer cannot be
-        // converted to the internal_format.
-        if let Some(old_internal_format) = image_info.internal_format() {
-            if old_internal_format.components() > internal_format.components() {
-                return self.webgl_error(InvalidOperation);
-            }
-        }
-
         // NB: TexImage2D depth is always equal to 1
         handle_potential_webgl_error!(self, texture.initialize(target,
                                                                width as u32,