Implement Canvas pixel manipulation

components/canvas/canvas_paint_task.rs

@@ -3,13 +3,17 @@
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 
 use azure::azure_hl::{DrawTarget, SurfaceFormat, BackendType, StrokeOptions, DrawOptions};
-use azure::azure_hl::{ColorPattern, PatternRef};
+use azure::azure_hl::{ColorPattern, PatternRef, DrawSurfaceOptions, Filter};
+use azure::AzFloat;
+use geom::point::Point2D;
 use geom::rect::Rect;
 use geom::size::Size2D;
 use gfx::color;
 use util::task::spawn_named;
+use util::vec::byte_swap;
 
 use std::borrow::ToOwned;
+use std::ops::Add;
 use std::sync::mpsc::{channel, Sender};
 
 #[derive(Clone)]
@@ -19,6 +23,8 @@ pub enum CanvasMsg {
     StrokeRect(Rect<f32>),
     Recreate(Size2D<i32>),
     SendPixelContents(Sender<Vec<u8>>),
+    GetImageData(Rect<i32>, Size2D<i32>, Sender<Vec<u8>>),
+    PutImageData(Vec<u8>, Rect<i32>, Option<Rect<i32>>, Size2D<i32>),
     Close,
 }
 
@@ -51,6 +57,9 @@ impl CanvasPaintTask {
                     CanvasMsg::ClearRect(ref rect) => painter.clear_rect(rect),
                     CanvasMsg::Recreate(size) => painter.recreate(size),
                     CanvasMsg::SendPixelContents(chan) => painter.send_pixel_contents(chan),
+                    CanvasMsg::GetImageData(dest_rect, canvas_size, chan) => painter.get_image_data(dest_rect, canvas_size, chan),
+                    CanvasMsg::PutImageData(imagedata, image_data_rect, dirty_rect, canvas_size)
+                        => painter.put_image_data(imagedata, image_data_rect, dirty_rect, canvas_size),
                     CanvasMsg::Close => break,
                 }
             }
@@ -85,4 +94,101 @@ impl CanvasPaintTask {
             chan.send(element.to_vec()).unwrap();
         })
     }
+
+    fn get_image_data(&self, mut dest_rect: Rect<i32>, canvas_size: Size2D<i32>, chan: Sender<Vec<u8>>) {
+        if dest_rect.size.width < 0 {
+            dest_rect.size.width = -dest_rect.size.width;
+            dest_rect.origin.x -= dest_rect.size.width;
+        }
+        if dest_rect.size.height < 0 {
+            dest_rect.size.height = -dest_rect.size.height;
+            dest_rect.origin.y -= dest_rect.size.height;
+        }
+        if dest_rect.size.width == 0 {
+            dest_rect.size.width = 1;
+        }
+        if dest_rect.size.height == 0 {
+            dest_rect.size.height = 1;
+        }
+
+        let canvas_rect = Rect(Point2D(0i32, 0i32), canvas_size);
+        let src_read_rect = canvas_rect.intersection(&dest_rect).unwrap_or(Rect::zero());
+
+        let mut dest_data = Vec::new();
+        //load the canvas data to the source vector
+        if !src_read_rect.is_empty() && canvas_size.width != 0 && canvas_size.height != 0 {
+            let data_surface = self.drawtarget.snapshot().get_data_surface();
+            let mut src_data = Vec::new();
+            data_surface.with_data(|element| {
+                src_data = element.to_vec();
+            });
+
+            let stride = data_surface.stride();
+
+            //start offset of the copyable rectangle
+            let mut src = (src_read_rect.origin.y * stride + src_read_rect.origin.x * 4) as usize;
+            //copy the data to the destination vector
+            for _ in range(0, src_read_rect.size.height) {
+                let row = src_data.slice(src, src + (4 * src_read_rect.size.width) as usize);
+                dest_data.push_all(row);
+                src += stride as usize;
+            }
+        }
+        // bgra -> rgba
+        byte_swap(dest_data.as_mut_slice());
+        chan.send(dest_data).unwrap();
+    }
+
+    fn put_image_data(&mut self, mut imagedata: Vec<u8>, image_data_rect: Rect<i32>,
+                      dirty_rect: Option<Rect<i32>>, canvas_size: Size2D<i32>) {
+
+        if image_data_rect.size.width <= 0 || image_data_rect.size.height <= 0 {
+            return
+        }
+
+        assert!(image_data_rect.size.width * image_data_rect.size.height * 4 == imagedata.len() as i32);
+        // rgba -> bgra
+        byte_swap(imagedata.as_mut_slice());
+
+        let new_image_data_rect = Rect(Point2D(0i32, 0i32),
+            Size2D(image_data_rect.size.width, image_data_rect.size.height));
+
+        let new_dirty_rect = match dirty_rect {
+            Some(mut dirty_rect) => {
+                if dirty_rect.size.width < 0 {
+                    dirty_rect.origin.x = dirty_rect.origin.x + dirty_rect.size.width;
+                    dirty_rect.size.width = -dirty_rect.size.width;
+                }
+                if dirty_rect.size.height < 0 {
+                    dirty_rect.origin.y = dirty_rect.origin.y + dirty_rect.size.height;
+                    dirty_rect.size.height = -dirty_rect.size.height;
+                }
+                new_image_data_rect.intersection(&dirty_rect)
+            },
+            None => Some(new_image_data_rect)
+        };
+
+        if let Some(new_dirty_rect) = new_dirty_rect {
+            let moved_dirty_rect = Rect(new_dirty_rect.origin.add(image_data_rect.origin),
+                                        new_dirty_rect.size).intersection(&Rect(Point2D(0i32, 0i32),
+                                        canvas_size)).unwrap_or(Rect::zero());
+            if moved_dirty_rect.is_empty() {
+                return
+            }
+
+            let source_surface = self.drawtarget.create_source_surface_from_data(imagedata.as_slice(),
+                image_data_rect.size, image_data_rect.size.width * 4, SurfaceFormat::B8G8R8A8);
+
+            let draw_surface_options = DrawSurfaceOptions::new(Filter::Linear, true);
+            let draw_options = DrawOptions::new(1.0f64 as AzFloat, 0);
+
+            self.drawtarget.draw_surface(source_surface,
+                Rect(Point2D(moved_dirty_rect.origin.x as AzFloat, moved_dirty_rect.origin.y as AzFloat),
+                     Size2D(moved_dirty_rect.size.width as AzFloat, moved_dirty_rect.size.height as AzFloat)),
+                Rect(Point2D((moved_dirty_rect.origin.x - image_data_rect.origin.x) as AzFloat,
+                             (moved_dirty_rect.origin.y - image_data_rect.origin.y) as AzFloat),
+                     Size2D(moved_dirty_rect.size.width as AzFloat, moved_dirty_rect.size.height as AzFloat)),
+                draw_surface_options, draw_options);
+        }
+    }
 }

components/net/image/base.rs

@@ -5,6 +5,7 @@
 use std::iter::range_step;
 use stb_image::image as stb_image;
 use png;
+use util::vec::byte_swap;
 
 // FIXME: Images must not be copied every frame. Instead we should atomically
 // reference count them.
@@ -17,16 +18,6 @@ pub fn test_image_bin() -> Vec<u8> {
     TEST_IMAGE.iter().map(|&x| x).collect()
 }
 
-// TODO(pcwalton): Speed up with SIMD, or better yet, find some way to not do this.
-fn byte_swap(data: &mut [u8]) {
-    let length = data.len();
-    for i in range_step(0, length, 4) {
-        let r = data[i + 2];
-        data[i + 2] = data[i + 0];
-        data[i + 0] = r;
-    }
-}
-
 // TODO(pcwalton): Speed up with SIMD, or better yet, find some way to not do this.
 fn byte_swap_and_premultiply(data: &mut [u8]) {
     let length = data.len();

components/script/dom/canvasrenderingcontext2d.rs

@@ -4,19 +4,24 @@
 
 use dom::bindings::codegen::Bindings::CanvasRenderingContext2DBinding;
 use dom::bindings::codegen::Bindings::CanvasRenderingContext2DBinding::CanvasRenderingContext2DMethods;
+use dom::bindings::codegen::Bindings::ImageDataBinding::ImageDataMethods;
+use dom::bindings::error::Error::IndexSize;
+use dom::bindings::error::Fallible;
 use dom::bindings::global::{GlobalRef, GlobalField};
 use dom::bindings::js::{JS, JSRef, LayoutJS, Temporary};
 use dom::bindings::utils::{Reflector, reflect_dom_object};
-use dom::htmlcanvaselement::HTMLCanvasElement;
+use dom::htmlcanvaselement::{HTMLCanvasElement, HTMLCanvasElementHelpers};
+use dom::imagedata::{ImageData, ImageDataHelpers};
 
 use geom::point::Point2D;
 use geom::rect::Rect;
 use geom::size::Size2D;
 
 use canvas::canvas_paint_task::{CanvasMsg, CanvasPaintTask};
-use canvas::canvas_paint_task::CanvasMsg::{ClearRect, Close, FillRect, Recreate, StrokeRect};
+use canvas::canvas_paint_task::CanvasMsg::{ClearRect, Close, FillRect, Recreate, StrokeRect, GetImageData, PutImageData};
 
-use std::sync::mpsc::Sender;
+use std::num::{Float, ToPrimitive};
+use std::sync::mpsc::{channel, Sender};
 
 #[dom_struct]
 pub struct CanvasRenderingContext2D {
@@ -75,6 +80,48 @@ impl<'a> CanvasRenderingContext2DMethods for JSRef<'a, CanvasRenderingContext2D>
         let rect = Rect(Point2D(x as f32, y as f32), Size2D(width as f32, height as f32));
         self.renderer.send(StrokeRect(rect)).unwrap();
     }
+
+    fn CreateImageData(self, sw: f64, sh: f64) -> Fallible<Temporary<ImageData>> {
+        if sw == 0.0 || sh == 0.0 {
+            return Err(IndexSize)
+        }
+
+        Ok(ImageData::new(self.global.root().r(), sw.abs().to_u32().unwrap(), sh.abs().to_u32().unwrap(), None))
+    }
+
+    fn CreateImageData_(self, imagedata: JSRef<ImageData>) -> Fallible<Temporary<ImageData>> {
+        Ok(ImageData::new(self.global.root().r(), imagedata.Width(), imagedata.Height(), None))
+    }
+
+    fn GetImageData(self, sx: f64, sy: f64, sw: f64, sh: f64) -> Fallible<Temporary<ImageData>> {
+        if sw == 0.0 || sh == 0.0 {
+            return Err(IndexSize)
+        }
+
+        let (sender, receiver) = channel::<Vec<u8>>();
+        let dest_rect = Rect(Point2D(sx.to_i32().unwrap(), sy.to_i32().unwrap()), Size2D(sw.to_i32().unwrap(), sh.to_i32().unwrap()));
+        let canvas_size = self.canvas.root().r().get_size();
+        self.renderer.send(GetImageData(dest_rect, canvas_size, sender)).unwrap();
+        let data = receiver.recv().unwrap();
+        Ok(ImageData::new(self.global.root().r(), sw.abs().to_u32().unwrap(), sh.abs().to_u32().unwrap(), Some(data)))
+    }
+
+    fn PutImageData(self, imagedata: JSRef<ImageData>, dx: f64, dy: f64) {
+        let data = imagedata.get_data_array(&self.global.root().r());
+        let image_data_rect = Rect(Point2D(dx.to_i32().unwrap(), dy.to_i32().unwrap()), imagedata.get_size());
+        let dirty_rect = None;
+        let canvas_size = self.canvas.root().r().get_size();
+        self.renderer.send(PutImageData(data, image_data_rect, dirty_rect, canvas_size)).unwrap()
+    }
+
+    fn PutImageData_(self, imagedata: JSRef<ImageData>, dx: f64, dy: f64,
+                     dirtyX: f64, dirtyY: f64, dirtyWidth: f64, dirtyHeight: f64) {
+        let data = imagedata.get_data_array(&self.global.root().r());
+        let image_data_rect = Rect(Point2D(dx.to_i32().unwrap(), dy.to_i32().unwrap()), Size2D(imagedata.Width().to_i32().unwrap(), imagedata.Height().to_i32().unwrap()));
+        let dirty_rect = Some(Rect(Point2D(dirtyX.to_i32().unwrap(), dirtyY.to_i32().unwrap()), Size2D(dirtyWidth.to_i32().unwrap(), dirtyHeight.to_i32().unwrap())));
+        let canvas_size = self.canvas.root().r().get_size();
+        self.renderer.send(PutImageData(data, image_data_rect, dirty_rect, canvas_size)).unwrap()
+    }
 }
 
 #[unsafe_destructor]

components/script/dom/htmlcanvaselement.rs

@@ -83,6 +83,16 @@ impl LayoutHTMLCanvasElementHelpers for LayoutJS<HTMLCanvasElement> {
     }
 }
 
+pub trait HTMLCanvasElementHelpers {
+    fn get_size(&self) -> Size2D<i32>;
+}
+
+impl<'a> HTMLCanvasElementHelpers for JSRef<'a, HTMLCanvasElement> {
+    fn get_size(&self) -> Size2D<i32> {
+        Size2D(self.Width() as i32, self.Height() as i32)
+    }
+}
+
 impl<'a> HTMLCanvasElementMethods for JSRef<'a, HTMLCanvasElement> {
     fn Width(self) -> u32 {
         self.width.get()

components/script/dom/imagedata.rs

@@ -0,0 +1,87 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+use dom::bindings::codegen::Bindings::ImageDataBinding;
+use dom::bindings::codegen::Bindings::ImageDataBinding::ImageDataMethods;
+use dom::bindings::global::GlobalRef;
+use dom::bindings::js::{JSRef, Temporary};
+use dom::bindings::utils::{Reflector, reflect_dom_object};
+use geom::size::Size2D;
+use js::jsapi::{JSContext, JSObject};
+use js::jsfriendapi::bindgen::{JS_NewUint8ClampedArray, JS_GetUint8ClampedArrayData};
+use libc::uint8_t;
+use std::vec::Vec;
+use collections::slice::from_raw_buf;
+use std::ptr;
+
+#[dom_struct]
+#[allow(raw_pointer_derive)]
+pub struct ImageData {
+    reflector_: Reflector,
+    width: u32,
+    height: u32,
+    data: *mut JSObject,
+}
+
+impl ImageData {
+    #[allow(unsafe_blocks)]
+    fn new_inherited(width: u32, height: u32, data: Option<Vec<u8>>, global: GlobalRef) -> ImageData {
+        unsafe {
+            let cx = global.get_cx();
+            let js_object: *mut JSObject = JS_NewUint8ClampedArray(cx, width * height * 4);
+
+            if let Some(vec) = data {
+                let js_object_data: *mut uint8_t = JS_GetUint8ClampedArrayData(js_object, cx);
+                ptr::copy_nonoverlapping_memory(js_object_data, vec.as_ptr(), vec.len())
+            }
+
+            ImageData {
+                reflector_: Reflector::new(),
+                width: width,
+                height: height,
+                data: js_object,
+            }
+        }
+    }
+
+    pub fn new(global: GlobalRef, width: u32, height: u32, data: Option<Vec<u8>>) -> Temporary<ImageData> {
+        reflect_dom_object(box ImageData::new_inherited(width, height, data, global),
+                           global, ImageDataBinding::Wrap)
+    }
+}
+
+pub trait ImageDataHelpers {
+    fn get_data_array(self, global: &GlobalRef) -> Vec<u8>;
+    fn get_size(&self) -> Size2D<i32>;
+}
+
+impl<'a> ImageDataHelpers for JSRef<'a, ImageData> {
+    #[allow(unsafe_blocks)]
+    fn get_data_array(self, global: &GlobalRef) -> Vec<u8> {
+        unsafe {
+            let cx = global.get_cx();
+            let data: *const uint8_t = JS_GetUint8ClampedArrayData(self.Data(cx), cx) as *const uint8_t;
+            let len = self.Width() * self.Height() * 4;
+            from_raw_buf(&data, len as uint).to_vec()
+        }
+    }
+
+    fn get_size(&self) -> Size2D<i32> {
+        Size2D(self.Width() as i32, self.Height() as i32)
+    }
+}
+
+impl<'a> ImageDataMethods for JSRef<'a, ImageData> {
+    fn Width(self) -> u32 {
+        self.width
+    }
+
+    fn Height(self) -> u32 {
+        self.height
+    }
+
+    fn Data(self, _: *mut JSContext) -> *mut JSObject {
+        self.data
+    }
+}

components/script/dom/mod.rs

@@ -290,6 +290,7 @@ pub mod htmltrackelement;
 pub mod htmlulistelement;
 pub mod htmlvideoelement;
 pub mod htmlunknownelement;
+pub mod imagedata;
 pub mod keyboardevent;
 pub mod location;
 pub mod messageevent;

components/script/dom/webidls/CanvasRenderingContext2D.webidl

@@ -96,9 +96,12 @@ interface CanvasRenderingContext2D {
   //void removeHitRegion(DOMString id);
 
   // pixel manipulation
-  //ImageData createImageData(double sw, double sh);
-  //ImageData createImageData(ImageData imagedata);
-  //ImageData getImageData(double sx, double sy, double sw, double sh);
-  //void putImageData(ImageData imagedata, double dx, double dy);
-  //void putImageData(ImageData imagedata, double dx, double dy, double dirtyX, double dirtyY, double dirtyWidth, double dirtyHeight);
+  [Throws]
+  ImageData createImageData(double sw, double sh);
+  [Throws]
+  ImageData createImageData(ImageData imagedata);
+  [Throws]
+  ImageData getImageData(double sx, double sy, double sw, double sh);
+  void putImageData(ImageData imagedata, double dx, double dy);
+  void putImageData(ImageData imagedata, double dx, double dy, double dirtyX, double dirtyY, double dirtyWidth, double dirtyHeight);
 };

components/script/dom/webidls/ImageData.webidl

@@ -0,0 +1,23 @@
+/* -*- Mode: IDL; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this file,
+ * You can obtain one at http://mozilla.org/MPL/2.0/.
+ *
+ * The origin of this IDL file is
+ * http://www.whatwg.org/specs/web-apps/current-work/multipage/the-canvas-element.html#imagedata
+ *
+ * © Copyright 2004-2011 Apple Computer, Inc., Mozilla Foundation, and Opera Software ASA.
+ * You are granted a license to use, reproduce and create derivative works of this document.
+ */
+
+//[Constructor(unsigned long sw, unsigned long sh),
+//Constructor(Uint8ClampedArray data, unsigned long sw, optional unsigned long sh),
+//Exposed=(Window,Worker)]
+interface ImageData {
+	//[Constant]
+	readonly attribute unsigned long width;
+	//[Constant]
+	readonly attribute unsigned long height;
+	//[Constant, StoreInSlot]
+	readonly attribute Uint8ClampedArray data;
+};