diff options
Diffstat (limited to 'components/script/dom/canvasrenderingcontext2d.rs')
| -rw-r--r-- | components/script/dom/canvasrenderingcontext2d.rs | 231 |
1 files changed, 99 insertions, 132 deletions
diff --git a/components/script/dom/canvasrenderingcontext2d.rs b/components/script/dom/canvasrenderingcontext2d.rs index 9adbaa3a734..dacabcccce5 100644 --- a/components/script/dom/canvasrenderingcontext2d.rs +++ b/components/script/dom/canvasrenderingcontext2d.rs @@ -5,7 +5,7 @@ use canvas_traits::canvas::{Canvas2dMsg, CanvasMsg, CanvasId}; use canvas_traits::canvas::{CompositionOrBlending, FillOrStrokeStyle, FillRule}; use canvas_traits::canvas::{LineCapStyle, LineJoinStyle, LinearGradientStyle}; -use canvas_traits::canvas::{RadialGradientStyle, RepetitionStyle, byte_swap_and_premultiply}; +use canvas_traits::canvas::{RadialGradientStyle, RepetitionStyle}; use cssparser::{Parser, ParserInput, RGBA}; use cssparser::Color as CSSColor; use dom::bindings::cell::DomRefCell; @@ -40,11 +40,11 @@ use net_traits::image_cache::ImageOrMetadataAvailable; use net_traits::image_cache::ImageResponse; use net_traits::image_cache::ImageState; use net_traits::image_cache::UsePlaceholder; -use num_traits::ToPrimitive; +use pixels; use profile_traits::ipc as profiled_ipc; use script_traits::ScriptMsg; use servo_url::ServoUrl; -use std::{cmp, fmt, mem}; +use std::{fmt, mem}; use std::cell::Cell; use std::str::FromStr; use std::sync::Arc; @@ -410,7 +410,7 @@ impl CanvasRenderingContext2D { Some((mut data, size)) => { // Pixels come from cache in BGRA order and drawImage expects RGBA so we // have to swap the color values - byte_swap_and_premultiply(&mut data); + pixels::byte_swap_and_premultiply_inplace(&mut data); let size = Size2D::new(size.width as f64, size.height as f64); (data, size) }, @@ -575,6 +575,28 @@ impl CanvasRenderingContext2D { fn set_origin_unclean(&self) { self.origin_clean.set(false) } + + pub fn get_rect(&self, rect: Rect<u32>) -> Vec<u8> { + assert!(self.origin_is_clean()); + + // FIXME(nox): This is probably wrong when this is a context for an + // offscreen canvas. + let canvas_size = self.canvas.as_ref().map_or(Size2D::zero(), |c| c.get_size()); + assert!(Rect::from_size(canvas_size).contains_rect(&rect)); + + let (sender, receiver) = ipc::bytes_channel().unwrap(); + self.send_canvas_2d_msg(Canvas2dMsg::GetImageData(rect, canvas_size, sender)); + let mut pixels = receiver.recv().unwrap().to_vec(); + + for chunk in pixels.chunks_mut(4) { + let b = chunk[0]; + chunk[0] = UNPREMULTIPLY_TABLE[256 * (chunk[3] as usize) + chunk[2] as usize]; + chunk[1] = UNPREMULTIPLY_TABLE[256 * (chunk[3] as usize) + chunk[1] as usize]; + chunk[2] = UNPREMULTIPLY_TABLE[256 * (chunk[3] as usize) + b as usize]; + } + + pixels + } } pub trait LayoutCanvasRenderingContext2DHelpers { @@ -1117,14 +1139,11 @@ impl CanvasRenderingContext2DMethods for CanvasRenderingContext2D { } // https://html.spec.whatwg.org/multipage/#dom-context-2d-createimagedata - fn CreateImageData(&self, sw: Finite<f64>, sh: Finite<f64>) -> Fallible<DomRoot<ImageData>> { - if *sw == 0.0 || *sh == 0.0 { + fn CreateImageData(&self, sw: i32, sh: i32) -> Fallible<DomRoot<ImageData>> { + if sw == 0 || sh == 0 { return Err(Error::IndexSize); } - - let sw = cmp::max(1, sw.abs().to_u32().unwrap()); - let sh = cmp::max(1, sh.abs().to_u32().unwrap()); - ImageData::new(&self.global(), sw, sh, None) + ImageData::new(&self.global(), sw.abs() as u32, sh.abs() as u32, None) } // https://html.spec.whatwg.org/multipage/#dom-context-2d-createimagedata @@ -1133,61 +1152,31 @@ impl CanvasRenderingContext2DMethods for CanvasRenderingContext2D { } // https://html.spec.whatwg.org/multipage/#dom-context-2d-getimagedata - fn GetImageData( - &self, - sx: Finite<f64>, - sy: Finite<f64>, - sw: Finite<f64>, - sh: Finite<f64>, - ) -> Fallible<DomRoot<ImageData>> { - if !self.origin_is_clean() { - return Err(Error::Security); - } - - let mut sx = *sx; - let mut sy = *sy; - let mut sw = *sw; - let mut sh = *sh; + fn GetImageData(&self, sx: i32, sy: i32, sw: i32, sh: i32) -> Fallible<DomRoot<ImageData>> { + // FIXME(nox): There are many arithmetic operations here that can + // overflow or underflow, this should probably be audited. - if sw == 0.0 || sh == 0.0 { + if sw == 0 || sh == 0 { return Err(Error::IndexSize); } - if sw < 0.0 { - sw = -sw; - sx -= sw; - } - if sh < 0.0 { - sh = -sh; - sy -= sh; + if !self.origin_is_clean() { + return Err(Error::Security); } - let sh = cmp::max(1, sh.to_u32().unwrap()); - let sw = cmp::max(1, sw.to_u32().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()); - let canvas_size = Size2D::new(canvas_size.width as f64, canvas_size.height as f64); - self.send_canvas_2d_msg(Canvas2dMsg::GetImageData(dest_rect, canvas_size, sender)); - let mut data = receiver.recv().unwrap(); - - // Byte swap and unmultiply alpha. - for chunk in data.chunks_mut(4) { - 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]; - } + let (origin, size) = adjust_size_sign(Point2D::new(sx, sy), Size2D::new(sw, sh)); + // FIXME(nox): This is probably wrong when this is a context for an + // offscreen canvas. + let canvas_size = self.canvas.as_ref().map_or(Size2D::zero(), |c| c.get_size()); + let read_rect = match pixels::clip(origin, size, canvas_size) { + Some(rect) => rect, + None => { + // All the pixels are outside the canvas surface. + return ImageData::new(&self.global(), size.width, size.height, None); + }, + }; - ImageData::new(&self.global(), sw, sh, Some(data.to_vec())) + ImageData::new(&self.global(), size.width, size.height, Some(self.get_rect(read_rect))) } // https://html.spec.whatwg.org/multipage/#dom-context-2d-putimagedata @@ -1196,21 +1185,23 @@ impl CanvasRenderingContext2DMethods for CanvasRenderingContext2D { } // https://html.spec.whatwg.org/multipage/#dom-context-2d-putimagedata + #[allow(unsafe_code)] fn PutImageData_( &self, imagedata: &ImageData, dx: i32, dy: i32, - mut dirty_x: i32, - mut dirty_y: i32, - mut dirty_width: i32, - mut dirty_height: i32, + dirty_x: i32, + dirty_y: i32, + dirty_width: i32, + dirty_height: i32, ) { // FIXME(nox): There are many arithmetic operations here that can // overflow or underflow, this should probably be audited. - let imagedata_size = Size2D::new(imagedata.Width() as i32, imagedata.Height() as i32); - if imagedata_size.width <= 0 || imagedata_size.height <= 0 { + + let imagedata_size = Size2D::new(imagedata.Width(), imagedata.Height()); + if imagedata_size.area() == 0 { return; } @@ -1220,76 +1211,37 @@ impl CanvasRenderingContext2DMethods for CanvasRenderingContext2D { // Step 2. // TODO: throw InvalidState if buffer is detached. - // Step 3. - if dirty_width < 0 { - dirty_x += dirty_width; - dirty_width = -dirty_width; - } - if dirty_height < 0 { - dirty_y += dirty_height; - dirty_height = -dirty_height; - } - - // Ignore any pixel that would be drawn before the beginning of the - // canvas surface. - let mut dest_x = dx + dirty_x; - let mut dest_y = dy + dirty_y; - if dest_x < 0 { - dirty_x -= dest_x; - dirty_width += dest_x; - dest_x = 0; - } - if dest_y < 0 { - dirty_y -= dest_y; - dirty_height += dest_y; - dest_y = 0; - } - - // Step 4. - if dirty_x < 0 { - dirty_width += dirty_x; - dirty_x = 0; - } - if dirty_y < 0 { - dirty_height += dirty_y; - dirty_y = 0; - } - - // Step 5. - if dirty_x + dirty_width > imagedata_size.width { - dirty_width = imagedata_size.width - dirty_x; - } - if dirty_y + dirty_height > imagedata_size.height { - dirty_height = imagedata_size.height - dirty_y; - } + // FIXME(nox): This is probably wrong when this is a context for an + // offscreen canvas. + let canvas_size = self.canvas.as_ref().map_or(Size2D::zero(), |c| c.get_size()); - // We take care of ignoring any pixel that would be drawn after the end - // of the canvas surface. - let canvas_size = self.canvas.as_ref().map_or(Size2D::zero(), |c| c.get_size()).to_i32(); - let origin = Point2D::new(dest_x, dest_y); - let drawable_size = (origin - canvas_size.to_vector().to_point()).to_size().abs(); - dirty_width = dirty_width.min(drawable_size.width); - dirty_height = dirty_height.min(drawable_size.height); - - // Step 6. - if dirty_width <= 0 || dirty_height <= 0 { - return; - } - - // FIXME(nox): There is no need to make a Vec<u8> of all the pixels - // if we didn't want to put the entire image. - let buffer = imagedata.get_data_array(); + // Steps 3-6. + let (src_origin, src_size) = adjust_size_sign( + Point2D::new(dirty_x, dirty_y), + Size2D::new(dirty_width, dirty_height), + ); + let src_rect = match pixels::clip(src_origin, src_size, imagedata_size) { + Some(rect) => rect, + None => return, + }; + let (dst_origin, _) = adjust_size_sign( + Point2D::new(dirty_x.saturating_add(dx), dirty_y.saturating_add(dy)), + Size2D::new(dirty_width, dirty_height), + ); + // By clipping to the canvas surface, we avoid sending any pixel + // that would fall outside it. + let dst_rect = match pixels::clip(dst_origin, src_rect.size, canvas_size) { + Some(rect) => rect, + None => return, + }; // Step 7. - self.send_canvas_2d_msg(Canvas2dMsg::PutImageData( - buffer.into(), - origin.to_vector(), - imagedata_size, - Rect::new( - Point2D::new(dirty_x, dirty_y), - Size2D::new(dirty_width, dirty_height), - ), - )); + let (sender, receiver) = ipc::bytes_channel().unwrap(); + let pixels = unsafe { + &imagedata.get_rect(Rect::new(src_rect.origin, dst_rect.size)) + }; + self.send_canvas_2d_msg(Canvas2dMsg::PutImageData(dst_rect, receiver)); + sender.send(pixels).unwrap(); self.mark_as_dirty(); } @@ -1539,7 +1491,7 @@ fn is_rect_valid(rect: Rect<f64>) -> bool { rect.size.width > 0.0 && rect.size.height > 0.0 } -// https://html.spec.whatwg.org/multipage/#serialisation-of-a-colour +// https://html.spec.whatwg.org/multipage/#serialisation-of-a-color fn serialize<W>(color: &RGBA, dest: &mut W) -> fmt::Result where W: fmt::Write, @@ -1570,3 +1522,18 @@ where ) } } + +fn adjust_size_sign( + mut origin: Point2D<i32>, + mut size: Size2D<i32>, +) -> (Point2D<i32>, Size2D<u32>) { + if size.width < 0 { + size.width = -size.width; + origin.x = origin.x.saturating_sub(size.width); + } + if size.height < 0 { + size.height = -size.height; + origin.y = origin.y.saturating_sub(size.height); + } + (origin, size.to_u32()) +} |