mozilla
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gecko-dev
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gecko-dev/servo/components/canvas/canvas_paint_task.rs

808 строки
33 KiB
Rust
Исходник Ответственный История

/* 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 azure::azure::{AzColor, AzFloat};
use azure::azure_hl::{AntialiasMode, CapStyle, CompositionOp, JoinStyle};
use azure::azure_hl::{BackendType, DrawOptions, DrawTarget, Pattern, StrokeOptions, SurfaceFormat};
use azure::azure_hl::{ColorPattern, DrawSurfaceOptions, Filter, PathBuilder};
use canvas_traits::*;
use euclid::matrix2d::Matrix2D;
use euclid::point::Point2D;
use euclid::rect::Rect;
use euclid::size::Size2D;
use gfx_traits::color;
use ipc_channel::ipc::IpcSharedMemory;
use ipc_channel::ipc::{self, IpcSender};
use ipc_channel::router::ROUTER;
use layers::platform::surface::NativeSurface;
use num::ToPrimitive;
use std::borrow::ToOwned;
use std::mem;
use std::sync::mpsc::{Sender, channel};
use util::opts;
use util::task::spawn_named;
use util::vec::byte_swap;
impl<'a> CanvasPaintTask<'a> {
/// It reads image data from the canvas
/// canvas_size: The size of the canvas we're reading from
/// read_rect: The area of the canvas we want to read from
fn read_pixels(&self, read_rect: Rect<i32>, canvas_size: Size2D<f64>) -> Vec<u8>{
let canvas_size = canvas_size.to_i32();
let canvas_rect = Rect::new(Point2D::new(0i32, 0i32), canvas_size);
let src_read_rect = canvas_rect.intersection(&read_rect).unwrap_or(Rect::zero());
let mut image_data = Vec::new();
if src_read_rect.is_empty() || canvas_size.width <= 0 && canvas_size.height <= 0 {
return image_data;
}
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 0..src_read_rect.size.height {
let row = &src_data[src .. src + (4 * src_read_rect.size.width) as usize];
image_data.push_all(row);
src += stride as usize;
}
image_data
}
}
pub struct CanvasPaintTask<'a> {
drawtarget: DrawTarget,
/// TODO(pcwalton): Support multiple paths.
path_builder: PathBuilder,
state: CanvasPaintState<'a>,
saved_states: Vec<CanvasPaintState<'a>>,
}
#[derive(Clone)]
struct CanvasPaintState<'a> {
draw_options: DrawOptions,
fill_style: Pattern,
stroke_style: Pattern,
stroke_opts: StrokeOptions<'a>,
/// The current 2D transform matrix.
transform: Matrix2D<f32>,
shadow_offset_x: f64,
shadow_offset_y: f64,
shadow_blur: f64,
shadow_color: AzColor,
}
impl<'a> CanvasPaintState<'a> {
fn new() -> CanvasPaintState<'a> {
let antialias = if opts::get().enable_canvas_antialiasing {
AntialiasMode::Default
} else {
AntialiasMode::None
};
CanvasPaintState {
draw_options: DrawOptions::new(1.0, CompositionOp::Over, antialias),
fill_style: Pattern::Color(ColorPattern::new(color::black())),
stroke_style: Pattern::Color(ColorPattern::new(color::black())),
stroke_opts: StrokeOptions::new(1.0, JoinStyle::MiterOrBevel, CapStyle::Butt, 10.0, &[]),
transform: Matrix2D::identity(),
shadow_offset_x: 0.0,
shadow_offset_y: 0.0,
shadow_blur: 0.0,
shadow_color: color::transparent(),
}
}
}
impl<'a> CanvasPaintTask<'a> {
fn new(size: Size2D<i32>) -> CanvasPaintTask<'a> {
let draw_target = CanvasPaintTask::create(size);
let path_builder = draw_target.create_path_builder();
CanvasPaintTask {
drawtarget: draw_target,
path_builder: path_builder,
state: CanvasPaintState::new(),
saved_states: Vec::new(),
}
}
/// Creates a new `CanvasPaintTask` and returns the out-of-process sender and the in-process
/// sender for it.
pub fn start(size: Size2D<i32>) -> (IpcSender<CanvasMsg>, Sender<CanvasMsg>) {
// TODO(pcwalton): Ask the pipeline to create this for us instead of spawning it directly.
// This will be needed for multiprocess Servo.
let (out_of_process_chan, out_of_process_port) = ipc::channel::<CanvasMsg>().unwrap();
let (in_process_chan, in_process_port) = channel();
ROUTER.route_ipc_receiver_to_mpsc_sender(out_of_process_port, in_process_chan.clone());
spawn_named("CanvasTask".to_owned(), move || {
let mut painter = CanvasPaintTask::new(size);
loop {
let msg = in_process_port.recv();
match msg.unwrap() {
CanvasMsg::Canvas2d(message) => {
match message {
Canvas2dMsg::FillRect(ref rect) => painter.fill_rect(rect),
Canvas2dMsg::StrokeRect(ref rect) => painter.stroke_rect(rect),
Canvas2dMsg::ClearRect(ref rect) => painter.clear_rect(rect),
Canvas2dMsg::BeginPath => painter.begin_path(),
Canvas2dMsg::ClosePath => painter.close_path(),
Canvas2dMsg::Fill => painter.fill(),
Canvas2dMsg::Stroke => painter.stroke(),
Canvas2dMsg::Clip => painter.clip(),
Canvas2dMsg::DrawImage(imagedata, image_size, dest_rect, source_rect,
smoothing_enabled) => {
painter.draw_image(imagedata, image_size, dest_rect, source_rect, smoothing_enabled)
}
Canvas2dMsg::DrawImageSelf(image_size, dest_rect, source_rect, smoothing_enabled) => {
painter.draw_image_self(image_size, dest_rect, source_rect, smoothing_enabled)
}
Canvas2dMsg::MoveTo(ref point) => painter.move_to(point),
Canvas2dMsg::LineTo(ref point) => painter.line_to(point),
Canvas2dMsg::Rect(ref rect) => painter.rect(rect),
Canvas2dMsg::QuadraticCurveTo(ref cp, ref pt) => {
painter.quadratic_curve_to(cp, pt)
}
Canvas2dMsg::BezierCurveTo(ref cp1, ref cp2, ref pt) => {
painter.bezier_curve_to(cp1, cp2, pt)
}
Canvas2dMsg::Arc(ref center, radius, start, end, ccw) => {
painter.arc(center, radius, start, end, ccw)
}
Canvas2dMsg::ArcTo(ref cp1, ref cp2, radius) => {
painter.arc_to(cp1, cp2, radius)
}
Canvas2dMsg::RestoreContext => painter.restore_context_state(),
Canvas2dMsg::SaveContext => painter.save_context_state(),
Canvas2dMsg::SetFillStyle(style) => painter.set_fill_style(style),
Canvas2dMsg::SetStrokeStyle(style) => painter.set_stroke_style(style),
Canvas2dMsg::SetLineWidth(width) => painter.set_line_width(width),
Canvas2dMsg::SetLineCap(cap) => painter.set_line_cap(cap),
Canvas2dMsg::SetLineJoin(join) => painter.set_line_join(join),
Canvas2dMsg::SetMiterLimit(limit) => painter.set_miter_limit(limit),
Canvas2dMsg::SetTransform(ref matrix) => painter.set_transform(matrix),
Canvas2dMsg::SetGlobalAlpha(alpha) => painter.set_global_alpha(alpha),
Canvas2dMsg::SetGlobalComposition(op) => painter.set_global_composition(op),
Canvas2dMsg::GetImageData(dest_rect, canvas_size, chan)
=> painter.image_data(dest_rect, canvas_size, chan),
Canvas2dMsg::PutImageData(imagedata, offset, image_data_size, dirty_rect)
=> painter.put_image_data(imagedata, offset, image_data_size, dirty_rect),
Canvas2dMsg::SetShadowOffsetX(value) => painter.set_shadow_offset_x(value),
Canvas2dMsg::SetShadowOffsetY(value) => painter.set_shadow_offset_y(value),
Canvas2dMsg::SetShadowBlur(value) => painter.set_shadow_blur(value),
Canvas2dMsg::SetShadowColor(ref color) => painter.set_shadow_color(color.to_azcolor()),
}
},
CanvasMsg::Common(message) => {
match message {
CanvasCommonMsg::Close => break,
CanvasCommonMsg::Recreate(size) => painter.recreate(size),
}
},
CanvasMsg::FromLayout(message) => {
match message {
FromLayoutMsg::SendPixelContents(chan) => {
painter.send_pixel_contents(chan)
}
}
}
CanvasMsg::FromPaint(message) => {
match message {
FromPaintMsg::SendNativeSurface(chan) => {
painter.send_native_surface(chan)
}
}
}
CanvasMsg::WebGL(_) => panic!("Wrong message sent to Canvas2D task"),
}
}
});
(out_of_process_chan, in_process_chan)
}
fn save_context_state(&mut self) {
self.saved_states.push(self.state.clone());
}
fn restore_context_state(&mut self) {
if let Some(state) = self.saved_states.pop() {
mem::replace(&mut self.state, state);
self.drawtarget.set_transform(&self.state.transform);
self.drawtarget.pop_clip();
}
}
fn fill_rect(&self, rect: &Rect<f32>) {
if is_zero_size_gradient(&self.state.fill_style) {
return; // Paint nothing if gradient size is zero.
}
let draw_rect = Rect::new(rect.origin,
match self.state.fill_style {
Pattern::Surface(ref surface) => {
let surface_size = surface.size();
match (surface.repeat_x, surface.repeat_y) {
(true, true) => rect.size,
(true, false) => Size2D::new(rect.size.width, surface_size.height as f32),
(false, true) => Size2D::new(surface_size.width as f32, rect.size.height),
(false, false) => Size2D::new(surface_size.width as f32, surface_size.height as f32),
}
},
_ => rect.size,
}
);
if self.need_to_draw_shadow() {
self.draw_with_shadow(&draw_rect, |new_draw_target: &DrawTarget| {
new_draw_target.fill_rect(&draw_rect, self.state.fill_style.to_pattern_ref(),
Some(&self.state.draw_options));
});
} else {
self.drawtarget.fill_rect(&draw_rect, self.state.fill_style.to_pattern_ref(),
Some(&self.state.draw_options));
}
}
fn clear_rect(&self, rect: &Rect<f32>) {
self.drawtarget.clear_rect(rect);
}
fn stroke_rect(&self, rect: &Rect<f32>) {
if is_zero_size_gradient(&self.state.stroke_style) {
return; // Paint nothing if gradient size is zero.
}
if self.need_to_draw_shadow() {
self.draw_with_shadow(&rect, |new_draw_target: &DrawTarget| {
new_draw_target.stroke_rect(rect, self.state.stroke_style.to_pattern_ref(),
&self.state.stroke_opts, &self.state.draw_options);
});
} else if rect.size.width == 0. || rect.size.height == 0. {
let cap = match self.state.stroke_opts.line_join {
JoinStyle::Round => CapStyle::Round,
_ => CapStyle::Butt
};
let stroke_opts =
StrokeOptions::new(self.state.stroke_opts.line_width,
self.state.stroke_opts.line_join,
cap,
self.state.stroke_opts.miter_limit,
self.state.stroke_opts.mDashPattern);
self.drawtarget.stroke_line(rect.origin, rect.bottom_right(),
self.state.stroke_style.to_pattern_ref(),
&stroke_opts, &self.state.draw_options);
} else {
self.drawtarget.stroke_rect(rect, self.state.stroke_style.to_pattern_ref(),
&self.state.stroke_opts, &self.state.draw_options);
}
}
fn begin_path(&mut self) {
self.path_builder = self.drawtarget.create_path_builder()
}
fn close_path(&self) {
self.path_builder.close()
}
fn fill(&self) {
if is_zero_size_gradient(&self.state.fill_style) {
return; // Paint nothing if gradient size is zero.
}
self.drawtarget.fill(&self.path_builder.finish(),
self.state.fill_style.to_pattern_ref(),
&self.state.draw_options);
}
fn stroke(&self) {
if is_zero_size_gradient(&self.state.stroke_style) {
return; // Paint nothing if gradient size is zero.
}
self.drawtarget.stroke(&self.path_builder.finish(),
self.state.stroke_style.to_pattern_ref(),
&self.state.stroke_opts,
&self.state.draw_options);
}
fn clip(&self) {
self.drawtarget.push_clip(&self.path_builder.finish());
}
fn draw_image(&self, image_data: Vec<u8>, image_size: Size2D<f64>,
dest_rect: Rect<f64>, source_rect: Rect<f64>, smoothing_enabled: bool) {
// We round up the floating pixel values to draw the pixels
let source_rect = source_rect.ceil();
// It discards the extra pixels (if any) that won't be painted
let image_data = crop_image(image_data, image_size, source_rect);
if self.need_to_draw_shadow() {
let rect = Rect::new(Point2D::new(dest_rect.origin.x as f32, dest_rect.origin.y as f32),
Size2D::new(dest_rect.size.width as f32, dest_rect.size.height as f32));
self.draw_with_shadow(&rect, |new_draw_target: &DrawTarget| {
write_image(&new_draw_target, image_data, source_rect.size, dest_rect,
smoothing_enabled, self.state.draw_options.composition,
self.state.draw_options.alpha);
});
} else {
write_image(&self.drawtarget, image_data, source_rect.size, dest_rect,
smoothing_enabled, self.state.draw_options.composition,
self.state.draw_options.alpha);
}
}
fn draw_image_self(&self, image_size: Size2D<f64>,
dest_rect: Rect<f64>, source_rect: Rect<f64>,
smoothing_enabled: bool) {
// Reads pixels from source image
// In this case source and target are the same canvas
let image_data = self.read_pixels(source_rect.to_i32(), image_size);
if self.need_to_draw_shadow() {
let rect = Rect::new(Point2D::new(dest_rect.origin.x as f32, dest_rect.origin.y as f32),
Size2D::new(dest_rect.size.width as f32, dest_rect.size.height as f32));
self.draw_with_shadow(&rect, |new_draw_target: &DrawTarget| {
write_image(&new_draw_target, image_data, source_rect.size, dest_rect,
smoothing_enabled, self.state.draw_options.composition,
self.state.draw_options.alpha);
});
} else {
// Writes on target canvas
write_image(&self.drawtarget, image_data, image_size, dest_rect,
smoothing_enabled, self.state.draw_options.composition,
self.state.draw_options.alpha);
}
}
fn move_to(&self, point: &Point2D<AzFloat>) {
self.path_builder.move_to(*point)
}
fn line_to(&self, point: &Point2D<AzFloat>) {
self.path_builder.line_to(*point)
}
fn rect(&self, rect: &Rect<f32>) {
self.path_builder.move_to(Point2D::new(rect.origin.x, rect.origin.y));
self.path_builder.line_to(Point2D::new(rect.origin.x + rect.size.width, rect.origin.y));
self.path_builder.line_to(Point2D::new(rect.origin.x + rect.size.width,
rect.origin.y + rect.size.height));
self.path_builder.line_to(Point2D::new(rect.origin.x, rect.origin.y + rect.size.height));
self.path_builder.close();
}
fn quadratic_curve_to(&self,
cp: &Point2D<AzFloat>,
endpoint: &Point2D<AzFloat>) {
self.path_builder.quadratic_curve_to(cp, endpoint)
}
fn bezier_curve_to(&self,
cp1: &Point2D<AzFloat>,
cp2: &Point2D<AzFloat>,
endpoint: &Point2D<AzFloat>) {
self.path_builder.bezier_curve_to(cp1, cp2, endpoint)
}
fn arc(&self,
center: &Point2D<AzFloat>,
radius: AzFloat,
start_angle: AzFloat,
end_angle: AzFloat,
ccw: bool) {
self.path_builder.arc(*center, radius, start_angle, end_angle, ccw)
}
fn arc_to(&self,
cp1: &Point2D<AzFloat>,
cp2: &Point2D<AzFloat>,
radius: AzFloat) {
let cp0 = self.path_builder.get_current_point();
let cp1 = *cp1;
let cp2 = *cp2;
if (cp0.x == cp1.x && cp0.y == cp1.y) || cp1 == cp2 || radius == 0.0 {
self.line_to(&cp1);
return;
}
// if all three control points lie on a single straight line,
// connect the first two by a straight line
let direction = (cp2.x - cp1.x) * (cp0.y - cp1.y) + (cp2.y - cp1.y) * (cp1.x - cp0.x);
if direction == 0.0 {
self.line_to(&cp1);
return;
}
// otherwise, draw the Arc
let a2 = (cp0.x - cp1.x).powi(2) + (cp0.y - cp1.y).powi(2);
let b2 = (cp1.x - cp2.x).powi(2) + (cp1.y - cp2.y).powi(2);
let d = {
let c2 = (cp0.x - cp2.x).powi(2) + (cp0.y - cp2.y).powi(2);
let cosx = (a2 + b2 - c2) / (2.0 * (a2 * b2).sqrt());
let sinx = (1.0 - cosx.powi(2)).sqrt();
radius / ((1.0 - cosx) / sinx)
};
// first tangent point
let anx = (cp1.x - cp0.x) / a2.sqrt();
let any = (cp1.y - cp0.y) / a2.sqrt();
let tp1 = Point2D::new(cp1.x - anx * d, cp1.y - any * d);
// second tangent point
let bnx = (cp1.x - cp2.x) / b2.sqrt();
let bny = (cp1.y - cp2.y) / b2.sqrt();
let tp2 = Point2D::new(cp1.x - bnx * d, cp1.y - bny * d);
// arc center and angles
let anticlockwise = direction < 0.0;
let cx = tp1.x + any * radius * if anticlockwise { 1.0 } else { -1.0 };
let cy = tp1.y - anx * radius * if anticlockwise { 1.0 } else { -1.0 };
let angle_start = (tp1.y - cy).atan2(tp1.x - cx);
let angle_end = (tp2.y - cy).atan2(tp2.x - cx);
self.line_to(&tp1);
if [cx, cy, angle_start, angle_end].iter().all(|x| x.is_finite()) {
self.arc(&Point2D::new(cx, cy), radius,
angle_start, angle_end, anticlockwise);
}
}
fn set_fill_style(&mut self, style: FillOrStrokeStyle) {
self.state.fill_style = style.to_azure_pattern(&self.drawtarget)
}
fn set_stroke_style(&mut self, style: FillOrStrokeStyle) {
self.state.stroke_style = style.to_azure_pattern(&self.drawtarget)
}
fn set_line_width(&mut self, width: f32) {
self.state.stroke_opts.line_width = width;
}
fn set_line_cap(&mut self, cap: LineCapStyle) {
self.state.stroke_opts.line_cap = cap.to_azure_style();
}
fn set_line_join(&mut self, join: LineJoinStyle) {
self.state.stroke_opts.line_join = join.to_azure_style();
}
fn set_miter_limit(&mut self, limit: f32) {
self.state.stroke_opts.miter_limit = limit;
}
fn set_transform(&mut self, transform: &Matrix2D<f32>) {
self.state.transform = *transform;
self.drawtarget.set_transform(transform)
}
fn set_global_alpha(&mut self, alpha: f32) {
self.state.draw_options.alpha = alpha;
}
fn set_global_composition(&mut self, op: CompositionOrBlending) {
self.state.draw_options.set_composition_op(op.to_azure_style());
}
fn create(size: Size2D<i32>) -> DrawTarget {
DrawTarget::new(BackendType::Skia, size, SurfaceFormat::B8G8R8A8)
}
fn recreate(&mut self, size: Size2D<i32>) {
self.drawtarget = CanvasPaintTask::create(size);
}
fn send_pixel_contents(&mut self, chan: IpcSender<IpcSharedMemory>) {
self.drawtarget.snapshot().get_data_surface().with_data(|element| {
chan.send(IpcSharedMemory::from_bytes(element)).unwrap();
})
}
fn send_native_surface(&self, _chan: Sender<NativeSurface>) {
// FIXME(mrobinson): We need a handle on the NativeDisplay to create compatible
// NativeSurfaces for the compositor.
unimplemented!()
}
fn image_data(&self,
dest_rect: Rect<i32>,
canvas_size: Size2D<f64>,
chan: IpcSender<Vec<u8>>) {
let mut dest_data = self.read_pixels(dest_rect, canvas_size);
// bgra -> rgba
byte_swap(&mut dest_data);
chan.send(dest_data).unwrap();
}
// https://html.spec.whatwg.org/multipage/#dom-context-2d-putimagedata
fn put_image_data(&mut self, imagedata: Vec<u8>,
offset: Point2D<f64>,
image_data_size: Size2D<f64>,
mut dirty_rect: Rect<f64>) {
if image_data_size.width <= 0.0 || image_data_size.height <= 0.0 {
return
}
assert!(image_data_size.width * image_data_size.height * 4.0 == imagedata.len() as f64);
// Step 1. TODO (neutered data)
// Step 2.
if dirty_rect.size.width < 0.0f64 {
dirty_rect.origin.x += dirty_rect.size.width;
dirty_rect.size.width = -dirty_rect.size.width;
}
if dirty_rect.size.height < 0.0f64 {
dirty_rect.origin.y += dirty_rect.size.height;
dirty_rect.size.height = -dirty_rect.size.height;
}
// Step 3.
if dirty_rect.origin.x < 0.0f64 {
dirty_rect.size.width += dirty_rect.origin.x;
dirty_rect.origin.x = 0.0f64;
}
if dirty_rect.origin.y < 0.0f64 {
dirty_rect.size.height += dirty_rect.origin.y;
dirty_rect.origin.y = 0.0f64;
}
// Step 4.
if dirty_rect.max_x() > image_data_size.width {
dirty_rect.size.width = image_data_size.width - dirty_rect.origin.x;
}
if dirty_rect.max_y() > image_data_size.height {
dirty_rect.size.height = image_data_size.height - dirty_rect.origin.y;
}
// 5) If either dirtyWidth or dirtyHeight is negative or zero,
// stop without affecting any bitmaps
if dirty_rect.size.width <= 0.0 || dirty_rect.size.height <= 0.0 {
return
}
// Step 6.
let dest_rect = dirty_rect.translate(&offset).to_i32();
// azure_hl operates with integers. We need to cast the image size
let image_size = image_data_size.to_i32();
let first_pixel = dest_rect.origin - offset.to_i32();
let mut src_line = (first_pixel.y * (image_size.width * 4) + first_pixel.x * 4) as usize;
let mut dest =
Vec::with_capacity((dest_rect.size.width * dest_rect.size.height * 4) as usize);
for _ in 0 .. dest_rect.size.height {
let mut src_offset = src_line;
for _ in 0 .. dest_rect.size.width {
// Premultiply alpha and swap RGBA -> BGRA.
// TODO: may want a precomputed premultiply table to make this fast. (#6969)
let alpha = imagedata[src_offset + 3] as f32 / 255.;
dest.push((imagedata[src_offset + 2] as f32 * alpha) as u8);
dest.push((imagedata[src_offset + 1] as f32 * alpha) as u8);
dest.push((imagedata[src_offset + 0] as f32 * alpha) as u8);
dest.push(imagedata[src_offset + 3]);
src_offset += 4;
}
src_line += (image_size.width * 4) as usize;
}
let source_surface = self.drawtarget.create_source_surface_from_data(
&dest,
dest_rect.size, dest_rect.size.width * 4, SurfaceFormat::B8G8R8A8);
self.drawtarget.copy_surface(source_surface,
Rect::new(Point2D::new(0, 0), dest_rect.size),
dest_rect.origin);
}
fn set_shadow_offset_x(&mut self, value: f64) {
self.state.shadow_offset_x = value;
}
fn set_shadow_offset_y(&mut self, value: f64) {
self.state.shadow_offset_y = value;
}
fn set_shadow_blur(&mut self, value: f64) {
self.state.shadow_blur = value;
}
fn set_shadow_color(&mut self, value: AzColor) {
self.state.shadow_color = value;
}
// https://html.spec.whatwg.org/multipage/#when-shadows-are-drawn
fn need_to_draw_shadow(&self) -> bool {
self.state.shadow_color.a != 0.0f32 &&
(self.state.shadow_offset_x != 0.0f64 ||
self.state.shadow_offset_y != 0.0f64 ||
self.state.shadow_blur != 0.0f64)
}
fn create_draw_target_for_shadow(&self, source_rect: &Rect<f32>) -> DrawTarget {
let draw_target = self.drawtarget.create_similar_draw_target(&Size2D::new(source_rect.size.width as i32,
source_rect.size.height as i32),
self.drawtarget.get_format());
let matrix = Matrix2D::identity().translate(-source_rect.origin.x as AzFloat,
-source_rect.origin.y as AzFloat)
.mul(&self.state.transform);
draw_target.set_transform(&matrix);
draw_target
}
fn draw_with_shadow<F>(&self, rect: &Rect<f32>, draw_shadow_source: F)
where F: FnOnce(&DrawTarget)
{
let shadow_src_rect = self.state.transform.transform_rect(rect);
let new_draw_target = self.create_draw_target_for_shadow(&shadow_src_rect);
draw_shadow_source(&new_draw_target);
self.drawtarget.draw_surface_with_shadow(new_draw_target.snapshot(),
&Point2D::new(shadow_src_rect.origin.x as AzFloat,
shadow_src_rect.origin.y as AzFloat),
&self.state.shadow_color,
&Point2D::new(self.state.shadow_offset_x as AzFloat,
self.state.shadow_offset_y as AzFloat),
(self.state.shadow_blur / 2.0f64) as AzFloat,
self.state.draw_options.composition);
}
}
/// Used by drawImage to get rid of the extra pixels of the image data that
/// won't be copied to the canvas
/// image_data: Color pixel data of the image
/// image_size: Image dimensions
/// crop_rect: It determines the area of the image we want to keep
fn crop_image(image_data: Vec<u8>,
image_size: Size2D<f64>,
crop_rect: Rect<f64>) -> Vec<u8>{
// We're going to iterate over a pixel values array so we need integers
let crop_rect = crop_rect.to_i32();
let image_size = image_size.to_i32();
// Assuming 4 bytes per pixel and row-major order for storage
// (consecutive elements in a pixel row of the image are contiguous in memory)
let stride = image_size.width * 4;
let image_bytes_length = image_size.height * image_size.width * 4;
let crop_area_bytes_length = crop_rect.size.height * crop_rect.size.height * 4;
// If the image size is less or equal than the crop area we do nothing
if image_bytes_length <= crop_area_bytes_length {
return image_data;
}
let mut new_image_data = Vec::new();
let mut src = (crop_rect.origin.y * stride + crop_rect.origin.x * 4) as usize;
for _ in (0..crop_rect.size.height) {
let row = &image_data[src .. src + (4 * crop_rect.size.width) as usize];
new_image_data.push_all(row);
src += stride as usize;
}
new_image_data
}
/// It writes an image to the destination target
/// draw_target: the destination target where the image_data will be copied
/// image_data: Pixel information of the image to be written. It takes RGBA8
/// image_size: The size of the image to be written
/// dest_rect: Area of the destination target where the pixels will be copied
/// smoothing_enabled: It determines if smoothing is applied to the image result
fn write_image(draw_target: &DrawTarget,
mut image_data: Vec<u8>,
image_size: Size2D<f64>,
dest_rect: Rect<f64>,
smoothing_enabled: bool,
composition_op: CompositionOp,
global_alpha: f32) {
if image_data.is_empty() {
return
}
let image_rect = Rect::new(Point2D::zero(), image_size);
// rgba -> bgra
byte_swap(&mut image_data);
// From spec https://html.spec.whatwg.org/multipage/#dom-context-2d-drawimage
// When scaling up, if the imageSmoothingEnabled attribute is set to true, the user agent should attempt
// to apply a smoothing algorithm to the image data when it is scaled.
// Otherwise, the image must be rendered using nearest-neighbor interpolation.
let filter = if smoothing_enabled {
Filter::Linear
} else {
Filter::Point
};
// azure_hl operates with integers. We need to cast the image size
let image_size = image_size.to_i32();
let source_surface = draw_target.create_source_surface_from_data(
&image_data,
image_size, image_size.width * 4, SurfaceFormat::B8G8R8A8);
let draw_surface_options = DrawSurfaceOptions::new(filter, true);
let draw_options = DrawOptions::new(global_alpha, composition_op, AntialiasMode::None);
draw_target.draw_surface(source_surface,
dest_rect.to_azfloat(),
image_rect.to_azfloat(),
draw_surface_options,
draw_options);
}
fn is_zero_size_gradient(pattern: &Pattern) -> bool {
if let &Pattern::LinearGradient(ref gradient) = pattern {
if gradient.is_zero_size() {
return true;
}
}
return false;
}
pub trait PointToi32 {
fn to_i32(&self) -> Point2D<i32>;
}
impl PointToi32 for Point2D<f64> {
fn to_i32(&self) -> Point2D<i32> {
Point2D::new(self.x.to_i32().unwrap(),
self.y.to_i32().unwrap())
}
}
pub trait SizeToi32 {
fn to_i32(&self) -> Size2D<i32>;
}
impl SizeToi32 for Size2D<f64> {
fn to_i32(&self) -> Size2D<i32> {
Size2D::new(self.width.to_i32().unwrap(),
self.height.to_i32().unwrap())
}
}
pub trait RectToi32 {
fn to_i32(&self) -> Rect<i32>;
fn ceil(&self) -> Rect<f64>;
}
impl RectToi32 for Rect<f64> {
fn to_i32(&self) -> Rect<i32> {
Rect::new(Point2D::new(self.origin.x.to_i32().unwrap(),
self.origin.y.to_i32().unwrap()),
Size2D::new(self.size.width.to_i32().unwrap(),
self.size.height.to_i32().unwrap()))
}
fn ceil(&self) -> Rect<f64> {
Rect::new(Point2D::new(self.origin.x.ceil(),
self.origin.y.ceil()),
Size2D::new(self.size.width.ceil(),
self.size.height.ceil()))
}
}
pub trait ToAzFloat {
fn to_azfloat(&self) -> Rect<AzFloat>;
}
impl ToAzFloat for Rect<f64> {
fn to_azfloat(&self) -> Rect<AzFloat> {
Rect::new(Point2D::new(self.origin.x as AzFloat, self.origin.y as AzFloat),
Size2D::new(self.size.width as AzFloat, self.size.height as AzFloat))
}
}
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