Clip display list based on frame viewport

Instead of creating a display list for the entire page, only create one
for an area that expands around the viewport. On my machine this makes
incremental layout of http://timecube.com 50% faster.
This commit is contained in:
Martin Robinson 2014-10-22 14:00:09 -07:00
parent f4471f0602
commit c7327450ef
11 changed files with 130 additions and 34 deletions

View file

@ -28,37 +28,37 @@
//! a datatype.
use dom::bindings::js::JS;
use dom::bindings::utils::{Reflectable, Reflector};
use dom::bindings::utils::{Reflectable, Reflector, WindowProxyHandler};
use dom::node::{Node, TrustedNodeAddress};
use collections::hash::{Hash, Hasher};
use geom::rect::Rect;
use html5ever::tree_builder::QuirksMode;
use http::headers::request::HeaderCollection as RequestHeaderCollection;
use http::headers::response::HeaderCollection as ResponseHeaderCollection;
use http::method::Method;
use js::jsapi::{JSObject, JSTracer, JS_CallTracer, JSTRACE_OBJECT};
use js::jsval::JSVal;
use js::rust::Cx;
use layout_interface::{LayoutRPC, LayoutChan};
use libc;
use std::rc::Rc;
use std::cell::{Cell, RefCell};
use url::Url;
use msg::constellation_msg::{PipelineId, SubpageId, WindowSizeData};
use net::image_cache_task::ImageCacheTask;
use script_traits::ScriptControlChan;
use std::collections::hashmap::HashMap;
use collections::hash::{Hash, Hasher};
use style::PropertyDeclarationBlock;
use std::comm::{Receiver, Sender};
use string_cache::{Atom, Namespace};
use js::rust::Cx;
use http::headers::response::HeaderCollection as ResponseHeaderCollection;
use http::headers::request::HeaderCollection as RequestHeaderCollection;
use http::method::Method;
use std::io::timer::Timer;
use script_traits::UntrustedNodeAddress;
use servo_msg::compositor_msg::ScriptListener;
use servo_msg::constellation_msg::ConstellationChan;
use servo_util::smallvec::{SmallVec1, SmallVec};
use servo_util::str::LengthOrPercentageOrAuto;
use layout_interface::{LayoutRPC, LayoutChan};
use dom::node::{Node, TrustedNodeAddress};
use dom::bindings::utils::WindowProxyHandler;
use html5ever::tree_builder::QuirksMode;
use std::cell::{Cell, RefCell};
use std::collections::hashmap::HashMap;
use std::comm::{Receiver, Sender};
use std::io::timer::Timer;
use std::rc::Rc;
use string_cache::{Atom, Namespace};
use style::PropertyDeclarationBlock;
use url::Url;
/// A trait to allow tracing (only) DOM objects.
pub trait JSTraceable {
@ -200,6 +200,7 @@ no_jsmanaged_fields!(uint, u8, u16, u32, u64)
no_jsmanaged_fields!(int, i8, i16, i32, i64)
no_jsmanaged_fields!(Sender<T>)
no_jsmanaged_fields!(Receiver<T>)
no_jsmanaged_fields!(Rect<T>)
no_jsmanaged_fields!(ImageCacheTask, ScriptControlChan)
no_jsmanaged_fields!(Atom, Namespace, Timer)
no_jsmanaged_fields!(PropertyDeclarationBlock)

View file

@ -109,6 +109,8 @@ pub struct Reflow {
pub id: uint,
/// The type of query if any to perform during this reflow.
pub query_type: ReflowQueryType,
/// A clipping rectangle for the page, an enlarged rectangle containing the viewport.
pub page_clip_rect: Rect<Au>,
}
/// Encapsulates a channel to the layout task.

View file

@ -19,19 +19,21 @@ use layout_interface::{
};
use script_traits::{UntrustedNodeAddress, ScriptControlChan};
use geom::{Point2D, Rect};
use geom::{Point2D, Rect, Size2D};
use js::rust::Cx;
use servo_msg::compositor_msg::PerformingLayout;
use servo_msg::compositor_msg::ScriptListener;
use servo_msg::constellation_msg::{ConstellationChan, WindowSizeData};
use servo_msg::constellation_msg::{PipelineId, SubpageId};
use servo_net::resource_task::ResourceTask;
use servo_util::geometry::Au;
use servo_util::geometry::{Au, MAX_RECT};
use servo_util::geometry;
use servo_util::str::DOMString;
use servo_util::smallvec::{SmallVec1, SmallVec};
use std::cell::Cell;
use std::comm::{channel, Receiver, Empty, Disconnected};
use std::mem::replace;
use std::num::abs;
use std::rc::Rc;
use url::Url;
@ -98,6 +100,10 @@ pub struct Page {
/// Number of unnecessary potential reflows that were skipped since the last reflow
pub avoided_reflows: Cell<int>,
/// An enlarged rectangle around the page contents visible in the viewport, used
/// to prevent creating display list items for content that is far away from the viewport.
pub page_clip_rect: Cell<Rect<Au>>,
}
pub struct PageIterator {
@ -164,6 +170,7 @@ impl Page {
damaged: Cell::new(false),
pending_reflows: Cell::new(0),
avoided_reflows: Cell::new(0),
page_clip_rect: Cell::new(MAX_RECT),
}
}
@ -236,6 +243,49 @@ impl Page {
}
None
}
fn should_move_clip_rect(&self, clip_rect: Rect<Au>, new_viewport: Rect<f32>) -> bool{
let clip_rect = Rect(Point2D(geometry::to_frac_px(clip_rect.origin.x) as f32,
geometry::to_frac_px(clip_rect.origin.y) as f32),
Size2D(geometry::to_frac_px(clip_rect.size.width) as f32,
geometry::to_frac_px(clip_rect.size.height) as f32));
// We only need to move the clip rect if the viewport is getting near the edge of
// our preexisting clip rect. We use half of the size of the viewport as a heuristic
// for "close."
static VIEWPORT_SCROLL_MARGIN_SIZE: f32 = 0.5;
let viewport_scroll_margin = new_viewport.size * VIEWPORT_SCROLL_MARGIN_SIZE;
abs(clip_rect.origin.x - new_viewport.origin.x) <= viewport_scroll_margin.width ||
abs(clip_rect.max_x() - new_viewport.max_x()) <= viewport_scroll_margin.width ||
abs(clip_rect.origin.y - new_viewport.origin.y) <= viewport_scroll_margin.height ||
abs(clip_rect.max_y() - new_viewport.max_y()) <= viewport_scroll_margin.height
}
pub fn set_page_clip_rect_with_new_viewport(&self, viewport: Rect<f32>) -> bool {
// We use a clipping rectangle that is five times the size of the of the viewport,
// so that we don't collect display list items for areas too far outside the viewport,
// but also don't trigger reflows every time the viewport changes.
static VIEWPORT_EXPANSION: f32 = 2.0; // 2 lengths on each side plus original length is 5 total.
let proposed_clip_rect = geometry::f32_rect_to_au_rect(
viewport.inflate(viewport.size.width * VIEWPORT_EXPANSION,
viewport.size.height * VIEWPORT_EXPANSION));
let clip_rect = self.page_clip_rect.get();
if proposed_clip_rect == clip_rect {
return false;
}
let had_clip_rect = clip_rect != MAX_RECT;
if had_clip_rect && !self.should_move_clip_rect(clip_rect, viewport) {
return false;
}
self.page_clip_rect.set(proposed_clip_rect);
// If we didn't have a clip rect, the previous display doesn't need rebuilding
// because it was built for infinite clip (MAX_RECT).
had_clip_rect
}
}
impl Iterator<Rc<Page>> for PageIterator {
@ -375,6 +425,7 @@ impl Page {
script_join_chan: join_chan,
id: last_reflow_id.get(),
query_type: query_type,
page_clip_rect: self.page_clip_rect.get(),
};
let LayoutChan(ref chan) = self.layout_chan;

View file

@ -40,9 +40,9 @@ use devtools_traits::{DevtoolScriptControlMsg, EvaluateJS, EvaluateJSReply, GetD
use devtools_traits::{GetChildren, GetLayout};
use script_traits::{CompositorEvent, ResizeEvent, ReflowEvent, ClickEvent, MouseDownEvent};
use script_traits::{MouseMoveEvent, MouseUpEvent, ConstellationControlMsg, ScriptTaskFactory};
use script_traits::{ResizeMsg, AttachLayoutMsg, LoadMsg, SendEventMsg, ResizeInactiveMsg};
use script_traits::{ExitPipelineMsg, NewLayoutInfo, OpaqueScriptLayoutChannel, ScriptControlChan};
use script_traits::{ReflowCompleteMsg, UntrustedNodeAddress};
use script_traits::{ResizeMsg, AttachLayoutMsg, LoadMsg, ViewportMsg, SendEventMsg};
use script_traits::{ResizeInactiveMsg, ExitPipelineMsg, NewLayoutInfo, OpaqueScriptLayoutChannel};
use script_traits::{ScriptControlChan, ReflowCompleteMsg, UntrustedNodeAddress};
use servo_msg::compositor_msg::{FinishedLoading, LayerId, Loading};
use servo_msg::compositor_msg::{ScriptListener};
use servo_msg::constellation_msg::{ConstellationChan, LoadCompleteMsg, LoadUrlMsg, NavigationDirection};
@ -495,6 +495,13 @@ impl ScriptTask {
pending.push_all_move(node_addresses);
needs_reflow.insert(id);
}
FromConstellation(ViewportMsg(id, rect)) => {
let mut page = self.page.borrow_mut();
let inner_page = page.find(id).expect("Page rect message sent to nonexistent pipeline");
if inner_page.set_page_clip_rect_with_new_viewport(rect) {
needs_reflow.insert(id);
}
}
_ => {
sequential.push(event);
}
@ -530,6 +537,7 @@ impl ScriptTask {
FromConstellation(ReflowCompleteMsg(id, reflow_id)) => self.handle_reflow_complete_msg(id, reflow_id),
FromConstellation(ResizeInactiveMsg(id, new_size)) => self.handle_resize_inactive_msg(id, new_size),
FromConstellation(ExitPipelineMsg(id)) => if self.handle_exit_pipeline_msg(id) { return false },
FromConstellation(ViewportMsg(..)) => fail!("should have handled ViewportMsg already"),
FromScript(ExitWindowMsg(id)) => self.handle_exit_window_msg(id),
FromConstellation(ResizeMsg(..)) => fail!("should have handled ResizeMsg already"),
FromScript(XHRProgressMsg(addr, progress)) => XMLHttpRequest::handle_progress(addr, progress),