servo/components/layout/webrender_helpers.rs
Martin Robinson ef82d772c1 Don't promote all scrollable regions to stacking contexts
Instead annotate all flows with their owning ScrollRoots. When
processing the display list items into a flattened display list, we add
PushScrollRoot and PopScrollRoot to signal when scrolling regions start
and end. It is possible for content from different scrolling regions to
intersect and when they do, the stack of scrolling regions is
duplicated.  When these duplicated scrolling regions stacks reach
WebRender, it will scroll them in tandem.

The PushScrollRoot and PopScrollRoot items are currently represented as
StackingContexts in WebRender, but eventually these will be replaced
with special WebRender display items.

Fixes #13529.
Fixed #13298.
2016-11-05 18:36:45 +01:00

562 lines
26 KiB
Rust

/* 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/. */
// TODO(gw): This contains helper traits and implementations for converting Servo display lists
// into WebRender display lists. In the future, this step should be completely removed.
// This might be achieved by sharing types between WR and Servo display lists, or
// completely converting layout to directly generate WebRender display lists, for example.
use app_units::Au;
use euclid::{Matrix4D, Point2D, Rect, Size2D, TypedRect};
use gfx::display_list::{BorderRadii, BoxShadowClipMode, ClippingRegion};
use gfx::display_list::{DisplayItem, DisplayList, DisplayListTraversal};
use gfx::display_list::{StackingContext, StackingContextType};
use gfx_traits::{FragmentType, ScrollPolicy, StackingContextId, ScrollRootId};
use style::computed_values::{image_rendering, mix_blend_mode};
use style::computed_values::filter::{self, Filter};
use style::values::computed::BorderStyle;
use webrender_traits::{self, AuxiliaryListsBuilder, DisplayListId, PipelineId};
trait WebRenderStackingContextConverter {
fn convert_to_webrender<'a>(&self,
traversal: &mut DisplayListTraversal<'a>,
api: &mut webrender_traits::RenderApi,
pipeline_id: webrender_traits::PipelineId,
epoch: webrender_traits::Epoch,
frame_builder: &mut WebRenderFrameBuilder,
scroll_layer_id: Option<webrender_traits::ScrollLayerId>)
-> webrender_traits::StackingContextId;
fn convert_children_to_webrender<'a>(&self,
traversal: &mut DisplayListTraversal<'a>,
api: &mut webrender_traits::RenderApi,
pipeline_id: webrender_traits::PipelineId,
epoch: webrender_traits::Epoch,
builder: &mut webrender_traits::DisplayListBuilder,
frame_builder: &mut WebRenderFrameBuilder,
force_positioned_stacking_level: bool);
}
pub trait WebRenderDisplayListConverter {
fn convert_to_webrender(&self,
api: &mut webrender_traits::RenderApi,
pipeline_id: webrender_traits::PipelineId,
epoch: webrender_traits::Epoch,
frame_builder: &mut WebRenderFrameBuilder)
-> webrender_traits::StackingContextId;
}
trait WebRenderDisplayItemConverter {
fn convert_to_webrender(&self,
builder: &mut webrender_traits::DisplayListBuilder,
frame_builder: &mut WebRenderFrameBuilder);
}
trait ToBorderStyle {
fn to_border_style(&self) -> webrender_traits::BorderStyle;
}
impl ToBorderStyle for BorderStyle {
fn to_border_style(&self) -> webrender_traits::BorderStyle {
match *self {
BorderStyle::none => webrender_traits::BorderStyle::None,
BorderStyle::solid => webrender_traits::BorderStyle::Solid,
BorderStyle::double => webrender_traits::BorderStyle::Double,
BorderStyle::dotted => webrender_traits::BorderStyle::Dotted,
BorderStyle::dashed => webrender_traits::BorderStyle::Dashed,
BorderStyle::hidden => webrender_traits::BorderStyle::Hidden,
BorderStyle::groove => webrender_traits::BorderStyle::Groove,
BorderStyle::ridge => webrender_traits::BorderStyle::Ridge,
BorderStyle::inset => webrender_traits::BorderStyle::Inset,
BorderStyle::outset => webrender_traits::BorderStyle::Outset,
}
}
}
trait ToBoxShadowClipMode {
fn to_clip_mode(&self) -> webrender_traits::BoxShadowClipMode;
}
impl ToBoxShadowClipMode for BoxShadowClipMode {
fn to_clip_mode(&self) -> webrender_traits::BoxShadowClipMode {
match *self {
BoxShadowClipMode::None => webrender_traits::BoxShadowClipMode::None,
BoxShadowClipMode::Inset => webrender_traits::BoxShadowClipMode::Inset,
BoxShadowClipMode::Outset => webrender_traits::BoxShadowClipMode::Outset,
}
}
}
trait ToSizeF {
fn to_sizef(&self) -> Size2D<f32>;
}
trait ToPointF {
fn to_pointf(&self) -> Point2D<f32>;
}
impl ToPointF for Point2D<Au> {
fn to_pointf(&self) -> Point2D<f32> {
Point2D::new(self.x.to_f32_px(), self.y.to_f32_px())
}
}
impl ToSizeF for Size2D<Au> {
fn to_sizef(&self) -> Size2D<f32> {
Size2D::new(self.width.to_f32_px(), self.height.to_f32_px())
}
}
trait ToRectF {
fn to_rectf(&self) -> Rect<f32>;
}
impl ToRectF for Rect<Au> {
fn to_rectf(&self) -> Rect<f32> {
let x = self.origin.x.to_f32_px();
let y = self.origin.y.to_f32_px();
let w = self.size.width.to_f32_px();
let h = self.size.height.to_f32_px();
Rect::new(Point2D::new(x, y), Size2D::new(w, h))
}
}
trait ToClipRegion {
fn to_clip_region(&self, frame_builder: &mut WebRenderFrameBuilder)
-> webrender_traits::ClipRegion;
}
impl ToClipRegion for ClippingRegion {
fn to_clip_region(&self, frame_builder: &mut WebRenderFrameBuilder)
-> webrender_traits::ClipRegion {
webrender_traits::ClipRegion::new(&self.main.to_rectf(),
self.complex.iter().map(|complex_clipping_region| {
webrender_traits::ComplexClipRegion::new(
complex_clipping_region.rect.to_rectf(),
complex_clipping_region.radii.to_border_radius(),
)
}).collect(),
None,
&mut frame_builder.auxiliary_lists_builder)
}
}
trait ToBorderRadius {
fn to_border_radius(&self) -> webrender_traits::BorderRadius;
}
impl ToBorderRadius for BorderRadii<Au> {
fn to_border_radius(&self) -> webrender_traits::BorderRadius {
webrender_traits::BorderRadius {
top_left: self.top_left.to_sizef(),
top_right: self.top_right.to_sizef(),
bottom_left: self.bottom_left.to_sizef(),
bottom_right: self.bottom_right.to_sizef(),
}
}
}
trait ToBlendMode {
fn to_blend_mode(&self) -> webrender_traits::MixBlendMode;
}
impl ToBlendMode for mix_blend_mode::T {
fn to_blend_mode(&self) -> webrender_traits::MixBlendMode {
match *self {
mix_blend_mode::T::normal => webrender_traits::MixBlendMode::Normal,
mix_blend_mode::T::multiply => webrender_traits::MixBlendMode::Multiply,
mix_blend_mode::T::screen => webrender_traits::MixBlendMode::Screen,
mix_blend_mode::T::overlay => webrender_traits::MixBlendMode::Overlay,
mix_blend_mode::T::darken => webrender_traits::MixBlendMode::Darken,
mix_blend_mode::T::lighten => webrender_traits::MixBlendMode::Lighten,
mix_blend_mode::T::color_dodge => webrender_traits::MixBlendMode::ColorDodge,
mix_blend_mode::T::color_burn => webrender_traits::MixBlendMode::ColorBurn,
mix_blend_mode::T::hard_light => webrender_traits::MixBlendMode::HardLight,
mix_blend_mode::T::soft_light => webrender_traits::MixBlendMode::SoftLight,
mix_blend_mode::T::difference => webrender_traits::MixBlendMode::Difference,
mix_blend_mode::T::exclusion => webrender_traits::MixBlendMode::Exclusion,
mix_blend_mode::T::hue => webrender_traits::MixBlendMode::Hue,
mix_blend_mode::T::saturation => webrender_traits::MixBlendMode::Saturation,
mix_blend_mode::T::color => webrender_traits::MixBlendMode::Color,
mix_blend_mode::T::luminosity => webrender_traits::MixBlendMode::Luminosity,
}
}
}
trait ToImageRendering {
fn to_image_rendering(&self) -> webrender_traits::ImageRendering;
}
impl ToImageRendering for image_rendering::T {
fn to_image_rendering(&self) -> webrender_traits::ImageRendering {
match *self {
image_rendering::T::crisp_edges => webrender_traits::ImageRendering::CrispEdges,
image_rendering::T::auto => webrender_traits::ImageRendering::Auto,
image_rendering::T::pixelated => webrender_traits::ImageRendering::Pixelated,
}
}
}
trait ToFilterOps {
fn to_filter_ops(&self) -> Vec<webrender_traits::FilterOp>;
}
impl ToFilterOps for filter::T {
fn to_filter_ops(&self) -> Vec<webrender_traits::FilterOp> {
let mut result = Vec::with_capacity(self.filters.len());
for filter in self.filters.iter() {
match *filter {
Filter::Blur(radius) => result.push(webrender_traits::FilterOp::Blur(radius)),
Filter::Brightness(amount) => result.push(webrender_traits::FilterOp::Brightness(amount)),
Filter::Contrast(amount) => result.push(webrender_traits::FilterOp::Contrast(amount)),
Filter::Grayscale(amount) => result.push(webrender_traits::FilterOp::Grayscale(amount)),
Filter::HueRotate(angle) => result.push(webrender_traits::FilterOp::HueRotate(angle.0)),
Filter::Invert(amount) => result.push(webrender_traits::FilterOp::Invert(amount)),
Filter::Opacity(amount) => result.push(webrender_traits::FilterOp::Opacity(amount)),
Filter::Saturate(amount) => result.push(webrender_traits::FilterOp::Saturate(amount)),
Filter::Sepia(amount) => result.push(webrender_traits::FilterOp::Sepia(amount)),
}
}
result
}
}
impl WebRenderStackingContextConverter for StackingContext {
fn convert_children_to_webrender<'a>(&self,
traversal: &mut DisplayListTraversal<'a>,
api: &mut webrender_traits::RenderApi,
pipeline_id: webrender_traits::PipelineId,
epoch: webrender_traits::Epoch,
builder: &mut webrender_traits::DisplayListBuilder,
frame_builder: &mut WebRenderFrameBuilder,
_force_positioned_stacking_level: bool) {
while let Some(item) = traversal.next() {
match item {
&DisplayItem::PushStackingContext(ref stacking_context_item) => {
let stacking_context = &stacking_context_item.stacking_context;
debug_assert!(stacking_context.context_type == StackingContextType::Real);
builder.push_stacking_context(
stacking_context.convert_to_webrender(traversal,
api,
pipeline_id,
epoch,
frame_builder,
None));
}
&DisplayItem::PushScrollRoot(ref item) => {
let stacking_context = StackingContext::new(
StackingContextId::new(0),
StackingContextType::Real,
&item.scroll_root.clip,
&TypedRect::new(Point2D::zero(), item.scroll_root.size),
0,
filter::T::new(Vec::new()),
mix_blend_mode::T::normal,
Matrix4D::identity(),
Matrix4D::identity(),
true,
ScrollPolicy::Scrollable,
ScrollRootId::root());
let scroll_layer_id =
Some(frame_builder.next_scroll_layer_id(item.scroll_root.id));
builder.push_stacking_context(
stacking_context.convert_to_webrender(traversal,
api,
pipeline_id,
epoch,
frame_builder,
scroll_layer_id));
}
&DisplayItem::PopStackingContext(_) | &DisplayItem::PopScrollRoot(_) => return,
_ => item.convert_to_webrender(builder, frame_builder),
}
}
}
fn convert_to_webrender<'a>(&self,
traversal: &mut DisplayListTraversal<'a>,
api: &mut webrender_traits::RenderApi,
pipeline_id: webrender_traits::PipelineId,
epoch: webrender_traits::Epoch,
frame_builder: &mut WebRenderFrameBuilder,
scroll_layer_id: Option<webrender_traits::ScrollLayerId>)
-> webrender_traits::StackingContextId {
let webrender_scroll_policy = match self.scroll_policy {
ScrollPolicy::Scrollable => webrender_traits::ScrollPolicy::Scrollable,
ScrollPolicy::FixedPosition => webrender_traits::ScrollPolicy::Fixed,
};
let mut sc =
webrender_traits::StackingContext::new(scroll_layer_id,
webrender_scroll_policy,
self.bounds.to_rectf(),
self.overflow.to_rectf(),
self.z_index,
&self.transform,
&self.perspective,
self.establishes_3d_context,
self.blend_mode.to_blend_mode(),
self.filters.to_filter_ops(),
&mut frame_builder.auxiliary_lists_builder);
let mut builder = webrender_traits::DisplayListBuilder::new();
self.convert_children_to_webrender(traversal,
api,
pipeline_id,
epoch,
&mut builder,
frame_builder,
false);
frame_builder.add_display_list(api, builder.finalize(), &mut sc);
frame_builder.add_stacking_context(api, pipeline_id, sc)
}
}
impl WebRenderDisplayListConverter for DisplayList {
fn convert_to_webrender(&self,
api: &mut webrender_traits::RenderApi,
pipeline_id: webrender_traits::PipelineId,
epoch: webrender_traits::Epoch,
frame_builder: &mut WebRenderFrameBuilder)
-> webrender_traits::StackingContextId {
let mut traversal = DisplayListTraversal::new(self);
let item = traversal.next();
match item {
Some(&DisplayItem::PushStackingContext(ref stacking_context_item)) => {
let stacking_context = &stacking_context_item.stacking_context;
let scroll_layer_id =
Some(frame_builder.next_scroll_layer_id(ScrollRootId::root()));
stacking_context.convert_to_webrender(&mut traversal,
api,
pipeline_id,
epoch,
frame_builder,
scroll_layer_id)
}
_ => unreachable!("DisplayList did not start with StackingContext."),
}
}
}
impl WebRenderDisplayItemConverter for DisplayItem {
fn convert_to_webrender(&self,
builder: &mut webrender_traits::DisplayListBuilder,
frame_builder: &mut WebRenderFrameBuilder) {
match *self {
DisplayItem::SolidColor(ref item) => {
let color = item.color;
if color.a > 0.0 {
builder.push_rect(item.base.bounds.to_rectf(),
item.base.clip.to_clip_region(frame_builder),
color);
}
}
DisplayItem::Text(ref item) => {
let mut origin = item.baseline_origin.clone();
let mut glyphs = vec!();
for slice in item.text_run.natural_word_slices_in_visual_order(&item.range) {
for glyph in slice.glyphs.iter_glyphs_for_byte_range(&slice.range) {
let glyph_advance = if glyph.char_is_space() {
glyph.advance() + item.text_run.extra_word_spacing
} else {
glyph.advance()
};
if !slice.glyphs.is_whitespace() {
let glyph_offset = glyph.offset().unwrap_or(Point2D::zero());
let glyph = webrender_traits::GlyphInstance {
index: glyph.id(),
x: (origin.x + glyph_offset.x).to_f32_px(),
y: (origin.y + glyph_offset.y).to_f32_px(),
};
glyphs.push(glyph);
}
origin.x = origin.x + glyph_advance;
};
}
if glyphs.len() > 0 {
builder.push_text(item.base.bounds.to_rectf(),
item.base.clip.to_clip_region(frame_builder),
glyphs,
item.text_run.font_key,
item.text_color,
item.text_run.actual_pt_size,
item.blur_radius,
&mut frame_builder.auxiliary_lists_builder);
}
}
DisplayItem::Image(ref item) => {
if let Some(id) = item.webrender_image.key {
if item.stretch_size.width > Au(0) &&
item.stretch_size.height > Au(0) {
builder.push_image(item.base.bounds.to_rectf(),
item.base.clip.to_clip_region(frame_builder),
item.stretch_size.to_sizef(),
item.tile_spacing.to_sizef(),
item.image_rendering.to_image_rendering(),
id);
}
}
}
DisplayItem::WebGL(ref item) => {
builder.push_webgl_canvas(item.base.bounds.to_rectf(),
item.base.clip.to_clip_region(frame_builder),
item.context_id);
}
DisplayItem::Border(ref item) => {
let rect = item.base.bounds.to_rectf();
let left = webrender_traits::BorderSide {
width: item.border_widths.left.to_f32_px(),
color: item.color.left,
style: item.style.left.to_border_style(),
};
let top = webrender_traits::BorderSide {
width: item.border_widths.top.to_f32_px(),
color: item.color.top,
style: item.style.top.to_border_style(),
};
let right = webrender_traits::BorderSide {
width: item.border_widths.right.to_f32_px(),
color: item.color.right,
style: item.style.right.to_border_style(),
};
let bottom = webrender_traits::BorderSide {
width: item.border_widths.bottom.to_f32_px(),
color: item.color.bottom,
style: item.style.bottom.to_border_style(),
};
let radius = item.radius.to_border_radius();
builder.push_border(rect,
item.base.clip.to_clip_region(frame_builder),
left,
top,
right,
bottom,
radius);
}
DisplayItem::Gradient(ref item) => {
let rect = item.base.bounds.to_rectf();
let start_point = item.start_point.to_pointf();
let end_point = item.end_point.to_pointf();
builder.push_gradient(rect,
item.base.clip.to_clip_region(frame_builder),
start_point,
end_point,
item.stops.clone(),
&mut frame_builder.auxiliary_lists_builder);
}
DisplayItem::Line(..) => {
println!("TODO DisplayItem::Line");
}
DisplayItem::BoxShadow(ref item) => {
let rect = item.base.bounds.to_rectf();
let box_bounds = item.box_bounds.to_rectf();
builder.push_box_shadow(rect,
item.base.clip.to_clip_region(frame_builder),
box_bounds,
item.offset.to_pointf(),
item.color,
item.blur_radius.to_f32_px(),
item.spread_radius.to_f32_px(),
item.border_radius.to_f32_px(),
item.clip_mode.to_clip_mode());
}
DisplayItem::Iframe(ref item) => {
let rect = item.base.bounds.to_rectf();
let pipeline_id = item.iframe.to_webrender();
builder.push_iframe(rect,
item.base.clip.to_clip_region(frame_builder),
pipeline_id);
}
DisplayItem::PushStackingContext(_) |
DisplayItem::PopStackingContext(_) |
DisplayItem::PushScrollRoot(_) |
DisplayItem::PopScrollRoot(_) =>
unreachable!("Tried to convert a scroll root or stacking context structure item."),
}
}
}
pub struct WebRenderFrameBuilder {
pub stacking_contexts: Vec<(webrender_traits::StackingContextId,
webrender_traits::StackingContext)>,
pub display_lists: Vec<(DisplayListId, webrender_traits::BuiltDisplayList)>,
pub auxiliary_lists_builder: AuxiliaryListsBuilder,
pub root_pipeline_id: PipelineId,
pub next_scroll_layer_id: usize,
}
impl WebRenderFrameBuilder {
pub fn new(root_pipeline_id: PipelineId) -> WebRenderFrameBuilder {
WebRenderFrameBuilder {
stacking_contexts: vec![],
display_lists: vec![],
auxiliary_lists_builder: AuxiliaryListsBuilder::new(),
root_pipeline_id: root_pipeline_id,
next_scroll_layer_id: 0,
}
}
pub fn add_stacking_context(&mut self,
api: &mut webrender_traits::RenderApi,
pipeline_id: PipelineId,
stacking_context: webrender_traits::StackingContext)
-> webrender_traits::StackingContextId {
assert!(pipeline_id == self.root_pipeline_id);
let id = api.next_stacking_context_id();
self.stacking_contexts.push((id, stacking_context));
id
}
pub fn add_display_list(&mut self,
api: &mut webrender_traits::RenderApi,
display_list: webrender_traits::BuiltDisplayList,
stacking_context: &mut webrender_traits::StackingContext)
-> DisplayListId {
let id = api.next_display_list_id();
stacking_context.display_lists.push(id);
self.display_lists.push((id, display_list));
id
}
pub fn next_scroll_layer_id(&mut self,
scroll_root_id: ScrollRootId)
-> webrender_traits::ScrollLayerId {
let scroll_layer_id = self.next_scroll_layer_id;
self.next_scroll_layer_id += 1;
webrender_traits::ScrollLayerId::new(self.root_pipeline_id,
scroll_layer_id,
scroll_root_id.convert_to_webrender())
}
}
trait WebRenderScrollRootIdConverter {
fn convert_to_webrender(&self) -> webrender_traits::ServoScrollRootId;
}
impl WebRenderScrollRootIdConverter for ScrollRootId {
fn convert_to_webrender(&self) -> webrender_traits::ServoScrollRootId {
webrender_traits::ServoScrollRootId(self.0)
}
}
trait WebRenderFragmentTypeConverter {
fn convert_to_webrender(&self) -> webrender_traits::FragmentType;
}
impl WebRenderFragmentTypeConverter for FragmentType {
fn convert_to_webrender(&self) -> webrender_traits::FragmentType {
match *self {
FragmentType::FragmentBody => webrender_traits::FragmentType::FragmentBody,
FragmentType::BeforePseudoContent => {
webrender_traits::FragmentType::BeforePseudoContent
}
FragmentType::AfterPseudoContent => webrender_traits::FragmentType::AfterPseudoContent,
}
}
}