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display_list_flattener.rs
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display_list_flattener.rs
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/* 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 api::{AlphaType, BorderDetails, BorderDisplayItem, BuiltDisplayListIter, ClipAndScrollInfo};
use api::{ClipId, ColorF, ComplexClipRegion, DeviceIntPoint, DeviceIntRect, DeviceIntSize};
use api::{DevicePixelScale, DeviceUintRect, DisplayItemRef, ExtendMode, ExternalScrollId};
use api::{FilterOp, FontInstanceKey, GlyphInstance, GlyphOptions, GlyphRasterSpace, GradientStop};
use api::{IframeDisplayItem, ImageKey, ImageRendering, ItemRange, LayoutPoint};
use api::{LayoutPrimitiveInfo, LayoutRect, LayoutSize, LayoutTransform, LayoutVector2D};
use api::{LineOrientation, LineStyle, LocalClip, NinePatchBorderSource, PipelineId};
use api::{PropertyBinding, ReferenceFrame, RepeatMode, ScrollFrameDisplayItem, ScrollSensitivity};
use api::{Shadow, SpecificDisplayItem, StackingContext, StickyFrameDisplayItem, TexelRect};
use api::{ClipMode, TransformStyle, YuvColorSpace, YuvData};
use clip::{ClipChainId, ClipRegion, ClipSource, ClipStore};
use clip_scroll_tree::{ClipScrollTree, SpatialNodeIndex};
use euclid::vec2;
use frame_builder::{ChasePrimitive, FrameBuilder, FrameBuilderConfig};
use glyph_rasterizer::FontInstance;
use gpu_cache::GpuCacheHandle;
use gpu_types::BrushFlags;
use hit_test::{HitTestingItem, HitTestingRun};
use image::simplify_repeated_primitive;
use internal_types::{FastHashMap, FastHashSet};
use picture::PictureCompositeMode;
use prim_store::{BrushClipMaskKind, BrushKind, BrushPrimitive, BrushSegmentDescriptor};
use prim_store::{EdgeAaSegmentMask, ImageSource};
use prim_store::{BorderSource, BrushSegment, PictureIndex, PrimitiveContainer, PrimitiveIndex, PrimitiveStore};
use prim_store::{OpacityBinding, ScrollNodeAndClipChain, TextRunPrimitiveCpu};
use render_backend::{DocumentView};
use resource_cache::{FontInstanceMap, ImageRequest};
use scene::{Scene, ScenePipeline, StackingContextHelpers};
use scene_builder::{BuiltScene, SceneRequest};
use spatial_node::{SpatialNodeType, StickyFrameInfo};
use std::{f32, iter, mem};
use tiling::{CompositeOps, ScrollbarPrimitive};
use util::{MaxRect, RectHelpers, recycle_vec};
static DEFAULT_SCROLLBAR_COLOR: ColorF = ColorF {
r: 0.3,
g: 0.3,
b: 0.3,
a: 0.6,
};
/// A data structure that keeps track of mapping between API ClipIds and the indices used
/// internally in the ClipScrollTree to avoid having to do HashMap lookups. ClipIdToIndexMapper is
/// responsible for mapping both ClipId to ClipChainIndex and ClipId to SpatialNodeIndex.
#[derive(Default)]
pub struct ClipIdToIndexMapper {
clip_chain_map: FastHashMap<ClipId, ClipChainId>,
spatial_node_map: FastHashMap<ClipId, SpatialNodeIndex>,
}
impl ClipIdToIndexMapper {
pub fn add_clip_chain(&mut self, id: ClipId, index: ClipChainId) {
let _old_value = self.clip_chain_map.insert(id, index);
debug_assert!(_old_value.is_none());
}
pub fn map_to_parent_clip_chain(&mut self, id: ClipId, parent_id: &ClipId) {
let parent_chain_id = self.get_clip_chain_id(parent_id);
self.add_clip_chain(id, parent_chain_id);
}
pub fn map_spatial_node(&mut self, id: ClipId, index: SpatialNodeIndex) {
let _old_value = self.spatial_node_map.insert(id, index);
debug_assert!(_old_value.is_none());
}
pub fn get_clip_chain_id(&self, id: &ClipId) -> ClipChainId {
self.clip_chain_map[id]
}
pub fn get_spatial_node_index(&self, id: ClipId) -> SpatialNodeIndex {
match id {
ClipId::Clip(..) |
ClipId::Spatial(..) => {
self.spatial_node_map[&id]
}
ClipId::ClipChain(_) => panic!("Tried to use ClipChain as scroll node."),
}
}
}
/// A structure that converts a serialized display list into a form that WebRender
/// can use to later build a frame. This structure produces a FrameBuilder. Public
/// members are typically those that are destructured into the FrameBuilder.
pub struct DisplayListFlattener<'a> {
/// The scene that we are currently flattening.
scene: &'a Scene,
/// The ClipScrollTree that we are currently building during flattening.
clip_scroll_tree: &'a mut ClipScrollTree,
/// The map of all font instances.
font_instances: FontInstanceMap,
/// A set of pipelines that the caller has requested be made available as
/// output textures.
output_pipelines: &'a FastHashSet<PipelineId>,
/// The data structure that converting between ClipId and the various index
/// types that the ClipScrollTree uses.
id_to_index_mapper: ClipIdToIndexMapper,
/// A stack of scroll nodes used during display list processing to properly
/// parent new scroll nodes.
reference_frame_stack: Vec<(ClipId, SpatialNodeIndex)>,
/// A stack of stacking context properties.
sc_stack: Vec<FlattenedStackingContext>,
/// A stack of the current pictures.
picture_stack: Vec<PictureIndex>,
/// A stack of the currently active shadows
shadow_stack: Vec<(Shadow, PictureIndex)>,
/// The stack keeping track of the root clip chains associated with pipelines.
pipeline_clip_chain_stack: Vec<ClipChainId>,
/// A list of scrollbar primitives.
pub scrollbar_prims: Vec<ScrollbarPrimitive>,
/// The store of primitives.
pub prim_store: PrimitiveStore,
/// Information about all primitives involved in hit testing.
pub hit_testing_runs: Vec<HitTestingRun>,
/// The store which holds all complex clipping information.
pub clip_store: ClipStore,
/// The configuration to use for the FrameBuilder. We consult this in
/// order to determine the default font.
pub config: FrameBuilderConfig,
}
impl<'a> DisplayListFlattener<'a> {
pub fn create_frame_builder(
old_builder: FrameBuilder,
scene: &Scene,
clip_scroll_tree: &mut ClipScrollTree,
font_instances: FontInstanceMap,
view: &DocumentView,
output_pipelines: &FastHashSet<PipelineId>,
frame_builder_config: &FrameBuilderConfig,
new_scene: &mut Scene,
scene_id: u64,
) -> FrameBuilder {
// We checked that the root pipeline is available on the render backend.
let root_pipeline_id = scene.root_pipeline_id.unwrap();
let root_pipeline = scene.pipelines.get(&root_pipeline_id).unwrap();
let background_color = root_pipeline
.background_color
.and_then(|color| if color.a > 0.0 { Some(color) } else { None });
let mut flattener = DisplayListFlattener {
scene,
clip_scroll_tree,
font_instances,
config: *frame_builder_config,
output_pipelines,
id_to_index_mapper: ClipIdToIndexMapper::default(),
hit_testing_runs: recycle_vec(old_builder.hit_testing_runs),
scrollbar_prims: recycle_vec(old_builder.scrollbar_prims),
reference_frame_stack: Vec::new(),
picture_stack: Vec::new(),
shadow_stack: Vec::new(),
sc_stack: Vec::new(),
pipeline_clip_chain_stack: vec![ClipChainId::NONE],
prim_store: old_builder.prim_store.recycle(),
clip_store: old_builder.clip_store.recycle(),
};
flattener.push_root(
root_pipeline_id,
&root_pipeline.viewport_size,
&root_pipeline.content_size,
);
flattener.setup_viewport_offset(view.inner_rect, view.accumulated_scale_factor());
flattener.flatten_root(root_pipeline, &root_pipeline.viewport_size);
debug_assert!(flattener.picture_stack.is_empty());
new_scene.root_pipeline_id = Some(root_pipeline_id);
new_scene.pipeline_epochs = scene.pipeline_epochs.clone();
new_scene.pipelines = scene.pipelines.clone();
FrameBuilder::with_display_list_flattener(
view.inner_rect,
background_color,
view.window_size,
scene_id,
flattener,
)
}
fn get_complex_clips(
&self,
pipeline_id: PipelineId,
complex_clips: ItemRange<ComplexClipRegion>,
) -> impl 'a + Iterator<Item = ComplexClipRegion> {
//Note: we could make this a bit more complex to early out
// on `complex_clips.is_empty()` if it's worth it
self.scene
.get_display_list_for_pipeline(pipeline_id)
.get(complex_clips)
}
fn get_clip_chain_items(
&self,
pipeline_id: PipelineId,
items: ItemRange<ClipId>,
) -> impl 'a + Iterator<Item = ClipId> {
self.scene
.get_display_list_for_pipeline(pipeline_id)
.get(items)
}
fn flatten_root(&mut self, pipeline: &'a ScenePipeline, frame_size: &LayoutSize) {
let pipeline_id = pipeline.pipeline_id;
let reference_frame_info = self.simple_scroll_and_clip_chain(
&ClipId::root_reference_frame(pipeline_id),
);
let root_scroll_node = ClipId::root_scroll_node(pipeline_id);
let scroll_frame_info = self.simple_scroll_and_clip_chain(&root_scroll_node);
self.push_stacking_context(
pipeline_id,
CompositeOps::default(),
TransformStyle::Flat,
true,
true,
root_scroll_node,
None,
GlyphRasterSpace::Screen,
);
// For the root pipeline, there's no need to add a full screen rectangle
// here, as it's handled by the framebuffer clear.
if self.scene.root_pipeline_id != Some(pipeline_id) {
if let Some(pipeline) = self.scene.pipelines.get(&pipeline_id) {
if let Some(bg_color) = pipeline.background_color {
let root_bounds = LayoutRect::new(LayoutPoint::zero(), *frame_size);
let info = LayoutPrimitiveInfo::new(root_bounds);
self.add_solid_rectangle(
reference_frame_info,
&info,
bg_color,
None,
Vec::new(),
);
}
}
}
self.flatten_items(&mut pipeline.display_list.iter(), pipeline_id, LayoutVector2D::zero());
if self.config.enable_scrollbars {
let scrollbar_rect = LayoutRect::new(LayoutPoint::zero(), LayoutSize::new(10.0, 70.0));
let container_rect = LayoutRect::new(LayoutPoint::zero(), *frame_size);
self.add_scroll_bar(
reference_frame_info.spatial_node_index,
&LayoutPrimitiveInfo::new(scrollbar_rect),
DEFAULT_SCROLLBAR_COLOR,
ScrollbarInfo(scroll_frame_info.spatial_node_index, container_rect),
);
}
self.pop_stacking_context();
}
fn flatten_items(
&mut self,
traversal: &mut BuiltDisplayListIter<'a>,
pipeline_id: PipelineId,
reference_frame_relative_offset: LayoutVector2D,
) {
loop {
let subtraversal = {
let item = match traversal.next() {
Some(item) => item,
None => break,
};
if SpecificDisplayItem::PopReferenceFrame == *item.item() {
return;
}
if SpecificDisplayItem::PopStackingContext == *item.item() {
return;
}
self.flatten_item(
item,
pipeline_id,
reference_frame_relative_offset,
)
};
// If flatten_item created a sub-traversal, we need `traversal` to have the
// same state as the completed subtraversal, so we reinitialize it here.
if let Some(subtraversal) = subtraversal {
*traversal = subtraversal;
}
}
}
fn flatten_sticky_frame(
&mut self,
item: &DisplayItemRef,
info: &StickyFrameDisplayItem,
clip_and_scroll: &ScrollNodeAndClipChain,
parent_id: &ClipId,
reference_frame_relative_offset: &LayoutVector2D,
) {
let frame_rect = item.rect().translate(reference_frame_relative_offset);
let sticky_frame_info = StickyFrameInfo::new(
frame_rect,
info.margins,
info.vertical_offset_bounds,
info.horizontal_offset_bounds,
info.previously_applied_offset,
);
let index = self.clip_scroll_tree.add_sticky_frame(
clip_and_scroll.spatial_node_index, /* parent id */
sticky_frame_info,
info.id.pipeline_id(),
);
self.id_to_index_mapper.map_spatial_node(info.id, index);
self.id_to_index_mapper.map_to_parent_clip_chain(info.id, parent_id);
}
fn flatten_scroll_frame(
&mut self,
item: &DisplayItemRef,
info: &ScrollFrameDisplayItem,
pipeline_id: PipelineId,
clip_and_scroll_ids: &ClipAndScrollInfo,
reference_frame_relative_offset: &LayoutVector2D,
) {
let complex_clips = self.get_complex_clips(pipeline_id, item.complex_clip().0);
let clip_region = ClipRegion::create_for_clip_node(
*item.clip_rect(),
complex_clips,
info.image_mask,
reference_frame_relative_offset,
);
// Just use clip rectangle as the frame rect for this scroll frame.
// This is useful when calculating scroll extents for the
// SpatialNode::scroll(..) API as well as for properly setting sticky
// positioning offsets.
let frame_rect = item.clip_rect().translate(reference_frame_relative_offset);
let content_rect = item.rect().translate(reference_frame_relative_offset);
debug_assert!(info.clip_id != info.scroll_frame_id);
self.add_clip_node(info.clip_id, clip_and_scroll_ids.scroll_node_id, clip_region);
self.add_scroll_frame(
info.scroll_frame_id,
info.clip_id,
info.external_id,
pipeline_id,
&frame_rect,
&content_rect.size,
info.scroll_sensitivity,
);
}
fn flatten_reference_frame(
&mut self,
traversal: &mut BuiltDisplayListIter<'a>,
pipeline_id: PipelineId,
item: &DisplayItemRef,
reference_frame: &ReferenceFrame,
scroll_node_id: ClipId,
reference_frame_relative_offset: LayoutVector2D,
) {
self.push_reference_frame(
reference_frame.id,
Some(scroll_node_id),
pipeline_id,
reference_frame.transform,
reference_frame.perspective,
reference_frame_relative_offset + item.rect().origin.to_vector(),
);
self.flatten_items(traversal, pipeline_id, LayoutVector2D::zero());
self.pop_reference_frame();
}
fn flatten_stacking_context(
&mut self,
traversal: &mut BuiltDisplayListIter<'a>,
pipeline_id: PipelineId,
item: &DisplayItemRef,
stacking_context: &StackingContext,
scroll_node_id: ClipId,
reference_frame_relative_offset: LayoutVector2D,
is_backface_visible: bool,
) {
// Avoid doing unnecessary work for empty stacking contexts.
if traversal.current_stacking_context_empty() {
traversal.skip_current_stacking_context();
return;
}
let composition_operations = {
// TODO(optimization?): self.traversal.display_list()
let display_list = self.scene.get_display_list_for_pipeline(pipeline_id);
CompositeOps::new(
stacking_context.filter_ops_for_compositing(display_list, item.filters()),
stacking_context.mix_blend_mode_for_compositing(),
)
};
self.push_stacking_context(
pipeline_id,
composition_operations,
stacking_context.transform_style,
is_backface_visible,
false,
scroll_node_id,
stacking_context.clip_node_id,
stacking_context.glyph_raster_space,
);
self.flatten_items(
traversal,
pipeline_id,
reference_frame_relative_offset + item.rect().origin.to_vector(),
);
self.pop_stacking_context();
}
fn flatten_iframe(
&mut self,
item: &DisplayItemRef,
info: &IframeDisplayItem,
clip_and_scroll_ids: &ClipAndScrollInfo,
reference_frame_relative_offset: &LayoutVector2D,
) {
let iframe_pipeline_id = info.pipeline_id;
let pipeline = match self.scene.pipelines.get(&iframe_pipeline_id) {
Some(pipeline) => pipeline,
None => {
debug_assert!(info.ignore_missing_pipeline);
return
},
};
//TODO: use or assert on `clip_and_scroll_ids.clip_node_id` ?
let clip_chain_index = self.add_clip_node(
info.clip_id,
clip_and_scroll_ids.scroll_node_id,
ClipRegion::create_for_clip_node_with_local_clip(
&LocalClip::from(*item.clip_rect()),
reference_frame_relative_offset
),
);
self.pipeline_clip_chain_stack.push(clip_chain_index);
let bounds = item.rect();
let origin = *reference_frame_relative_offset + bounds.origin.to_vector();
self.push_reference_frame(
ClipId::root_reference_frame(iframe_pipeline_id),
Some(info.clip_id),
iframe_pipeline_id,
None,
None,
origin,
);
let iframe_rect = LayoutRect::new(LayoutPoint::zero(), bounds.size);
self.add_scroll_frame(
ClipId::root_scroll_node(iframe_pipeline_id),
ClipId::root_reference_frame(iframe_pipeline_id),
Some(ExternalScrollId(0, iframe_pipeline_id)),
iframe_pipeline_id,
&iframe_rect,
&pipeline.content_size,
ScrollSensitivity::ScriptAndInputEvents,
);
self.flatten_root(pipeline, &iframe_rect.size);
self.pop_reference_frame();
self.pipeline_clip_chain_stack.pop();
}
fn flatten_item<'b>(
&'b mut self,
item: DisplayItemRef<'a, 'b>,
pipeline_id: PipelineId,
reference_frame_relative_offset: LayoutVector2D,
) -> Option<BuiltDisplayListIter<'a>> {
let clip_and_scroll_ids = item.clip_and_scroll();
let clip_and_scroll = self.map_clip_and_scroll(&clip_and_scroll_ids);
let prim_info = item.get_layout_primitive_info(&reference_frame_relative_offset);
match *item.item() {
SpecificDisplayItem::Image(ref info) => {
self.add_image(
clip_and_scroll,
&prim_info,
info.stretch_size,
info.tile_spacing,
None,
info.image_key,
info.image_rendering,
info.alpha_type,
);
}
SpecificDisplayItem::YuvImage(ref info) => {
self.add_yuv_image(
clip_and_scroll,
&prim_info,
info.yuv_data,
info.color_space,
info.image_rendering,
);
}
SpecificDisplayItem::Text(ref text_info) => {
self.add_text(
clip_and_scroll,
reference_frame_relative_offset,
&prim_info,
&text_info.font_key,
&text_info.color,
item.glyphs(),
text_info.glyph_options,
);
}
SpecificDisplayItem::Rectangle(ref info) => {
self.add_solid_rectangle(
clip_and_scroll,
&prim_info,
info.color,
None,
Vec::new(),
);
}
SpecificDisplayItem::ClearRectangle => {
self.add_clear_rectangle(
clip_and_scroll,
&prim_info,
);
}
SpecificDisplayItem::Line(ref info) => {
self.add_line(
clip_and_scroll,
&prim_info,
info.wavy_line_thickness,
info.orientation,
&info.color,
info.style,
);
}
SpecificDisplayItem::Gradient(ref info) => {
let brush_kind = self.create_brush_kind_for_gradient(
&prim_info,
info.gradient.start_point,
info.gradient.end_point,
item.gradient_stops(),
info.gradient.extend_mode,
info.tile_size,
info.tile_spacing,
);
let prim = PrimitiveContainer::Brush(BrushPrimitive::new(brush_kind, None));
self.add_primitive(clip_and_scroll, &prim_info, Vec::new(), prim);
}
SpecificDisplayItem::RadialGradient(ref info) => {
let brush_kind = self.create_brush_kind_for_radial_gradient(
&prim_info,
info.gradient.center,
info.gradient.start_offset * info.gradient.radius.width,
info.gradient.end_offset * info.gradient.radius.width,
info.gradient.radius.width / info.gradient.radius.height,
item.gradient_stops(),
info.gradient.extend_mode,
info.tile_size,
info.tile_spacing,
);
let prim = PrimitiveContainer::Brush(BrushPrimitive::new(brush_kind, None));
self.add_primitive(clip_and_scroll, &prim_info, Vec::new(), prim);
}
SpecificDisplayItem::BoxShadow(ref box_shadow_info) => {
let bounds = box_shadow_info
.box_bounds
.translate(&reference_frame_relative_offset);
let mut prim_info = prim_info.clone();
prim_info.rect = bounds;
self.add_box_shadow(
clip_and_scroll,
&prim_info,
&box_shadow_info.offset,
&box_shadow_info.color,
box_shadow_info.blur_radius,
box_shadow_info.spread_radius,
box_shadow_info.border_radius,
box_shadow_info.clip_mode,
);
}
SpecificDisplayItem::Border(ref info) => {
self.add_border(
clip_and_scroll,
&prim_info,
info,
item.gradient_stops(),
);
}
SpecificDisplayItem::PushStackingContext(ref info) => {
let mut subtraversal = item.sub_iter();
self.flatten_stacking_context(
&mut subtraversal,
pipeline_id,
&item,
&info.stacking_context,
clip_and_scroll_ids.scroll_node_id,
reference_frame_relative_offset,
prim_info.is_backface_visible,
);
return Some(subtraversal);
}
SpecificDisplayItem::PushReferenceFrame(ref info) => {
let mut subtraversal = item.sub_iter();
self.flatten_reference_frame(
&mut subtraversal,
pipeline_id,
&item,
&info.reference_frame,
clip_and_scroll_ids.scroll_node_id,
reference_frame_relative_offset,
);
return Some(subtraversal);
}
SpecificDisplayItem::Iframe(ref info) => {
self.flatten_iframe(
&item,
info,
&clip_and_scroll_ids,
&reference_frame_relative_offset
);
}
SpecificDisplayItem::Clip(ref info) => {
let complex_clips = self.get_complex_clips(pipeline_id, item.complex_clip().0);
let clip_region = ClipRegion::create_for_clip_node(
*item.clip_rect(),
complex_clips,
info.image_mask,
&reference_frame_relative_offset,
);
self.add_clip_node(info.id, clip_and_scroll_ids.scroll_node_id, clip_region);
}
SpecificDisplayItem::ClipChain(ref info) => {
// For a user defined clip-chain the parent (if specified) must
// refer to another user defined clip-chain. If none is specified,
// the parent is the root clip-chain for the given pipeline. This
// is used to provide a root clip chain for iframes.
let mut parent_clip_chain_id = match info.parent {
Some(id) => {
self.id_to_index_mapper.get_clip_chain_id(&ClipId::ClipChain(id))
}
None => {
self.pipeline_clip_chain_stack.last().cloned().unwrap()
}
};
// Create a linked list of clip chain nodes. To do this, we will
// create a clip chain node + clip source for each listed clip id,
// and link these together, with the root of this list parented to
// the parent clip chain node found above. For this API, the clip
// id that is specified for an existing clip chain node is used to
// get the index of the clip sources that define that clip node.
let mut clip_chain_id = parent_clip_chain_id;
// For each specified clip id
for item in self.get_clip_chain_items(pipeline_id, item.clip_chain_items()) {
// Map the ClipId to an existing clip chain node.
let item_clip_chain_id = self
.id_to_index_mapper
.get_clip_chain_id(&item);
// Get the id of the clip sources entry for that clip chain node.
let clip_sources_id = self
.clip_store
.get_clip_chain(item_clip_chain_id)
.clip_sources_id;
// Add a new clip chain node, which references the same clip sources, and
// parent it to the current parent.
clip_chain_id = self
.clip_store
.add_clip_chain(clip_sources_id, parent_clip_chain_id);
// For the next clip node, use this new clip chain node as the parent,
// to form a linked list.
parent_clip_chain_id = clip_chain_id;
}
// Map the last entry in the clip chain to the supplied ClipId. This makes
// this ClipId available as a source to other user defined clip chains.
self.id_to_index_mapper.add_clip_chain(ClipId::ClipChain(info.id), clip_chain_id);
},
SpecificDisplayItem::ScrollFrame(ref info) => {
self.flatten_scroll_frame(
&item,
info,
pipeline_id,
&clip_and_scroll_ids,
&reference_frame_relative_offset
);
}
SpecificDisplayItem::StickyFrame(ref info) => {
self.flatten_sticky_frame(
&item,
info,
&clip_and_scroll,
&clip_and_scroll_ids.scroll_node_id,
&reference_frame_relative_offset
);
}
// Do nothing; these are dummy items for the display list parser
SpecificDisplayItem::SetGradientStops => {}
SpecificDisplayItem::PopStackingContext | SpecificDisplayItem::PopReferenceFrame => {
unreachable!("Should have returned in parent method.")
}
SpecificDisplayItem::PushShadow(shadow) => {
let mut prim_info = prim_info.clone();
prim_info.rect = LayoutRect::zero();
self
.push_shadow(shadow, clip_and_scroll, &prim_info);
}
SpecificDisplayItem::PopAllShadows => {
self.pop_all_shadows();
}
}
None
}
// Given a list of clip sources, a positioning node and
// a parent clip chain, return a new clip chain entry.
// If the supplied list of clip sources is empty, then
// just return the parent clip chain id directly.
fn build_clip_chain(
&mut self,
clip_sources: Vec<ClipSource>,
spatial_node_index: SpatialNodeIndex,
default_clip_chain_id: ClipChainId,
) -> ClipChainId {
if clip_sources.is_empty() {
default_clip_chain_id
} else {
// Add a range of clip sources.
let clip_sources_id = self
.clip_store
.add_clip_sources(clip_sources, spatial_node_index);
// Add clip chain node that references the clip source range.
self.clip_store.add_clip_chain(
clip_sources_id,
default_clip_chain_id,
)
}
}
/// Create a primitive and add it to the prim store. This method doesn't
/// add the primitive to the draw list, so can be used for creating
/// sub-primitives.
pub fn create_primitive(
&mut self,
info: &LayoutPrimitiveInfo,
clip_chain_id: ClipChainId,
container: PrimitiveContainer,
) -> PrimitiveIndex {
let stacking_context = self.sc_stack.last().expect("bug: no stacking context!");
self.prim_store.add_primitive(
&info.rect,
&info.clip_rect,
info.is_backface_visible && stacking_context.is_backface_visible,
clip_chain_id,
info.tag,
container,
)
}
pub fn add_primitive_to_hit_testing_list(
&mut self,
info: &LayoutPrimitiveInfo,
clip_and_scroll: ScrollNodeAndClipChain
) {
let tag = match info.tag {
Some(tag) => tag,
None => return,
};
let new_item = HitTestingItem::new(tag, info);
match self.hit_testing_runs.last_mut() {
Some(&mut HitTestingRun(ref mut items, prev_clip_and_scroll))
if prev_clip_and_scroll == clip_and_scroll => {
items.push(new_item);
return;
}
_ => {}
}
self.hit_testing_runs.push(HitTestingRun(vec![new_item], clip_and_scroll));
}
/// Add an already created primitive to the draw lists.
pub fn add_primitive_to_draw_list(
&mut self,
prim_index: PrimitiveIndex,
spatial_node_index: SpatialNodeIndex,
) {
// Add primitive to the top-most Picture on the stack.
let pic_index = self.picture_stack.last().unwrap();
let pic = &mut self.prim_store.pictures[pic_index.0];
pic.add_primitive(prim_index, spatial_node_index);
}
/// Convenience interface that creates a primitive entry and adds it
/// to the draw list.
pub fn add_primitive(
&mut self,
clip_and_scroll: ScrollNodeAndClipChain,
info: &LayoutPrimitiveInfo,
clip_sources: Vec<ClipSource>,
container: PrimitiveContainer,
) {
if !self.shadow_stack.is_empty() {
// TODO(gw): Restructure this so we don't need to move the shadow
// stack out (borrowck due to create_primitive below).
let shadow_stack = mem::replace(&mut self.shadow_stack, Vec::new());
for &(ref shadow, shadow_pic_index) in &shadow_stack {
// Offset the local rect and clip rect by the shadow offset.
let mut info = info.clone();
info.rect = info.rect.translate(&shadow.offset);
info.clip_rect = info.clip_rect.translate(&shadow.offset);
// Offset any local clip sources by the shadow offset.
let clip_sources: Vec<ClipSource> = clip_sources
.iter()
.map(|cs| cs.offset(&shadow.offset))
.collect();
let clip_chain_id = self.build_clip_chain(
clip_sources,
clip_and_scroll.spatial_node_index,
clip_and_scroll.clip_chain_id,
);
// Construct and add a primitive for the given shadow.
let shadow_prim_index = self.create_primitive(
&info,
clip_chain_id,
container.create_shadow(shadow),
);
// Add the new primitive to the shadow picture.
let shadow_pic = &mut self.prim_store.pictures[shadow_pic_index.0];
shadow_pic.add_primitive(
shadow_prim_index,
clip_and_scroll.spatial_node_index,
);
}
self.shadow_stack = shadow_stack;
}
if container.is_visible() {
let clip_chain_id = self.build_clip_chain(
clip_sources,
clip_and_scroll.spatial_node_index,
clip_and_scroll.clip_chain_id,
);
let prim_index = self.create_primitive(info, clip_chain_id, container);
if cfg!(debug_assertions) && ChasePrimitive::LocalRect(info.rect) == self.config.chase_primitive {
println!("Chasing {:?}", prim_index);
self.prim_store.chase_id = Some(prim_index);
}
self.add_primitive_to_hit_testing_list(info, clip_and_scroll);
self.add_primitive_to_draw_list(
prim_index,
clip_and_scroll.spatial_node_index,
);
}
}
pub fn push_stacking_context(
&mut self,
pipeline_id: PipelineId,
composite_ops: CompositeOps,
transform_style: TransformStyle,
is_backface_visible: bool,
is_pipeline_root: bool,
spatial_node: ClipId,
clipping_node: Option<ClipId>,
glyph_raster_space: GlyphRasterSpace,
) {
let spatial_node_index = self.id_to_index_mapper.get_spatial_node_index(spatial_node);
let clip_chain_id = match clipping_node {
Some(ref clipping_node) => self.id_to_index_mapper.get_clip_chain_id(clipping_node),
None => ClipChainId::NONE,
};
// Construct the necessary set of Picture primitives
// to draw this stacking context.
let current_reference_frame_index = self.current_reference_frame_index();
// An arbitrary large clip rect. For now, we don't
// specify a clip specific to the stacking context.
// However, now that they are represented as Picture
// primitives, we can apply any kind of clip mask
// to them, as for a normal primitive. This is needed
// to correctly handle some CSS cases (see #1957).
let max_clip = LayoutRect::max_rect();
// If there is no root picture, create one for the main framebuffer.
if self.sc_stack.is_empty() {
// Should be no pictures at all if the stack is empty...
debug_assert!(self.prim_store.pictures.is_empty());
debug_assert_eq!(transform_style, TransformStyle::Flat);
// This picture stores primitive runs for items on the
// main framebuffer.
let pic_index = self.prim_store.add_image_picture(
None,
false,
pipeline_id,
current_reference_frame_index,
None,
true,
);
self.picture_stack.push(pic_index);
} else if composite_ops.mix_blend_mode.is_some() && self.sc_stack.len() > 2 {
// If we have a mix-blend-mode, and we aren't the primary framebuffer,
// the stacking context needs to be isolated to blend correctly as per
// the CSS spec.
// TODO(gw): The way we detect not being the primary framebuffer (len > 2)
// is hacky and depends on how we create a root stacking context
// during flattening.
let parent_pic_index = self.picture_stack.last().unwrap();
let parent_pic = &mut self.prim_store.pictures[parent_pic_index.0];
// If not already isolated for some other reason,
// make this picture as isolated.
if parent_pic.composite_mode.is_none() {
parent_pic.composite_mode = Some(PictureCompositeMode::Blit);
}
}
// Get the transform-style of the parent stacking context,
// which determines if we *might* need to draw this on
// an intermediate surface for plane splitting purposes.
let parent_transform_style = match self.sc_stack.last() {
Some(sc) => sc.transform_style,
None => TransformStyle::Flat,
};
// If this is preserve-3d *or* the parent is, then this stacking
// context is participating in the 3d rendering context. In that
// case, hoist the picture up to the 3d rendering context
// container, so that it's rendered as a sibling with other
// elements in this context.
let participating_in_3d_context =
composite_ops.count() == 0 &&
(parent_transform_style == TransformStyle::Preserve3D ||
transform_style == TransformStyle::Preserve3D);
// If this is participating in a 3d context *and* the
// parent was not a 3d context, then this must be the
// element that establishes a new 3d context.
let establishes_3d_context =
participating_in_3d_context &&
parent_transform_style == TransformStyle::Flat;
let rendering_context_3d_pic_index = if establishes_3d_context {
// If establishing a 3d context, we need to add a picture
// that will be the container for all the planes and any
// un-transformed content.
let container_index = self.prim_store.add_image_picture(
None,
false,
pipeline_id,
current_reference_frame_index,
None,
true,
);