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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
use api::{BorderRadius, ClipMode, HitTestResultItem, HitTestResult, ItemTag, PrimitiveFlags};
use api::{PipelineId, ApiHitTester};
use api::units::*;
use crate::clip::{rounded_rectangle_contains_point, ClipNodeId, ClipTreeBuilder};
use crate::clip::{polygon_contains_point, ClipItemKey, ClipItemKeyKind};
use crate::prim_store::PolygonKey;
use crate::scene_builder_thread::Interners;
use crate::spatial_tree::{SpatialNodeIndex, SpatialTree, get_external_scroll_offset};
use crate::internal_types::{FastHashMap, LayoutPrimitiveInfo};
use std::sync::{Arc, Mutex};
use crate::util::{LayoutToWorldFastTransform};
pub struct SharedHitTester {
// We don't really need a mutex here. We could do with some sort of
// atomic-atomic-ref-counted pointer (an Arc which would let the pointer
// be swapped atomically like an AtomicPtr).
// In practive this shouldn't cause performance issues, though.
hit_tester: Mutex<Arc<HitTester>>,
}
impl SharedHitTester {
pub fn new() -> Self {
SharedHitTester {
hit_tester: Mutex::new(Arc::new(HitTester::empty())),
}
}
pub fn get_ref(&self) -> Arc<HitTester> {
let guard = self.hit_tester.lock().unwrap();
Arc::clone(&*guard)
}
pub(crate) fn update(&self, new_hit_tester: Arc<HitTester>) {
let mut guard = self.hit_tester.lock().unwrap();
*guard = new_hit_tester;
}
}
impl ApiHitTester for SharedHitTester {
fn hit_test(&self,
point: WorldPoint,
) -> HitTestResult {
self.get_ref().hit_test(HitTest::new(point))
}
}
/// A copy of important spatial node data to use during hit testing. This a copy of
/// data from the SpatialTree that will persist as a new frame is under construction,
/// allowing hit tests consistent with the currently rendered frame.
#[derive(MallocSizeOf)]
struct HitTestSpatialNode {
/// The pipeline id of this node.
pipeline_id: PipelineId,
/// World transform for content transformed by this node.
world_content_transform: LayoutToWorldFastTransform,
/// World viewport transform for content transformed by this node.
world_viewport_transform: LayoutToWorldFastTransform,
/// The accumulated external scroll offset for this spatial node.
external_scroll_offset: LayoutVector2D,
}
#[derive(MallocSizeOf)]
struct HitTestClipNode {
/// A particular point must be inside all of these regions to be considered clipped in
/// for the purposes of a hit test.
region: HitTestRegion,
/// The positioning node for this clip
spatial_node_index: SpatialNodeIndex,
/// Parent clip node
parent: ClipNodeId,
}
impl HitTestClipNode {
fn new(
item: &ClipItemKey,
interners: &Interners,
parent: ClipNodeId,
) -> Self {
let region = match item.kind {
ClipItemKeyKind::Rectangle(rect, mode) => {
HitTestRegion::Rectangle(rect.into(), mode)
}
ClipItemKeyKind::RoundedRectangle(rect, radius, mode) => {
HitTestRegion::RoundedRectangle(rect.into(), radius.into(), mode)
}
ClipItemKeyKind::ImageMask(rect, _, polygon_handle) => {
if let Some(handle) = polygon_handle {
// Retrieve the polygon data from the interner.
let polygon = &interners.polygon[handle];
HitTestRegion::Polygon(rect.into(), *polygon)
} else {
HitTestRegion::Rectangle(rect.into(), ClipMode::Clip)
}
}
ClipItemKeyKind::BoxShadow(..) => HitTestRegion::Invalid,
};
HitTestClipNode {
region,
spatial_node_index: item.spatial_node_index,
parent,
}
}
}
#[derive(Clone, MallocSizeOf)]
struct HitTestingItem {
rect: LayoutRect,
tag: ItemTag,
animation_id: u64,
is_backface_visible: bool,
spatial_node_index: SpatialNodeIndex,
clip_node_id: ClipNodeId,
}
impl HitTestingItem {
fn new(
tag: ItemTag,
animation_id: u64,
info: &LayoutPrimitiveInfo,
spatial_node_index: SpatialNodeIndex,
clip_node_id: ClipNodeId,
) -> HitTestingItem {
HitTestingItem {
rect: info.rect,
tag,
animation_id,
is_backface_visible: info.flags.contains(PrimitiveFlags::IS_BACKFACE_VISIBLE),
spatial_node_index,
clip_node_id,
}
}
}
/// Statistics about allocation sizes of current hit tester,
/// used to pre-allocate size of the next hit tester.
pub struct HitTestingSceneStats {
pub clip_nodes_count: usize,
pub items_count: usize,
}
impl HitTestingSceneStats {
pub fn empty() -> Self {
HitTestingSceneStats {
clip_nodes_count: 0,
items_count: 0,
}
}
}
#[derive(MallocSizeOf, Debug, Copy, Clone)]
pub struct ClipNodeIndex(u32);
/// Defines the immutable part of a hit tester for a given scene.
/// The hit tester is recreated each time a frame is built, since
/// it relies on the current values of the spatial tree.
/// However, the clip chain and item definitions don't change,
/// so they are created once per scene, and shared between
/// hit tester instances via Arc.
#[derive(MallocSizeOf)]
pub struct HitTestingScene {
clip_nodes: FastHashMap<ClipNodeId, HitTestClipNode>,
/// List of hit testing primitives.
items: Vec<HitTestingItem>,
}
impl HitTestingScene {
/// Construct a new hit testing scene, pre-allocating to size
/// provided by previous scene stats.
pub fn new(stats: &HitTestingSceneStats) -> Self {
HitTestingScene {
clip_nodes: FastHashMap::default(),
items: Vec::with_capacity(stats.items_count),
}
}
/// Get stats about the current scene allocation sizes.
pub fn get_stats(&self) -> HitTestingSceneStats {
HitTestingSceneStats {
clip_nodes_count: 0,
items_count: self.items.len(),
}
}
fn add_clip_node(
&mut self,
clip_node_id: ClipNodeId,
clip_tree_builder: &ClipTreeBuilder,
interners: &Interners,
) {
if clip_node_id == ClipNodeId::NONE {
return;
}
if !self.clip_nodes.contains_key(&clip_node_id) {
let src_clip_node = clip_tree_builder.get_node(clip_node_id);
let clip_item = &interners.clip[src_clip_node.handle];
let clip_node = HitTestClipNode::new(
&clip_item.key,
interners,
src_clip_node.parent,
);
self.clip_nodes.insert(clip_node_id, clip_node);
self.add_clip_node(
src_clip_node.parent,
clip_tree_builder,
interners,
);
}
}
/// Add a hit testing primitive.
pub fn add_item(
&mut self,
tag: ItemTag,
anim_id: u64,
info: &LayoutPrimitiveInfo,
spatial_node_index: SpatialNodeIndex,
clip_node_id: ClipNodeId,
clip_tree_builder: &ClipTreeBuilder,
interners: &Interners,
) {
self.add_clip_node(
clip_node_id,
clip_tree_builder,
interners,
);
let item = HitTestingItem::new(
tag,
anim_id,
info,
spatial_node_index,
clip_node_id,
);
self.items.push(item);
}
}
#[derive(MallocSizeOf)]
enum HitTestRegion {
Invalid,
Rectangle(LayoutRect, ClipMode),
RoundedRectangle(LayoutRect, BorderRadius, ClipMode),
Polygon(LayoutRect, PolygonKey),
}
impl HitTestRegion {
fn contains(&self, point: &LayoutPoint) -> bool {
match *self {
HitTestRegion::Rectangle(ref rectangle, ClipMode::Clip) =>
rectangle.contains(*point),
HitTestRegion::Rectangle(ref rectangle, ClipMode::ClipOut) =>
!rectangle.contains(*point),
HitTestRegion::RoundedRectangle(rect, radii, ClipMode::Clip) =>
rounded_rectangle_contains_point(point, &rect, &radii),
HitTestRegion::RoundedRectangle(rect, radii, ClipMode::ClipOut) =>
!rounded_rectangle_contains_point(point, &rect, &radii),
HitTestRegion::Polygon(rect, polygon) =>
polygon_contains_point(point, &rect, &polygon),
HitTestRegion::Invalid => true,
}
}
}
#[derive(MallocSizeOf)]
pub struct HitTester {
#[ignore_malloc_size_of = "Arc"]
scene: Arc<HitTestingScene>,
spatial_nodes: FastHashMap<SpatialNodeIndex, HitTestSpatialNode>,
}
impl HitTester {
pub fn empty() -> Self {
HitTester {
scene: Arc::new(HitTestingScene::new(&HitTestingSceneStats::empty())),
spatial_nodes: FastHashMap::default(),
}
}
pub fn new(
scene: Arc<HitTestingScene>,
spatial_tree: &SpatialTree,
) -> HitTester {
let mut hit_tester = HitTester {
scene,
spatial_nodes: FastHashMap::default(),
};
hit_tester.read_spatial_tree(spatial_tree);
hit_tester
}
fn read_spatial_tree(
&mut self,
spatial_tree: &SpatialTree,
) {
self.spatial_nodes.clear();
self.spatial_nodes.reserve(spatial_tree.spatial_node_count());
spatial_tree.visit_nodes(|index, node| {
//TODO: avoid inverting more than necessary:
// - if the coordinate system is non-invertible, no need to try any of these concrete transforms
// - if there are other places where inversion is needed, let's not repeat the step
self.spatial_nodes.insert(index, HitTestSpatialNode {
pipeline_id: node.pipeline_id,
world_content_transform: spatial_tree
.get_world_transform(index)
.into_fast_transform(),
world_viewport_transform: spatial_tree
.get_world_viewport_transform(index)
.into_fast_transform(),
external_scroll_offset: get_external_scroll_offset(spatial_tree, index),
});
});
}
pub fn hit_test(&self, test: HitTest) -> HitTestResult {
let mut result = HitTestResult::default();
let mut current_spatial_node_index = SpatialNodeIndex::INVALID;
let mut point_in_layer = None;
// For each hit test primitive
for item in self.scene.items.iter().rev() {
let scroll_node = &self.spatial_nodes[&item.spatial_node_index];
let pipeline_id = scroll_node.pipeline_id;
// Update the cached point in layer space, if the spatial node
// changed since last primitive.
if item.spatial_node_index != current_spatial_node_index {
point_in_layer = scroll_node
.world_content_transform
.inverse()
.and_then(|inverted| inverted.project_point2d(test.point));
current_spatial_node_index = item.spatial_node_index;
}
// Only consider hit tests on transformable layers.
let point_in_layer = match point_in_layer {
Some(p) => p,
None => continue,
};
// If the item's rect or clip rect don't contain this point, it's
// not a valid hit.
if !item.rect.contains(point_in_layer) {
continue;
}
// See if any of the clips for this primitive cull out the item.
let mut current_clip_node_id = item.clip_node_id;
let mut is_valid = true;
while current_clip_node_id != ClipNodeId::NONE {
let clip_node = &self.scene.clip_nodes[¤t_clip_node_id];
let transform = self
.spatial_nodes[&clip_node.spatial_node_index]
.world_content_transform;
if let Some(transformed_point) = transform
.inverse()
.and_then(|inverted| inverted.project_point2d(test.point))
{
if !clip_node.region.contains(&transformed_point) {
is_valid = false;
break;
}
}
current_clip_node_id = clip_node.parent;
}
if !is_valid {
continue;
}
// Don't hit items with backface-visibility:hidden if they are facing the back.
if !item.is_backface_visible && scroll_node.world_content_transform.is_backface_visible() {
continue;
}
result.items.push(HitTestResultItem {
pipeline: pipeline_id,
tag: item.tag,
animation_id: item.animation_id,
});
}
result.items.dedup();
result
}
}
#[derive(MallocSizeOf)]
pub struct HitTest {
point: WorldPoint,
}
impl HitTest {
pub fn new(
point: WorldPoint,
) -> HitTest {
HitTest {
point,
}
}
}