15821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// Copyright (c) 2011 The Chromium Authors. All rights reserved. 25821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// Use of this source code is governed by a BSD-style license that can be 35821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// found in the LICENSE file. 45821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 55821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)#include "ppapi/utility/graphics/paint_aggregator.h" 65821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 75821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)#include <algorithm> 85821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 95821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)#include "ppapi/cpp/logging.h" 105821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 115821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// ---------------------------------------------------------------------------- 125821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// ALGORITHM NOTES 135821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// 145821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// We attempt to maintain a scroll rect in the presence of invalidations that 155821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// are contained within the scroll rect. If an invalidation crosses a scroll 165821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// rect, then we just treat the scroll rect as an invalidation rect. 175821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// 185821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// For invalidations performed prior to scrolling and contained within the 195821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// scroll rect, we offset the invalidation rects to account for the fact that 205821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// the consumer will perform scrolling before painting. 215821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// 225821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// We only support scrolling along one axis at a time. A diagonal scroll will 235821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// therefore be treated as an invalidation. 245821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// ---------------------------------------------------------------------------- 255821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 265821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)namespace pp { 275821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 285821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)PaintAggregator::PaintUpdate::PaintUpdate() : has_scroll(false) {} 295821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 305821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)PaintAggregator::PaintUpdate::~PaintUpdate() {} 315821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 325821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)PaintAggregator::InternalPaintUpdate::InternalPaintUpdate() {} 335821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 345821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)PaintAggregator::InternalPaintUpdate::~InternalPaintUpdate() {} 355821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 365821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)Rect PaintAggregator::InternalPaintUpdate::GetScrollDamage() const { 375821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // Should only be scrolling in one direction at a time. 385821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) PP_DCHECK(!(scroll_delta.x() && scroll_delta.y())); 395821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 405821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) Rect damaged_rect; 415821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 425821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // Compute the region we will expose by scrolling, and paint that into a 435821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // shared memory section. 445821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) if (scroll_delta.x()) { 455821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) int32_t dx = scroll_delta.x(); 465821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) damaged_rect.set_y(scroll_rect.y()); 475821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) damaged_rect.set_height(scroll_rect.height()); 485821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) if (dx > 0) { 495821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) damaged_rect.set_x(scroll_rect.x()); 505821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) damaged_rect.set_width(dx); 515821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) } else { 525821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) damaged_rect.set_x(scroll_rect.right() + dx); 535821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) damaged_rect.set_width(-dx); 545821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) } 555821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) } else { 565821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) int32_t dy = scroll_delta.y(); 575821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) damaged_rect.set_x(scroll_rect.x()); 585821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) damaged_rect.set_width(scroll_rect.width()); 595821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) if (dy > 0) { 605821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) damaged_rect.set_y(scroll_rect.y()); 615821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) damaged_rect.set_height(dy); 625821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) } else { 635821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) damaged_rect.set_y(scroll_rect.bottom() + dy); 645821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) damaged_rect.set_height(-dy); 655821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) } 665821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) } 675821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 685821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // In case the scroll offset exceeds the width/height of the scroll rect 695821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) return scroll_rect.Intersect(damaged_rect); 705821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)} 715821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 725821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)Rect PaintAggregator::InternalPaintUpdate::GetPaintBounds() const { 735821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) Rect bounds; 745821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) for (size_t i = 0; i < paint_rects.size(); ++i) 755821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) bounds = bounds.Union(paint_rects[i]); 765821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) return bounds; 775821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)} 785821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 795821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)PaintAggregator::PaintAggregator() 805821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) : max_redundant_paint_to_scroll_area_(0.8f), 815821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) max_paint_rects_(10) { 825821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)} 835821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 845821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)bool PaintAggregator::HasPendingUpdate() const { 855821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) return !update_.scroll_rect.IsEmpty() || !update_.paint_rects.empty(); 865821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)} 875821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 885821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)void PaintAggregator::ClearPendingUpdate() { 895821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) update_ = InternalPaintUpdate(); 905821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)} 915821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 925821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)PaintAggregator::PaintUpdate PaintAggregator::GetPendingUpdate() const { 935821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // Convert the internal paint update to the external one, which includes a 945821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // bit more precomputed info for the caller. 955821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) PaintUpdate ret; 965821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) ret.scroll_delta = update_.scroll_delta; 975821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) ret.scroll_rect = update_.scroll_rect; 985821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) ret.has_scroll = ret.scroll_delta.x() != 0 || ret.scroll_delta.y() != 0; 995821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 1005821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) ret.paint_rects.reserve(update_.paint_rects.size() + 1); 1015821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) for (size_t i = 0; i < update_.paint_rects.size(); i++) 1025821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) ret.paint_rects.push_back(update_.paint_rects[i]); 1035821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 1045821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) ret.paint_bounds = update_.GetPaintBounds(); 1055821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 1065821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // Also include the scroll damage (if any) in the paint rects. 1075821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) if (ret.has_scroll) { 1085821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) PP_Rect scroll_damage = update_.GetScrollDamage(); 1095821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) ret.paint_rects.push_back(scroll_damage); 1105821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) ret.paint_bounds = ret.paint_bounds.Union(scroll_damage); 1115821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) } 1125821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 1135821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) return ret; 1145821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)} 1155821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 1165821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)void PaintAggregator::InvalidateRect(const Rect& rect) { 1175821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // Combine overlapping paints using smallest bounding box. 1185821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) for (size_t i = 0; i < update_.paint_rects.size(); ++i) { 1195821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) const Rect& existing_rect = update_.paint_rects[i]; 1205821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) if (existing_rect.Contains(rect)) // Optimize out redundancy. 1215821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) return; 1225821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) if (rect.Intersects(existing_rect) || rect.SharesEdgeWith(existing_rect)) { 1235821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // Re-invalidate in case the union intersects other paint rects. 1245821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) Rect combined_rect = existing_rect.Union(rect); 1255821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) update_.paint_rects.erase(update_.paint_rects.begin() + i); 1265821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) InvalidateRect(combined_rect); 1275821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) return; 1285821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) } 1295821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) } 1305821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 1315821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // Add a non-overlapping paint. 1325821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) update_.paint_rects.push_back(rect); 1335821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 1345821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // If the new paint overlaps with a scroll, then it forces an invalidation of 1355821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // the scroll. If the new paint is contained by a scroll, then trim off the 1365821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // scroll damage to avoid redundant painting. 1375821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) if (!update_.scroll_rect.IsEmpty()) { 1385821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) if (ShouldInvalidateScrollRect(rect)) { 1395821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) InvalidateScrollRect(); 1405821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) } else if (update_.scroll_rect.Contains(rect)) { 1415821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) update_.paint_rects[update_.paint_rects.size() - 1] = 1425821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) rect.Subtract(update_.GetScrollDamage()); 1435821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) if (update_.paint_rects[update_.paint_rects.size() - 1].IsEmpty()) 1445821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) update_.paint_rects.erase(update_.paint_rects.end() - 1); 1455821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) } 1465821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) } 1475821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 1485821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) if (update_.paint_rects.size() > max_paint_rects_) 1495821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) CombinePaintRects(); 1505821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)} 1515821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 1525821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)void PaintAggregator::ScrollRect(const Rect& clip_rect, const Point& amount) { 1535821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // We only support scrolling along one axis at a time. 1545821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) if (amount.x() != 0 && amount.y() != 0) { 1555821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) InvalidateRect(clip_rect); 1565821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) return; 1575821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) } 1585821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 1595821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // We can only scroll one rect at a time. 1605821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) if (!update_.scroll_rect.IsEmpty() && update_.scroll_rect != clip_rect) { 1615821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) InvalidateRect(clip_rect); 1625821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) return; 1635821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) } 1645821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 1655821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // Again, we only support scrolling along one axis at a time. Make sure this 1665821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // update doesn't scroll on a different axis than any existing one. 1675821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) if ((amount.x() && update_.scroll_delta.y()) || 1685821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) (amount.y() && update_.scroll_delta.x())) { 1695821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) InvalidateRect(clip_rect); 1705821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) return; 1715821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) } 1725821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 1735821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // The scroll rect is new or isn't changing (though the scroll amount may 1745821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // be changing). 1755821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) update_.scroll_rect = clip_rect; 1765821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) update_.scroll_delta += amount; 1775821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 1785821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // We might have just wiped out a pre-existing scroll. 1795821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) if (update_.scroll_delta == Point()) { 1805821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) update_.scroll_rect = Rect(); 1815821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) return; 1825821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) } 1835821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 1845821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // Adjust any contained paint rects and check for any overlapping paints. 1855821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) for (size_t i = 0; i < update_.paint_rects.size(); ++i) { 1865821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) if (update_.scroll_rect.Contains(update_.paint_rects[i])) { 1875821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) update_.paint_rects[i] = ScrollPaintRect(update_.paint_rects[i], amount); 1885821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // The rect may have been scrolled out of view. 1895821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) if (update_.paint_rects[i].IsEmpty()) { 1905821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) update_.paint_rects.erase(update_.paint_rects.begin() + i); 1915821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) i--; 1925821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) } 1935821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) } else if (update_.scroll_rect.Intersects(update_.paint_rects[i])) { 1945821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) InvalidateScrollRect(); 1955821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) return; 1965821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) } 1975821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) } 1985821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 1995821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // If the new scroll overlaps too much with contained paint rects, then force 2005821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // an invalidation of the scroll. 2015821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) if (ShouldInvalidateScrollRect(Rect())) 2025821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) InvalidateScrollRect(); 2035821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)} 2045821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 2055821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)Rect PaintAggregator::ScrollPaintRect(const Rect& paint_rect, 2065821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) const Point& amount) const { 2075821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) Rect result = paint_rect; 2085821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 2095821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) result.Offset(amount); 2105821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) result = update_.scroll_rect.Intersect(result); 2115821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 2125821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // Subtract out the scroll damage rect to avoid redundant painting. 2135821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) return result.Subtract(update_.GetScrollDamage()); 2145821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)} 2155821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 2165821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)bool PaintAggregator::ShouldInvalidateScrollRect(const Rect& rect) const { 2175821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) if (!rect.IsEmpty()) { 2185821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) if (!update_.scroll_rect.Intersects(rect)) 2195821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) return false; 2205821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 2215821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) if (!update_.scroll_rect.Contains(rect)) 2225821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) return true; 2235821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) } 2245821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 2255821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // Check if the combined area of all contained paint rects plus this new 2265821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // rect comes too close to the area of the scroll_rect. If so, then we 2275821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // might as well invalidate the scroll rect. 2285821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 2295821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) int paint_area = rect.size().GetArea(); 2305821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) for (size_t i = 0; i < update_.paint_rects.size(); ++i) { 2315821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) const Rect& existing_rect = update_.paint_rects[i]; 2325821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) if (update_.scroll_rect.Contains(existing_rect)) 2335821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) paint_area += existing_rect.size().GetArea(); 2345821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) } 2355821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) int scroll_area = update_.scroll_rect.size().GetArea(); 2365821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) if (float(paint_area) / float(scroll_area) > max_redundant_paint_to_scroll_area_) 2375821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) return true; 2385821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 2395821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) return false; 2405821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)} 2415821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 2425821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)void PaintAggregator::InvalidateScrollRect() { 2435821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) Rect scroll_rect = update_.scroll_rect; 2445821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) update_.scroll_rect = Rect(); 2455821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) update_.scroll_delta = Point(); 2465821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) InvalidateRect(scroll_rect); 2475821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)} 2485821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 2495821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)void PaintAggregator::CombinePaintRects() { 2505821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // Combine paint rects down to at most two rects: one inside the scroll_rect 2515821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // and one outside the scroll_rect. If there is no scroll_rect, then just 2525821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // use the smallest bounding box for all paint rects. 2535821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // 2545821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // NOTE: This is a fairly simple algorithm. We could get fancier by only 2555821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // combining two rects to get us under the max_paint_rects limit, but if we 2565821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // reach this method then it means we're hitting a rare case, so there's no 2575821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // need to over-optimize it. 2585821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // 2595821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) if (update_.scroll_rect.IsEmpty()) { 2605821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) Rect bounds = update_.GetPaintBounds(); 2615821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) update_.paint_rects.clear(); 2625821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) update_.paint_rects.push_back(bounds); 2635821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) } else { 2645821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) Rect inner, outer; 2655821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) for (size_t i = 0; i < update_.paint_rects.size(); ++i) { 2665821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) const Rect& existing_rect = update_.paint_rects[i]; 2675821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) if (update_.scroll_rect.Contains(existing_rect)) { 2685821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) inner = inner.Union(existing_rect); 2695821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) } else { 2705821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) outer = outer.Union(existing_rect); 2715821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) } 2725821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) } 2735821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) update_.paint_rects.clear(); 2745821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) update_.paint_rects.push_back(inner); 2755821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) update_.paint_rects.push_back(outer); 2765821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) } 2775821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)} 2785821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 2795821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)} // namespace pp 280