Treat (private, internal) grid bounds as doubly-inclusive in SkTileGrid.

src/core/SkTileGrid.cpp

 /*
  * Copyright 2012 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include "SkTileGrid.h"
 
 SkTileGrid::SkTileGrid(int xTiles, int yTiles, const SkTileGridFactory::TileGridInfo& info)
@@ skipping 44 matching lines @@
 void SkTileGrid::commonAdjust(SkRect* rect) const {
     // Apply our offset.
     rect->offset(fOffset);
 
     // Scrunch the bounds in just a little to make the right and bottom edges
     // exclusive.  We want bounds of exactly one tile to hit exactly one tile.
     rect->fRight  -= SK_ScalarNearlyZero;
     rect->fBottom -= SK_ScalarNearlyZero;
 }
 
-// Convert user-space bounds to grid tiles they cover (LT inclusive, RB exclusive).
+// Convert user-space bounds to grid tiles they cover (LT and RB both inclusive).
 void SkTileGrid::userToGrid(const SkRect& user, SkIRect* grid) const {
     grid->fLeft   = SkPin32(user.left()   * fInvWidth , 0, fXTiles - 1);
     grid->fTop    = SkPin32(user.top()    * fInvHeight, 0, fYTiles - 1);
-    grid->fRight  = SkPin32(user.right()  * fInvWidth , 0, fXTiles - 1) + 1;
-    grid->fBottom = SkPin32(user.bottom() * fInvHeight, 0, fYTiles - 1) + 1;
+    grid->fRight  = SkPin32(user.right()  * fInvWidth , 0, fXTiles - 1);
+    grid->fBottom = SkPin32(user.bottom() * fInvHeight, 0, fYTiles - 1);
 }
 
 void SkTileGrid::insert(unsigned opIndex, const SkRect& originalBounds, bool) {
     SkRect bounds = originalBounds;
     bounds.outset(fMarginWidth, fMarginHeight);
     this->commonAdjust(&bounds);
 
     // TODO(mtklein): can we assert this instead to save an intersection in Release mode,
     // or just allow out-of-bound insertions to insert anyway (clamped to nearest tile)?
     if (!SkRect::Intersects(bounds, fGridBounds)) {
         return;
     }
 
     SkIRect grid;
     this->userToGrid(bounds, &grid);
 
-    for (int y = grid.fTop; y < grid.fBottom; y++) {
-        for (int x = grid.fLeft; x < grid.fRight; x++) {
+    for (int y = grid.fTop; y <= grid.fBottom; y++) {
+        for (int x = grid.fLeft; x <= grid.fRight; x++) {
             fTiles[y * fXTiles + x].push(opIndex);
         }
     }
 }
 
 // Number of tiles for which data is allocated on the stack in
 // SkTileGrid::search. If malloc becomes a bottleneck, we may consider
 // increasing this number. Typical large web page, say 2k x 16k, would
 // require 512 tiles of size 256 x 256 pixels.
 static const int kStackAllocationTileCount = 1024;
 
 void SkTileGrid::search(const SkRect& originalQuery, SkTDArray<unsigned>* results) const {
     // The inset counteracts the outset that applied in 'insert', which optimizes
     // for lookups of size 'tileInterval + 2 * margin' (aligned with the tile grid).
     SkRect query = originalQuery;
     query.inset(fMarginWidth, fMarginHeight);
     this->commonAdjust(&query);
 
     // The inset may have inverted the rectangle, so sort().
     // TODO(mtklein): It looks like we only end up with inverted bounds in unit tests
     // that make explicitly inverted queries, not from insetting.  If we can drop support for
     // unsorted bounds (i.e. we don't see them outside unit tests), I think we can drop this.
     query.sort();
 
     // No intersection check.  We optimize for queries that are in bounds.
     // We're safe anyway: userToGrid() will clamp out-of-bounds queries to nearest tile.
     SkIRect grid;
     this->userToGrid(query, &grid);
 
-    const int tilesHit = (grid.fRight - grid.fLeft) * (grid.fBottom - grid.fTop);
+    const int tilesHit = (grid.fRight - grid.fLeft + 1) * (grid.fBottom - grid.fTop + 1);
     SkASSERT(tilesHit > 0);
 
     if (tilesHit == 1) {
         // A performance shortcut.  The merging code below would work fine here too.
         *results = fTiles[grid.fTop * fXTiles + grid.fLeft];
         return;
     }
 
     // We've got to merge the data in many tiles into a single sorted and deduplicated stream.
     // We do a simple k-way merge based on the value of opIndex.
 
     // Gather pointers to the starts and ends of the tiles to merge.
     SkAutoSTArray<kStackAllocationTileCount, const unsigned*> starts(tilesHit), ends(tilesHit);
     int i = 0;
-    for (int y = grid.fTop; y < grid.fBottom; y++) {
-        for (int x = grid.fLeft; x < grid.fRight; x++) {
+    for (int y = grid.fTop; y <= grid.fBottom; y++) {
+        for (int x = grid.fLeft; x <= grid.fRight; x++) {
             starts[i] = fTiles[y * fXTiles + x].begin();
             ends[i]   = fTiles[y * fXTiles + x].end();
             i++;
         }
     }
 
     // Merge tiles into results until they're fully consumed.
     results->reset();
     while (true) {
         // The tiles themselves are already ordered, so the earliest op is at the front of some
@@ skipping 13 matching lines @@
         // We did find an earliest op. Output it, and step forward every tile that contains it.
         results->push(earliest);
         for (int i = 0; i < starts.count(); i++) {
             if (starts[i] < ends[i] && *starts[i] == earliest) {
                 starts[i]++;
             }
         }
     }
 }