Use device-space stroke width for SkDraw::drawRect() quick-reject

src/core/SkDraw.cpp

 /*
  * Copyright 2006 The Android Open Source Project
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include "SkDraw.h"
 #include "SkBlitter.h"
 #include "SkCanvas.h"
@@ skipping 717 matching lines @@
                         this->drawPath(path, p, NULL, true);
                     }
                     path.rewind();
                 }
                 break;
             }
         }
     }
 }
 
+static inline SkPoint compute_stroke_size(const SkPaint& paint, const SkMatrix& matrix) {
+    SkASSERT(matrix.rectStaysRect());
+    SkASSERT(SkPaint::kFill_Style != paint.getStyle());
+
+    SkVector size;
+    SkPoint pt = { paint.getStrokeWidth(), paint.getStrokeWidth() };
+    matrix.mapVectors(&size, &pt, 1);
+    return SkPoint::Make(SkScalarAbs(size.fX), SkScalarAbs(size.fY));
+}
+
 static bool easy_rect_join(const SkPaint& paint, const SkMatrix& matrix,
                            SkPoint* strokeSize) {
     if (SkPaint::kMiter_Join != paint.getStrokeJoin() ||
         paint.getStrokeMiter() < SK_ScalarSqrt2) {
         return false;
     }
 
-    SkASSERT(matrix.rectStaysRect());
-    SkPoint pt = { paint.getStrokeWidth(), paint.getStrokeWidth() };
-    matrix.mapVectors(strokeSize, &pt, 1);
-    strokeSize->fX = SkScalarAbs(strokeSize->fX);
-    strokeSize->fY = SkScalarAbs(strokeSize->fY);
+    *strokeSize = compute_stroke_size(paint, matrix);
     return true;
 }
 
 SkDraw::RectType SkDraw::ComputeRectType(const SkPaint& paint,
                                          const SkMatrix& matrix,
                                          SkPoint* strokeSize) {
     RectType rtype;
     const SkScalar width = paint.getStrokeWidth();
     const bool zeroWidth = (0 == width);
     SkPaint::Style style = paint.getStyle();
@@ skipping 55 matching lines @@
             draw.fMatrix = matrix;
         }
         SkPath  tmp;
         tmp.addRect(prePaintRect);
         tmp.setFillType(SkPath::kWinding_FillType);
         draw.drawPath(tmp, paint, NULL, true);
         return;
     }
 
     SkRect devRect;
-    if (paintMatrix) {
-        // skip the paintMatrix when transforming the rect by the CTM
-        fMatrix->mapPoints(rect_points(devRect), rect_points(*postPaintRect), 2);
-    } else {
-        fMatrix->mapPoints(rect_points(devRect), rect_points(prePaintRect), 2);
-    }
-    // transform rect into devRect
+    const SkRect& paintRect = paintMatrix ? *postPaintRect : prePaintRect;
+    // skip the paintMatrix when transforming the rect by the CTM
+    fMatrix->mapPoints(rect_points(devRect), rect_points(paintRect), 2);
     devRect.sort();
 
     // look for the quick exit, before we build a blitter
-    SkIRect ir = devRect.roundOut();
+    SkRect bbox = devRect;
     if (paint.getStyle() != SkPaint::kFill_Style) {
         // extra space for hairlines
         if (paint.getStrokeWidth() == 0) {
-            ir.outset(1, 1);
+            bbox.outset(1, 1);
         } else {
-            SkScalar radius = SkScalarHalf(paint.getStrokeWidth());
-            ir.outset(radius, radius);
+            // For kStroke_RectType, strokeSize is already computed.
+            const SkPoint& ssize = (kStroke_RectType == rtype)
+                ? strokeSize
+                : compute_stroke_size(paint, *fMatrix);
+            bbox.outset(SkScalarHalf(ssize.x()), SkScalarHalf(ssize.y()));
         }
     }
+
+    SkIRect ir = bbox.roundOut();
     if (fRC->quickReject(ir)) {
         return;
     }
 
     SkDeviceLooper looper(*fBitmap, *fRC, ir, paint.isAntiAlias());
     while (looper.next()) {
         SkRect localDevRect;
         looper.mapRect(&localDevRect, devRect);
         SkMatrix localMatrix;
         looper.mapMatrix(&localMatrix, *matrix);
@@ skipping 1536 matching lines @@
         mask->fImage = SkMask::AllocImage(size);
         memset(mask->fImage, 0, mask->computeImageSize());
     }
 
     if (SkMask::kJustComputeBounds_CreateMode != mode) {
         draw_into_mask(*mask, devPath, style);
     }
 
     return true;
 }