Remove confusing behavior of Rect::intersect() and rename

bug:24670525

Removes silly 'do nothing if rects do not intersect' behavior, and
changes the name to clarify the difference (contrasting against
SkRect::intersect())

bug:24670525

Change-Id: Id2ca1cfea1a9d720d4dc70b251f426d9916f8b53

1 files changed, 18 insertions, 29 deletions

diff --git a/libs/hwui/Rect.h b/libs/hwui/Rect.h
index 4c4cd3da3be4..50199db75640 100644
--- a/libs/hwui/Rect.h
+++ b/libs/hwui/Rect.h
@@ -125,25 +125,32 @@ public:
     }
 
     bool intersects(float l, float t, float r, float b) const {
-        return !intersectWith(l, t, r, b).isEmpty();
+        float tempLeft = std::max(left, l);
+        float tempTop = std::max(top, t);
+        float tempRight = std::min(right, r);
+        float tempBottom = std::min(bottom, b);
+
+        return ((tempLeft < tempRight) && (tempTop < tempBottom)); // !isEmpty
     }
 
     bool intersects(const Rect& r) const {
         return intersects(r.left, r.top, r.right, r.bottom);
     }
 
-    bool intersect(float l, float t, float r, float b) {
-        Rect tmp(l, t, r, b);
-        intersectWith(tmp);
-        if (!tmp.isEmpty()) {
-            set(tmp);
-            return true;
-        }
-        return false;
+    /**
+     * This method is named 'doIntersect' instead of 'intersect' so as not to be confused with
+     * SkRect::intersect / android.graphics.Rect#intersect behavior, which do not modify the object
+     * if the intersection of the rects would be empty.
+     */
+    void doIntersect(float l, float t, float r, float b) {
+        left = std::max(left, l);
+        top = std::max(top, t);
+        right = std::min(right, r);
+        bottom = std::min(bottom, b);
     }
 
-    bool intersect(const Rect& r) {
-        return intersect(r.left, r.top, r.right, r.bottom);
+    void doIntersect(const Rect& r) {
+        doIntersect(r.left, r.top, r.right, r.bottom);
     }
 
     inline bool contains(float l, float t, float r, float b) const {
@@ -271,24 +278,6 @@ public:
     void dump(const char* label = nullptr) const {
         ALOGD("%s[l=%f t=%f r=%f b=%f]", label ? label : "Rect", left, top, right, bottom);
     }
-
-private:
-    void intersectWith(Rect& tmp) const {
-        tmp.left = std::max(left, tmp.left);
-        tmp.top = std::max(top, tmp.top);
-        tmp.right = std::min(right, tmp.right);
-        tmp.bottom = std::min(bottom, tmp.bottom);
-    }
-
-    Rect intersectWith(float l, float t, float r, float b) const {
-        Rect tmp;
-        tmp.left = std::max(left, l);
-        tmp.top = std::max(top, t);
-        tmp.right = std::min(right, r);
-        tmp.bottom = std::min(bottom, b);
-        return tmp;
-    }
-
 }; // class Rect
 
 }; // namespace uirenderer