cleanup and optimize rect intersect routines

src/core/SkRect.cpp

Index: src/core/SkRect.cpp
diff --git a/src/core/SkRect.cpp b/src/core/SkRect.cpp
index 12f76526a5d0fc0dc52e00430869156befc6f2bd..7340098d2fb479df095a32c83354a20f02909648 100644
--- a/src/core/SkRect.cpp
+++ b/src/core/SkRect.cpp
@@ -99,51 +99,27 @@ bool SkRect::setBoundsCheck(const SkPoint pts[], int count) {
     return isFinite;
 }
 
-bool SkRect::intersect(SkScalar left, SkScalar top, SkScalar right,
-                       SkScalar bottom) {
-    if (left < right && top < bottom && !this->isEmpty() && // check for empties
-        fLeft < right && left < fRight && fTop < bottom && top < fBottom)
-    {
-        if (fLeft < left) fLeft = left;
-        if (fTop < top) fTop = top;
-        if (fRight > right) fRight = right;
-        if (fBottom > bottom) fBottom = bottom;
-        return true;
-    }
-    return false;
+#define CHECK_INTERSECT(al, at, ar, ab, bl, bt, br, bb) \
+    SkScalar L = SkMaxScalar(al, bl);                   \
+    SkScalar R = SkMinScalar(ar, br);                   \
+    SkScalar T = SkMaxScalar(at, bt);                   \
+    SkScalar B = SkMinScalar(ab, bb);                   \
+    do { if (L >= R || T >= B) return false; } while (0)
+
+bool SkRect::intersect(SkScalar left, SkScalar top, SkScalar right, SkScalar bottom) {
+    CHECK_INTERSECT(left, top, right, bottom, fLeft, fTop, fRight, fBottom);

[caryclark, 2014/10/09 20:19:47]

Is this the same as

     if (!Intersects(left, top, right, bottom, fLeft, fTop, fRight, fBottom)) {
         return false;
     }

+    this->setLTRB(L, T, R, B);
+    return true;
 }
 
 bool SkRect::intersect(const SkRect& r) {
     return this->intersect(r.fLeft, r.fTop, r.fRight, r.fBottom);
 }
 
-bool SkRect::intersect2(const SkRect& r) {
-    SkScalar L = SkMaxScalar(fLeft, r.fLeft);
-    SkScalar R = SkMinScalar(fRight, r.fRight);
-    if (L >= R) {
-        return false;
-    }
-    SkScalar T = SkMaxScalar(fTop, r.fTop);
-    SkScalar B = SkMinScalar(fBottom, r.fBottom);
-    if (T >= B) {
-        return false;
-    }
-    this->set(L, T, R, B);
-    return true;
-}
-
 bool SkRect::intersect(const SkRect& a, const SkRect& b) {
-
-    if (!a.isEmpty() && !b.isEmpty() &&
-        a.fLeft < b.fRight && b.fLeft < a.fRight &&
-        a.fTop < b.fBottom && b.fTop < a.fBottom) {
-        fLeft   = SkMaxScalar(a.fLeft,   b.fLeft);
-        fTop    = SkMaxScalar(a.fTop,    b.fTop);
-        fRight  = SkMinScalar(a.fRight,  b.fRight);
-        fBottom = SkMinScalar(a.fBottom, b.fBottom);
-        return true;
-    }
-    return false;
+    CHECK_INTERSECT(a.fLeft, a.fTop, a.fRight, a.fBottom, b.fLeft, b.fTop, b.fRight, b.fBottom);
+    this->setLTRB(L, T, R, B);
+    return true;
 }
 
 void SkRect::join(SkScalar left, SkScalar top, SkScalar right, SkScalar bottom) {
@@ -162,3 +138,4 @@ void SkRect::join(SkScalar left, SkScalar top, SkScalar right, SkScalar bottom)
         fBottom = SkMaxScalar(fBottom, bottom);
     }
 }
+