handle large rects, rename helper

To fix gm/bigrect, needed to do adjust "largest" rect so it doesn't become empty when round-tripping with SkRect/SkIRect.
I renamed it after this.

Bug: skia:
Change-Id: I747782c8456da603cf298275d2300ea1996e7629
Reviewed-on: https://skia-review.googlesource.com/95563
Commit-Queue: Mike Reed <reed@google.com>
Reviewed-by: Yuqian Li <liyuqian@google.com>

1 files changed, 9 insertions, 5 deletions

diff --git a/src/core/SkRectPriv.h b/src/core/SkRectPriv.h
index a8f40db005..16c9535cc8 100644
--- a/src/core/SkRectPriv.h
+++ b/src/core/SkRectPriv.h
@@ -12,18 +12,22 @@
 
 class SkRectPriv {
 public:
-    static SkIRect MakeILargest() {
-        const int32_t ihalf = SK_MaxS32 >> 1;
-        return { -ihalf, -ihalf, ihalf, ihalf };
+    // Returns an irect that is very large, and can be safely round-trip with SkRect and still
+    // be considered non-empty (i.e. width/height > 0) even if we round-out the SkRect.
+    static SkIRect MakeILarge() {
+        // SK_MaxS32 >> 1 seemed better, but it did not survive round-trip with SkRect and rounding.
+        // Also, 1 << 29 can be perfectly represented in float, while SK_MaxS32 >> 1 cannot.
+        const int32_t large = 1 << 29;
+        return { -large, -large, large, large };
     }
 
     static SkIRect MakeILargestInverted() {
         return { SK_MaxS32, SK_MaxS32, SK_MinS32, SK_MinS32 };
     }
 
-    static SkRect MakeLargestS32() {
+    static SkRect MakeLargeS32() {
         SkRect r;
-        r.set(MakeILargest());
+        r.set(MakeILarge());
         return r;
     }