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>

9 files changed, 21 insertions, 17 deletions

diff --git a/experimental/sksg/SkSGNode.cpp b/experimental/sksg/SkSGNode.cpp
index b634175b21..74867ef819 100644
--- a/experimental/sksg/SkSGNode.cpp
+++ b/experimental/sksg/SkSGNode.cpp
@@ -40,7 +40,7 @@ private:
 
 Node::Node(uint32_t invalTraits)
     : fInvalReceiver(nullptr)
-    , fBounds(SkRectPriv::MakeLargestS32())
+    , fBounds(SkRectPriv::MakeLargeS32())
     , fInvalTraits(invalTraits)
     , fFlags(kInvalidated_Flag) {}
 
diff --git a/src/core/SkDraw.cpp b/src/core/SkDraw.cpp
index a0f08e5916..77af440caf 100644
--- a/src/core/SkDraw.cpp
+++ b/src/core/SkDraw.cpp
@@ -782,7 +782,7 @@ void SkDraw::drawRect(const SkRect& prePaintRect, const SkPaint& paint,
         }
     }
 
-    if (!SkRectPriv::MakeLargestS32().contains(bbox)) {
+    if (!SkRectPriv::MakeLargeS32().contains(bbox)) {
         // bbox.roundOut() is undefined; use slow path.
         draw_rect_as_path(*this, prePaintRect, paint, matrix);
         return;
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;
     }
 
diff --git a/src/core/SkScan_Path.cpp b/src/core/SkScan_Path.cpp
index 21e2ecbf55..f2a18b631e 100644
--- a/src/core/SkScan_Path.cpp
+++ b/src/core/SkScan_Path.cpp
@@ -644,8 +644,8 @@ void SkScan::FillPath(const SkPath& path, const SkRegion& origClip,
 
     SkRect bounds = path.getBounds();
     bool irPreClipped = false;
-    if (!SkRectPriv::MakeLargestS32().contains(bounds)) {
-        if (!bounds.intersect(SkRectPriv::MakeLargestS32())) {
+    if (!SkRectPriv::MakeLargeS32().contains(bounds)) {
+        if (!bounds.intersect(SkRectPriv::MakeLargeS32())) {
             bounds.setEmpty();
         }
         irPreClipped = true;
diff --git a/src/core/SkThreadedBMPDevice.cpp b/src/core/SkThreadedBMPDevice.cpp
index bdb5f95c7a..a61e9b29d8 100644
--- a/src/core/SkThreadedBMPDevice.cpp
+++ b/src/core/SkThreadedBMPDevice.cpp
@@ -74,7 +74,7 @@ SkThreadedBMPDevice::DrawState::DrawState(SkThreadedBMPDevice* dev) {
 
 SkIRect SkThreadedBMPDevice::transformDrawBounds(const SkRect& drawBounds) const {
     if (drawBounds == SkRectPriv::MakeLargest()) {
-        return SkRectPriv::MakeILargest();
+        return SkRectPriv::MakeILarge();
     }
     SkRect transformedBounds;
     this->ctm().mapRect(&transformedBounds, drawBounds);
diff --git a/tests/RectTest.cpp b/tests/RectTest.cpp
index 39ba073725..6a588b7b6c 100644
--- a/tests/RectTest.cpp
+++ b/tests/RectTest.cpp
@@ -96,11 +96,11 @@ DEF_TEST(Rect_grow, reporter) {
 }
 
 DEF_TEST(Rect_largest, reporter) {
-    REPORTER_ASSERT(reporter, !SkRectPriv::MakeILargest().isEmpty());
+    REPORTER_ASSERT(reporter, !SkRectPriv::MakeILarge().isEmpty());
     REPORTER_ASSERT(reporter,  SkRectPriv::MakeILargestInverted().isEmpty());
 
     REPORTER_ASSERT(reporter, !SkRectPriv::MakeLargest().isEmpty());
-    REPORTER_ASSERT(reporter, !SkRectPriv::MakeLargestS32().isEmpty());
+    REPORTER_ASSERT(reporter, !SkRectPriv::MakeLargeS32().isEmpty());
     REPORTER_ASSERT(reporter,  SkRectPriv::MakeLargestInverted().isEmpty());
 }
 
diff --git a/tests/SGTest.cpp b/tests/SGTest.cpp
index b0101bc034..1228e666e7 100644
--- a/tests/SGTest.cpp
+++ b/tests/SGTest.cpp
@@ -68,7 +68,7 @@ static void inval_test1(skiatest::Reporter* reporter) {
         // Initial revalidation.
         check_inval(reporter, root,
                     SkRect::MakeWH(100, 100),
-                    SkRectPriv::MakeLargestS32(),
+                    SkRectPriv::MakeLargeS32(),
                     nullptr);
     }
 
@@ -138,7 +138,7 @@ static void inval_test2(skiatest::Reporter* reporter) {
         // Initial revalidation.
         check_inval(reporter, root,
                     SkRect::MakeWH(100, 100),
-                    SkRectPriv::MakeLargestS32(),
+                    SkRectPriv::MakeLargeS32(),
                     nullptr);
     }
 
diff --git a/tests/WindowRectanglesTest.cpp b/tests/WindowRectanglesTest.cpp
index 84fdca2237..d6c4756168 100644
--- a/tests/WindowRectanglesTest.cpp
+++ b/tests/WindowRectanglesTest.cpp
@@ -48,7 +48,7 @@ DEF_TEST(WindowRectangles, reporter) {
         REPORTER_ASSERT(reporter, B.data() != A.data());
         REPORTER_ASSERT(reporter, B != A);
 
-        B.addWindow(SkRectPriv::MakeILargest());
+        B.addWindow(SkRectPriv::MakeILarge());
         REPORTER_ASSERT(reporter, B != A);
 
         REPORTER_ASSERT(reporter, !memcmp(A.data(), windowData,
@@ -56,7 +56,7 @@ DEF_TEST(WindowRectangles, reporter) {
         REPORTER_ASSERT(reporter, !memcmp(B.data(), windowData,
                                           (GrWindowRectangles::kMaxWindows - 1) * sizeof(SkIRect)));
         REPORTER_ASSERT(reporter,
-                        B.data()[GrWindowRectangles::kMaxWindows - 1] == SkRectPriv::MakeILargest());
+                        B.data()[GrWindowRectangles::kMaxWindows - 1] == SkRectPriv::MakeILarge());
     }
     {
         GrWindowRectangles A(wr), B(wr);
diff --git a/tools/debugger/SkDebugCanvas.cpp b/tools/debugger/SkDebugCanvas.cpp
index 0b46439d33..0bfd85f7f9 100644
--- a/tools/debugger/SkDebugCanvas.cpp
+++ b/tools/debugger/SkDebugCanvas.cpp
@@ -88,7 +88,7 @@ SkDebugCanvas::SkDebugCanvas(int width, int height)
     // rounded out. The following code creates a nearly maximal rect that will
     // not get collapsed by the coming conversions (Due to precision loss the
     // inset has to be surprisingly large).
-    SkIRect largeIRect = SkRectPriv::MakeILargest();
+    SkIRect largeIRect = SkRectPriv::MakeILarge();
     largeIRect.inset(1024, 1024);
     SkRect large = SkRect::Make(largeIRect);
 #ifdef SK_DEBUG