commit c20d6706cc0220956c43a020a1a71c4e73a468e0
author mtklein <mtklein@chromium.org> Tue Jun 21 12:03:37 2016 -0700
committer Commit bot <commit-bot@chromium.org> Tue Jun 21 12:03:37 2016 -0700
tree e9af6669411e11164888e4bb44d20788277ea98a
parent d733ddceef018d5ec7d715b059cee05b5b3aa304

Cherry-pick 875e13ca0 to M52.

TBR=

Original description:
    Simplify mask/clip intersection, making sure to explicitly check for an empty mask.

    Previously we were only asserting the mask wasn't empty, which isn't necessarily true when we're given pathological float coordinates like +Inf or NaN.

    A local run of nanobench --match text_ was not able to show this is faster or slower.

    This patch fixed this first Chrome bug on my desktop, and the second is probably a dupe.
    BUG=chromium:619378,chromium:613912

    GOLD_TRYBOT_URL= https://gold.skia.org/search?issue=2073873002

    Review-Url: https://codereview.chromium.org/2073873002
GOLD_TRYBOT_URL= https://gold.skia.org/search2?unt=true&query=source_type%3Dgm&master=false&issue=2085023002
NOTREECHECKS=true
NOTRY=true
NOPRESUBMIT=true

Review-Url: https://codereview.chromium.org/2085023002

src/core/SkDraw.cpp

diff --git a/src/core/SkDraw.cpp b/src/core/SkDraw.cpp
index 8847942..213c42c 100644
--- a/src/core/SkDraw.cpp
+++ b/src/core/SkDraw.cpp
@@ -1460,10 +1460,13 @@
     void operator()(const SkGlyph& glyph, SkPoint position, SkPoint rounding) {
         position += rounding;
         // Prevent glyphs from being drawn outside of or straddling the edge of device space.
-        if (position.fX > INT_MAX - (INT16_MAX + UINT16_MAX) ||
-            position.fX < INT_MIN - (INT16_MIN + 0 /*UINT16_MIN*/) ||
-            position.fY > INT_MAX - (INT16_MAX + UINT16_MAX) ||
-            position.fY < INT_MIN - (INT16_MIN + 0 /*UINT16_MIN*/)) {
+        // Comparisons written a little weirdly so that NaN coordinates are treated safely.
+        auto gt = [](float a, int b) { return !(a <= (float)b); };
+        auto lt = [](float a, int b) { return !(a >= (float)b); };
+        if (gt(position.fX, INT_MAX - (INT16_MAX + UINT16_MAX)) ||
+            lt(position.fX, INT_MIN - (INT16_MIN + 0 /*UINT16_MIN*/)) ||
+            gt(position.fY, INT_MAX - (INT16_MAX + UINT16_MAX)) ||
+            lt(position.fY, INT_MIN - (INT16_MIN + 0 /*UINT16_MIN*/))) {
             return;
         }
 
@@ -1479,6 +1482,7 @@
 
         SkMask mask;
         mask.fBounds.set(left, top, right, bottom);
+        SkASSERT(!mask.fBounds.isEmpty());
 
         if (fUseRegionToDraw) {
             SkRegion::Cliperator clipper(*fClip, mask.fBounds);

tests/DrawTextTest.cpp

diff --git a/tests/DrawTextTest.cpp b/tests/DrawTextTest.cpp
index f2da450..bf9bd39 100644
--- a/tests/DrawTextTest.cpp
+++ b/tests/DrawTextTest.cpp
@@ -11,8 +11,10 @@
 #include "SkPaint.h"
 #include "SkPoint.h"
 #include "SkRect.h"
+#include "SkSurface.h"
 #include "SkTypes.h"
 #include "Test.h"
+#include <math.h>
 
 static const SkColor bgColor = SK_ColorWHITE;
 
@@ -111,3 +113,21 @@
         }
     }
 }
+
+// Test drawing text at some unusual coordinates.
+// We measure success by not crashing or asserting.
+DEF_TEST(DrawText_weirdCoordinates, r) {
+    auto surface = SkSurface::MakeRasterN32Premul(10,10);
+    auto canvas = surface->getCanvas();
+
+    SkScalar oddballs[] = { 0.0f, (float)INFINITY, (float)NAN, 34359738368.0f };
+
+    for (auto x : oddballs) {
+        canvas->drawText("a", 1, +x, 0.0f, SkPaint());
+        canvas->drawText("a", 1, -x, 0.0f, SkPaint());
+    }
+    for (auto y : oddballs) {
+        canvas->drawText("a", 1, 0.0f, +y, SkPaint());
+        canvas->drawText("a", 1, 0.0f, -y, SkPaint());
+    }
+}