Fix to check for inf when generating quadratic points

BUG=skia:3453

Review URL: https://codereview.chromium.org/948043003

3 files changed, 49 insertions, 18 deletions

diff --git a/gm/conicpaths.cpp b/gm/conicpaths.cpp
index a5d5ee6d24..661f19fba9 100644
--- a/gm/conicpaths.cpp
+++ b/gm/conicpaths.cpp
@@ -72,6 +72,20 @@ protected:
             closedEllipse->moveTo(0,  0);
             closedEllipse->conicTo(100, 100, 0, 0, SK_ScalarHalf);
         }
+        {
+            const SkScalar w = SkScalarSqrt(2)/2;
+            fGiantCircle.moveTo(2.1e+11f, -1.05e+11f);
+            fGiantCircle.conicTo(2.1e+11f, 0, 1.05e+11f, 0, w);
+            fGiantCircle.conicTo(0, 0, 0, -1.05e+11f, w);
+            fGiantCircle.conicTo(0, -2.1e+11f, 1.05e+11f, -2.1e+11f, w);
+            fGiantCircle.conicTo(2.1e+11f, -2.1e+11f, 2.1e+11f, -1.05e+11f, w);
+
+        }
+    }
+
+    void drawGiantCircle(SkCanvas* canvas) {
+        SkPaint paint;
+        canvas->drawPath(fGiantCircle, paint);
     }
 
     void onDraw(SkCanvas* canvas) SK_OVERRIDE {
@@ -104,10 +118,13 @@ protected:
             canvas->translate(0, 110);
         }
         canvas->restore();
+
+        this->drawGiantCircle(canvas);  
     }
 
 private:
     SkTArray<SkPath> fPaths;
+    SkPath           fGiantCircle;
     typedef skiagm::GM INHERITED;
 };
 DEF_GM( return SkNEW(ConicPathsGM); )
diff --git a/src/core/SkPoint.cpp b/src/core/SkPoint.cpp
index 20bc33666e..aabde2786d 100644
--- a/src/core/SkPoint.cpp
+++ b/src/core/SkPoint.cpp
@@ -223,7 +223,9 @@ SkScalar SkPoint::distanceToLineBetweenSqd(const SkPoint& a,
                   1 == kRight_Side);
         *side = (Side) SkScalarSignAsInt(det);
     }
-    return SkScalarMulDiv(det, det, uLengthSqd);
+    SkScalar temp = det / uLengthSqd;
+    temp *= det;
+    return temp;
 }
 
 SkScalar SkPoint::distanceToLineSegmentBetweenSqd(const SkPoint& a,
@@ -256,6 +258,8 @@ SkScalar SkPoint::distanceToLineSegmentBetweenSqd(const SkPoint& a,
         return b.distanceToSqd(*this);
     } else {
         SkScalar det = u.cross(v);
-        return SkScalarMulDiv(det, det, uLengthSqd);
+        SkScalar temp = det / uLengthSqd;
+        temp *= det;
+        return temp;
     }
 }
diff --git a/src/gpu/GrPathUtils.cpp b/src/gpu/GrPathUtils.cpp
index 8e7a01d091..2a906664f2 100644
--- a/src/gpu/GrPathUtils.cpp
+++ b/src/gpu/GrPathUtils.cpp
@@ -51,15 +51,20 @@ uint32_t GrPathUtils::quadraticPointCount(const SkPoint points[],
         // subdivide x = log4(d/tol) times. x subdivisions creates 2^(x)
         // points.
         // 2^(log4(x)) = sqrt(x);
-        int temp = SkScalarCeilToInt(SkScalarSqrt(SkScalarDiv(d, tol)));
-        int pow2 = GrNextPow2(temp);
-        // Because of NaNs & INFs we can wind up with a degenerate temp
-        // such that pow2 comes out negative. Also, our point generator
-        // will always output at least one pt.
-        if (pow2 < 1) {
-            pow2 = 1;
+        SkScalar divSqrt = SkScalarSqrt(SkScalarDiv(d, tol));
+        if (((SkScalar)SK_MaxS32) <= divSqrt) {
+            return MAX_POINTS_PER_CURVE;
+        } else {
+            int temp = SkScalarCeilToInt(divSqrt);
+            int pow2 = GrNextPow2(temp);
+            // Because of NaNs & INFs we can wind up with a degenerate temp
+            // such that pow2 comes out negative. Also, our point generator
+            // will always output at least one pt.
+            if (pow2 < 1) {
+                pow2 = 1;
+            }
+            return SkTMin(pow2, MAX_POINTS_PER_CURVE);
         }
-        return SkTMin(pow2, MAX_POINTS_PER_CURVE);
     }
 }
 
@@ -102,15 +107,20 @@ uint32_t GrPathUtils::cubicPointCount(const SkPoint points[],
     if (d <= tol) {
         return 1;
     } else {
-        int temp = SkScalarCeilToInt(SkScalarSqrt(SkScalarDiv(d, tol)));
-        int pow2 = GrNextPow2(temp);
-        // Because of NaNs & INFs we can wind up with a degenerate temp
-        // such that pow2 comes out negative. Also, our point generator
-        // will always output at least one pt.
-        if (pow2 < 1) {
-            pow2 = 1;
+        SkScalar divSqrt = SkScalarSqrt(SkScalarDiv(d, tol));
+        if (((SkScalar)SK_MaxS32) <= divSqrt) {
+            return MAX_POINTS_PER_CURVE;
+        } else {
+            int temp = SkScalarCeilToInt(SkScalarSqrt(SkScalarDiv(d, tol)));
+            int pow2 = GrNextPow2(temp);
+            // Because of NaNs & INFs we can wind up with a degenerate temp
+            // such that pow2 comes out negative. Also, our point generator
+            // will always output at least one pt.
+            if (pow2 < 1) {
+                pow2 = 1;
+            }
+            return SkTMin(pow2, MAX_POINTS_PER_CURVE);
         }
-        return SkTMin(pow2, MAX_POINTS_PER_CURVE);
     }
 }