handle large conic weights

tests/GeometryTest.cpp

 /*
  * Copyright 2011 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include "SkGeometry.h"
 #include "Test.h"
 #include "SkRandom.h"
@@ skipping 127 matching lines @@
         SkVector mid = conic.evalTangentAt(.5f);
         SkVector end = conic.evalTangentAt(1);
         REPORTER_ASSERT(reporter, start.fX && start.fY);
         REPORTER_ASSERT(reporter, mid.fX && mid.fY);
         REPORTER_ASSERT(reporter, end.fX && end.fY);
         REPORTER_ASSERT(reporter, SkScalarNearlyZero(start.cross(mid)));
         REPORTER_ASSERT(reporter, SkScalarNearlyZero(mid.cross(end)));
     }
 }
 
+static void test_this_conic_to_quad(skiatest::Reporter* r, const SkPoint pts[3], SkScalar w) {
+    SkAutoConicToQuads quadder;
+    const SkPoint* qpts = quadder.computeQuads(pts, w, 0.25);
+    const int qcount = quadder.countQuads();
+    const int pcount = qcount * 2 + 1;
+
+    REPORTER_ASSERT(r, SkPointsAreFinite(qpts, pcount));
+}
+
+/**
+ *  We need to ensure that when a conic is approximated by quads, that we always return finite
+ *  values in the quads.
+ *
+ *  Inspired by crbug_627414
+ */
+static void test_conic_to_quads(skiatest::Reporter* reporter) {
+    const SkPoint triples[] = {
+        { 0, 0 }, { 1, 0 }, { 1, 1 },
+        { 3.58732e-43f, 2.72084f }, { 3.00392f, 3.00392f },
+        { 0, 0 }, { 100000, 0 }, { 100000, 100000 },
+        { 0, 0 }, { 1e30f, 0 }, { 1e30f, 1e30f },
+    };
+    const int N = sizeof(triples) / sizeof(SkPoint);
+
+    for (int i = 0; i < N; i += 3) {
+        const SkPoint* pts = &triples[i];
+
+        SkRect bounds;
+        bounds.set(pts, 3);
+
+        SkScalar w = 1e30f;
+        do {
+            w *= 2;
+            test_this_conic_to_quad(reporter, pts, w);
+        } while (SkScalarIsFinite(w));
+        test_this_conic_to_quad(reporter, pts, SK_ScalarNaN);
+    }
+}
+
 static void test_cubic_tangents(skiatest::Reporter* reporter) {
     SkPoint pts[] = {
         { 10, 20}, {10, 20}, {20, 30}, {30, 40},
         { 10, 20}, {15, 25}, {20, 30}, {30, 40},
         { 10, 20}, {20, 30}, {30, 40}, {30, 40},
     };
     int count = (int) SK_ARRAY_COUNT(pts) / 4;
     for (int index = 0; index < count; ++index) {
         SkConic conic(&pts[index * 3], 0.707f);
         SkVector start, mid, end;
@@ skipping 28 matching lines @@
     for (int i = 0; i < 4; ++i) {
         REPORTER_ASSERT(reporter, nearly_equal(cubic[i], dst[i]));
     }
 
     testChopCubic(reporter);
     test_evalquadat(reporter);
     test_conic(reporter);
     test_cubic_tangents(reporter);
     test_quad_tangents(reporter);
     test_conic_tangents(reporter);
+    test_conic_to_quads(reporter);
 }