1 /*
2 * Copyright 2023 Google LLC
3 *
4 * Use of this source code is governed by a BSD-style license that can be
5 * found in the LICENSE file.
6 */
7
8 #include "fuzz/Fuzz.h"
9 #include "include/private/base/SkAssert.h"
10 #include "include/private/base/SkFloatingPoint.h"
11 #include "src/base/SkCubics.h"
12 #include "src/base/SkQuads.h"
13 #include "src/base/SkUtils.h"
14
15 #include <cmath>
16
fuzz_quad_real_roots(double A,double B,double C)17 static void fuzz_quad_real_roots(double A, double B, double C) {
18 double roots[2];
19 const int numSolutions = SkQuads::RootsReal(A, B, C, roots);
20 SkASSERT_RELEASE(numSolutions >= 0 && numSolutions <= 2);
21 for (int i = 0; i < numSolutions; i++) {
22 SkASSERT_RELEASE(std::isfinite(roots[i]));
23 // You may be tempted to add assertions that plug the provided solutions into
24 // the quadratic equation and verify that the result is zero. Be advised
25 // that the fuzzer is very good at finding float values that result in
26 // seemingly arbitrarily large errors, due to the imprecision of floating
27 // point math. Unless the input range is sufficiently small, such an
28 // effort seems fruitless.
29 }
30 if (numSolutions == 2) {
31 // Roots should not be duplicated
32 SkASSERT_RELEASE(!sk_doubles_nearly_equal_ulps(roots[0], roots[1]));
33 }
34 }
35
DEF_FUZZ(QuadRoots,fuzz)36 DEF_FUZZ(QuadRoots, fuzz) {
37 double A, B, C;
38 fuzz->next(&A);
39 fuzz->next(&B);
40 fuzz->next(&C);
41
42 // Uncomment for easy test case creation
43 // SkDebugf("A %16e (0x%lx) B %16e (0x%lx) C %16e (0x%lx)\n",
44 // A, sk_bit_cast<uint64_t>(A), B, sk_bit_cast<uint64_t>(B),
45 // C, sk_bit_cast<uint64_t>(C));
46
47 fuzz_quad_real_roots(A, B, C);
48 }
49