skia2/fuzz/FuzzCommon.cpp

/*
 * Copyright 2018 Google Inc.
 *
 * Use of this source code is governed by a BSD-style license that can be
 * found in the LICENSE file.
 */

#include "Fuzz.h"
#include "FuzzCommon.h"

// allows some float values for path points
void FuzzPath(Fuzz* fuzz, SkPath* path, int maxOps) {
    if (maxOps <= 0) {
        return;
    }
    uint8_t fillType;
    fuzz->nextRange(&fillType, 0, (uint8_t)SkPath::kInverseEvenOdd_FillType);
    path->setFillType((SkPath::FillType)fillType);
    uint8_t numOps;
    fuzz->nextRange(&numOps, 0, maxOps);
    for (uint8_t i = 0; i < numOps; ++i) {
        uint8_t op;
        fuzz->nextRange(&op, 0, 32);
        bool test;
        SkPath p;
        SkMatrix m;
        SkRRect rr;
        SkRect r;
        SkPath::Direction dir;
        unsigned int ui;
        SkScalar a, b, c, d, e, f;
        switch (op) {
            case 0:
                fuzz_nice_float(fuzz, &a, &b);
                path->moveTo(a, b);
                break;
            case 1:
                fuzz_nice_float(fuzz, &a, &b);
                path->rMoveTo(a, b);
                break;
            case 2:
                fuzz_nice_float(fuzz, &a, &b);
                path->lineTo(a, b);
                break;
            case 3:
                fuzz_nice_float(fuzz, &a, &b);
                path->rLineTo(a, b);
                break;
            case 4:
                fuzz_nice_float(fuzz, &a, &b, &c, &d);
                path->quadTo(a, b, c, d);
                break;
            case 5:
                fuzz_nice_float(fuzz, &a, &b, &c, &d);
                path->rQuadTo(a, b, c, d);
                break;
            case 6:
                fuzz_nice_float(fuzz, &a, &b, &c, &d, &e);
                path->conicTo(a, b, c, d, e);
                break;
            case 7:
                fuzz_nice_float(fuzz, &a, &b, &c, &d, &e);
                path->rConicTo(a, b, c, d, e);
                break;
            case 8:
                fuzz_nice_float(fuzz, &a, &b, &c, &d, &e, &f);
                path->cubicTo(a, b, c, d, e, f);
                break;
            case 9:
                fuzz_nice_float(fuzz, &a, &b, &c, &d, &e, &f);
                path->rCubicTo(a, b, c, d, e, f);
                break;
            case 10:
                fuzz_nice_float(fuzz, &a, &b, &c, &d, &e);
                path->arcTo(a, b, c, d, e);
                break;
            case 11:
                fuzz_nice_float(fuzz, &a, &b);
                fuzz->next(&r, &test);
                path->arcTo(r, a, b, test);
                break;
            case 12:
                path->close();
                break;
            case 13:
                fuzz->next(&r);
                fuzz->nextRange(&ui, 0, 1);
                dir = static_cast<SkPath::Direction>(ui);
                path->addRect(r, dir);
                break;
            case 14:
                fuzz->nextRange(&ui, 0, 1);
                dir = static_cast<SkPath::Direction>(ui);
                fuzz->next(&r, &ui);
                path->addRect(r, dir, ui);
                break;
            case 15:
                fuzz->nextRange(&ui, 0, 1);
                dir = static_cast<SkPath::Direction>(ui);
                fuzz->next(&r);
                path->addOval(r, dir);
                break;
            case 16:
                fuzz->nextRange(&ui, 0, 1);
                dir = static_cast<SkPath::Direction>(ui);
                fuzz->next(&r, &ui);
                path->addOval(r, dir, ui);
                break;
            case 17:
                fuzz->nextRange(&ui, 0, 1);
                dir = static_cast<SkPath::Direction>(ui);
                fuzz_nice_float(fuzz, &a, &b, &c);
                path->addCircle(a, b, c, dir);
                break;
            case 18:
                fuzz->next(&r);
                fuzz_nice_float(fuzz, &a, &b);
                path->addArc(r, a, b);
                break;
            case 19:
                fuzz_nice_float(fuzz, &a, &b);
                fuzz->next(&r);
                fuzz->nextRange(&ui, 0, 1);
                dir = static_cast<SkPath::Direction>(ui);
                path->addRoundRect(r, a, b, dir);
                break;
            case 20:
                fuzz->next(&rr);
                fuzz->nextRange(&ui, 0, 1);
                dir = static_cast<SkPath::Direction>(ui);
                path->addRRect(rr, dir);
                break;
            case 21:
                fuzz->nextRange(&ui, 0, 1);
                dir = static_cast<SkPath::Direction>(ui);
                fuzz->next(&rr, &ui);
                path->addRRect(rr, dir, ui);
                break;
            case 22: {
                fuzz->nextRange(&ui, 0, 1);
                SkPath::AddPathMode mode = static_cast<SkPath::AddPathMode>(ui);
                fuzz->next(&m);
                FuzzPath(fuzz, &p, maxOps-1);
                path->addPath(p, m, mode);
                break;
            }
            case 23: {
                fuzz->nextRange(&ui, 0, 1);
                SkPath::AddPathMode mode = static_cast<SkPath::AddPathMode>(ui);
                fuzz->next(&m);
                path->addPath(*path, m, mode);
                break;
            }
            case 24:
                FuzzPath(fuzz, &p, maxOps-1);
                path->reverseAddPath(p);
                break;
            case 25:
                path->addPath(*path);
                break;
            case 26:
                path->reverseAddPath(*path);
                break;
            case 27:
                fuzz_nice_float(fuzz, &a, &b);
                path->offset(a, b, path);
                break;
            case 28:
                FuzzPath(fuzz, &p, maxOps-1);
                fuzz_nice_float(fuzz, &a, &b);
                p.offset(a, b, path);
                break;
            case 29:
                fuzz->next(&m);
                path->transform(m, path);
                break;
            case 30:
                FuzzPath(fuzz, &p, maxOps-1);
                fuzz->next(&m);
                p.transform(m, path);
                break;
            case 31:
                fuzz_nice_float(fuzz, &a, &b);
                path->setLastPt(a, b);
                break;
            case 32:
                path->shrinkToFit();
                break;

            default:
                SkASSERT(false);
                break;
        }
    }
}

// allows all float values for path points
void BuildPath(Fuzz* fuzz, SkPath* path, int last_verb) {
  while (!fuzz->exhausted()) {
    // Use a uint8_t to conserve bytes.  This makes our "fuzzed bytes footprint"
    // smaller, which leads to more efficient fuzzing.
    uint8_t operation;
    fuzz->next(&operation);
    SkScalar a,b,c,d,e,f;

    switch (operation % (last_verb + 1)) {
      case SkPath::Verb::kMove_Verb:
        fuzz->next(&a, &b);
        path->moveTo(a, b);
        break;

      case SkPath::Verb::kLine_Verb:
        fuzz->next(&a, &b);
        path->lineTo(a, b);
        break;

      case SkPath::Verb::kQuad_Verb:
        fuzz->next(&a, &b, &c, &d);
        path->quadTo(a, b, c, d);
        break;

      case SkPath::Verb::kConic_Verb:
        fuzz->next(&a, &b, &c, &d, &e);
        path->conicTo(a, b, c, d, e);
        break;

      case SkPath::Verb::kCubic_Verb:
        fuzz->next(&a, &b, &c, &d, &e, &f);
        path->cubicTo(a, b, c, d, e, f);
        break;

      case SkPath::Verb::kClose_Verb:
        path->close();
        break;

      case SkPath::Verb::kDone_Verb:
        // In this case, simply exit.
        return;
    }
  }
}