PathOpsExtendedTest.cpp revision 406654be7a930b484159f5bca107d3b11d8a9ede 
1/*
2 * Copyright 2012 Google Inc.
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 "PathOpsExtendedTest.h"
9#include "PathOpsThreadedCommon.h"
10#include "SkBitmap.h"
11#include "SkCanvas.h"
12#include "SkForceLinking.h"
13#include "SkMatrix.h"
14#include "SkPaint.h"
15#include "SkRTConf.h"
16#include "SkStream.h"
17#include "SkTaskGroup.h"
18#include "SkThread.h"
19
20#ifdef SK_BUILD_FOR_MAC
21#include <sys/sysctl.h>
22#endif
23
24__SK_FORCE_IMAGE_DECODER_LINKING;
25
26static const char marker[] =
27    "</div>\n"
28    "\n"
29    "<script type=\"text/javascript\">\n"
30    "\n"
31    "var testDivs = [\n";
32
33static const char* opStrs[] = {
34    "kDifference_PathOp",
35    "kIntersect_PathOp",
36    "kUnion_PathOp",
37    "kXor_PathOp",
38    "kReverseDifference_PathOp",
39};
40
41static const char* opSuffixes[] = {
42    "d",
43    "i",
44    "u",
45    "o",
46};
47
48static bool gShowPath = false;
49static bool gComparePathsAssert = true;
50static bool gPathStrAssert = true;
51
52#if DEBUG_SHOW_TEST_NAME
53static void showPathData(const SkPath& path) {
54    SkPath::RawIter iter(path);
55    uint8_t verb;
56    SkPoint pts[4];
57    SkPoint firstPt = {0, 0}, lastPt = {0, 0};
58    bool firstPtSet = false;
59    bool lastPtSet = true;
60    while ((verb = iter.next(pts)) != SkPath::kDone_Verb) {
61        switch (verb) {
62            case SkPath::kMove_Verb:
63                if (firstPtSet && lastPtSet && firstPt != lastPt) {
64                    SkDebugf("{{%1.9g,%1.9g}, {%1.9g,%1.9g}},\n", lastPt.fX, lastPt.fY,
65                            firstPt.fX, firstPt.fY);
66                    lastPtSet = false;
67                }
68                firstPt = pts[0];
69                firstPtSet = true;
70                continue;
71            case SkPath::kLine_Verb:
72                SkDebugf("{{%1.9g,%1.9g}, {%1.9g,%1.9g}},\n", pts[0].fX, pts[0].fY,
73                        pts[1].fX, pts[1].fY);
74                lastPt = pts[1];
75                lastPtSet = true;
76                break;
77            case SkPath::kQuad_Verb:
78                SkDebugf("{{%1.9g,%1.9g}, {%1.9g,%1.9g}, {%1.9g,%1.9g}},\n",
79                        pts[0].fX, pts[0].fY, pts[1].fX, pts[1].fY, pts[2].fX, pts[2].fY);
80                lastPt = pts[2];
81                lastPtSet = true;
82                break;
83            case SkPath::kCubic_Verb:
84                SkDebugf("{{%1.9g,%1.9g}, {%1.9g,%1.9g}, {%1.9g,%1.9g}, {%1.9g,%1.9g}},\n",
85                        pts[0].fX, pts[0].fY, pts[1].fX, pts[1].fY, pts[2].fX, pts[2].fY,
86                        pts[3].fX, pts[3].fY);
87                lastPt = pts[3];
88                lastPtSet = true;
89                break;
90            case SkPath::kClose_Verb:
91                if (firstPtSet && lastPtSet && firstPt != lastPt) {
92                    SkDebugf("{{%1.9g,%1.9g}, {%1.9g,%1.9g}},\n", lastPt.fX, lastPt.fY,
93                            firstPt.fX, firstPt.fY);
94                }
95                firstPtSet = lastPtSet = false;
96                break;
97            default:
98                SkDEBUGFAIL("bad verb");
99                return;
100        }
101    }
102    if (firstPtSet && lastPtSet && firstPt != lastPt) {
103        SkDebugf("{{%1.9g,%1.9g}, {%1.9g,%1.9g}},\n", lastPt.fX, lastPt.fY,
104                firstPt.fX, firstPt.fY);
105    }
106}
107#endif
108
109void showOp(const SkPathOp op) {
110    switch (op) {
111        case kDifference_PathOp:
112            SkDebugf("op difference\n");
113            break;
114        case kIntersect_PathOp:
115            SkDebugf("op intersect\n");
116            break;
117        case kUnion_PathOp:
118            SkDebugf("op union\n");
119            break;
120        case kXOR_PathOp:
121            SkDebugf("op xor\n");
122            break;
123        case kReverseDifference_PathOp:
124            SkDebugf("op reverse difference\n");
125            break;
126        default:
127            SkASSERT(0);
128    }
129}
130
131#if DEBUG_SHOW_TEST_NAME
132static char hexorator(int x) {
133    if (x < 10) {
134        return x + '0';
135    }
136    x -= 10;
137    SkASSERT(x < 26);
138    return x + 'A';
139}
140#endif
141
142void ShowTestName(PathOpsThreadState* state, int a, int b, int c, int d) {
143#if DEBUG_SHOW_TEST_NAME
144    state->fSerialNo[0] = hexorator(state->fA);
145    state->fSerialNo[1] = hexorator(state->fB);
146    state->fSerialNo[2] = hexorator(state->fC);
147    state->fSerialNo[3] = hexorator(state->fD);
148    state->fSerialNo[4] = hexorator(a);
149    state->fSerialNo[5] = hexorator(b);
150    state->fSerialNo[6] = hexorator(c);
151    state->fSerialNo[7] = hexorator(d);
152    state->fSerialNo[8] = '\0';
153    SkDebugf("%s\n", state->fSerialNo);
154    if (strcmp(state->fSerialNo, state->fKey) == 0) {
155        SkDebugf("%s\n", state->fPathStr);
156    }
157#endif
158}
159
160const int bitWidth = 64;
161const int bitHeight = 64;
162
163static void scaleMatrix(const SkPath& one, const SkPath& two, SkMatrix& scale) {
164    SkRect larger = one.getBounds();
165    larger.join(two.getBounds());
166    SkScalar largerWidth = larger.width();
167    if (largerWidth < 4) {
168        largerWidth = 4;
169    }
170    SkScalar largerHeight = larger.height();
171    if (largerHeight < 4) {
172        largerHeight = 4;
173    }
174    SkScalar hScale = (bitWidth - 2) / largerWidth;
175    SkScalar vScale = (bitHeight - 2) / largerHeight;
176    scale.reset();
177    scale.preScale(hScale, vScale);
178}
179
180static int pathsDrawTheSame(SkBitmap& bits, const SkPath& scaledOne, const SkPath& scaledTwo,
181        int& error2x2) {
182    if (bits.width() == 0) {
183        bits.allocN32Pixels(bitWidth * 2, bitHeight);
184    }
185    SkCanvas canvas(bits);
186    canvas.drawColor(SK_ColorWHITE);
187    SkPaint paint;
188    canvas.save();
189    const SkRect& bounds1 = scaledOne.getBounds();
190    canvas.translate(-bounds1.fLeft + 1, -bounds1.fTop + 1);
191    canvas.drawPath(scaledOne, paint);
192    canvas.restore();
193    canvas.save();
194    canvas.translate(-bounds1.fLeft + 1 + bitWidth, -bounds1.fTop + 1);
195    canvas.drawPath(scaledTwo, paint);
196    canvas.restore();
197    int errors2 = 0;
198    int errors = 0;
199    for (int y = 0; y < bitHeight - 1; ++y) {
200        uint32_t* addr1 = bits.getAddr32(0, y);
201        uint32_t* addr2 = bits.getAddr32(0, y + 1);
202        uint32_t* addr3 = bits.getAddr32(bitWidth, y);
203        uint32_t* addr4 = bits.getAddr32(bitWidth, y + 1);
204        for (int x = 0; x < bitWidth - 1; ++x) {
205            // count 2x2 blocks
206            bool err = addr1[x] != addr3[x];
207            if (err) {
208                errors2 += addr1[x + 1] != addr3[x + 1]
209                        && addr2[x] != addr4[x] && addr2[x + 1] != addr4[x + 1];
210                errors++;
211            }
212        }
213    }
214    error2x2 = errors2;
215    return errors;
216}
217
218static int pathsDrawTheSame(const SkPath& one, const SkPath& two, SkBitmap& bits, SkPath& scaledOne,
219        SkPath& scaledTwo, int& error2x2) {
220    SkMatrix scale;
221    scaleMatrix(one, two, scale);
222    one.transform(scale, &scaledOne);
223    two.transform(scale, &scaledTwo);
224    return pathsDrawTheSame(bits, scaledOne, scaledTwo, error2x2);
225}
226
227bool drawAsciiPaths(const SkPath& one, const SkPath& two, bool drawPaths) {
228    if (!drawPaths) {
229        return true;
230    }
231    const SkRect& bounds1 = one.getBounds();
232    const SkRect& bounds2 = two.getBounds();
233    SkRect larger = bounds1;
234    larger.join(bounds2);
235    SkBitmap bits;
236    char out[256];
237    int bitWidth = SkScalarCeilToInt(larger.width()) + 2;
238    if (bitWidth * 2 + 1 >= (int) sizeof(out)) {
239        return false;
240    }
241    int bitHeight = SkScalarCeilToInt(larger.height()) + 2;
242    if (bitHeight >= (int) sizeof(out)) {
243        return false;
244    }
245    bits.allocN32Pixels(bitWidth * 2, bitHeight);
246    SkCanvas canvas(bits);
247    canvas.drawColor(SK_ColorWHITE);
248    SkPaint paint;
249    canvas.save();
250    canvas.translate(-bounds1.fLeft + 1, -bounds1.fTop + 1);
251    canvas.drawPath(one, paint);
252    canvas.restore();
253    canvas.save();
254    canvas.translate(-bounds1.fLeft + 1 + bitWidth, -bounds1.fTop + 1);
255    canvas.drawPath(two, paint);
256    canvas.restore();
257    for (int y = 0; y < bitHeight; ++y) {
258        uint32_t* addr1 = bits.getAddr32(0, y);
259        int x;
260        char* outPtr = out;
261        for (x = 0; x < bitWidth; ++x) {
262            *outPtr++ = addr1[x] == (uint32_t) -1 ? '_' : 'x';
263        }
264        *outPtr++ = '|';
265        for (x = bitWidth; x < bitWidth * 2; ++x) {
266            *outPtr++ = addr1[x] == (uint32_t) -1 ? '_' : 'x';
267        }
268        *outPtr++ = '\0';
269        SkDebugf("%s\n", out);
270    }
271    return true;
272}
273
274static int comparePaths(skiatest::Reporter* reporter, const char* filename, const SkPath& one,
275        const SkPath& two, SkBitmap& bitmap) {
276    int errors2x2;
277    SkPath scaledOne, scaledTwo;
278    (void) pathsDrawTheSame(one, two, bitmap, scaledOne, scaledTwo, errors2x2);
279    if (errors2x2 == 0) {
280        return 0;
281    }
282    const int MAX_ERRORS = 9;
283    REPORTER_ASSERT(reporter, errors2x2 <= MAX_ERRORS || !gComparePathsAssert);
284    return errors2x2 > MAX_ERRORS ? errors2x2 : 0;
285}
286
287const int gTestFirst = 4;
288static int gTestNo = gTestFirst;
289static SkTDArray<SkPathOp> gTestOp;
290
291static void showPathOpPath(const char* testName, const SkPath& one, const SkPath& two,
292        const SkPath& a, const SkPath& b, const SkPath& scaledOne, const SkPath& scaledTwo,
293        const SkPathOp shapeOp, const SkMatrix& scale) {
294    SkASSERT((unsigned) shapeOp < SK_ARRAY_COUNT(opStrs));
295    SkString defaultTestName;
296    if (!testName) {
297        defaultTestName.printf("xOp%d%s", gTestNo, opSuffixes[shapeOp]);
298        testName = defaultTestName.c_str();
299    }
300    SkDebugf("static void %s(skiatest::Reporter* reporter, const char* filename) {\n", testName);
301    *gTestOp.append() = shapeOp;
302    ++gTestNo;
303    SkDebugf("    SkPath path, pathB;\n");
304#if DEBUG_SHOW_TEST_NAME
305    SkPathOpsDebug::ShowOnePath(a, "path", false);
306    SkPathOpsDebug::ShowOnePath(b, "pathB", false);
307#endif
308    SkDebugf("    testPathOp(reporter, path, pathB, %s, filename);\n", opStrs[shapeOp]);
309    SkDebugf("}\n");
310    drawAsciiPaths(scaledOne, scaledTwo, true);
311}
312
313void ShowTestArray() {
314    for (int x = gTestFirst; x < gTestNo; ++x) {
315        SkDebugf("    TEST(xOp%d%s),\n", x, opSuffixes[gTestOp[x - gTestFirst]]);
316    }
317}
318
319SK_DECLARE_STATIC_MUTEX(compareDebugOut3);
320SK_DECLARE_STATIC_MUTEX(compareDebugOut4);
321static int comparePaths(skiatest::Reporter* reporter, const char* testName, const SkPath& one,
322        const SkPath& scaledOne, const SkPath& two, const SkPath& scaledTwo, SkBitmap& bitmap,
323        const SkPath& a, const SkPath& b, const SkPathOp shapeOp, const SkMatrix& scale) {
324    int errors2x2;
325    (void) pathsDrawTheSame(bitmap, scaledOne, scaledTwo, errors2x2);
326    if (errors2x2 == 0) {
327        if (gShowPath) {
328            showPathOpPath(testName, one, two, a, b, scaledOne, scaledTwo, shapeOp, scale);
329        }
330        return 0;
331    }
332    const int MAX_ERRORS = 8;
333    if (errors2x2 > MAX_ERRORS && gComparePathsAssert) {
334        SkAutoMutexAcquire autoM(compareDebugOut3);
335        SkDebugf("\n*** this test fails ***\n");
336        showPathOpPath(testName, one, two, a, b, scaledOne, scaledTwo, shapeOp, scale);
337        REPORTER_ASSERT(reporter, 0);
338    } else if (gShowPath || errors2x2 == MAX_ERRORS || errors2x2 == MAX_ERRORS - 1) {
339        SkAutoMutexAcquire autoM(compareDebugOut4);
340        showPathOpPath(testName, one, two, a, b, scaledOne, scaledTwo, shapeOp, scale);
341    }
342    return errors2x2 > MAX_ERRORS ? errors2x2 : 0;
343}
344
345// Default values for when reporter->verbose() is false.
346static int testNumber = 55;
347static const char* testName = "pathOpTest";
348
349static void writeTestName(const char* nameSuffix, SkMemoryWStream& outFile) {
350    outFile.writeText(testName);
351    outFile.writeDecAsText(testNumber);
352    ++testNumber;
353    if (nameSuffix) {
354        outFile.writeText(nameSuffix);
355    }
356}
357
358static void outputToStream(const char* pathStr, const char* pathPrefix, const char* nameSuffix,
359        const char* testFunction, bool twoPaths, SkMemoryWStream& outFile) {
360#if 0
361    outFile.writeText("<div id=\"");
362    writeTestName(nameSuffix, outFile);
363    outFile.writeText("\">\n");
364    if (pathPrefix) {
365        outFile.writeText(pathPrefix);
366    }
367    outFile.writeText(pathStr);
368    outFile.writeText("</div>\n\n");
369
370    outFile.writeText(marker);
371    outFile.writeText("    ");
372    writeTestName(nameSuffix, outFile);
373    outFile.writeText(",\n\n\n");
374#endif
375    outFile.writeText("static void ");
376    writeTestName(nameSuffix, outFile);
377    outFile.writeText("(skiatest::Reporter* reporter) {\n    SkPath path");
378    if (twoPaths) {
379        outFile.writeText(", pathB");
380    }
381    outFile.writeText(";\n");
382    if (pathPrefix) {
383        outFile.writeText(pathPrefix);
384    }
385    outFile.writeText(pathStr);
386    outFile.writeText("    ");
387    outFile.writeText(testFunction);
388    outFile.writeText("\n}\n\n");
389#if 0
390    outFile.writeText("static void (*firstTest)() = ");
391    writeTestName(nameSuffix, outFile);
392    outFile.writeText(";\n\n");
393
394    outFile.writeText("static struct {\n");
395    outFile.writeText("    void (*fun)();\n");
396    outFile.writeText("    const char* str;\n");
397    outFile.writeText("} tests[] = {\n");
398    outFile.writeText("    TEST(");
399    writeTestName(nameSuffix, outFile);
400    outFile.writeText("),\n");
401#endif
402    outFile.flush();
403}
404
405SK_DECLARE_STATIC_MUTEX(simplifyDebugOut);
406bool testSimplify(SkPath& path, bool useXor, SkPath& out, PathOpsThreadState& state,
407                  const char* pathStr) {
408    SkPath::FillType fillType = useXor ? SkPath::kEvenOdd_FillType : SkPath::kWinding_FillType;
409    path.setFillType(fillType);
410#if DEBUG_SHOW_TEST_NAME
411    if (gShowPath) {
412        SkPathOpsDebug::ShowOnePath(path, "path", false);
413    }
414#endif
415    if (!Simplify(path, &out)) {
416        SkDebugf("%s did not expect failure\n", __FUNCTION__);
417        REPORTER_ASSERT(state.fReporter, 0);
418        return false;
419    }
420    if (!state.fReporter->verbose()) {
421        return true;
422    }
423    int result = comparePaths(state.fReporter, NULL, path, out, *state.fBitmap);
424    if (result && gPathStrAssert) {
425        SkAutoMutexAcquire autoM(simplifyDebugOut);
426        char temp[8192];
427        sk_bzero(temp, sizeof(temp));
428        SkMemoryWStream stream(temp, sizeof(temp));
429        const char* pathPrefix = NULL;
430        const char* nameSuffix = NULL;
431        if (fillType == SkPath::kEvenOdd_FillType) {
432            pathPrefix = "    path.setFillType(SkPath::kEvenOdd_FillType);\n";
433            nameSuffix = "x";
434        }
435        const char testFunction[] = "testSimplify(reporter, path);";
436        outputToStream(pathStr, pathPrefix, nameSuffix, testFunction, false, stream);
437        SkDebugf(temp);
438        REPORTER_ASSERT(state.fReporter, 0);
439    }
440    state.fReporter->bumpTestCount();
441    return result == 0;
442}
443
444bool testSimplify(skiatest::Reporter* reporter, const SkPath& path, const char* filename) {
445#if DEBUG_SHOW_TEST_NAME
446    showPathData(path);
447#endif
448    SkPath out;
449    if (!Simplify(path, &out)) {
450        SkDebugf("%s did not expect failure\n", __FUNCTION__);
451        REPORTER_ASSERT(reporter, 0);
452        return false;
453    }
454    SkBitmap bitmap;
455    int result = comparePaths(reporter, filename, path, out, bitmap);
456    if (result && gPathStrAssert) {
457        REPORTER_ASSERT(reporter, 0);
458    }
459    reporter->bumpTestCount();
460    return result == 0;
461}
462
463#if DEBUG_SHOW_TEST_NAME
464static void showName(const SkPath& a, const SkPath& b, const SkPathOp shapeOp) {
465    SkDebugf("\n");
466    showPathData(a);
467    showOp(shapeOp);
468    showPathData(b);
469}
470#endif
471
472static bool innerPathOp(skiatest::Reporter* reporter, const SkPath& a, const SkPath& b,
473                 const SkPathOp shapeOp, const char* testName, bool threaded) {
474#if DEBUG_SHOW_TEST_NAME
475    showName(a, b, shapeOp);
476#endif
477    SkPath out;
478    if (!Op(a, b, shapeOp, &out) ) {
479        SkDebugf("%s did not expect failure\n", __FUNCTION__);
480        REPORTER_ASSERT(reporter, 0);
481        return false;
482    }
483    if (threaded && !reporter->verbose()) {
484        return true;
485    }
486    SkPath pathOut, scaledPathOut;
487    SkRegion rgnA, rgnB, openClip, rgnOut;
488    openClip.setRect(-16000, -16000, 16000, 16000);
489    rgnA.setPath(a, openClip);
490    rgnB.setPath(b, openClip);
491    rgnOut.op(rgnA, rgnB, (SkRegion::Op) shapeOp);
492    rgnOut.getBoundaryPath(&pathOut);
493
494    SkMatrix scale;
495    scaleMatrix(a, b, scale);
496    SkRegion scaledRgnA, scaledRgnB, scaledRgnOut;
497    SkPath scaledA, scaledB;
498    scaledA.addPath(a, scale);
499    scaledA.setFillType(a.getFillType());
500    scaledB.addPath(b, scale);
501    scaledB.setFillType(b.getFillType());
502    scaledRgnA.setPath(scaledA, openClip);
503    scaledRgnB.setPath(scaledB, openClip);
504    scaledRgnOut.op(scaledRgnA, scaledRgnB, (SkRegion::Op) shapeOp);
505    scaledRgnOut.getBoundaryPath(&scaledPathOut);
506    SkBitmap bitmap;
507    SkPath scaledOut;
508    scaledOut.addPath(out, scale);
509    scaledOut.setFillType(out.getFillType());
510    int result = comparePaths(reporter, testName, pathOut, scaledPathOut, out, scaledOut, bitmap,
511            a, b, shapeOp, scale);
512    if (result && gPathStrAssert) {
513        REPORTER_ASSERT(reporter, 0);
514    }
515    reporter->bumpTestCount();
516    return result == 0;
517}
518
519bool testPathOp(skiatest::Reporter* reporter, const SkPath& a, const SkPath& b,
520                 const SkPathOp shapeOp, const char* testName) {
521    return innerPathOp(reporter, a, b, shapeOp, testName, false);
522}
523
524bool testPathFailOp(skiatest::Reporter* reporter, const SkPath& a, const SkPath& b,
525                 const SkPathOp shapeOp, const char* testName) {
526#if DEBUG_SHOW_TEST_NAME
527    showName(a, b, shapeOp);
528#endif
529    SkPath out;
530    if (Op(a, b, shapeOp, &out) ) {
531        SkDebugf("%s test is expected to fail\n", __FUNCTION__);
532        REPORTER_ASSERT(reporter, 0);
533        return false;
534    }
535    return true;
536}
537
538bool testThreadedPathOp(skiatest::Reporter* reporter, const SkPath& a, const SkPath& b,
539                 const SkPathOp shapeOp, const char* testName) {
540    return innerPathOp(reporter, a, b, shapeOp, testName, true);
541}
542
543SK_DECLARE_STATIC_MUTEX(gMutex);
544
545void initializeTests(skiatest::Reporter* reporter, const char* test) {
546#if 0  // doesn't work yet
547    SK_CONF_SET("images.jpeg.suppressDecoderWarnings", true);
548    SK_CONF_SET("images.png.suppressDecoderWarnings", true);
549#endif
550    if (reporter->verbose()) {
551        SkAutoMutexAcquire lock(gMutex);
552        testName = test;
553        size_t testNameSize = strlen(test);
554        SkFILEStream inFile("../../experimental/Intersection/op.htm");
555        if (inFile.isValid()) {
556            SkTDArray<char> inData;
557            inData.setCount((int) inFile.getLength());
558            size_t inLen = inData.count();
559            inFile.read(inData.begin(), inLen);
560            inFile.setPath(NULL);
561            char* insert = strstr(inData.begin(), marker);
562            if (insert) {
563                insert += sizeof(marker) - 1;
564                const char* numLoc = insert + 4 /* indent spaces */ + testNameSize - 1;
565                testNumber = atoi(numLoc) + 1;
566            }
567        }
568    }
569}
570
571void outputProgress(char* ramStr, const char* pathStr, SkPath::FillType pathFillType) {
572    const char testFunction[] = "testSimplify(path);";
573    const char* pathPrefix = NULL;
574    const char* nameSuffix = NULL;
575    if (pathFillType == SkPath::kEvenOdd_FillType) {
576        pathPrefix = "    path.setFillType(SkPath::kEvenOdd_FillType);\n";
577        nameSuffix = "x";
578    }
579    SkMemoryWStream rRamStream(ramStr, PATH_STR_SIZE);
580    outputToStream(pathStr, pathPrefix, nameSuffix, testFunction, false, rRamStream);
581}
582
583void outputProgress(char* ramStr, const char* pathStr, SkPathOp op) {
584    const char testFunction[] = "testOp(path);";
585    SkASSERT((size_t) op < SK_ARRAY_COUNT(opSuffixes));
586    const char* nameSuffix = opSuffixes[op];
587    SkMemoryWStream rRamStream(ramStr, PATH_STR_SIZE);
588    outputToStream(pathStr, NULL, nameSuffix, testFunction, true, rRamStream);
589}
590
591void RunTestSet(skiatest::Reporter* reporter, TestDesc tests[], size_t count,
592                void (*firstTest)(skiatest::Reporter* , const char* filename),
593                void (*stopTest)(skiatest::Reporter* , const char* filename), bool reverse) {
594    size_t index;
595    if (firstTest) {
596        index = count - 1;
597        while (index > 0 && tests[index].fun != firstTest) {
598            --index;
599        }
600#if DEBUG_SHOW_TEST_NAME
601        SkDebugf("<div id=\"%s\">\n", tests[index].str);
602        SkDebugf("  %s [%s]\n", __FUNCTION__, tests[index].str);
603#endif
604        (*tests[index].fun)(reporter, tests[index].str);
605        if (tests[index].fun == stopTest) {
606            return;
607        }
608    }
609    index = reverse ? count - 1 : 0;
610    size_t last = reverse ? 0 : count - 1;
611    do {
612        if (tests[index].fun != firstTest) {
613    #if DEBUG_SHOW_TEST_NAME
614            SkDebugf("<div id=\"%s\">\n", tests[index].str);
615            SkDebugf("  %s [%s]\n", __FUNCTION__, tests[index].str);
616    #endif
617            (*tests[index].fun)(reporter, tests[index].str);
618        }
619        if (tests[index].fun == stopTest) {
620            SkDebugf("lastTest\n");
621            break;
622        }
623        if (index == last) {
624            break;
625        }
626        index += reverse ? -1 : 1;
627    } while (true);
628}
629