sk_tool_utils.cpp revision 5a625e08f05157c1519012d8d04942c8f7606ba8
1dce2b2fa9d6b26414a8d5a55918e4d7ca2ab1baaElliott Hughes/*
2dce2b2fa9d6b26414a8d5a55918e4d7ca2ab1baaElliott Hughes * Copyright 2014 Google Inc.
3dce2b2fa9d6b26414a8d5a55918e4d7ca2ab1baaElliott Hughes *
4dce2b2fa9d6b26414a8d5a55918e4d7ca2ab1baaElliott Hughes * Use of this source code is governed by a BSD-style license that can be
5dce2b2fa9d6b26414a8d5a55918e4d7ca2ab1baaElliott Hughes * found in the LICENSE file.
6dce2b2fa9d6b26414a8d5a55918e4d7ca2ab1baaElliott Hughes */
7dce2b2fa9d6b26414a8d5a55918e4d7ca2ab1baaElliott Hughes
8dce2b2fa9d6b26414a8d5a55918e4d7ca2ab1baaElliott Hughes#include "sk_tool_utils.h"
9dce2b2fa9d6b26414a8d5a55918e4d7ca2ab1baaElliott Hughes#include "sk_tool_utils_flags.h"
10dce2b2fa9d6b26414a8d5a55918e4d7ca2ab1baaElliott Hughes
11dce2b2fa9d6b26414a8d5a55918e4d7ca2ab1baaElliott Hughes#include "Resources.h"
12dce2b2fa9d6b26414a8d5a55918e4d7ca2ab1baaElliott Hughes#include "SkBitmap.h"
13dce2b2fa9d6b26414a8d5a55918e4d7ca2ab1baaElliott Hughes#include "SkCanvas.h"
14dce2b2fa9d6b26414a8d5a55918e4d7ca2ab1baaElliott Hughes#include "SkCommonFlags.h"
15dce2b2fa9d6b26414a8d5a55918e4d7ca2ab1baaElliott Hughes#include "SkFontMgr.h"
16e5fea3d504609d22337a5311d3ce0e72314bceeeNarayan Kamath#include "SkFontStyle.h"
17dce2b2fa9d6b26414a8d5a55918e4d7ca2ab1baaElliott Hughes#include "SkPixelRef.h"
18dce2b2fa9d6b26414a8d5a55918e4d7ca2ab1baaElliott Hughes#include "SkPM4f.h"
19dce2b2fa9d6b26414a8d5a55918e4d7ca2ab1baaElliott Hughes#include "SkPoint3.h"
20dce2b2fa9d6b26414a8d5a55918e4d7ca2ab1baaElliott Hughes#include "SkShader.h"
21dce2b2fa9d6b26414a8d5a55918e4d7ca2ab1baaElliott Hughes#include "SkTestScalerContext.h"
22dce2b2fa9d6b26414a8d5a55918e4d7ca2ab1baaElliott Hughes#include "SkTextBlob.h"
23dce2b2fa9d6b26414a8d5a55918e4d7ca2ab1baaElliott Hughes
24dce2b2fa9d6b26414a8d5a55918e4d7ca2ab1baaElliott HughesDEFINE_bool(portableFonts, false, "Use portable fonts");
25dce2b2fa9d6b26414a8d5a55918e4d7ca2ab1baaElliott Hughes
26dce2b2fa9d6b26414a8d5a55918e4d7ca2ab1baaElliott Hughesnamespace sk_tool_utils {
27dce2b2fa9d6b26414a8d5a55918e4d7ca2ab1baaElliott Hughes
28dce2b2fa9d6b26414a8d5a55918e4d7ca2ab1baaElliott Hughes/* these are the default fonts chosen by Chrome for serif, sans-serif, and monospace */
29dce2b2fa9d6b26414a8d5a55918e4d7ca2ab1baaElliott Hughesstatic const char* gStandardFontNames[][3] = {
30dce2b2fa9d6b26414a8d5a55918e4d7ca2ab1baaElliott Hughes    { "Times", "Helvetica", "Courier" }, // Mac
31dce2b2fa9d6b26414a8d5a55918e4d7ca2ab1baaElliott Hughes    { "Times New Roman", "Helvetica", "Courier" }, // iOS
32dce2b2fa9d6b26414a8d5a55918e4d7ca2ab1baaElliott Hughes    { "Times New Roman", "Arial", "Courier New" }, // Win
33dce2b2fa9d6b26414a8d5a55918e4d7ca2ab1baaElliott Hughes    { "Times New Roman", "Arial", "Monospace" }, // Ubuntu
34dce2b2fa9d6b26414a8d5a55918e4d7ca2ab1baaElliott Hughes    { "serif", "sans-serif", "monospace" }, // Android
35dce2b2fa9d6b26414a8d5a55918e4d7ca2ab1baaElliott Hughes    { "Tinos", "Arimo", "Cousine" } // ChromeOS
36dce2b2fa9d6b26414a8d5a55918e4d7ca2ab1baaElliott Hughes};
37dce2b2fa9d6b26414a8d5a55918e4d7ca2ab1baaElliott Hughes
38dce2b2fa9d6b26414a8d5a55918e4d7ca2ab1baaElliott Hughesconst char* platform_font_name(const char* name) {
39dce2b2fa9d6b26414a8d5a55918e4d7ca2ab1baaElliott Hughes    SkString platform = major_platform_os_name();
40dce2b2fa9d6b26414a8d5a55918e4d7ca2ab1baaElliott Hughes    int index;
41dce2b2fa9d6b26414a8d5a55918e4d7ca2ab1baaElliott Hughes    if (!strcmp(name, "serif")) {
42dce2b2fa9d6b26414a8d5a55918e4d7ca2ab1baaElliott Hughes        index = 0;
43    } else if (!strcmp(name, "san-serif")) {
44        index = 1;
45    } else if (!strcmp(name, "monospace")) {
46        index = 2;
47    } else {
48        return name;
49    }
50    if (platform.equals("Mac")) {
51        return gStandardFontNames[0][index];
52    }
53    if (platform.equals("iOS")) {
54        return gStandardFontNames[1][index];
55    }
56    if (platform.equals("Win")) {
57        return gStandardFontNames[2][index];
58    }
59    if (platform.equals("Ubuntu") || platform.equals("Debian")) {
60        return gStandardFontNames[3][index];
61    }
62    if (platform.equals("Android")) {
63        return gStandardFontNames[4][index];
64    }
65    if (platform.equals("ChromeOS")) {
66        return gStandardFontNames[5][index];
67    }
68    return name;
69}
70
71const char* platform_os_emoji() {
72    const char* osName = platform_os_name();
73    if (!strcmp(osName, "Android") || !strcmp(osName, "Ubuntu") || !strcmp(osName, "Debian")) {
74        return "CBDT";
75    }
76    if (!strncmp(osName, "Mac", 3) || !strncmp(osName, "iOS", 3)) {
77        return "SBIX";
78    }
79    if (!strncmp(osName, "Win", 3)) {
80        return "COLR";
81    }
82    return "";
83}
84
85sk_sp<SkTypeface> emoji_typeface() {
86    if (!strcmp(sk_tool_utils::platform_os_emoji(), "CBDT")) {
87        return MakeResourceAsTypeface("/fonts/Funkster.ttf");
88    }
89    if (!strcmp(sk_tool_utils::platform_os_emoji(), "SBIX")) {
90        return SkTypeface::MakeFromName("Apple Color Emoji", SkFontStyle());
91    }
92    if (!strcmp(sk_tool_utils::platform_os_emoji(), "COLR")) {
93        sk_sp<SkFontMgr> fm(SkFontMgr::RefDefault());
94        const char *colorEmojiFontName = "Segoe UI Emoji";
95        sk_sp<SkTypeface> typeface(fm->matchFamilyStyle(colorEmojiFontName, SkFontStyle()));
96        if (typeface) {
97            return typeface;
98        }
99        sk_sp<SkTypeface> fallback(fm->matchFamilyStyleCharacter(
100            colorEmojiFontName, SkFontStyle(), nullptr /* bcp47 */, 0 /* bcp47Count */,
101            0x1f4b0 /* character: �� */));
102        if (fallback) {
103            return fallback;
104        }
105        // If we don't have Segoe UI Emoji and can't find a fallback, try Segoe UI Symbol.
106        // Windows 7 does not have Segoe UI Emoji; Segoe UI Symbol has the (non - color) emoji.
107        return SkTypeface::MakeFromName("Segoe UI Symbol", SkFontStyle());
108    }
109    return nullptr;
110}
111
112const char* emoji_sample_text() {
113    if (!strcmp(sk_tool_utils::platform_os_emoji(), "CBDT")) {
114        return "Hamburgefons";
115    }
116    if (!strcmp(sk_tool_utils::platform_os_emoji(), "SBIX") ||
117        !strcmp(sk_tool_utils::platform_os_emoji(), "COLR"))
118    {
119        return "\xF0\x9F\x92\xB0" "\xF0\x9F\x8F\xA1" "\xF0\x9F\x8E\x85"  // ������
120               "\xF0\x9F\x8D\xAA" "\xF0\x9F\x8D\x95" "\xF0\x9F\x9A\x80"  // ������
121               "\xF0\x9F\x9A\xBB" "\xF0\x9F\x92\xA9" "\xF0\x9F\x93\xB7" // ������
122               "\xF0\x9F\x93\xA6" // ��
123               "\xF0\x9F\x87\xBA" "\xF0\x9F\x87\xB8" "\xF0\x9F\x87\xA6"; // ������
124    }
125    return "";
126}
127
128const char* platform_os_name() {
129    for (int index = 0; index < FLAGS_key.count(); index += 2) {
130        if (!strcmp("os", FLAGS_key[index])) {
131            return FLAGS_key[index + 1];
132        }
133    }
134    // when running SampleApp or dm without a --key pair, omit the platform name
135    return "";
136}
137
138// omit version number in returned value
139SkString major_platform_os_name() {
140    SkString name;
141    for (int index = 0; index < FLAGS_key.count(); index += 2) {
142        if (!strcmp("os", FLAGS_key[index])) {
143            const char* platform = FLAGS_key[index + 1];
144            const char* end = platform;
145            while (*end && (*end < '0' || *end > '9')) {
146                ++end;
147            }
148            name.append(platform, end - platform);
149            break;
150        }
151    }
152    return name;
153}
154
155const char* platform_extra_config(const char* config) {
156    for (int index = 0; index < FLAGS_key.count(); index += 2) {
157        if (!strcmp("extra_config", FLAGS_key[index]) && !strcmp(config, FLAGS_key[index + 1])) {
158            return config;
159        }
160    }
161    return "";
162}
163
164const char* colortype_name(SkColorType ct) {
165    switch (ct) {
166        case kUnknown_SkColorType:      return "Unknown";
167        case kAlpha_8_SkColorType:      return "Alpha_8";
168        case kARGB_4444_SkColorType:    return "ARGB_4444";
169        case kRGB_565_SkColorType:      return "RGB_565";
170        case kRGBA_8888_SkColorType:    return "RGBA_8888";
171        case kBGRA_8888_SkColorType:    return "BGRA_8888";
172        case kRGBA_F16_SkColorType:     return "RGBA_F16";
173        default:
174            SkASSERT(false);
175            return "unexpected colortype";
176    }
177}
178
179SkColor color_to_565(SkColor color) {
180    SkPMColor pmColor = SkPreMultiplyColor(color);
181    U16CPU color16 = SkPixel32ToPixel16(pmColor);
182    return SkPixel16ToColor(color16);
183}
184
185sk_sp<SkTypeface> create_portable_typeface(const char* name, SkFontStyle style) {
186    return create_font(name, style);
187}
188
189void set_portable_typeface(SkPaint* paint, const char* name, SkFontStyle style) {
190    paint->setTypeface(create_font(name, style));
191}
192
193void write_pixels(SkCanvas* canvas, const SkBitmap& bitmap, int x, int y,
194                  SkColorType colorType, SkAlphaType alphaType) {
195    SkBitmap tmp(bitmap);
196    const SkImageInfo info = SkImageInfo::Make(tmp.width(), tmp.height(), colorType, alphaType);
197
198    canvas->writePixels(info, tmp.getPixels(), tmp.rowBytes(), x, y);
199}
200
201sk_sp<SkShader> create_checkerboard_shader(SkColor c1, SkColor c2, int size) {
202    SkBitmap bm;
203    bm.allocPixels(SkImageInfo::MakeS32(2 * size, 2 * size, kPremul_SkAlphaType));
204    bm.eraseColor(c1);
205    bm.eraseArea(SkIRect::MakeLTRB(0, 0, size, size), c2);
206    bm.eraseArea(SkIRect::MakeLTRB(size, size, 2 * size, 2 * size), c2);
207    return SkShader::MakeBitmapShader(
208            bm, SkShader::kRepeat_TileMode, SkShader::kRepeat_TileMode);
209}
210
211SkBitmap create_checkerboard_bitmap(int w, int h, SkColor c1, SkColor c2, int checkSize) {
212    SkBitmap bitmap;
213    bitmap.allocPixels(SkImageInfo::MakeS32(w, h, kPremul_SkAlphaType));
214    SkCanvas canvas(bitmap);
215
216    sk_tool_utils::draw_checkerboard(&canvas, c1, c2, checkSize);
217    return bitmap;
218}
219
220void draw_checkerboard(SkCanvas* canvas, SkColor c1, SkColor c2, int size) {
221    SkPaint paint;
222    paint.setShader(create_checkerboard_shader(c1, c2, size));
223    paint.setBlendMode(SkBlendMode::kSrc);
224    canvas->drawPaint(paint);
225}
226
227SkBitmap create_string_bitmap(int w, int h, SkColor c, int x, int y,
228                              int textSize, const char* str) {
229    SkBitmap bitmap;
230    bitmap.allocN32Pixels(w, h);
231    SkCanvas canvas(bitmap);
232
233    SkPaint paint;
234    paint.setAntiAlias(true);
235    sk_tool_utils::set_portable_typeface(&paint);
236    paint.setColor(c);
237    paint.setTextSize(SkIntToScalar(textSize));
238
239    canvas.clear(0x00000000);
240    canvas.drawString(str, SkIntToScalar(x), SkIntToScalar(y), paint);
241
242    // Tag data as sRGB (without doing any color space conversion). Color-space aware configs
243    // will process this correctly but legacy configs will render as if this returned N32.
244    SkBitmap result;
245    result.setInfo(SkImageInfo::MakeS32(w, h, kPremul_SkAlphaType));
246    result.setPixelRef(sk_ref_sp(bitmap.pixelRef()), 0, 0);
247    return result;
248}
249
250void add_to_text_blob(SkTextBlobBuilder* builder, const char* text, const SkPaint& origPaint,
251                      SkScalar x, SkScalar y) {
252    SkPaint paint(origPaint);
253    SkTDArray<uint16_t> glyphs;
254
255    size_t len = strlen(text);
256    glyphs.append(paint.textToGlyphs(text, len, nullptr));
257    paint.textToGlyphs(text, len, glyphs.begin());
258
259    paint.setTextEncoding(SkPaint::kGlyphID_TextEncoding);
260    const SkTextBlobBuilder::RunBuffer& run = builder->allocRun(paint, glyphs.count(), x, y,
261                                                                nullptr);
262    memcpy(run.glyphs, glyphs.begin(), glyphs.count() * sizeof(uint16_t));
263}
264
265#if !defined(__clang__) && defined(_MSC_VER)
266    // MSVC takes ~2 minutes to compile this function with optimization.
267    // We don't really care to wait that long for this function.
268    #pragma optimize("", off)
269#endif
270void make_big_path(SkPath& path) {
271    #include "BigPathBench.inc"
272}
273
274static float gaussian2d_value(int x, int y, float sigma) {
275    // don't bother with the scale term since we're just going to normalize the
276    // kernel anyways
277    float temp = expf(-(x*x + y*y)/(2*sigma*sigma));
278    return temp;
279}
280
281static float* create_2d_kernel(float sigma, int* filterSize) {
282    // We will actually take 2*halfFilterSize+1 samples (i.e., our filter kernel
283    // sizes are always odd)
284    int halfFilterSize = SkScalarCeilToInt(6*sigma)/2;
285    int wh = *filterSize = 2*halfFilterSize + 1;
286
287    float* temp = new float[wh*wh];
288
289    float filterTot = 0.0f;
290    for (int yOff = 0; yOff < wh; ++yOff) {
291        for (int xOff = 0; xOff < wh; ++xOff) {
292            temp[yOff*wh+xOff] = gaussian2d_value(xOff-halfFilterSize, yOff-halfFilterSize, sigma);
293
294            filterTot += temp[yOff*wh+xOff];
295        }
296    }
297
298    // normalize the kernel
299    for (int yOff = 0; yOff < wh; ++yOff) {
300        for (int xOff = 0; xOff < wh; ++xOff) {
301            temp[yOff*wh+xOff] /= filterTot;
302        }
303    }
304
305    return temp;
306}
307
308static SkPMColor blur_pixel(const SkBitmap& bm, int x, int y, float* kernel, int wh) {
309    SkASSERT(wh & 0x1);
310
311    int halfFilterSize = (wh-1)/2;
312
313    float r = 0.0f, g = 0.0f, b = 0.0f;
314    for (int yOff = 0; yOff < wh; ++yOff) {
315        int ySamp = y + yOff - halfFilterSize;
316
317        if (ySamp < 0) {
318            ySamp = 0;
319        } else if (ySamp > bm.height()-1) {
320            ySamp = bm.height()-1;
321        }
322
323        for (int xOff = 0; xOff < wh; ++xOff) {
324            int xSamp = x + xOff - halfFilterSize;
325
326            if (xSamp < 0) {
327                xSamp = 0;
328            } else if (xSamp > bm.width()-1) {
329                xSamp = bm.width()-1;
330            }
331
332            float filter = kernel[yOff*wh + xOff];
333
334            SkPMColor c = *bm.getAddr32(xSamp, ySamp);
335
336            r += SkGetPackedR32(c) * filter;
337            g += SkGetPackedG32(c) * filter;
338            b += SkGetPackedB32(c) * filter;
339        }
340    }
341
342    U8CPU r8, g8, b8;
343
344    r8 = (U8CPU) (r+0.5f);
345    g8 = (U8CPU) (g+0.5f);
346    b8 = (U8CPU) (b+0.5f);
347
348    return SkPackARGB32(255, r8, g8, b8);
349}
350
351SkBitmap slow_blur(const SkBitmap& src, float sigma) {
352    SkBitmap dst;
353
354    dst.allocN32Pixels(src.width(), src.height(), true);
355
356    int wh;
357    std::unique_ptr<float[]> kernel(create_2d_kernel(sigma, &wh));
358
359    for (int y = 0; y < src.height(); ++y) {
360        for (int x = 0; x < src.width(); ++x) {
361            *dst.getAddr32(x, y) = blur_pixel(src, x, y, kernel.get(), wh);
362        }
363    }
364
365    return dst;
366}
367
368// compute the intersection point between the diagonal and the ellipse in the
369// lower right corner
370static SkPoint intersection(SkScalar w, SkScalar h) {
371    SkASSERT(w > 0.0f || h > 0.0f);
372
373    return SkPoint::Make(w / SK_ScalarSqrt2, h / SK_ScalarSqrt2);
374}
375
376// Use the intersection of the corners' diagonals with their ellipses to shrink
377// the bounding rect
378SkRect compute_central_occluder(const SkRRect& rr) {
379    const SkRect r = rr.getBounds();
380
381    SkScalar newL = r.fLeft, newT = r.fTop, newR = r.fRight, newB = r.fBottom;
382
383    SkVector radii = rr.radii(SkRRect::kUpperLeft_Corner);
384    if (!radii.isZero()) {
385        SkPoint p = intersection(radii.fX, radii.fY);
386
387        newL = SkTMax(newL, r.fLeft + radii.fX - p.fX);
388        newT = SkTMax(newT, r.fTop + radii.fY - p.fY);
389    }
390
391    radii = rr.radii(SkRRect::kUpperRight_Corner);
392    if (!radii.isZero()) {
393        SkPoint p = intersection(radii.fX, radii.fY);
394
395        newR = SkTMin(newR, r.fRight + p.fX - radii.fX);
396        newT = SkTMax(newT, r.fTop + radii.fY - p.fY);
397    }
398
399    radii = rr.radii(SkRRect::kLowerRight_Corner);
400    if (!radii.isZero()) {
401        SkPoint p = intersection(radii.fX, radii.fY);
402
403        newR = SkTMin(newR, r.fRight + p.fX - radii.fX);
404        newB = SkTMin(newB, r.fBottom - radii.fY + p.fY);
405    }
406
407    radii = rr.radii(SkRRect::kLowerLeft_Corner);
408    if (!radii.isZero()) {
409        SkPoint p = intersection(radii.fX, radii.fY);
410
411        newL = SkTMax(newL, r.fLeft + radii.fX - p.fX);
412        newB = SkTMin(newB, r.fBottom - radii.fY + p.fY);
413    }
414
415    return SkRect::MakeLTRB(newL, newT, newR, newB);
416}
417
418// The widest inset rect
419SkRect compute_widest_occluder(const SkRRect& rr) {
420    const SkRect& r = rr.getBounds();
421
422    const SkVector& ul = rr.radii(SkRRect::kUpperLeft_Corner);
423    const SkVector& ur = rr.radii(SkRRect::kUpperRight_Corner);
424    const SkVector& lr = rr.radii(SkRRect::kLowerRight_Corner);
425    const SkVector& ll = rr.radii(SkRRect::kLowerLeft_Corner);
426
427    SkScalar maxT = SkTMax(ul.fY, ur.fY);
428    SkScalar maxB = SkTMax(ll.fY, lr.fY);
429
430    return SkRect::MakeLTRB(r.fLeft, r.fTop + maxT, r.fRight, r.fBottom - maxB);
431
432}
433
434// The tallest inset rect
435SkRect compute_tallest_occluder(const SkRRect& rr) {
436    const SkRect& r = rr.getBounds();
437
438    const SkVector& ul = rr.radii(SkRRect::kUpperLeft_Corner);
439    const SkVector& ur = rr.radii(SkRRect::kUpperRight_Corner);
440    const SkVector& lr = rr.radii(SkRRect::kLowerRight_Corner);
441    const SkVector& ll = rr.radii(SkRRect::kLowerLeft_Corner);
442
443    SkScalar maxL = SkTMax(ul.fX, ll.fX);
444    SkScalar maxR = SkTMax(ur.fX, lr.fX);
445
446    return SkRect::MakeLTRB(r.fLeft + maxL, r.fTop, r.fRight - maxR, r.fBottom);
447}
448
449bool copy_to(SkBitmap* dst, SkColorType dstColorType, const SkBitmap& src) {
450    SkPixmap srcPM;
451    if (!src.peekPixels(&srcPM)) {
452        return false;
453    }
454
455    SkBitmap tmpDst;
456    SkImageInfo dstInfo = srcPM.info().makeColorType(dstColorType);
457    if (!tmpDst.setInfo(dstInfo)) {
458        return false;
459    }
460
461    if (!tmpDst.tryAllocPixels()) {
462        return false;
463    }
464
465    SkPixmap dstPM;
466    if (!tmpDst.peekPixels(&dstPM)) {
467        return false;
468    }
469
470    if (!srcPM.readPixels(dstPM)) {
471        return false;
472    }
473
474    dst->swap(tmpDst);
475    return true;
476}
477
478void copy_to_g8(SkBitmap* dst, const SkBitmap& src) {
479    SkASSERT(kBGRA_8888_SkColorType == src.colorType() ||
480             kRGBA_8888_SkColorType == src.colorType());
481
482    SkImageInfo grayInfo = src.info().makeColorType(kGray_8_SkColorType);
483    dst->allocPixels(grayInfo);
484    uint8_t* dst8 = (uint8_t*)dst->getPixels();
485    const uint32_t* src32 = (const uint32_t*)src.getPixels();
486
487    const int w = src.width();
488    const int h = src.height();
489    const bool isBGRA = (kBGRA_8888_SkColorType == src.colorType());
490    for (int y = 0; y < h; ++y) {
491        if (isBGRA) {
492            // BGRA
493            for (int x = 0; x < w; ++x) {
494                uint32_t s = src32[x];
495                dst8[x] = SkComputeLuminance((s >> 16) & 0xFF, (s >> 8) & 0xFF, s & 0xFF);
496            }
497        } else {
498            // RGBA
499            for (int x = 0; x < w; ++x) {
500                uint32_t s = src32[x];
501                dst8[x] = SkComputeLuminance(s & 0xFF, (s >> 8) & 0xFF, (s >> 16) & 0xFF);
502            }
503        }
504        src32 = (const uint32_t*)((const char*)src32 + src.rowBytes());
505        dst8 += dst->rowBytes();
506    }
507}
508
509    //////////////////////////////////////////////////////////////////////////////////////////////
510
511    static int scale255(float x) {
512        return sk_float_round2int(x * 255);
513    }
514
515    static unsigned diff(const SkColorType ct, const void* a, const void* b) {
516        int dr = 0,
517            dg = 0,
518            db = 0,
519            da = 0;
520        switch (ct) {
521            case kRGBA_8888_SkColorType:
522            case kBGRA_8888_SkColorType: {
523                SkPMColor c0 = *(const SkPMColor*)a;
524                SkPMColor c1 = *(const SkPMColor*)b;
525                dr = SkGetPackedR32(c0) - SkGetPackedR32(c1);
526                dg = SkGetPackedG32(c0) - SkGetPackedG32(c1);
527                db = SkGetPackedB32(c0) - SkGetPackedB32(c1);
528                da = SkGetPackedA32(c0) - SkGetPackedA32(c1);
529            } break;
530            case kRGB_565_SkColorType: {
531                uint16_t c0 = *(const uint16_t*)a;
532                uint16_t c1 = *(const uint16_t*)b;
533                dr = SkGetPackedR16(c0) - SkGetPackedR16(c1);
534                dg = SkGetPackedG16(c0) - SkGetPackedG16(c1);
535                db = SkGetPackedB16(c0) - SkGetPackedB16(c1);
536            } break;
537            case kARGB_4444_SkColorType: {
538                uint16_t c0 = *(const uint16_t*)a;
539                uint16_t c1 = *(const uint16_t*)b;
540                dr = SkGetPackedR4444(c0) - SkGetPackedR4444(c1);
541                dg = SkGetPackedG4444(c0) - SkGetPackedG4444(c1);
542                db = SkGetPackedB4444(c0) - SkGetPackedB4444(c1);
543                da = SkGetPackedA4444(c0) - SkGetPackedA4444(c1);
544            } break;
545            case kAlpha_8_SkColorType:
546            case kGray_8_SkColorType:
547                da = (const uint8_t*)a - (const uint8_t*)b;
548                break;
549            case kRGBA_F16_SkColorType: {
550                const SkPM4f* c0 = (const SkPM4f*)a;
551                const SkPM4f* c1 = (const SkPM4f*)b;
552                dr = scale255(c0->r() - c1->r());
553                dg = scale255(c0->g() - c1->g());
554                db = scale255(c0->b() - c1->b());
555                da = scale255(c0->a() - c1->a());
556            } break;
557            default:
558                return 0;
559        }
560        dr = SkAbs32(dr);
561        dg = SkAbs32(dg);
562        db = SkAbs32(db);
563        da = SkAbs32(da);
564        return SkMax32(dr, SkMax32(dg, SkMax32(db, da)));
565    }
566
567    bool equal_pixels(const SkPixmap& a, const SkPixmap& b, unsigned maxDiff) {
568        if (a.width() != b.width() ||
569            a.height() != b.height() ||
570            a.colorType() != b.colorType() ||
571            a.colorSpace() != b.colorSpace())
572        {
573            return false;
574        }
575
576        for (int y = 0; y < a.height(); ++y) {
577            const char* aptr = (const char*)a.addr(0, y);
578            const char* bptr = (const char*)b.addr(0, y);
579            if (memcmp(aptr, bptr, a.width() * a.info().bytesPerPixel())) {
580                for (int x = 0; x < a.width(); ++x) {
581                    if (diff(a.colorType(), a.addr(x, y), b.addr(x, y)) > maxDiff) {
582                        return false;
583                    }
584                }
585            }
586            aptr += a.rowBytes();
587            bptr += b.rowBytes();
588        }
589        return true;
590    }
591
592    bool equal_pixels(const SkBitmap& bm0, const SkBitmap& bm1, unsigned maxDiff) {
593        SkPixmap pm0, pm1;
594        return bm0.peekPixels(&pm0) && bm1.peekPixels(&pm1) && equal_pixels(pm0, pm1, maxDiff);
595    }
596}  // namespace sk_tool_utils
597