xref: /aosp_15_r20/external/skia/tools/skdiff/skdiff_utils.cpp (revision c8dee2aa9b3f27cf6c858bd81872bdeb2c07ed17)
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 #include "include/codec/SkPngDecoder.h"
8 #include "include/core/SkBitmap.h"
9 #include "include/core/SkData.h"
10 #include "include/core/SkPixelRef.h"
11 #include "include/core/SkStream.h"
12 #include "include/core/SkTypes.h"
13 #include "include/encode/SkPngEncoder.h"
14 #include "tools/skdiff/skdiff.h"
15 #include "tools/skdiff/skdiff_utils.h"
16 
17 #include <memory>
18 
are_buffers_equal(SkData * skdata1,SkData * skdata2)19 bool are_buffers_equal(SkData* skdata1, SkData* skdata2) {
20     if ((nullptr == skdata1) || (nullptr == skdata2)) {
21         return false;
22     }
23     if (skdata1->size() != skdata2->size()) {
24         return false;
25     }
26     return (0 == memcmp(skdata1->data(), skdata2->data(), skdata1->size()));
27 }
28 
read_file(const char * file_path)29 sk_sp<SkData> read_file(const char* file_path) {
30     sk_sp<SkData> data(SkData::MakeFromFileName(file_path));
31     if (!data) {
32         SkDebugf("WARNING: could not open file <%s> for reading\n", file_path);
33     }
34     return data;
35 }
36 
get_bitmap(sk_sp<SkData> fileBits,DiffResource & resource,bool sizeOnly,bool ignoreColorSpace)37 bool get_bitmap(sk_sp<SkData> fileBits, DiffResource& resource, bool sizeOnly,
38                 bool ignoreColorSpace) {
39     static constexpr const SkCodecs::Decoder decoders[] = {
40         SkPngDecoder::Decoder(),
41     };
42 
43     auto codec = SkCodec::MakeFromData(std::move(fileBits), decoders);
44     if (!codec) {
45         SkDebugf("ERROR: could not create codec for <%s>\n", resource.fFullPath.c_str());
46         resource.fStatus = DiffResource::kCouldNotDecode_Status;
47         return false;
48     }
49 
50     // If we're "ignoring" color space, then we want the raw pixel values from each image, so we
51     // decode to the original color space. If we want to account for color spaces, then we want to
52     // decode each image to the same color space, so that colors that are the "same" (but encoded
53     // differently) are transformed to some canonical representation prior to comparison.
54     //
55     // TODO: Use something wider than sRGB to avoid clipping with out-of-gamut colors.
56     SkImageInfo info = codec->getInfo().makeColorType(kN32_SkColorType);
57     if (!ignoreColorSpace) {
58         info = info.makeColorSpace(SkColorSpace::MakeSRGB());
59     }
60 
61     if (!resource.fBitmap.setInfo(info.makeColorType(kN32_SkColorType))) {
62         SkDebugf("ERROR: could not set bitmap info for <%s>\n", resource.fFullPath.c_str());
63         resource.fStatus = DiffResource::kCouldNotDecode_Status;
64         return false;
65     }
66 
67     if (sizeOnly) {
68         return true;
69     }
70 
71     if (!resource.fBitmap.tryAllocPixels()) {
72         SkDebugf("ERROR: could not allocate pixels for <%s>\n", resource.fFullPath.c_str());
73         resource.fStatus = DiffResource::kCouldNotDecode_Status;
74         return false;
75     }
76 
77     if (SkCodec::kSuccess != codec->getPixels(resource.fBitmap.info(),
78             resource.fBitmap.getPixels(), resource.fBitmap.rowBytes())) {
79         SkDebugf("ERROR: codec failed for basePath <%s>\n", resource.fFullPath.c_str());
80         resource.fStatus = DiffResource::kCouldNotDecode_Status;
81         return false;
82     }
83 
84     resource.fStatus = DiffResource::kDecoded_Status;
85     return true;
86 }
87 
88 /** Thanks to PNG, we need to force all pixels 100% opaque. */
force_all_opaque(const SkBitmap & bitmap)89 static void force_all_opaque(const SkBitmap& bitmap) {
90    for (int y = 0; y < bitmap.height(); y++) {
91        for (int x = 0; x < bitmap.width(); x++) {
92            *bitmap.getAddr32(x, y) |= (SK_A32_MASK << SK_A32_SHIFT);
93        }
94    }
95 }
96 
write_bitmap(const SkString & path,const SkBitmap & bitmap)97 bool write_bitmap(const SkString& path, const SkBitmap& bitmap) {
98     SkBitmap copy;
99     if (!copy.tryAllocPixels(bitmap.info().makeColorType(kN32_SkColorType))) {
100         return false;
101     }
102     if (!bitmap.readPixels(copy.pixmap())) {
103         return false;
104     }
105     force_all_opaque(copy);
106 
107     SkFILEWStream file(path.c_str());
108     if (!file.isValid()) {
109         return false;
110     }
111 
112     return SkPngEncoder::Encode(&file, copy.pixmap(), {});
113 }
114 
115 /// Return a copy of the "input" string, within which we have replaced all instances
116 /// of oldSubstring with newSubstring.
117 ///
118 /// TODO: If we like this, we should move it into the core SkString implementation,
119 /// adding more checks and ample test cases, and paying more attention to efficiency.
replace_all(const SkString & input,const char oldSubstring[],const char newSubstring[])120 static SkString replace_all(const SkString &input,
121                             const char oldSubstring[], const char newSubstring[]) {
122     SkString output;
123     const char *input_cstr = input.c_str();
124     const char *first_char = input_cstr;
125     const char *match_char;
126     size_t oldSubstringLen = strlen(oldSubstring);
127     while ((match_char = strstr(first_char, oldSubstring))) {
128         output.append(first_char, (match_char - first_char));
129         output.append(newSubstring);
130         first_char = match_char + oldSubstringLen;
131     }
132     output.append(first_char);
133     return output;
134 }
135 
filename_to_derived_filename(const SkString & filename,const char * suffix)136 static SkString filename_to_derived_filename(const SkString& filename, const char *suffix) {
137     SkString diffName (filename);
138     const char* cstring = diffName.c_str();
139     size_t dotOffset = strrchr(cstring, '.') - cstring;
140     diffName.remove(dotOffset, diffName.size() - dotOffset);
141     diffName.append(suffix);
142 
143     // In case we recursed into subdirectories, replace slashes with something else
144     // so the diffs will all be written into a single flat directory.
145     diffName = replace_all(diffName, PATH_DIV_STR, "_");
146     return diffName;
147 }
148 
filename_to_diff_filename(const SkString & filename)149 SkString filename_to_diff_filename(const SkString& filename) {
150     return filename_to_derived_filename(filename, "-diff.png");
151 }
152 
filename_to_white_filename(const SkString & filename)153 SkString filename_to_white_filename(const SkString& filename) {
154     return filename_to_derived_filename(filename, "-white.png");
155 }
156 
create_and_write_diff_image(DiffRecord * drp,DiffMetricProc dmp,const int colorThreshold,const SkString & outputDir,const SkString & filename)157 void create_and_write_diff_image(DiffRecord* drp,
158                                  DiffMetricProc dmp,
159                                  const int colorThreshold,
160                                  const SkString& outputDir,
161                                  const SkString& filename) {
162     const int w = drp->fBase.fBitmap.width();
163     const int h = drp->fBase.fBitmap.height();
164 
165     if (w != drp->fComparison.fBitmap.width() || h != drp->fComparison.fBitmap.height()) {
166         drp->fResult = DiffRecord::kDifferentSizes_Result;
167     } else {
168         drp->fDifference.fBitmap.allocN32Pixels(w, h);
169 
170         drp->fWhite.fBitmap.allocN32Pixels(w, h);
171 
172         SkASSERT(DiffRecord::kUnknown_Result == drp->fResult);
173         compute_diff(drp, dmp, colorThreshold);
174         SkASSERT(DiffRecord::kUnknown_Result != drp->fResult);
175     }
176 
177     if (outputDir.isEmpty()) {
178         drp->fDifference.fStatus = DiffResource::kUnspecified_Status;
179         drp->fWhite.fStatus = DiffResource::kUnspecified_Status;
180 
181     } else {
182         drp->fDifference.fFilename = filename_to_diff_filename(filename);
183         drp->fDifference.fFullPath = outputDir;
184         drp->fDifference.fFullPath.append(drp->fDifference.fFilename);
185         drp->fDifference.fStatus = DiffResource::kSpecified_Status;
186 
187         drp->fWhite.fFilename = filename_to_white_filename(filename);
188         drp->fWhite.fFullPath = outputDir;
189         drp->fWhite.fFullPath.append(drp->fWhite.fFilename);
190         drp->fWhite.fStatus = DiffResource::kSpecified_Status;
191 
192         if (DiffRecord::kDifferentPixels_Result == drp->fResult) {
193             if (write_bitmap(drp->fDifference.fFullPath, drp->fDifference.fBitmap)) {
194                 drp->fDifference.fStatus = DiffResource::kExists_Status;
195             } else {
196                 drp->fDifference.fStatus = DiffResource::kDoesNotExist_Status;
197             }
198             if (write_bitmap(drp->fWhite.fFullPath, drp->fWhite.fBitmap)) {
199                 drp->fWhite.fStatus = DiffResource::kExists_Status;
200             } else {
201                 drp->fWhite.fStatus = DiffResource::kDoesNotExist_Status;
202             }
203         }
204     }
205 }
206