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 "skdiff.h"
8#include "skdiff_utils.h"
9#include "sk_tool_utils.h"
10#include "SkBitmap.h"
11#include "SkCodec.h"
12#include "SkData.h"
13#include "SkImageEncoder.h"
14#include "SkStream.h"
15#include "SkTypes.h"
16
17#include <memory>
18
19bool 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
29sk_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
37bool get_bitmap(sk_sp<SkData> fileBits, DiffResource& resource, bool sizeOnly) {
38    std::unique_ptr<SkCodec> codec(SkCodec::NewFromData(fileBits));
39    if (!codec) {
40        SkDebugf("ERROR: could not create codec for <%s>\n", resource.fFullPath.c_str());
41        resource.fStatus = DiffResource::kCouldNotDecode_Status;
42        return false;
43    }
44
45    if (!resource.fBitmap.setInfo(codec->getInfo().makeColorType(kN32_SkColorType))) {
46        SkDebugf("ERROR: could not set bitmap info for <%s>\n", resource.fFullPath.c_str());
47        resource.fStatus = DiffResource::kCouldNotDecode_Status;
48        return false;
49    }
50
51    if (sizeOnly) {
52        return true;
53    }
54
55    if (!resource.fBitmap.tryAllocPixels()) {
56        SkDebugf("ERROR: could not allocate pixels for <%s>\n", resource.fFullPath.c_str());
57        resource.fStatus = DiffResource::kCouldNotDecode_Status;
58        return false;
59    }
60
61    if (SkCodec::kSuccess != codec->getPixels(resource.fBitmap.info(),
62            resource.fBitmap.getPixels(), resource.fBitmap.rowBytes())) {
63        SkDebugf("ERROR: codec failed for basePath <%s>\n", resource.fFullPath.c_str());
64        resource.fStatus = DiffResource::kCouldNotDecode_Status;
65        return false;
66    }
67
68    resource.fStatus = DiffResource::kDecoded_Status;
69    return true;
70}
71
72/** Thanks to PNG, we need to force all pixels 100% opaque. */
73static void force_all_opaque(const SkBitmap& bitmap) {
74   for (int y = 0; y < bitmap.height(); y++) {
75       for (int x = 0; x < bitmap.width(); x++) {
76           *bitmap.getAddr32(x, y) |= (SK_A32_MASK << SK_A32_SHIFT);
77       }
78   }
79}
80
81bool write_bitmap(const SkString& path, const SkBitmap& bitmap) {
82    SkBitmap copy;
83    sk_tool_utils::copy_to(&copy, kN32_SkColorType, bitmap);
84    force_all_opaque(copy);
85    return sk_tool_utils::EncodeImageToFile(path.c_str(), copy,
86                                      SkEncodedImageFormat::kPNG, 100);
87}
88
89/// Return a copy of the "input" string, within which we have replaced all instances
90/// of oldSubstring with newSubstring.
91///
92/// TODO: If we like this, we should move it into the core SkString implementation,
93/// adding more checks and ample test cases, and paying more attention to efficiency.
94static SkString replace_all(const SkString &input,
95                            const char oldSubstring[], const char newSubstring[]) {
96    SkString output;
97    const char *input_cstr = input.c_str();
98    const char *first_char = input_cstr;
99    const char *match_char;
100    size_t oldSubstringLen = strlen(oldSubstring);
101    while ((match_char = strstr(first_char, oldSubstring))) {
102        output.append(first_char, (match_char - first_char));
103        output.append(newSubstring);
104        first_char = match_char + oldSubstringLen;
105    }
106    output.append(first_char);
107    return output;
108}
109
110static SkString filename_to_derived_filename(const SkString& filename, const char *suffix) {
111    SkString diffName (filename);
112    const char* cstring = diffName.c_str();
113    size_t dotOffset = strrchr(cstring, '.') - cstring;
114    diffName.remove(dotOffset, diffName.size() - dotOffset);
115    diffName.append(suffix);
116
117    // In case we recursed into subdirectories, replace slashes with something else
118    // so the diffs will all be written into a single flat directory.
119    diffName = replace_all(diffName, PATH_DIV_STR, "_");
120    return diffName;
121}
122
123SkString filename_to_diff_filename(const SkString& filename) {
124    return filename_to_derived_filename(filename, "-diff.png");
125}
126
127SkString filename_to_white_filename(const SkString& filename) {
128    return filename_to_derived_filename(filename, "-white.png");
129}
130
131void create_and_write_diff_image(DiffRecord* drp,
132                                 DiffMetricProc dmp,
133                                 const int colorThreshold,
134                                 const SkString& outputDir,
135                                 const SkString& filename) {
136    const int w = drp->fBase.fBitmap.width();
137    const int h = drp->fBase.fBitmap.height();
138
139    if (w != drp->fComparison.fBitmap.width() || h != drp->fComparison.fBitmap.height()) {
140        drp->fResult = DiffRecord::kDifferentSizes_Result;
141    } else {
142        drp->fDifference.fBitmap.allocN32Pixels(w, h);
143
144        drp->fWhite.fBitmap.allocN32Pixels(w, h);
145
146        SkASSERT(DiffRecord::kUnknown_Result == drp->fResult);
147        compute_diff(drp, dmp, colorThreshold);
148        SkASSERT(DiffRecord::kUnknown_Result != drp->fResult);
149    }
150
151    if (outputDir.isEmpty()) {
152        drp->fDifference.fStatus = DiffResource::kUnspecified_Status;
153        drp->fWhite.fStatus = DiffResource::kUnspecified_Status;
154
155    } else {
156        drp->fDifference.fFilename = filename_to_diff_filename(filename);
157        drp->fDifference.fFullPath = outputDir;
158        drp->fDifference.fFullPath.append(drp->fDifference.fFilename);
159        drp->fDifference.fStatus = DiffResource::kSpecified_Status;
160
161        drp->fWhite.fFilename = filename_to_white_filename(filename);
162        drp->fWhite.fFullPath = outputDir;
163        drp->fWhite.fFullPath.append(drp->fWhite.fFilename);
164        drp->fWhite.fStatus = DiffResource::kSpecified_Status;
165
166        if (DiffRecord::kDifferentPixels_Result == drp->fResult) {
167            if (write_bitmap(drp->fDifference.fFullPath, drp->fDifference.fBitmap)) {
168                drp->fDifference.fStatus = DiffResource::kExists_Status;
169            } else {
170                drp->fDifference.fStatus = DiffResource::kDoesNotExist_Status;
171            }
172            if (write_bitmap(drp->fWhite.fFullPath, drp->fWhite.fBitmap)) {
173                drp->fWhite.fStatus = DiffResource::kExists_Status;
174            } else {
175                drp->fWhite.fStatus = DiffResource::kDoesNotExist_Status;
176            }
177        }
178    }
179}
180