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      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 "SkBitmap.h"
     10 #include "SkData.h"
     11 #include "SkImageDecoder.h"
     12 #include "SkImageEncoder.h"
     13 #include "SkStream.h"
     14 #include "SkTemplates.h"
     15 #include "SkTypes.h"
     16 
     17 bool are_buffers_equal(SkData* skdata1, SkData* skdata2) {
     18     if ((NULL == skdata1) || (NULL == skdata2)) {
     19         return false;
     20     }
     21     if (skdata1->size() != skdata2->size()) {
     22         return false;
     23     }
     24     return (0 == memcmp(skdata1->data(), skdata2->data(), skdata1->size()));
     25 }
     26 
     27 SkData* read_file(const char* file_path) {
     28     SkData* data = SkData::NewFromFileName(file_path);
     29     if (!data) {
     30         SkDebugf("WARNING: could not open file <%s> for reading\n", file_path);
     31     }
     32     return data;
     33 }
     34 
     35 bool get_bitmap(SkData* fileBits, DiffResource& resource, SkImageDecoder::Mode mode) {
     36     SkMemoryStream stream(fileBits->data(), fileBits->size());
     37 
     38     SkImageDecoder* codec = SkImageDecoder::Factory(&stream);
     39     if (NULL == codec) {
     40         SkDebugf("ERROR: no codec found for <%s>\n", resource.fFullPath.c_str());
     41         resource.fStatus = DiffResource::kCouldNotDecode_Status;
     42         return false;
     43     }
     44 
     45     // In debug, the DLL will automatically be unloaded when this is deleted,
     46     // but that shouldn't be a problem in release mode.
     47     SkAutoTDelete<SkImageDecoder> ad(codec);
     48 
     49     stream.rewind();
     50     if (!codec->decode(&stream, &resource.fBitmap, kN32_SkColorType, mode)) {
     51         SkDebugf("ERROR: codec failed for basePath <%s>\n", resource.fFullPath.c_str());
     52         resource.fStatus = DiffResource::kCouldNotDecode_Status;
     53         return false;
     54     }
     55 
     56     resource.fStatus = DiffResource::kDecoded_Status;
     57     return true;
     58 }
     59 
     60 /** Thanks to PNG, we need to force all pixels 100% opaque. */
     61 static void force_all_opaque(const SkBitmap& bitmap) {
     62    SkAutoLockPixels lock(bitmap);
     63    for (int y = 0; y < bitmap.height(); y++) {
     64        for (int x = 0; x < bitmap.width(); x++) {
     65            *bitmap.getAddr32(x, y) |= (SK_A32_MASK << SK_A32_SHIFT);
     66        }
     67    }
     68 }
     69 
     70 bool write_bitmap(const SkString& path, const SkBitmap& bitmap) {
     71     SkBitmap copy;
     72     bitmap.copyTo(&copy, kN32_SkColorType);
     73     force_all_opaque(copy);
     74     return SkImageEncoder::EncodeFile(path.c_str(), copy,
     75                                       SkImageEncoder::kPNG_Type, 100);
     76 }
     77 
     78 /// Return a copy of the "input" string, within which we have replaced all instances
     79 /// of oldSubstring with newSubstring.
     80 ///
     81 /// TODO: If we like this, we should move it into the core SkString implementation,
     82 /// adding more checks and ample test cases, and paying more attention to efficiency.
     83 static SkString replace_all(const SkString &input,
     84                             const char oldSubstring[], const char newSubstring[]) {
     85     SkString output;
     86     const char *input_cstr = input.c_str();
     87     const char *first_char = input_cstr;
     88     const char *match_char;
     89     size_t oldSubstringLen = strlen(oldSubstring);
     90     while ((match_char = strstr(first_char, oldSubstring))) {
     91         output.append(first_char, (match_char - first_char));
     92         output.append(newSubstring);
     93         first_char = match_char + oldSubstringLen;
     94     }
     95     output.append(first_char);
     96     return output;
     97 }
     98 
     99 static SkString filename_to_derived_filename(const SkString& filename, const char *suffix) {
    100     SkString diffName (filename);
    101     const char* cstring = diffName.c_str();
    102     size_t dotOffset = strrchr(cstring, '.') - cstring;
    103     diffName.remove(dotOffset, diffName.size() - dotOffset);
    104     diffName.append(suffix);
    105 
    106     // In case we recursed into subdirectories, replace slashes with something else
    107     // so the diffs will all be written into a single flat directory.
    108     diffName = replace_all(diffName, PATH_DIV_STR, "_");
    109     return diffName;
    110 }
    111 
    112 SkString filename_to_diff_filename(const SkString& filename) {
    113     return filename_to_derived_filename(filename, "-diff.png");
    114 }
    115 
    116 SkString filename_to_white_filename(const SkString& filename) {
    117     return filename_to_derived_filename(filename, "-white.png");
    118 }
    119 
    120 void create_and_write_diff_image(DiffRecord* drp,
    121                                  DiffMetricProc dmp,
    122                                  const int colorThreshold,
    123                                  const SkString& outputDir,
    124                                  const SkString& filename) {
    125     const int w = drp->fBase.fBitmap.width();
    126     const int h = drp->fBase.fBitmap.height();
    127 
    128     if (w != drp->fComparison.fBitmap.width() || h != drp->fComparison.fBitmap.height()) {
    129         drp->fResult = DiffRecord::kDifferentSizes_Result;
    130     } else {
    131         drp->fDifference.fBitmap.allocN32Pixels(w, h);
    132 
    133         drp->fWhite.fBitmap.allocN32Pixels(w, h);
    134 
    135         SkASSERT(DiffRecord::kUnknown_Result == drp->fResult);
    136         compute_diff(drp, dmp, colorThreshold);
    137         SkASSERT(DiffRecord::kUnknown_Result != drp->fResult);
    138     }
    139 
    140     if (outputDir.isEmpty()) {
    141         drp->fDifference.fStatus = DiffResource::kUnspecified_Status;
    142         drp->fWhite.fStatus = DiffResource::kUnspecified_Status;
    143 
    144     } else {
    145         drp->fDifference.fFilename = filename_to_diff_filename(filename);
    146         drp->fDifference.fFullPath = outputDir;
    147         drp->fDifference.fFullPath.append(drp->fDifference.fFilename);
    148         drp->fDifference.fStatus = DiffResource::kSpecified_Status;
    149 
    150         drp->fWhite.fFilename = filename_to_white_filename(filename);
    151         drp->fWhite.fFullPath = outputDir;
    152         drp->fWhite.fFullPath.append(drp->fWhite.fFilename);
    153         drp->fWhite.fStatus = DiffResource::kSpecified_Status;
    154 
    155         if (DiffRecord::kDifferentPixels_Result == drp->fResult) {
    156             if (write_bitmap(drp->fDifference.fFullPath, drp->fDifference.fBitmap)) {
    157                 drp->fDifference.fStatus = DiffResource::kExists_Status;
    158             } else {
    159                 drp->fDifference.fStatus = DiffResource::kDoesNotExist_Status;
    160             }
    161             if (write_bitmap(drp->fWhite.fFullPath, drp->fWhite.fBitmap)) {
    162                 drp->fWhite.fStatus = DiffResource::kExists_Status;
    163             } else {
    164                 drp->fWhite.fStatus = DiffResource::kDoesNotExist_Status;
    165             }
    166         }
    167     }
    168 }
    169