corrade-nucleus-nucleons – Blame information for rev 36
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Rev | Author | Line No. | Line |
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36 | office | 1 | // compare |
2 | |||
3 | var spawn = require('cross-spawn'); |
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4 | |||
5 | /** |
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6 | * Compare two images uses graphicsmagicks `compare` command. |
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7 | * |
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8 | * gm.compare(img1, img2, 0.4, function (err, equal, equality) { |
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9 | * if (err) return handle(err); |
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10 | * console.log('The images are equal: %s', equal); |
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11 | * console.log('There equality was %d', equality); |
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12 | * }); |
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13 | * |
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14 | * @param {String} orig Path to an image. |
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15 | * @param {String} compareTo Path to another image to compare to `orig`. |
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16 | * @param {Number|Object} [options] Options object or the amount of difference to tolerate before failing - defaults to 0.4 |
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17 | * @param {Function} cb(err, Boolean, equality, rawOutput) |
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18 | */ |
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19 | |||
20 | module.exports = exports = function (proto) { |
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21 | function compare(orig, compareTo, options, cb) { |
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22 | |||
23 | var isImageMagick = this._options && this._options.imageMagick; |
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24 | var appPath = this._options && this._options.appPath || ''; |
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25 | var bin = isImageMagick |
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26 | ? appPath + 'compare' |
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27 | : appPath + 'gm' |
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28 | var args = ['-metric', 'mse', orig, compareTo] |
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29 | if (!isImageMagick) { |
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30 | args.unshift('compare'); |
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31 | } |
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32 | var tolerance = 0.4; |
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33 | // outputting the diff image |
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34 | if (typeof options === 'object') { |
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35 | |||
36 | if (options.highlightColor && options.highlightColor.indexOf('"') < 0) { |
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37 | options.highlightColor = '"' + options.highlightColor + '"'; |
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38 | } |
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39 | |||
40 | if (options.file) { |
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41 | if (typeof options.file !== 'string') { |
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42 | throw new TypeError('The path for the diff output is invalid'); |
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43 | } |
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44 | // graphicsmagick defaults to red |
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45 | if (options.highlightColor) { |
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46 | args.push('-highlight-color'); |
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47 | args.push(options.highlightColor); |
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48 | } |
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49 | if (options.highlightStyle) { |
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50 | args.push('-highlight-style') |
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51 | args.push(options.highlightStyle) |
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52 | } |
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53 | // For IM, filename is the last argument. For GM it's `-file <filename>` |
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54 | if (!isImageMagick) { |
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55 | args.push('-file'); |
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56 | } |
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57 | args.push(options.file); |
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58 | } |
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59 | |||
60 | if (typeof options.tolerance != 'undefined') { |
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61 | if (typeof options.tolerance !== 'number') { |
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62 | throw new TypeError('The tolerance value should be a number'); |
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63 | } |
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64 | tolerance = options.tolerance; |
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65 | } |
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66 | } else { |
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67 | // For ImageMagick diff file is required but we don't care about it, so null it out |
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68 | if (isImageMagick) { |
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69 | args.push('null:'); |
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70 | } |
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71 | |||
72 | if (typeof options == 'function') { |
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73 | cb = options; // tolerance value not provided, flip the cb place |
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74 | } else { |
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75 | tolerance = options |
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76 | } |
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77 | } |
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78 | |||
79 | var proc = spawn(bin, args); |
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80 | var stdout = ''; |
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81 | var stderr = ''; |
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82 | proc.stdout.on('data',function(data) { stdout+=data }); |
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83 | proc.stderr.on('data',function(data) { stderr+=data }); |
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84 | proc.on('close', function (code) { |
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85 | // ImageMagick returns err code 2 if err, 0 if similar, 1 if dissimilar |
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86 | if (isImageMagick) { |
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87 | if (code === 0) { |
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88 | return cb(null, 0 <= tolerance, 0, stdout); |
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89 | } |
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90 | else if (code === 1) { |
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91 | err = null; |
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92 | stdout = stderr; |
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93 | } else { |
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94 | return cb(stderr); |
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95 | } |
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96 | } else { |
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97 | if(code !== 0) { |
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98 | return cb(stderr); |
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99 | } |
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100 | } |
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101 | // Since ImageMagick similar gives err code 0 and no stdout, there's really no matching |
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102 | // Otherwise, output format for IM is `12.00 (0.123)` and for GM it's `Total: 0.123` |
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103 | var regex = isImageMagick ? /\((\d+\.?[\d\-\+e]*)\)/m : /Total: (\d+\.?\d*)/m; |
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104 | var match = regex.exec(stdout); |
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105 | if (!match) { |
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106 | err = new Error('Unable to parse output.\nGot ' + stdout); |
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107 | return cb(err); |
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108 | } |
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109 | |||
110 | var equality = parseFloat(match[1]); |
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111 | cb(null, equality <= tolerance, equality, stdout, orig, compareTo); |
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112 | }); |
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113 | } |
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114 | |||
115 | if (proto) { |
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116 | proto.compare = compare; |
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117 | } |
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118 | return compare; |
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119 | }; |
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120 |