{"id":105,"date":"2012-10-15T18:59:28","date_gmt":"2012-10-15T09:59:28","guid":{"rendered":"http:\/\/www.techscore.com\/blog\/?p=105"},"modified":"2018-11-14T16:33:59","modified_gmt":"2018-11-14T07:33:59","slug":"drawing-fractals","status":"publish","type":"post","link":"https:\/\/www.techscore.com\/blog\/2012\/10\/15\/drawing-fractals\/","title":{"rendered":"Canvas \u306e\u30d4\u30af\u30bb\u30eb\u64cd\u4f5c API \u3067\u30d5\u30e9\u30af\u30bf\u30eb\u56f3\u5f62\u3092\u63cf\u304f"},"content":{"rendered":"

\u3053\u3093\u306b\u3061\u306f\u3001\u9234\u6728\u3067\u3059\u3002<\/p>\n

\u6700\u8fd1 HTML5 \u95a2\u9023\u306e\u60c5\u5831\u3092\u8abf\u3079\u3066\u3044\u308b\u306e\u3067\u3059\u304c\u3001Canvas \u306f\u898b\u305f\u76ee\u3067\u5206\u304b\u308a\u3084\u3059\u304f\u3066\u697d\u3057\u3044\u3067\u3059\u3002<\/p>\n

\u4eca\u56de\u306f Canvas \u306b\u30d5\u30e9\u30af\u30bf\u30eb\u306e\u5b9a\u756a\u3001\u30de\u30f3\u30c7\u30eb\u30d6\u30ed\u30fc\u96c6\u5408\u3068\u30b8\u30e5\u30ea\u30a2\u96c6\u5408\u3092\u63cf\u3044\u3066\u307f\u305f\u3044\u3068\u601d\u3044\u307e\u3059\u3002<\/p>\n

\u30d5\u30e9\u30af\u30bf\u30eb\u3092\u7c21\u5358\u306b\u8aac\u660e\u3059\u308b\u3068\u3001\u90e8\u5206\u3092\u62e1\u5927\u3059\u308b\u3068\u5168\u4f53\u306b\u4f3c\u3066\u3044\u308b\uff08\u81ea\u5df1\u76f8\u4f3c\uff09\u306a\u3069\u306e\u7279\u5fb4\u3092\u6301\u3064\u3082\u306e\u3067\u3059\u3002\u8a00\u8449\u3067\u8aac\u660e\u3059\u308b\u3068\u5206\u304b\u308a\u3065\u3089\u3044\u306e\u3067\u3059\u304c\u3001\u4ee5\u4e0b\u306e\u753b\u50cf\u3092\u898b\u3066\u9802\u3051\u3070\u3001\u30d5\u30e9\u30af\u30bf\u30eb\u304c\u6301\u3064\u4e0d\u601d\u8b70\u306a\u96f0\u56f2\u6c17\u3092\u611f\u3058\u3066\u9802\u3051\u308b\u3068\u601d\u3044\u307e\u3059\u3002<\/p>\n

\"\u30de\u30f3\u30c7\u30eb\u30d6\u30ed\u30fc\u96c6\u5408\"<\/a>\"\u30b8\u30e5\u30ea\u30a2\u96c6\u5408\"<\/a><\/p>\n

\u5de6\u304c\u30de\u30f3\u30c7\u30eb\u30d6\u30ed\u30fc\u96c6\u5408\u3001\u53f3\u304c\u30b8\u30e5\u30ea\u30a2\u96c6\u5408\u3092\u305d\u308c\u305e\u308c\u8996\u899a\u5316\u3057\u305f\u3082\u306e\u3067\u3059\u3002<\/p>\n

Google \u306e\u753b\u50cf\u691c\u7d22\u3067\u300cfractal\u300d\u3092\u30ad\u30fc\u30ef\u30fc\u30c9\u306b\u691c\u7d22\u3059\u308b\u3068\u8272\u3005\u306a\u7a2e\u985e\u306e\u30d5\u30e9\u30af\u30bf\u30eb\u753b\u50cf\u3092\u898b\u3064\u3051\u308b\u3053\u3068\u304c\u3067\u304d\u307e\u3059\u3002\u898b\u308b\u3060\u3051\u3067\u3082\u697d\u3057\u3044\u306e\u3067\u3001\u8208\u5473\u306e\u3042\u308b\u65b9\u306f\u691c\u7d22\u3057\u3066\u307f\u3066\u304f\u3060\u3055\u3044\u3002<\/p>\n

Canvas \u3092\u4f7f\u3046<\/h2>\n

Canvas \u306f\u4ee5\u4e0b\u306e\u3088\u3046\u306b canvas \u8981\u7d20\u3067\u5b9a\u7fa9\u3057\u307e\u3059\u3002<\/p>\n

<canvas id=\"drawable\" width=\"256\" height=\"256\"><\/canvas><\/pre>\n
\u63cf\u753b\u9818\u57df\u306e\u5927\u304d\u3055\u306f width \u3068 height \u3067\u6307\u5b9a\u3057\u307e\u3059\u3002\u307e\u305f\u3001Javascript \u3067\u64cd\u4f5c\u3057\u3084\u3059\u3044\u3088\u3046\u306b \"drawable\" \u3068\u3044\u3046 id \u3082\u6307\u5b9a\u3057\u3066\u3044\u307e\u3059\u3002<\/p>\n
\u305d\u308c\u3067\u306f\u305f\u3081\u3057\u63cf\u304d\u3068\u3044\u3046\u3053\u3068\u3067\u3001\u5358\u7d14\u306a\u77e9\u5f62\u3092\u63cf\u753b\u3057\u3066\u307f\u307e\u3059\u3002<\/p>\n
<script>\r\n    \/\/ Canvas \u3092\u53d6\u5f97\u3059\u308b.\r\n    var canvas = document.getElementById(\"drawable\");\r\n\r\n    \/\/ \u63cf\u753b\u7528\u306e\u30b3\u30f3\u30c6\u30ad\u30b9\u30c8\u3092\u53d6\u5f97\u3059\u308b.\r\n    var context = canvas.getContext(\"2d\");\r\n\r\n    \/\/ \u5857\u308a\u3064\u3076\u3057\u30b9\u30bf\u30a4\u30eb\u3092\u6307\u5b9a\u3059\u308b.\r\n    context.fillStyle = \"#000000\";\r\n\r\n    \/\/ \u6307\u5b9a\u3057\u305f\u7bc4\u56f2\u3092\u5857\u308a\u3064\u3076\u3059.\r\n    context.fillRect(0, 0, 100, 100);\r\n<\/script><\/pre>\n
Canvas \u306b\u63cf\u753b\u3059\u308b\u306b\u306f\u3001document.getElementById(\"drawable\") \u3067\u4f5c\u6210\u3057\u305f Canvas \u3092\u53d6\u5f97\u3057\u3001canvas.getContext(\"2d\") \u3067\u63cf\u753b\u7528\u306e\u30b3\u30f3\u30c6\u30ad\u30b9\u30c8\u3092\u53d6\u5f97\u3057\u307e\u3059\u3002\u30b3\u30f3\u30c6\u30ad\u30b9\u30c8\u306b\u306f\u63cf\u753b\u7528\u306e\u30e1\u30bd\u30c3\u30c9\u304c\u3044\u304f\u3064\u304b\u63d0\u4f9b\u3055\u308c\u3066\u3044\u307e\u3059\u306e\u3067\u3001\u305d\u308c\u3089\u3092\u7528\u3044\u3066\u597d\u304d\u306b\u63cf\u753b\u3059\u308b\u3053\u3068\u304c\u3067\u304d\u307e\u3059\u3002\u3053\u3053\u3067\u306f fillStyle \u306b\u5857\u308a\u3064\u3076\u3057\u30b9\u30bf\u30a4\u30eb\u3092\u8a2d\u5b9a\u5f8c\u3001fillRect() \u3067\u77e9\u5f62\u3092\u63cf\u753b\u3057\u3066\u3044\u307e\u3059\u3002<\/p>\n
\u4e0a\u8a18\u30b3\u30fc\u30c9\u3092\u5b9f\u884c\u3059\u308b\u3068\u3001\u4ee5\u4e0b\u306e\u3088\u3046\u306a\u753b\u50cf\u304c\u5f97\u3089\u308c\u308b\u306f\u305a\u3067\u3059\u3002<\/p>\n
\"\u9ed2\"<\/a><\/p>\n
context \u306b\u306f\u4ed6\u306b\u3082\u591a\u304f\u306e\u6a5f\u80fd\u304c\u3042\u308a\u307e\u3059\u3002\u4f8b\u3048\u3070\u3001\u30b0\u30e9\u30c7\u30fc\u30b7\u30e7\u30f3\u3067\u63cf\u753b\u3059\u308b\u3053\u3068\u3084\u3001\u30d9\u30b8\u30a7\u66f2\u7dda\u3092\u63cf\u304f\u3053\u3068\u304c\u3067\u304d\u307e\u3059\u3002<\/p>\n
\u30d4\u30af\u30bb\u30eb\u64cd\u4f5c API<\/h2>\n
\u30b3\u30f3\u30c6\u30ad\u30b9\u30c8\u304c\u6301\u3064\u9ad8\u30ec\u30d9\u30eb API \u306f\u975e\u5e38\u306b\u4fbf\u5229\u3067\u3059\u304c\u3001\u6642\u306b\u306f\u30d4\u30af\u30bb\u30eb\u30c7\u30fc\u30bf\u3092\u76f4\u63a5\u6271\u3044\u305f\u3044\u3053\u3068\u3082\u3042\u308a\u307e\u3059\u3002\u305d\u306e\u3088\u3046\u306a\u6642\u306e\u305f\u3081\u306b\u3001\u30d4\u30af\u30bb\u30eb\u64cd\u4f5c API \u3068\u3044\u3046\u3082\u306e\u304c\u7528\u610f\u3055\u308c\u3066\u3044\u307e\u3059\u3002<\/p>\n
\u4ee5\u4e0b\u306e\u3088\u3046\u306b context.getImageData() \u3067\u53d6\u5f97\u3067\u304d\u308b ImageData \u30aa\u30d6\u30b8\u30a7\u30af\u30c8\u3092\u901a\u3058\u3066\u30d4\u30af\u30bb\u30eb\u30c7\u30fc\u30bf\u306b\u30a2\u30af\u30bb\u30b9\u3059\u308b\u3053\u3068\u304c\u3067\u304d\u307e\u3059\u3002<\/p>\n
<script>\r\n    var canvas = document.getElementById(\"drawable\");\r\n    var context = canvas.getContext(\"2d\");\r\n\r\n    \/\/ imageData \u3092\u901a\u3058\u3066\u30d4\u30af\u30bb\u30eb\u30c7\u30fc\u30bf\u306b\u30a2\u30af\u30bb\u30b9\u3067\u304d\u307e\u3059.\r\n    \/\/ imageData.width ... \u6a2a\u5e45\r\n    \/\/ imageData.height ... \u7e26\u5e45\r\n    \/\/ imageData.data \u304c\u30d4\u30af\u30bb\u30eb\u30c7\u30fc\u30bf\u306e\u914d\u5217 (R, G, B, A, R, G, B, A, ... \u306e\u7e70\u308a\u8fd4\u3057)\r\n    var imageData = context.getImageData(0, 0, canvas.width, canvas.height);\r\n    \/\/ ... \u30d4\u30af\u30bb\u30eb\u30c7\u30fc\u30bf\u3092\u64cd\u4f5c\u3059\u308b.\r\n\r\n    \/\/ \u30d4\u30af\u30bb\u30eb\u30c7\u30fc\u30bf\u3092\u63cf\u753b\u3059\u308b.\r\n    context.putImageData(imageData, 0, 0);\r\n<\/script><\/pre>\n
\u30b3\u30fc\u30c9\u4e2d\u306e\u30b3\u30e1\u30f3\u30c8\u306b\u3082\u8a18\u8ff0\u3057\u3066\u3044\u307e\u3059\u304c\u3001imageData.data \u304c\u30d4\u30af\u30bb\u30eb\u30c7\u30fc\u30bf\u306e\u914d\u5217\u3067\u3059\u3002<\/p>\n
\u914d\u5217\u306f 4 \u8981\u7d20\u3067 1 \u30d4\u30af\u30bb\u30eb\u5206\u306e\u60c5\u5831\u3092\u6301\u3061\u3001\u5148\u982d\u304b\u3089\u9806\u306b\u300c\u8d64(R)\u300d\u3001\u300c\u7dd1(G)\u300d\u3001\u300c\u9752(B)\u300d\u3001\u300c\u4e0d\u900f\u660e\u5ea6(A)\u300d\u3001\u300c\u8d64(R)\u300d\u3001\u300c\u7dd1(G)\u300d\u3001\u300c\u9752(B)\u300d\u3001\u300c\u4e0d\u900f\u660e\u5ea6(A)\u300d\u3001\u30fb\u30fb\u30fb\u3068\u3044\u3046\u9806\u756a\u3067\u60c5\u5831\u304c\u53ce\u3081\u3089\u308c\u3066\u3044\u307e\u3059\u3002\u3064\u307e\u308a\u3001\u5ea7\u6a19\u304c (x, y) \u306e\u8272\u60c5\u5831\u306b\u306f\u4ee5\u4e0b\u306e\u3088\u3046\u306b\u30a2\u30af\u30bb\u30b9\u3057\u307e\u3059\u3002<\/p>\n
imageData.data[(y * imageData.width + x) * 4 + 0] ... \u8d64(R)\r\nimageData.data[(y * imageData.width + x) * 4 + 1] ... \u7dd1(G)\r\nimageData.data[(y * imageData.width + x) * 4 + 2] ... \u9752(B)\r\nimageData.data[(y * imageData.width + x) * 4 + 3] ... \u4e0d\u900f\u660e\u5ea6(A)<\/pre>\n
\u4f8b\u3068\u3057\u3066\u3001\u5168\u30d4\u30af\u30bb\u30eb\u3092\u8d64\u304f\u5857\u308a\u3064\u3076\u3059\u30b3\u30fc\u30c9\u306f\u4ee5\u4e0b\u306e\u3088\u3046\u306b\u306a\u308a\u307e\u3059\u3002<\/p>\n
for(var y = 0; y < imageData.height; y++) {\r\n    for(var x = 0; x < imageData.width; x++) {\r\n        imageData.data[(y * imageData.width + x) * 4 + 0] = 0xFF; \/\/ \u8d64 (R)\r\n        imageData.data[(y * imageData.width + x) * 4 + 1] = 0x00; \/\/ \u7dd1 (G)\r\n        imageData.data[(y * imageData.width + x) * 4 + 2] = 0x00; \/\/ \u9752 (B)\r\n        imageData.data[(y * imageData.width + x) * 4 + 3] = 0xFF; \/\/ \u4e0d\u900f\u660e\u5ea6 (A)\r\n    }\r\n}<\/pre>\n
\u5b9f\u884c\u3059\u308b\u3068\u3001\u4ee5\u4e0b\u306e\u753b\u50cf\u304c\u5f97\u3089\u308c\u307e\u3059\u3002
\n\"\u8d64\"<\/a><\/p>\n
\u30d5\u30e9\u30af\u30bf\u30eb\u753b\u50cf\u3092\u63cf\u304f<\/h2>\n
\u3055\u3066\u3001\u30d4\u30af\u30bb\u30eb\u64cd\u4f5c\u306b\u6163\u308c\u3066\u304d\u305f\u3068\u3053\u308d\u3067\u3001\u30d5\u30e9\u30af\u30bf\u30eb\u753b\u50cf\u3092\u63cf\u3044\u3066\u307f\u305f\u3044\u3068\u601d\u3044\u307e\u3059\u3002\u5192\u982d\u3067\u3054\u7d39\u4ecb\u3057\u305f\u30de\u30f3\u30c7\u30eb\u30d6\u30ed\u30fc\u96c6\u5408\u3068\u30b8\u30e5\u30ea\u30a2\u96c6\u5408\u3092\u63cf\u304d\u307e\u3059\u3002<\/p>\n
<script>\r\n    function drawMandelbrotSet(imageData) {\r\n        var minReal = -2.0;\r\n        var maxReal = +1.0;\r\n        var minImag = -1.5;\r\n        var maxImag = +1.5;\r\n\r\n        for(var y = 0; y < imageData.height; y++) {\r\n            for(var x = 0; x < imageData.width; x++) {\r\n                var zReal = 0.0;\r\n                var zImag = 0.0;\r\n                var cReal = (maxReal - minReal) \/ imageData.width * x + minReal;\r\n                var cImag = (maxImag - minImag) \/ imageData.height * y + minImag;\r\n                setPixelColor(imageData, x, y, zReal, zImag, cReal, cImag);\r\n            }\r\n        }\r\n    }\r\n\r\n    function drawJuliaSet(imageData) {\r\n        var minReal = -1.5;\r\n        var maxReal = +1.5;\r\n        var minImag = -1.5;\r\n        var maxImag = +1.5;\r\n\r\n        for(var y = 0; y < imageData.height; y++) {\r\n            for(var x = 0; x < imageData.width; x++) {\r\n                var zReal = (maxReal - minReal) \/ imageData.width * x + minReal;\r\n                var zImag = (maxImag - minImag) \/ imageData.height * y + minImag;\r\n                var cReal = 0.3;\r\n                var cImag = 0.5;\r\n                setPixelColor(imageData, x, y, zReal, zImag, cReal, cImag);\r\n            }\r\n        }\r\n    }\r\n\r\n    function setPixelColor(imageData, x, y, zReal, zImag, cReal, cImag) {\r\n        for(var i = 0; i < 100; i++) {\r\n            if(zReal * zReal + zImag * zImag >= 4) {\r\n                imageData.data[(y * imageData.width + x) * 4 + 0] = i * 10 % 256;\r\n                imageData.data[(y * imageData.width + x) * 4 + 1] = i * 20 % 256;\r\n                imageData.data[(y * imageData.width + x) * 4 + 2] = i * 30 % 256;\r\n                imageData.data[(y * imageData.width + x) * 4 + 3] = 0xFF;\r\n                return;\r\n            }\r\n\r\n            var real = zReal * zReal - zImag * zImag + cReal;\r\n            var imag = 2 * zReal * zImag + cImag;\r\n            zReal = real;\r\n            zImag = imag;\r\n        }\r\n\r\n        imageData.data[(y * imageData.width + x) * 4 + 0] = 0x00;\r\n        imageData.data[(y * imageData.width + x) * 4 + 1] = 0x00;\r\n        imageData.data[(y * imageData.width + x) * 4 + 2] = 0x00;\r\n        imageData.data[(y * imageData.width + x) * 4 + 3] = 0xFF;\r\n    }\r\n\r\n    var canvas = document.getElementById(\"drawable\");\r\n    var context = canvas.getContext(\"2d\");\r\n    var imageData = context.getImageData(0, 0, canvas.width, canvas.height)\r\n\r\n    \/\/ \u30de\u30f3\u30c7\u30eb\u30d6\u30ed\u30fc\u96c6\u5408\u3092\u63cf\u304f.\r\n    drawMandelbrotSet(imageData);\r\n\r\n    \/\/ \u30b8\u30e5\u30ea\u30a2\u96c6\u5408\u3092\u63cf\u304f.\r\n    \/\/ drawJuliaSet(imageData);\r\n\r\n    context.putImageData(imageData, 0, 0);\r\n<\/script><\/pre>\n
\u30b3\u30fc\u30c9\u304c\u9577\u304f\u306a\u308b\u305f\u3081\u3001\u3044\u304f\u3064\u304b\u306e\u95a2\u6570\u306b\u5206\u5272\u3057\u307e\u3057\u305f\u3002<\/p>\n
drawMandelbrotSet() \u304c\u30de\u30f3\u30c7\u30eb\u30d6\u30ed\u30fc\u96c6\u5408\u3092\u63cf\u753b\u3059\u308b\u30e1\u30bd\u30c3\u30c9\u3001drawJuliaSet() \u304c\u30b8\u30e5\u30ea\u30a2\u96c6\u5408\u3092\u63cf\u753b\u3059\u308b\u30e1\u30bd\u30c3\u30c9\u3067\u3059\u3002\u30b8\u30e5\u30ea\u30a2\u96c6\u5408\u3092\u63cf\u304d\u305f\u3044\u5834\u5408\u306f\u300c\/\/ \u30b8\u30e5\u30ea\u30a2\u96c6\u5408\u3092\u63cf\u304f\u300d\u306e\u90e8\u5206\u306e\u30b3\u30e1\u30f3\u30c8\u30a2\u30a6\u30c8\u3092\u5916\u3057\u307e\u3059\u3002<\/p>\n
\u5b9f\u884c\u3059\u308b\u3068\u4ee5\u4e0b\u306e\u3088\u3046\u306a\u753b\u50cf\u304c\u5f97\u3089\u308c\u307e\u3059\u3002<\/p>\n
\"\u30de\u30f3\u30c7\u30eb\u30d6\u30ed\u30fc\u96c6\u5408\"<\/a>\"\u30b8\u30e5\u30ea\u30a2\u96c6\u5408\"<\/a><\/p>\n
\u30d4\u30af\u30bb\u30eb\u64cd\u4f5c API \u306f\u3001\u6700\u521d\u306b\u7d39\u4ecb\u3057\u305f fillRect() \u306e\u3088\u3046\u306a\u9ad8\u6c34\u6e96 API \u3068\u6bd4\u8f03\u3059\u308b\u3068\u975e\u5e38\u306b\u9ad8\u901f\u3067\u3059\u3002\u4eca\u56de\u306e\u3088\u3046\u306b 1 \u30d4\u30af\u30bb\u30eb\u3054\u3068\u306b\u8a08\u7b97\u3067\u8272\u3092\u6c42\u3081\u308b\u3088\u3046\u306a\u30b1\u30fc\u30b9\u3067\u306f\u3001\u30d4\u30af\u30bb\u30eb\u64cd\u4f5c API \u304c\u304a\u3059\u3059\u3081\u3067\u3059\u3002<\/p>\n
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