{"id":4518,"date":"2023-03-31T01:36:38","date_gmt":"2023-03-30T16:36:38","guid":{"rendered":"https:\/\/engineering.webstudio168.jp\/?p=4518"},"modified":"2023-03-31T01:36:39","modified_gmt":"2023-03-30T16:36:39","slug":"javascript-canvas-ripples","status":"publish","type":"post","link":"https:\/\/engineering.webstudio168.jp\/blog\/javascript-canvas-ripples\/","title":{"rendered":"JavaScript\u3067Canvas\u306b\u6ce2\u7d0b\u306e\u30a8\u30d5\u30a7\u30af\u30c8\u3092\u63cf\u753b\u3059\u308b\u30b5\u30f3\u30d7\u30eb\u30b9\u30af\u30ea\u30d7\u30c8"},"content":{"rendered":"\n<p class=\"wp-block-paragraph\">\u6ce2\u7d0b\u3092\u63cf\u753b\u3059\u308b\u30b5\u30f3\u30d7\u30eb\u30b3\u30fc\u30c9\u3067\u3059\u3002\u6c34\u305f\u307e\u308a\u306b\u96e8\u7c92\u304c\u843d\u3061\u308b\u3088\u3046\u306a\u611f\u3058\u306b\u306a\u3063\u3066\u3044\u307e\u3059\u3002<\/p>\n\n\n\n<canvas id=\"canvas\"><\/canvas>\n<style>\n#canvas {\n background: #333;\n width: 100%;\n}\n<\/style>\n<script>\n\/\/ Canvas\u8981\u7d20\u3092\u53d6\u5f97\u3059\u308b\nlet canvas = document.getElementById('canvas');\n\n\/\/ Canvas\u306e\u30b3\u30f3\u30c6\u30ad\u30b9\u30c8\u3092\u53d6\u5f97\u3059\u308b\nlet ctx = canvas.getContext('2d');\n\n\/\/ \u6ce2\u7d0b\u30a8\u30d5\u30a7\u30af\u30c8\u306e\u30d1\u30e9\u30e1\u30fc\u30bf\u30fc\u3092\u8a2d\u5b9a\u3059\u308b\nlet rippleEffects = [];\n\n\/\/ \u6ce2\u7d0b\u30a8\u30d5\u30a7\u30af\u30c8\u3092\u751f\u6210\u3059\u308b\u95a2\u6570\u3092\u5b9a\u7fa9\u3059\u308b\nfunction createRippleEffect() {\n  \/\/ \u6ce2\u7d0b\u306e\u30d1\u30e9\u30e1\u30fc\u30bf\u30fc\u3092\u30e9\u30f3\u30c0\u30e0\u306b\u751f\u6210\u3059\u308b\n  let centerX = Math.random() * canvas.width;\n  let centerY = Math.random() * canvas.height;\n  let radius = 0;\n  let maxRadius = Math.min(centerX, centerY);\n\n  \/\/ \u65b0\u3057\u3044\u6ce2\u7d0b\u30a8\u30d5\u30a7\u30af\u30c8\u3092\u751f\u6210\u3059\u308b\n  let rippleEffect = {\n    centerX: centerX,\n    centerY: centerY,\n    radius: radius,\n    maxRadius: maxRadius\n  };\n\n  \/\/ \u751f\u6210\u3057\u305f\u6ce2\u7d0b\u30a8\u30d5\u30a7\u30af\u30c8\u3092\u914d\u5217\u306b\u8ffd\u52a0\u3059\u308b\n  rippleEffects.push(rippleEffect);\n}\n\n\/\/ \u6ce2\u7d0b\u30a8\u30d5\u30a7\u30af\u30c8\u3092\u63cf\u753b\u3059\u308b\u95a2\u6570\u3092\u5b9a\u7fa9\u3059\u308b\nfunction drawRippleEffect(rippleEffect) {\n  \/\/ \u6ce2\u7d0b\u306e\u534a\u5f84\u3092\u5897\u52a0\u3055\u305b\u308b\n  rippleEffect.radius += 1;\n\n  \/\/ \u6ce2\u7d0b\u304c\u6700\u5927\u534a\u5f84\u306b\u9054\u3057\u305f\u5834\u5408\u306f\u3001\u914d\u5217\u304b\u3089\u6ce2\u7d0b\u30a8\u30d5\u30a7\u30af\u30c8\u3092\u524a\u9664\u3059\u308b\n  if (rippleEffect.radius > rippleEffect.maxRadius) {\n    let index = rippleEffects.indexOf(rippleEffect);\n    if (index !== -1) {\n      rippleEffects.splice(index, 1);\n    }\n    return;\n  }\n\n  \/\/ \u6ce2\u7d0b\u306e\u30b9\u30bf\u30a4\u30eb\u3092\u8a2d\u5b9a\u3059\u308b\n  ctx.strokeStyle = 'rgba(255, 255, 255, 0.5)';\n  ctx.lineWidth = 2;\n  ctx.beginPath();\n  ctx.arc(rippleEffect.centerX, rippleEffect.centerY, rippleEffect.radius, 0, 2 * Math.PI);\n  ctx.stroke();\n}\n\n\/\/ \u30a2\u30cb\u30e1\u30fc\u30b7\u30e7\u30f3\u3092\u958b\u59cb\u3059\u308b\u95a2\u6570\u3092\u5b9a\u7fa9\u3059\u308b\nfunction animate() {\n  \/\/ Canvas\u3092\u30af\u30ea\u30a2\u3059\u308b\n  ctx.clearRect(0, 0, canvas.width, canvas.height);\n\n  \/\/ \u65b0\u3057\u3044\u6ce2\u7d0b\u30a8\u30d5\u30a7\u30af\u30c8\u3092\u751f\u6210\u3059\u308b\n  createRippleEffect();\n\n  \/\/ \u3059\u3079\u3066\u306e\u6ce2\u7d0b\u30a8\u30d5\u30a7\u30af\u30c8\u3092\u63cf\u753b\u3059\u308b\n  for (var i = 0; i < rippleEffects.length; i++) {\n    drawRippleEffect(rippleEffects[i]);\n  }\n\n  \/\/ \u6b21\u306e\u30d5\u30ec\u30fc\u30e0\u3092\u30a2\u30cb\u30e1\u30fc\u30b7\u30e7\u30f3\u3059\u308b\n  requestAnimationFrame(animate);\n}\n\n\/\/ \u521d\u56de\u306e\u30a2\u30cb\u30e1\u30fc\u30b7\u30e7\u30f3\u3092\u958b\u59cb\u3059\u308b\nrequestAnimationFrame(animate);\n<\/script>\n\n\n\n<div class=\"hcb_wrap\"><pre class=\"prism undefined-numbers lang-html\" data-file=\"ripples-js-canvas.html\" data-lang=\"HTML\"><code>&lt;canvas id=&quot;canvas&quot;&gt;&lt;\/canvas&gt;\n\n&lt;style&gt;\n#canvas {\n background: #333;\n width: 100%;\n}\n&lt;\/style&gt;\n\n&lt;script&gt;\n\/\/ Canvas\u8981\u7d20\u3092\u53d6\u5f97\u3059\u308b\nlet canvas = document.getElementById(&#39;canvas&#39;);\n\n\/\/ Canvas\u306e\u30b3\u30f3\u30c6\u30ad\u30b9\u30c8\u3092\u53d6\u5f97\u3059\u308b\nlet ctx = canvas.getContext(&#39;2d&#39;);\n\nlet rippleEffects = [];\n\n\/\/ \u6ce2\u7d0b\u30a8\u30d5\u30a7\u30af\u30c8\u3092\u751f\u6210\u3059\u308b\u95a2\u6570\u3092\u5b9a\u7fa9\u3059\u308b\nfunction createRippleEffect() {\n  \/\/ \u6ce2\u7d0b\u306e\u30d1\u30e9\u30e1\u30fc\u30bf\u30fc\u3092\u30e9\u30f3\u30c0\u30e0\u306b\u751f\u6210\u3059\u308b\n  let centerX = Math.random() * canvas.width;\n  let centerY = Math.random() * canvas.height;\n  let radius = 0;\n  let maxRadius = Math.min(centerX, centerY);\n\n  \/\/ \u65b0\u3057\u3044\u6ce2\u7d0b\u30a8\u30d5\u30a7\u30af\u30c8\u3092\u751f\u6210\u3059\u308b\n  let rippleEffect = {\n    centerX: centerX,\n    centerY: centerY,\n    radius: radius,\n    maxRadius: maxRadius\n  };\n\n  \/\/ \u751f\u6210\u3057\u305f\u6ce2\u7d0b\u30a8\u30d5\u30a7\u30af\u30c8\u3092\u914d\u5217\u306b\u8ffd\u52a0\u3059\u308b\n  rippleEffects.push(rippleEffect);\n}\n\n\/\/ \u6ce2\u7d0b\u30a8\u30d5\u30a7\u30af\u30c8\u3092\u63cf\u753b\u3059\u308b\u95a2\u6570\u3092\u5b9a\u7fa9\u3059\u308b\nfunction drawRippleEffect(rippleEffect) {\n  \/\/ \u6ce2\u7d0b\u306e\u534a\u5f84\u3092\u5897\u52a0\u3055\u305b\u308b\n  rippleEffect.radius += 1;\n\n  \/\/ \u6ce2\u7d0b\u304c\u6700\u5927\u534a\u5f84\u306b\u9054\u3057\u305f\u5834\u5408\u306f\u3001\u914d\u5217\u304b\u3089\u6ce2\u7d0b\u30a8\u30d5\u30a7\u30af\u30c8\u3092\u524a\u9664\u3059\u308b\n  if (rippleEffect.radius &gt; rippleEffect.maxRadius) {\n    let index = rippleEffects.indexOf(rippleEffect);\n    if (index !== -1) {\n      rippleEffects.splice(index, 1);\n    }\n    return;\n  }\n\n  \/\/ \u6ce2\u7d0b\u306e\u30b9\u30bf\u30a4\u30eb\u3092\u8a2d\u5b9a\u3059\u308b\n  ctx.strokeStyle = &#39;rgba(255, 255, 255, 0.5)&#39;;\n  ctx.lineWidth = 2;\n  ctx.beginPath();\n  ctx.arc(rippleEffect.centerX, rippleEffect.centerY, rippleEffect.radius, 0, 2 * Math.PI);\n  ctx.stroke();\n}\n\n\/\/ \u30a2\u30cb\u30e1\u30fc\u30b7\u30e7\u30f3\u3092\u958b\u59cb\u3059\u308b\u95a2\u6570\u3092\u5b9a\u7fa9\u3059\u308b\nfunction animate() {\n  \/\/ Canvas\u3092\u30af\u30ea\u30a2\u3059\u308b\n  ctx.clearRect(0, 0, canvas.width, canvas.height);\n\n  \/\/ \u65b0\u3057\u3044\u6ce2\u7d0b\u30a8\u30d5\u30a7\u30af\u30c8\u3092\u751f\u6210\u3059\u308b\n  createRippleEffect();\n\n  \/\/ \u3059\u3079\u3066\u306e\u6ce2\u7d0b\u30a8\u30d5\u30a7\u30af\u30c8\u3092\u63cf\u753b\u3059\u308b\n  for (var i = 0; i &lt; rippleEffects.length; i++) {\n    drawRippleEffect(rippleEffects[i]);\n  }\n\n  \/\/ \u6b21\u306e\u30d5\u30ec\u30fc\u30e0\u3092\u30a2\u30cb\u30e1\u30fc\u30b7\u30e7\u30f3\u3059\u308b\n  requestAnimationFrame(animate);\n}\n\n\/\/ \u521d\u56de\u306e\u30a2\u30cb\u30e1\u30fc\u30b7\u30e7\u30f3\u3092\u958b\u59cb\u3059\u308b\nrequestAnimationFrame(animate);\n&lt;\/script&gt;<\/code><\/pre><\/div>\n\n\n\n<p class=\"wp-block-paragraph\">\u3068\u3044\u3046\u306e\u3092ChatGPT\u304c\u4f5c\u3063\u3066\u304f\u308c\u307e\u3057\u305f\u3002\u30a8\u30f3\u30b8\u30cb\u30a2\u8981\u3089\u306a\u304f\u306a\u308b\u5371\u6a5f\u611f\u304c\u2026\u2026<\/p>\n","protected":false},"excerpt":{"rendered":"<p>\u6ce2\u7d0b\u3092\u63cf\u753b\u3059\u308b\u30b5\u30f3\u30d7\u30eb\u30b3\u30fc\u30c9\u3067\u3059\u3002\u6c34\u305f\u307e\u308a\u306b\u96e8\u7c92\u304c\u843d\u3061\u308b\u3088\u3046\u306a\u611f\u3058\u306b\u306a\u3063\u3066\u3044\u307e\u3059\u3002 \u3068\u3044\u3046\u306e\u3092ChatGPT\u304c\u4f5c\u3063\u3066\u304f\u308c\u307e\u3057\u305f\u3002\u30a8\u30f3\u30b8\u30cb\u30a2\u8981\u3089\u306a\u304f\u306a\u308b\u5371\u6a5f\u611f\u304c\u2026\u2026<\/p>\n","protected":false},"author":1,"featured_media":4528,"comment_status":"closed","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[55],"tags":[8,92],"class_list":["post-4518","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-javascript","tag-javascript","tag-92"],"_links":{"self":[{"href":"https:\/\/engineering.webstudio168.jp\/blog\/wp-json\/wp\/v2\/posts\/4518","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/engineering.webstudio168.jp\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/engineering.webstudio168.jp\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/engineering.webstudio168.jp\/blog\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/engineering.webstudio168.jp\/blog\/wp-json\/wp\/v2\/comments?post=4518"}],"version-history":[{"count":9,"href":"https:\/\/engineering.webstudio168.jp\/blog\/wp-json\/wp\/v2\/posts\/4518\/revisions"}],"predecessor-version":[{"id":4527,"href":"https:\/\/engineering.webstudio168.jp\/blog\/wp-json\/wp\/v2\/posts\/4518\/revisions\/4527"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/engineering.webstudio168.jp\/blog\/wp-json\/wp\/v2\/media\/4528"}],"wp:attachment":[{"href":"https:\/\/engineering.webstudio168.jp\/blog\/wp-json\/wp\/v2\/media?parent=4518"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/engineering.webstudio168.jp\/blog\/wp-json\/wp\/v2\/categories?post=4518"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/engineering.webstudio168.jp\/blog\/wp-json\/wp\/v2\/tags?post=4518"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}