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diff --git a/files/ja/web/api/canvasrenderingcontext2d/globalcompositeoperation/index.html b/files/ja/web/api/canvasrenderingcontext2d/globalcompositeoperation/index.html new file mode 100644 index 0000000000..c176a9becd --- /dev/null +++ b/files/ja/web/api/canvasrenderingcontext2d/globalcompositeoperation/index.html @@ -0,0 +1,209 @@ +--- +title: CanvasRenderingContext2D.globalCompositeOperation +slug: Web/API/CanvasRenderingContext2D/globalCompositeOperation +tags: + - API + - Blending + - Canvas + - CanvasRenderingContext2D + - Compositing + - Property + - Reference +translation_of: Web/API/CanvasRenderingContext2D/globalCompositeOperation +--- +<div>{{APIRef}}</div> + +<p><code><strong>CanvasRenderingContext2D.globalCompositeOperation</strong></code>プロパティは、新たな図形を描くときに適用する合成処理の種類を定めます。種類は文字列で、合成やブレンドモードのいずれが用いられるのかを決めます。</p> + +<p>なお、<a href="/docs/Web/API/Canvas_API/Tutorial">Canvas Tutorial</a>の<a href="/docs/Web/API/Canvas_API/Tutorial/Compositing">Compositing and clipping</a>の章をご参照ください。</p> + +<h2 id="構文">構文</h2> + +<pre class="syntaxbox"><var><em>ctx</em>.globalCompositeOperation = 種類;</var></pre> + +<h3 id="種類">種類</h3> +<p>{{EmbedLiveSample("Compositing_example", 750, 7300, "" +,"../../ja/docs/Web/API/Canvas_API/Tutorial/Compositing/Example")}}</p><p> + +</p><h2 id="例">例</h2> + +<h3 id="Using_the_globalAlpha_property" name="Using_the_globalAlpha_property"><code>globalCompositeOperation</code>プロパティの使い方</h3> + +<p>つぎに抜き書きした簡単なコードは、描かれたふたつの矩形の重なりを<code>globalCompositeOperation</code>プロパティによって除いています。</p> + +<h4 id="HTML">HTML</h4> + +<pre class="brush: html"><canvas id="canvas"></canvas> +</pre> + +<h4 id="JavaScript">JavaScript</h4> + +<pre class="brush: js; highlight[4]">var canvas = document.getElementById("canvas"); +var ctx = canvas.getContext("2d"); + +ctx.globalCompositeOperation = "xor"; + +ctx.fillStyle = "blue"; +ctx.fillRect(10, 10, 100, 100); + +ctx.fillStyle = "red"; +ctx.fillRect(50, 50, 100, 100); +</pre> + +<p>以下のコードを書き替えると、Canvasの中身がどう変わるか実際に確かめられます。</p> + +<div class="hidden"> +<h6 id="Playable_code" name="Playable_code">Playable code</h6> + +<pre class="brush: html"><canvas id="canvas" width="400" height="200" class="playable-canvas"></canvas> +<div class="playable-buttons"> + <input id="edit" type="button" value="Edit" /> + <input id="reset" type="button" value="Reset" /> +</div> +<textarea id="code" class="playable-code" style="height:120px;"> +ctx.globalCompositeOperation = "xor"; + +ctx.fillStyle = "blue"; +ctx.fillRect(10, 10, 100, 100); + +ctx.fillStyle = "red"; +ctx.fillRect(50, 50, 100, 100);</textarea> +</pre> + +<pre class="brush: js">var canvas = document.getElementById("canvas"); +var ctx = canvas.getContext("2d"); +var textarea = document.getElementById("code"); +var reset = document.getElementById("reset"); +var edit = document.getElementById("edit"); +var code = textarea.value; + +function drawCanvas() { + ctx.clearRect(0, 0, canvas.width, canvas.height); + eval(textarea.value); +} + +reset.addEventListener("click", function() { + textarea.value = code; + drawCanvas(); +}); + +edit.addEventListener("click", function() { + textarea.focus(); +}) + +textarea.addEventListener("input", drawCanvas); +window.addEventListener("load", drawCanvas); +</pre> +</div> + +<p>{{ EmbedLiveSample('Playable_code', 700, 380) }}</p> + +<h2 id="仕様">仕様</h2> + +<table class="standard-table"> + <tbody> + <tr> + <th scope="col">仕様</th> + <th scope="col">状況</th> + <th scope="col">コメント</th> + </tr> + <tr> + <td>{{SpecName('HTML WHATWG', "scripting.html#dom-context-2d-globalcompositeoperation", "CanvasRenderingContext2D.globalCompositeOperation")}}</td> + <td>{{Spec2('HTML WHATWG')}}</td> + <td> </td> + </tr> + <tr> + <td>{{SpecName('Compositing')}}</td> + <td>{{Spec2('Compositing')}}</td> + <td> </td> + </tr> + </tbody> +</table> + +<h2 id="ブラウザの互換性">ブラウザの互換性</h2> + +<p>{{CompatibilityTable}}</p> + +<div id="compat-desktop"> +<table class="compat-table"> + <tbody> + <tr> + <th>Feature</th> + <th>Chrome</th> + <th>Firefox (Gecko)</th> + <th>Internet Explorer</th> + <th>Opera</th> + <th>Safari</th> + </tr> + <tr> + <td>Basic support</td> + <td>{{CompatVersionUnknown}}</td> + <td>{{CompatVersionUnknown}}</td> + <td>{{CompatVersionUnknown}}</td> + <td>{{CompatVersionUnknown}}</td> + <td>{{CompatVersionUnknown}}</td> + </tr> + <tr> + <td>Blend modes</td> + <td>{{CompatUnknown}}</td> + <td>{{ CompatGeckoDesktop("20") }}</td> + <td>{{CompatUnknown}}</td> + <td>{{CompatUnknown}}</td> + <td>{{CompatUnknown}}</td> + </tr> + </tbody> +</table> +</div> + +<div id="compat-mobile"> +<table class="compat-table"> + <tbody> + <tr> + <th>Feature</th> + <th>Android</th> + <th>Chrome for Android</th> + <th>Firefox Mobile (Gecko)</th> + <th>IE Mobile</th> + <th>Opera Mobile</th> + <th>Safari Mobile</th> + </tr> + <tr> + <td>Basic support</td> + <td>{{CompatVersionUnknown}}</td> + <td>{{CompatVersionUnknown}}</td> + <td>{{CompatVersionUnknown}}</td> + <td>{{CompatVersionUnknown}}</td> + <td>{{CompatVersionUnknown}}</td> + <td>{{CompatVersionUnknown}}</td> + </tr> + <tr> + <td>Blend modes</td> + <td>{{CompatUnknown}}</td> + <td>{{CompatUnknown}}</td> + <td>{{ CompatGeckoMobile("20") }}</td> + <td>{{CompatUnknown}}</td> + <td>{{CompatUnknown}}</td> + <td>{{CompatUnknown}}</td> + </tr> + </tbody> +</table> +</div> + +<h2 id="WebKitBlinkについての注釈">WebKit/Blinkについての注釈</h2> + +<ul> + <li>WebKit-とBlink-にもとづくブラウザでは、このプロパティのほかに標準でなく推奨されないメソッド<code>ctx.setCompositeOperation()</code>が実装されています。</li> +</ul> + +<h2 id="Geckoについての注釈">Geckoについての注釈</h2> + +<ul> + <li>初期のCanvas仕様の草案には、値として"darker"が定められていました。しかし、Firefoxはバージョン4で"darker"を除きました({{bug(571532)}}). なお、"darker"に近い効果が得られる値として<code>difference</code>を使うことについて、<a href="http://dropshado.ws/post/77229081704/firefox-doesnt-support-canvas-composite-darker">ブログ記事</a>の紹介が参考になります。</li> +</ul> + +<h2 id="参考情報">参考情報</h2> + +<ul> + <li>インタフェースを定義する{{domxref("CanvasRenderingContext2D")}}</li> + <li>{{domxref("CanvasRenderingContext2D.globalAlpha")}}</li> +</ul> |