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CanvasRenderingContext2D.translate() - Web API 接口参考编辑

Canvas 2D API的CanvasRenderingContext2D.translate() 方法对当前网格添加平移变换的方法。

语法

void ctx.translate(x, y);

translate() 方法, 将 canvas 按原始 x点的水平方向、原始的 y点垂直方向进行平移变换

示例

使用 translate 方法

这是一段使用 translate 方法的简单的代码片段。

HTML

<canvas id="canvas"></canvas>

JavaScript

var canvas = document.getElementById("canvas");
var ctx = canvas.getContext("2d");

ctx.translate(50, 50);
ctx.fillRect(0,0,100,100);

// reset current transformation matrix to the identity matrix
ctx.setTransform(1, 0, 0, 1, 0, 0);

修改下面的代码并在线查看 canvas 的变化：

Playable code

<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">
ctx.translate(50, 50);
ctx.fillRect(0,0,100,100);
ctx.setTransform(1, 0, 0, 1, 0, 0);</textarea>

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);

规范描述

Specification	Status	Comment
HTML Living Standard CanvasRenderingContext2D.translate	Living Standard

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