繪製路徑與SVG路徑數據（SVG路徑帆布路徑）

Question

我在SVG一個國家的詳細地圖中的區域以這種格式分離：

<path class="state-x-area" 
     d="m 575.8672,180.4954 c -0.6572,-0.0938 -2.252,-0.4688 -2.627,-0.375 -1.0313,0.1875 0.375,1.501 -0.1875,1.876 -0.4688,0.1875 -1.0313,-0.0938 -1.501,0.0938 -0.1875,0.0938 0.0938,0.4688 -0.0938,0.6572 -0.9375,0.75 -2.4385,0.8438 -3.377,1.6875 -1.125,1.0322 2.0635,3.6582 0.6572,4.6904 -3.2832,2.3447 -1.2197,-1.5947 -3.377,1.501 -0.2813,0.375 0.8438,0.4688 1.0313,0.9375 0.1875,0.376 -0.9375,0.2822 -0.9375,0.6572 0,0.1875 0.9375,1.4072 0.5625,1.876 -1.0313,1.0313 -2.5322,-0.5635 -3.4707,-0.5635 -1.4063,0 1.3135,1.3135 -1.0313,0.6572 -0.6572,-0.1875 -1.501,-1.2197 -1.7822,-1.7822 -0.1875,-0.1875 -0.376,-0.751 -0.4697,-0.5625 -0.375,0.5625 -0.2813,1.2188 -0.6563,1.6875 -1.2188,1.5947 -2.9082,0 -4.3145,0.4697 -0.1875,0.0938 0.1875,0.4688 0,0.6563 -0.8447,0.4688 -2.5332,0.375 -3.377,0 0,0 0,-0.0938 0.0938,-0.0938 0.4688,-0.4688 1.0313,-0.9375 1.2197,-1.4072 3.2822,0.1875 -0.4697,-2.0635 -1.4072,-2.626 -0.6563,-0.375 0.375,-1.5947 0.1875,-2.0635 -0.1875,-0.4697 -1.6885,0.8438 -1.3135,-0.376 0.2813,-0.8438 2.0635,-1.5938 1.4072,-2.1572 -0.4688,-0.375 -2.627,-0.1875 -2.4385,-1.3125 0.1875,-1.501 2.5322,-1.126 2.7197,-3.002 -0.0938,0 -0.0938,0 -0.1875,0 0.5625,0.0938 1.126,0.1875 1.7822,0.2813 0.75,0.0938 1.501,0.6563 2.251,0.75 0.751,0.0938 1.501,-0.4688 2.252,-0.375 0.4688,0.0938 0.75,0.751 1.2188,0.751 0.1875,0.0938 0.0938,-0.4697 0.2813,-0.5635 0.4697,-0.4688 1.2197,-0.6563 1.6885,-1.2188 0.376,-0.2822 0.0938,-0.9385 0.376,-1.2197 1.7813,-1.4072 3.6582,0.375 5.3457,-0.375 0.5635,-0.2813 0.6572,-1.126 1.2197,-1.3135 0.0938,-0.0938 3.1895,0.375 3.2832,0.2813 0.2813,-0.0938 -0.2813,-0.4688 -0.375,-0.75 -0.2813,-1.501 0.8438,-1.876 2.251,-1.876 0.3752,0 1.1262,2.9072 3.0959,4.502 l 0,0 z" 
     style="fill:#000;stroke:#fff;stroke-width:1" /> 

（我有很多的這樣的路徑）。

現在我需要通過Canvas完成所有工作（因爲需要重新設計和完成一項全新任務）。 我看到可以在Canvas中繪製路徑，但是我可以使用這種SVG路徑來做到這一點嗎？

Answer 1

在最近的Chrome，Firefox和Opera版本中，您可以使用Path2D API根據SVG路徑數據在Canvas中繪製路徑。 Path2D構造函數可以選擇將SVG路徑數據作爲輸入，並在Canvas上生成等效路徑。

截至編寫本文時，Internet Explorer和Safari似乎都不支持此API。因此，如果您需要支持這些瀏覽器，則必須使用任何一個轉換器將SVG路徑轉換爲等效的Canvas命令，然後將其放入使用中。使用Path2D API畫布

路徑：

window.onload = function() { 
 
    var canvas = document.getElementById('canvas'); 
 
    var ctx = canvas.getContext('2d'); 
 
    ctx.strokeStyle = '#000'; 
 
    ctx.lineWidth = 1; 
 
    ctx.fillStyle = '#000' 
 

 
    var p = new Path2D("m 75.8672,80.4954 c -0.6572,-0.0938 -2.252,-0.4688 -2.627,-0.375 -1.0313,0.1875 0.375,1.501 -0.1875,1.876 -0.4688,0.1875 -1.0313,-0.0938 -1.501,0.0938 -0.1875,0.0938 0.0938,0.4688 -0.0938,0.6572 -0.9375,0.75 -2.4385,0.8438 -3.377,1.6875 -1.125,1.0322 2.0635,3.6582 0.6572,4.6904 -3.2832,2.3447 -1.2197,-1.5947 -3.377,1.501 -0.2813,0.375 0.8438,0.4688 1.0313,0.9375 0.1875,0.376 -0.9375,0.2822 -0.9375,0.6572 0,0.1875 0.9375,1.4072 0.5625,1.876 -1.0313,1.0313 -2.5322,-0.5635 -3.4707,-0.5635 -1.4063,0 1.3135,1.3135 -1.0313,0.6572 -0.6572,-0.1875 -1.501,-1.2197 -1.7822,-1.7822 -0.1875,-0.1875 -0.376,-0.751 -0.4697,-0.5625 -0.375,0.5625 -0.2813,1.2188 -0.6563,1.6875 -1.2188,1.5947 -2.9082,0 -4.3145,0.4697 -0.1875,0.0938 0.1875,0.4688 0,0.6563 -0.8447,0.4688 -2.5332,0.375 -3.377,0 0,0 0,-0.0938 0.0938,-0.0938 0.4688,-0.4688 1.0313,-0.9375 1.2197,-1.4072 3.2822,0.1875 -0.4697,-2.0635 -1.4072,-2.626 -0.6563,-0.375 0.375,-1.5947 0.1875,-2.0635 -0.1875,-0.4697 -1.6885,0.8438 -1.3135,-0.376 0.2813,-0.8438 2.0635,-1.5938 1.4072,-2.1572 -0.4688,-0.375 -2.627,-0.1875 -2.4385,-1.3125 0.1875,-1.501 2.5322,-1.126 2.7197,-3.002 -0.0938,0 -0.0938,0 -0.1875,0 0.5625,0.0938 1.126,0.1875 1.7822,0.2813 0.75,0.0938 1.501,0.6563 2.251,0.75 0.751,0.0938 1.501,-0.4688 2.252,-0.375 0.4688,0.0938 0.75,0.751 1.2188,0.751 0.1875,0.0938 0.0938,-0.4697 0.2813,-0.5635 0.4697,-0.4688 1.2197,-0.6563 1.6885,-1.2188 0.376,-0.2822 0.0938,-0.9385 0.376,-1.2197 1.7813,-1.4072 3.6582,0.375 5.3457,-0.375 0.5635,-0.2813 0.6572,-1.126 1.2197,-1.3135 0.0938,-0.0938 3.1895,0.375 3.2832,0.2813 0.2813,-0.0938 -0.2813,-0.4688 -0.375,-0.75 -0.2813,-1.501 0.8438,-1.876 2.251,-1.876 0.3752,0 1.1262,2.9072 3.0959,4.502 l 0,0 z"); 
 
    ctx.stroke(p); 
 
    ctx.fill(p); 
 
}

<canvas id='canvas' height='600px' width='600px'></canvas>

SVG輸出：（用於比較）

<svg viewBox='0 0 600 600' height='600px' width='600px'> 
 
    <path class="state-x-area" d="m 75.8672,80.4954 c -0.6572,-0.0938 -2.252,-0.4688 -2.627,-0.375 -1.0313,0.1875 0.375,1.501 -0.1875,1.876 -0.4688,0.1875 -1.0313,-0.0938 -1.501,0.0938 -0.1875,0.0938 0.0938,0.4688 -0.0938,0.6572 -0.9375,0.75 -2.4385,0.8438 -3.377,1.6875 -1.125,1.0322 2.0635,3.6582 0.6572,4.6904 -3.2832,2.3447 -1.2197,-1.5947 -3.377,1.501 -0.2813,0.375 0.8438,0.4688 1.0313,0.9375 0.1875,0.376 -0.9375,0.2822 -0.9375,0.6572 0,0.1875 0.9375,1.4072 0.5625,1.876 -1.0313,1.0313 -2.5322,-0.5635 -3.4707,-0.5635 -1.4063,0 1.3135,1.3135 -1.0313,0.6572 -0.6572,-0.1875 -1.501,-1.2197 -1.7822,-1.7822 -0.1875,-0.1875 -0.376,-0.751 -0.4697,-0.5625 -0.375,0.5625 -0.2813,1.2188 -0.6563,1.6875 -1.2188,1.5947 -2.9082,0 -4.3145,0.4697 -0.1875,0.0938 0.1875,0.4688 0,0.6563 -0.8447,0.4688 -2.5332,0.375 -3.377,0 0,0 0,-0.0938 0.0938,-0.0938 0.4688,-0.4688 1.0313,-0.9375 1.2197,-1.4072 3.2822,0.1875 -0.4697,-2.0635 -1.4072,-2.626 -0.6563,-0.375 0.375,-1.5947 0.1875,-2.0635 -0.1875,-0.4697 -1.6885,0.8438 -1.3135,-0.376 0.2813,-0.8438 2.0635,-1.5938 1.4072,-2.1572 -0.4688,-0.375 -2.627,-0.1875 -2.4385,-1.3125 0.1875,-1.501 2.5322,-1.126 2.7197,-3.002 -0.0938,0 -0.0938,0 -0.1875,0 0.5625,0.0938 1.126,0.1875 1.7822,0.2813 0.75,0.0938 1.501,0.6563 2.251,0.75 0.751,0.0938 1.501,-0.4688 2.252,-0.375 0.4688,0.0938 0.75,0.751 1.2188,0.751 0.1875,0.0938 0.0938,-0.4697 0.2813,-0.5635 0.4697,-0.4688 1.2197,-0.6563 1.6885,-1.2188 0.376,-0.2822 0.0938,-0.9385 0.376,-1.2197 1.7813,-1.4072 3.6582,0.375 5.3457,-0.375 0.5635,-0.2813 0.6572,-1.126 1.2197,-1.3135 0.0938,-0.0938 3.1895,0.375 3.2832,0.2813 0.2813,-0.0938 -0.2813,-0.4688 -0.375,-0.75 -0.2813,-1.501 0.8438,-1.876 2.251,-1.876 0.3752,0 1.1262,2.9072 3.0959,4.502 l 0,0 z" 
 
    style="fill:#000;stroke:#fff;stroke-width:1" /> 
 
</svg>

^{注：我已經修改了moveTo命令座標同時在SVG和Canvas路徑，使輸出更加明顯，而無需切換到全屏模式。}

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參考文獻：

• Drawing shapes on Canvas
• Path2D API - MDN