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December 9, 2021 07:56
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High DPI plugin - add Retina canvas support to OCanvas
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const highDPIPlugin = function () { | |
const scale = window.devicePixelRatio || 1; | |
if (scale === 1) { | |
return; | |
} | |
Object.defineProperty(this, "width", { | |
enumerable: true, | |
configurable: true, | |
set(value) { | |
this.canvasElement.style.width = value + "px"; | |
this.canvasElement.width = value * scale; | |
this.canvas.scale(scale, scale); | |
this.background.set(this.settings.background); | |
this.redraw(); | |
}, | |
get() { | |
return this.canvasElement.width; | |
}, | |
}); | |
Object.defineProperty(this, "height", { | |
enumerable: true, | |
configurable: true, | |
set(value) { | |
this.canvasElement.height = value * scale; | |
this.canvasElement.style.height = value + "px"; | |
this.canvas.scale(scale, scale); | |
this.background.set(this.settings.background); | |
this.redraw(); | |
}, | |
get() { | |
return this.canvasElement.height; | |
}, | |
}); | |
// node_modules/ocanvas/src/mouse.js | |
this.mouse.getPos = function (e: { pageX: number; pageY: number }) { | |
let canvas = this.core.canvasElement; | |
let boundingRect = canvas.getBoundingClientRect(); | |
let scaleX = canvas.width / canvas.clientWidth; | |
let scaleY = canvas.height / canvas.clientHeight; | |
// Calculate the mouse position relative to the viewport. | |
// e.clientX exists, but has been incorrect in older versions of webkit. | |
let clientX = e.pageX - window.pageXOffset; | |
let clientY = e.pageY - window.pageYOffset; | |
let x = (scaleX * (clientX - Math.round(boundingRect.left))) / scale; | |
let y = (scaleY * (clientY - Math.round(boundingRect.top))) / scale; | |
return { x, y }; | |
}; | |
}; | |
oCanvas.registerPlugin("highDPI", highDPIPlugin); |
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