References.

[JustSleepTilSunSet]

https://book.vue.tw/CH1/1-3-computed-and-methods.html https://vuejs.org/api/composition-api-setup.html https://stackoverflow.com/questions/73134550/how-do-you-get-variables-from-the-setup-script-in-vue3 https://developer.mozilla.org/en-US/docs/Web/API/CanvasRenderingContext2D/lineTo https://developer.mozilla.org/zh-CN/docs/Web/API/MouseEvent/pageX https://developer.mozilla.org/zh-CN/docs/Web/API/HTMLElement/offsetLeft https://stackoverflow.com/questions/31729668/how-to-declare-any-module-in-typescript https://stackoverflow.com/questions/40349987/how-to-suppress-error-ts2533-object-is-possibly-null-or-undefined https://developer.mozilla.org/zh-TW/docs/Web/API/Canvas_API/Tutorial/Applying_styles_and_colors https://stackoverflow.com/questions/6796194/canvas-getcontext2d-returns-null https://stackoverflow.com/questions/38142308/canvas-drag-on-mouse-movement

[JustSleepTilSunSet]

deploy to githubpage: https://hackmd.io/@c36ICNyhQE6-iTXKxoIocg/rkJxgxhDI

[JustSleepTilSunSet]

canvas setting: https://stackoverflow.com/questions/15685698/getting-binary-base64-data-from-html5-canvas-readasbinarystring https://stackoverflow.com/questions/64857713/how-download-base64-data-as-image https://stackoverflow.com/questions/20488590/set-background-fill-stroke-and-opacity-of-html5-canvas https://stackoverflow.com/questions/44446343/download-canvas-to-png-black-background