HTML Canvas Coordinate

画布坐标

HTML 画布是一个二维的网格。

ɗaukar ɗin saɓu ɗin ɗaukar a (0,0).

A karkashin ɗaya ɗin karaɗe, a ɗaukar ɗin: fillRect(0,0,150,75).

kaɓan ɗin: sabon kuma tashi ɗaya ɗin 150x75 pixel daga ɗaukar ɗin ɗaukar (0,0).

ciwon ɗin ɗaukar

Domin ɗaukar ɗaya ɗin ɗaukar a cikin ɗaya ɗin ɗaukar, zaɓu x da y:

saɓu hoto:

Domin tashi ɗaya a ɗaya ɗin saɓu, zaɓu hoto ɗin:

• moveTo(x,y) - Ananɗin ɗaukar hoto
• lineTo(x,y) - Ananɗin ɗaukar hoto

Domin tashi ɗaya, kaɓan zaɓu ɗaya ɗin '颜料' ɗaya, sabon kuma stroke().

ciwon

Domin ɗaukar hoto a (0,0), domin ɗaukar hoto a (200,100). Sabon kuma zaɓu wayin stroke() domin tashi ɗaya:

const canvas = document.getElementById("myCanvas");
const ctx = canvas.getContext("2d");
ctx.moveTo(0, 0);
ctx.lineTo(200, 100);
ctx.stroke();

Try it yourself

saɓu ɗaya:

Domin tashi ɗaya ɗin saɓu ɗaya a ɗaya ɗin saɓu, zaɓu hoto ɗin:

• beginPath() - Hade sabon hoto
• arc(x,y,r,startangle,endangle) - Ananɗin ɗummaɓaɓa / kwaya

Domin saɓu ɗaya ɗin arc() zaɓu: kaiɓi ɗaukar ɗummaɓaɓa 0, kaiɓi ɗaukar ɗummaɓaɓa 2*Math.PI. x da y zaɓu x da y gurɗe ɗaya. r zaɓu rarrin ɗaya.

ciwon

saɓu arc() wayin zuwa ɗaya. Sabon kuma zaɓu wayin stroke() domin tashi ɗaya:

const canvas = document.getElementById("myCanvas");
const ctx = canvas.getContext("2d");
ctx.beginPath();
ctx.arc(95, 50, 40, 0, 2 * Math.PI);
ctx.stroke();

Try it yourself

See also:

Complete Canvas Reference Manual of CodeW3C.com