Text rotation in HTML5 plotting

Text rotation in HTML5 plotting
Text rotation in HTML5 plotting

Text rotation in GDI/GDI + is a relatively easy task. The rotation in HTML5 Canvas is slightly different from that in GDI/GDI +. First, let's look at a figure:

Sample Code of text Rotation

Ctx. beginPath (); ctx. fillStyle = "#000000"; ctx. font = "52pt Calibri"; ctx. textAlign = "center"; ctx. fillText (this. end, endX, endY); ctx. save (); ctx. translate (endX, endY); ctx. rotate (Math. PI/6); ctx. fillText ("text 2", 0, 0); ctx. restore ();

Code Description

The rotate of canvas is for the canvas. It can also be understood as the state machine of OPENGS, which is global for the canvas. Therefore, if you want to rotate the text at a specified position, first move the source of the image to this position, then rotate the canvas, and finally output the text at (0, 0). Remember that it must be (0, 0) location.