Html5 canvas rotates around the center, html5canvas
<! DOCTYPE html PUBLIC "-// W3C // dtd xhtml 1.0 Transitional // EN "" http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd "> <Html xmlns =" http://www.w3.org/1999/xhtml "> <Head> <meta http-equiv =" Content-Type "content =" text/html; charset = UTF-8 "/> <title> rotate around the center </title> <script src =" js/modernizr. js "> </script>
This time we set variables... Does it seem like an inexplicable kind?
Var x = 100; var y = 100; var width = 50; var height = 50;
Then we use the context. translate function to translate the canvas origin point to the center point of the Red Square.
This function can move the canvas origin point to (x, y. Set the X coordinate value of the origin point to the X value (100) in the upper left corner of the Red Square)
Add half of the width. You can use the variable you created to control the property of this Red Square.
X + 0.5 * width
Then Y coordinates
Then execute the translation function.
Then rotate
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