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I know it's something wrong with my transformations in drawGuy. Can anyone help me figure out how to rotate just the image? Currently it rotates fine, but I something with the transforms is distorting it, so that it doesn't follow the mouse correctly.

http://gist.github./232194

I know it's something wrong with my transformations in drawGuy. Can anyone help me figure out how to rotate just the image? Currently it rotates fine, but I something with the transforms is distorting it, so that it doesn't follow the mouse correctly.

  • javascript
  • canvas
  • rotation
Share Improve this question asked Nov 11, 2009 at 18:59 Timothy McDowellTimothy McDowell 2372 silver badges10 bronze badges
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1 Answer 1

Reset to default 7

Instead of translating forward and then translating backward again, simply push your current state onto the stack before you traslate/rotate, and when you're done - pop your state back off the stack. This is how most graphical applications make use of translations/rotations.

Also, you're translating by x, y, then additionally calling ctx.drawImage(guy, x, y). This is going to, in effect, double the offset. I'd either get rid of the translate call, or change the position arguments for the drawImage call to 0, 0.

function drawGuy() {
    ctx.save();                                                                                                                        
    ctx.translate(x,y);     
    ctx.rotate(angle * Math.PI / 180);                                                                               
    ctx.drawImage(guy, 0, 0); 
    ctx.restore();                                            
}

Check out the spec about context.save() and context.restore() (the way canvas does state push/pop), here.

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