# Help on drawing API **URL:** \ **Category:** Uncategorized\ **Created:** [July 31, 2002, 11:26pm UTC](https://forum.kirupa.com/t/help-on-drawing-api/857 "2002-07-31T23:26:15Z")\ **Posts on this page:** 8\ **Page:** 1
**Author:** ![kateamen](https://avatars.discourse-cdn.com/v4/letter/k/fbc32d/32.png) [@kateamen](https://forum.kirupa.com/u/kateamen)\ **Post date:** [July 31, 2002, 11:26pm UTC](https://forum.kirupa.com/t/help-on-drawing-api/857/1 "2002-07-31T23:26:15Z")
hey peeps… need help again regarding the drawing API… if you’d look at my old posts recently I encountered a problem regarding drawing API… well actually, ilyaslamasse (thanks again) helped me come up with a way to draw a square in the screen… it’s not me drawing it actually… he ended up giving me a script wherein it writes itself on the screen… okay… so I have the square and all… I ended up being able to draw a triangle also but that’s the same as the square coz you just end up manipulating the array values… the real prob is how to draw a circle using the same method… can anyone help please??? just leave me a message for further questions… thanks!!! 🙂 ---
**Author:** ![system](https://canada1.discourse-cdn.com/flex011/uploads/kirupa/original/3X/6/2/621e5c11736f46532526e61be85940af4230f3e5.png) [@system](https://forum.kirupa.com/u/system)\ **Post date:** [August 1, 2002, 7:09am UTC](https://forum.kirupa.com/t/help-on-drawing-api/857/2 "2002-08-01T07:09:19Z")
one might expect the curveTo method to produce a circle. initially it seems that the circles it produces are a little wonky, but as these smart folks have shown, with a little tweaking you can get a pretty good circle. [http://chattyfig.figleaf.com/flashcoders-wiki/index.php?CodeOnlyCircle](http://chattyfig.figleaf.com/flashcoders-wiki/index.php?CodeOnlyCircle) ---
**Author:** ![system](https://canada1.discourse-cdn.com/flex011/uploads/kirupa/original/3X/6/2/621e5c11736f46532526e61be85940af4230f3e5.png) [@system](https://forum.kirupa.com/u/system)\ **Post date:** [August 1, 2002, 7:19am UTC](https://forum.kirupa.com/t/help-on-drawing-api/857/3 "2002-08-01T07:19:24Z")
hi… thanks for posting back… I tried putting the code in through the expert mode coz i figure it wouldn’t matter which way I inputed it but then nothing turns out… do I do anything to the keyframe first before putting an action into the frame??? thanks… :nerd: Movieclip.prototype.drawCircle(r, x, y) { var rx = r+x, ry = r + y, xr = x - r, yr = y - r; var r07 = r \* 0.7071, r04 = r \* 0.4142; ``` this.moveTo(rx, y); this.curveTo(rx, r04 + y, r07 + x, r07 + y); this.curveTo(r04 + x, ry, x, ry); this.curveTo(x - r04 , ry, x - r07 , r07 + y); this.curveTo(xr, r04 + y, xr, y); this.curveTo(xr, y - r04 , x - r07 , y - r07 ); this.curveTo(x - r04 , yr, x, yr); this.curveTo(r04 + x, yr, r07 + x, y - r07 ); this.curveTo(rx, y - r04 , rx, y); ``` } ---
**Author:** ![system](https://canada1.discourse-cdn.com/flex011/uploads/kirupa/original/3X/6/2/621e5c11736f46532526e61be85940af4230f3e5.png) [@system](https://forum.kirupa.com/u/system)\ **Post date:** [August 1, 2002, 7:57am UTC](https://forum.kirupa.com/t/help-on-drawing-api/857/4 "2002-08-01T07:57:47Z")
did you set a lineStyle before drawing the circle? this in frame 1 will draw a circle: ```auto MovieClip.prototype.drawCircle = function(r, x, y){ this.moveTo(x+r, y); this.curveTo(r+x, -0.4142*r+y, 0.7071*r+x, -0.7071*r+y); this.curveTo(0.4142*r+x, -r+y, x, -r+y); this.curveTo(-0.4142*r+x, -r+y, -0.7071*r+x, -0.7071*r+y); this.curveTo(-r+x, -0.4142*r+y, -r+x, y); this.curveTo(-r+x, 0.4142*r+y, -0.7071*r+x, 0.7071*r+y); this.curveTo(-0.4142*r+x, r+y, x, r+y); this.curveTo(0.4142*r+x, r+y, 0.7071*r+x, 0.7071*r+y); this.curveTo(r+x, 0.4142*r+y, r+x, y); } _root.lineStyle(0); _root.drawCircle(50,100,100); ``` ---
**Author:** ![system](https://canada1.discourse-cdn.com/flex011/uploads/kirupa/original/3X/6/2/621e5c11736f46532526e61be85940af4230f3e5.png) [@system](https://forum.kirupa.com/u/system)\ **Post date:** [August 1, 2002, 8:02am UTC](https://forum.kirupa.com/t/help-on-drawing-api/857/5 "2002-08-01T08:02:23Z")
Argh! Too fast! But these guys are amazing. I did a little thinggy with that prototype: put this in the first frame of your movie, then press, drag and release ```auto MovieClip.prototype.drawCircle = function(r, x, y){ this.moveTo(x+r, y); this.curveTo(r+x, -0.4142*r+y, 0.7071*r+x, -0.7071*r+y); this.curveTo(0.4142*r+x, -r+y, x, -r+y); this.curveTo(-0.4142*r+x, -r+y, -0.7071*r+x, -0.7071*r+y); this.curveTo(-r+x, -0.4142*r+y, -r+x, y); this.curveTo(-r+x, 0.4142*r+y, -0.7071*r+x, 0.7071*r+y); this.curveTo(-0.4142*r+x, r+y, x, r+y); this.curveTo(0.4142*r+x, r+y, 0.7071*r+x, 0.7071*r+y); this.curveTo(r+x, 0.4142*r+y, r+x, y); } _root.lineStyle(2,0x000000,100); _root.onMouseDown=function(){ x=_xmouse; y=_ymouse; } _root.onMouseUp=function(){ var dx=_xmouse-x; var dy=_ymouse-y; this.drawCircle(Math.sqrt(dx*dx+dy*dy),x,y); } ``` pom :asian: ---
**Author:** ![system](https://canada1.discourse-cdn.com/flex011/uploads/kirupa/original/3X/6/2/621e5c11736f46532526e61be85940af4230f3e5.png) [@system](https://forum.kirupa.com/u/system)\ **Post date:** [August 1, 2002, 8:08am UTC](https://forum.kirupa.com/t/help-on-drawing-api/857/6 "2002-08-01T08:08:55Z")
or just slightly different, the prototype then: ```auto _root.onMouseDown=function(){ x=_xmouse; y=_ymouse; this.onMouseMove = function(){ var dx=_xmouse-x; var dy=_ymouse-y; this.clear(); this.lineStyle(2); this.drawCircle(Math.sqrt(dx*dx+dy*dy),x,y); } } _root.onMouseUp=function(){ this.onMouseMove = null; } ``` ---
**Author:** ![system](https://canada1.discourse-cdn.com/flex011/uploads/kirupa/original/3X/6/2/621e5c11736f46532526e61be85940af4230f3e5.png) [@system](https://forum.kirupa.com/u/system)\ **Post date:** [August 1, 2002, 12:28pm UTC](https://forum.kirupa.com/t/help-on-drawing-api/857/7 "2002-08-01T12:28:42Z")
😛 Nice! And you can do pretty much the same with all kinds of forms… I can see there’s even the code for an ellipse on that site. Lots of fun in perspective 🙂 pom :asian: ---
**Author:** ![system](https://canada1.discourse-cdn.com/flex011/uploads/kirupa/original/3X/6/2/621e5c11736f46532526e61be85940af4230f3e5.png) [@system](https://forum.kirupa.com/u/system)\ **Post date:** [August 1, 2002, 12:36pm UTC](https://forum.kirupa.com/t/help-on-drawing-api/857/8 "2002-08-01T12:36:55Z")
Oh, but I just noticed: with your code, you can only have 1 circle at a time, contrary to my example. Gnark gnark gnark:P ```auto i=1; _root.onMouseDown=function(){ this.createEmptyMovieClip("holder"+i,i); x=_xmouse; y=_ymouse; _root["holder"+i].onMouseMove = function(){ var dx=_xmouse-x; var dy=_ymouse-y; this.clear(); this.lineStyle(2); this.drawCircle(Math.sqrt(dx*dx+dy*dy),x,y); } } _root.onMouseUp=function(){ _root["holder"+i].onMouseMove = null; i++; } ``` pom :asian: