I cobbled together a poor hack for plotting equidistant points on an ellipse. I'm going to post the code here, with comments, so future archive searches will yield something. This might be ugly in email, but it is complete. It requires a library mc with linkage "circle."
/* background: ellipse: http://www.devx.com/webdev/Article/28728 circle: http://www.devx.com/webdev/Article/28502 Rich Shupe, FMA http://www.fmaonline.com */ // //initial values var i:Number = 0; var j:Boolean = true; var angle:Number = 0; // //degrees to radians function deg2rad(degree:Number):Number { return degree * (Math.PI / 180); } // //distance between two points function pDp(x1:Number, y1:Number, x2:Number, y2:Number):Number { return Math.sqrt(((x1 - x2) * (x1 - x2)) + ((y1 - y2) * (y1 - y2))); } // //draw ellipse using param values function drawEllipseWithPoints(eWidth:Number, eHeight:Number, eCenterX:Number, eCenterY:Number, dotGap:Number) { //horz and vert "radii" of ellipse, based on width and height var xRadius:Number = eWidth / 2; var yRadius:Number = eHeight / 2; while (true) { //convert theta degrees to radians var radian:Number = deg2rad(angle); //use flag to create one point until next point required if (j) { //create first point, known as circle 0 for later use var dot:MovieClip = this.attachMovie("circle", "circle" + i, i + 1); //mostly legit calculation of point on ellipse dot._x = eCenterX + xRadius * Math.cos(radian); dot._y = eCenterY + yRadius * Math.sin(radian); //increment counter for unique instance names and level i++; //disable point creation until next use j = false; } //calculate each point with 1-degree change in theta, // but only plot point when desired var tempX:Number = eCenterX + xRadius * Math.cos(radian); var tempY:Number = eCenterY + yRadius * Math.sin(radian); var myD:Number = pDp(dot._x, dot._y, tempX, tempY); //only create next point if distance is greater than desired gap if (myD > dotGap) { j = true; } //points don't continue to overlap when plotted equidistantly. // stop drawing when ellipse is complete. var quitD:Number = pDp(circle0._x, circle0._y, tempX, tempY); if (myD > dotGap && quitD < dotGap) { //last point doesn't look right, so put it midway between first and // second to last point. dot._x = this["circle" + (i - 2)]._x + (this["circle0"]._x - this["circle" + (i - 2)]._x) / 2; dot._y = this["circle" + (i - 2)]._y + (this["circle0"]._y - this["circle" + (i - 2)]._y) / 2; //use B.S. "magic number" of .07 * ration of width/height for wide // and height/width for tall ellipses dot._x += dotGap * (.07 * (eWidth / eHeight)); dot._y += dotGap * (.07 * (eHeight / eWidth)); // when finished, break out of the loop. break; } //increase theta by 1 angle++; } } // drawEllipseWithPoints(400, 200, (Stage.width / 2), (Stage.height / 2), 10); // stop(); _______________________________________________ Flashcoders@chattyfig.figleaf.com To change your subscription options or search the archive: http://chattyfig.figleaf.com/mailman/listinfo/flashcoders Brought to you by Fig Leaf Software Premier Authorized Adobe Consulting and Training http://www.figleaf.com http://training.figleaf.com
