ベジェ曲線を応用してみた。


ベジェ曲線の応用です。
 
 

 
 
 

 
ある案件で「ふらふらと文字列が等速で走る」というお題をいただきました。
ライブラリーを使うことや力学的に力を与える事を検討しましたが、ベジェ曲線を使うことにしました。
ベジェ曲線を応用して、曲線点を検出して移動距離を積分的にはかっていく方法です。
 
submitボタンで文字が走り出します。visible linesボタンでラインが見えるようになります。編集もできます。

ベジェ曲線上を文字が等速で走らせる – wonderfl build flash online

 
[sourcecode language=”as3″]
package{
import flash.events.StatusEvent;
import com.bit101.components.*;
import net.hires.debug.Stats;
import flash.display.Sprite;
import flash.display.StageAlign;
import flash.display.StageScaleMode;
import flash.text.TextField;
import flash.text.TextFieldType;
import flash.display.MovieClip;
import flash.events.MouseEvent;
import flash.events.Event;

public class FlashTest extends Sprite{
private var lines:Lines;
private var text_txt:TextField;
public function FlashTest ():void{

stage.align=StageAlign.TOP_LEFT;
stage.scaleMode=StageScaleMode.NO_SCALE;

var stats:Stats=new Stats();
addChild( stats );

lines=new Lines();
lines.visible=false;
addChild(lines);
lines.init();

text_txt = new TextField();
text_txt.type=TextFieldType.INPUT;
text_txt.border=true;
text_txt.borderColor=0xCCCCCC;
text_txt.x=75;
text_txt.y=5;
text_txt.width = 350;
text_txt.height = 20;
text_txt.text = "ベジェ曲線上を文字が等速で走ります。ここにインプットもできますよ。";
addChild(text_txt);

var submit_btn:PushButton=new PushButton();
submit_btn.x=75;
submit_btn.y=30;
submit_btn.label="submit";
addChild(submit_btn);
submit_btn.addEventListener(MouseEvent.CLICK,nclick);
var visible_btn:PushButton=new PushButton();
visible_btn.x=75;
visible_btn.y=55;
visible_btn.label="visible lines"
addChild(visible_btn);
visible_btn.addEventListener(MouseEvent.CLICK,vclick);
setRunText()
}
/**/
private function nclick(evt:MouseEvent):void {
setRunText()
}
private function setRunText():void{
var rt:RunText=new RunText(lines);
addChild(rt);
rt.init(lines,text_txt.text);
}
private function vclick(evt:MouseEvent):void{
lines.visible=!lines.visible;
}
}
}
//package{
import flash.display.MovieClip;
import flash.display.Graphics;

import flash.events.Event;
import flash.events.MouseEvent;

class Lines extends MovieClip{
private var total:uint=300;
private var v:Number =10;
private var i:uint;
private var p_num:uint=6;
//
public var dot_ar:Array=new Array();

private var p_ar:Array=new Array();
//
private var d_mc:MovieClip;
private var drag_c_mc:MovieClip;
private var press_flag:Boolean=false;
//
private var gv:Graphics;
//
public function Lines(){
}
public function init():void{
gv=this.graphics;
p_ar=new Array();
for (i=0; i<p_num; i++) {
var p_mc:MovieClip=new MovieClip()
p_ar.push(p_mc)

addChild(p_mc)

var c_line_mc:MovieClip=new MovieClip();
var c_line_g:Graphics=c_line_mc.graphics;
p_mc.c_line_mc=c_line_mc;
p_mc.addChild(c_line_mc);

p_mc.x=100+(stage.stageWidth-200)*Math.random()
p_mc.y=100+(stage.stageHeight-200)*Math.random()
var center_mc:MovieClip=new MovieClip();
var pb_g:Graphics=center_mc.graphics;
pb_g.beginFill(0xcccccc,0.1)
pb_g.drawCircle(0,0,20);

p_mc.addChild(center_mc);
center_mc.addEventListener(MouseEvent.MOUSE_DOWN,mdwn);
//
p_mc.buttonMode=true;
var ra:Number=Math.PI*Math.random();
var c0_p:MovieClip=new MovieClip();
var pg:Graphics=c0_p.graphics;
pg.beginFill(0x000000);
pg.drawCircle(0,0,5);
p_mc.addChild(c0_p);
c0_p.x=100*Math.cos(ra);
c0_p.y=100*Math.sin(ra);
//
p_mc.addChild(c0_p);

var c1_p:MovieClip=new MovieClip();
pg=c1_p.graphics;
pg.beginFill(0x000000);
pg.drawCircle(0,0,5);
p_mc.addChild(c1_p);
c1_p.x=100*Math.cos(ra-Math.PI);
c1_p.y=100*Math.sin(ra-Math.PI);
//
p_mc.p_ar=new Array(c0_p,c1_p)
c0_p.another=c1_p;
c1_p.another=c0_p;
c0_p.flag=true;
c1_p.flag=true;
c0_p.addEventListener(Event.ENTER_FRAME,c_ent);
c1_p.addEventListener(Event.ENTER_FRAME,c_ent);
c0_p.addEventListener(MouseEvent.MOUSE_DOWN,c_press);
c1_p.addEventListener(MouseEvent.MOUSE_DOWN,c_press);
//
c_line_g.lineStyle(1,0×000000,0.5)
c_line_g.moveTo(0,0)
c_line_g.lineTo(c0_p.x,c0_p.y);
//
c_line_g.moveTo(0,0)
c_line_g.lineTo(c1_p.x,c1_p.y);

//
p_mc.addChild(c0_p);
}
//
drawLines();
addEventListener(Event.ENTER_FRAME,ent);
}

private function mdwn(evt:MouseEvent):void {
press_flag=true;
d_mc=evt.currentTarget as MovieClip;
MovieClip(d_mc.parent).startDrag();
stage.addEventListener(MouseEvent.MOUSE_UP,mup);
}
private function mup(evt:MouseEvent):void {
press_flag=false;
d_mc.stopDrag();
stage.removeEventListener(MouseEvent.MOUSE_UP,mup);
}

private function c_press(evt:MouseEvent):void{
press_flag=true;
//
var _mc:MovieClip=evt.currentTarget as MovieClip;
_mc.flag=false;
_mc.startDrag();
drag_c_mc=_mc;
stage.addEventListener(MouseEvent.MOUSE_UP,stage_mup);
}
private function stage_mup(evt:MouseEvent):void{
press_flag=false;
//
drag_c_mc.stopDrag();
drag_c_mc.flag=true;
stage.removeEventListener(MouseEvent.MOUSE_UP,stage_mup);

}
//
private function c_ent(evt:Event):void{
var _mc:MovieClip=evt.currentTarget as MovieClip;
if(_mc.flag){
var another:MovieClip=_mc.another;
var another_theta:Number=Math.atan2(another.y,another.x);
var another_r:Number=Math.sqrt(Math.pow(another.y,2)+Math.pow(another.x,2))
_mc.x=another_r*Math.cos(another_theta+Math.PI);
_mc.y=another_r*Math.sin(another_theta+Math.PI);
}
}
//
private function ent(evt:Event):void{
if(press_flag){
drawLines();
}
}
//
private function drawLines():void{
var i:uint
gv.clear();
gv.lineStyle(1,0×000000,0.5);
dot_ar=new Array();
for(i=0;i<p_ar.length-1;i++){
drawLine(p_ar[i],p_ar[i+1]);
}
drawCP();
}
//
private function drawLine(p0:MovieClip,p1:MovieClip):void {
gv.moveTo(p0.x,p0.y);
var c0:MovieClip=p0.p_ar[1];
var c1:MovieClip=p1.p_ar[0];
dot_ar.push([p0.x,p0.y]);
var i:uint;
//
for (i=1; i<total; i++) {
var cnt:Number=i/total;
var c0p0x:Number=(p0.x+c0.x)*cnt+p0.x*(1-cnt);
var c0p0y:Number=(p0.y+c0.y)*cnt+p0.y*(1-cnt);
var c0c1x:Number=(p1.x+c1.x)*cnt+(p0.x+c0.x)*(1-cnt);
var c0c1y:Number=(p1.y+c1.y)*cnt+(p0.y+c0.y)*(1-cnt);

//
var c1p1x:Number=p1.x*cnt+(p1.x+c1.x)*(1-cnt);
var c1p1y:Number=p1.y*cnt+(p1.y+c1.y)*(1-cnt);
//
var cc0x:Number=c0c1x*cnt+c0p0x*(1-cnt);
var cc0y:Number=c0c1y*cnt+c0p0y*(1-cnt);
var cc1x:Number=c1p1x*cnt+c0c1x*(1-cnt);
var cc1y:Number=c1p1y*cnt+c0c1y*(1-cnt);
//
var px:Number=cc1x*cnt+cc0x*(1-cnt);
var py:Number=cc1y*cnt+cc0y*(1-cnt);
gv.lineTo(px,py);
dot_ar.push([px,py])
}
gv.lineTo(p1.x,p1.y);
//

}
private function drawCP():void{
var i:uint;

for (i=0; i<p_ar.length; i++) {
var p_mc:MovieClip=p_ar[i];
var c_line_mc:MovieClip=p_mc.c_line_mc;
var c_g:Graphics=c_line_mc.graphics;
c_g.clear()
c_g.lineStyle(1,0×000000,0.5)
var c0_p:MovieClip=p_mc.p_ar[0];
var c1_p:MovieClip=p_mc.p_ar[1];
c_g.moveTo(0,0)
c_g.lineTo(c0_p.x,c0_p.y);
//
c_g.moveTo(0,0)
c_g.lineTo(c1_p.x,c1_p.y);
}
}
//
}

import flash.display.MovieClip;

import flash.text.TextField;
import flash.text.TextFormat;

import flash.display.BitmapData;
import flash.geom.Matrix;
import flash.geom.ColorTransform;
import flash.geom.Rectangle;
import flash.display.Bitmap;

import flash.text.AntiAliasType;
import flash.display.BlendMode;
import flash.display.PixelSnapping;

import flash.events.Event;

class RunText extends MovieClip{
private var lines:MovieClip;
//
private var v:Number=10

private var lgt:Number;
private var cnt:Number;
private var _ar:Array;
private var delete_ar:Array
public function RunText(_mc:MovieClip):void{
lines=_mc;
}

public function init(_mc:MovieClip,txt:String):void{
var i:uint
cnt=0;
lgt=txt.length;
_ar=new Array();
delete_ar=new Array();
for(i=0;i<lgt;i++){
var st:String=txt.substr(i,1);
var _mc:MovieClip=new MovieClip();
addChild(_mc);
setText(_mc,st);
_ar.push(_mc)
}

addEventListener(Event.ENTER_FRAME,ent);
}
//
private function setText(_mc:MovieClip,txt:String):void {
var tf:TextField=new TextField();
tf.selectable=false;
tf.antiAliasType=AntiAliasType.ADVANCED;
tf.multiline=true;
tf.wordWrap=true;
//
var format:TextFormat=new TextFormat();
format.size=18;
format.color=0xFF0000;
tf.defaultTextFormat=format;
//
tf.text=txt
//
tf.width=tf.textWidth+5;
var bw:Number=tf.width
var bh:Number=tf.textHeight
//
var bmp_data : BitmapData = new BitmapData(bw,bh , true , 0xFFFFFF);
var matrix : Matrix = new Matrix();
var color : ColorTransform = new ColorTransform();
var rect : Rectangle = new Rectangle(0,0,tf.width,tf.textHeight);
bmp_data.draw(tf, matrix, color, BlendMode.NORMAL, rect, true);
var bmp_obj : Bitmap = new Bitmap( bmp_data , PixelSnapping.AUTO , true);
bmp_obj.x=bmp_obj.width*-0.5;
bmp_obj.y=bmp_obj.height*-0.5;
//
//
_mc.addChild(bmp_obj)
_mc.cnt=1;
_mc.x=lines.dot_ar[0][0];
_mc.y=lines.dot_ar[0][1];
}
//
private function ent(evt:Event):void{
var i:uint;
var ii:uint;
//
var dot_ar:Array=lines.dot_ar
var top_mc:MovieClip=_ar[0]
var Length:Number=0;
var n:uint=0;
for(i=top_mc.cnt;i<dot_ar.length;i++){
n++;
Length+=Math.sqrt(Math.pow(dot_ar[i][0]-dot_ar[i-1][0],2)+Math.pow(dot_ar[i][1]-dot_ar[i-1][1],2));
if(Length>v){
break;
}
}
top_mc.cnt+=n;

for(i=1;i<_ar.length;i++){
var _mc:MovieClip=_ar[i];
Length=0;
n=0;
for(ii=top_mc.cnt-2;ii>=0;ii–){
n++;
Length+=Math.sqrt(Math.pow(dot_ar[ii][0]-dot_ar[ii+1][0],2)+Math.pow(dot_ar[ii][1]-dot_ar[ii+1][1],2));
if(Length>20*i){
break;
}
if(ii==0){
n=0
}
}
if(n!=0){
_mc.cnt=top_mc.cnt-n;
}
mc_move(_mc,dot_ar);
//
}
mc_move(top_mc,dot_ar);
//
}
//
private function mc_move(_mc:MovieClip,dot_ar:Array):void{
if(_mc.cnt>=dot_ar.length){
//uzuStart(_mc);

textComp();
}else if (_mc.cnt>0) {
var theta:Number=Math.atan2(dot_ar[_mc.cnt][1]-dot_ar[_mc.cnt-1][1],dot_ar[_mc.cnt][0]-dot_ar[_mc.cnt-1][0]);
_mc.rotation=theta*(180/Math.PI)
_mc.x=dot_ar[_mc.cnt][0];
_mc.y=dot_ar[_mc.cnt][1];
}
}
//
private function textComp():void{
var _mc:MovieClip=_ar.shift();
_mc.visible=false;
delete_ar.push(_mc);
cnt++;
if(cnt==lgt){
removeEventListener(Event.ENTER_FRAME,ent);
parent.removeChild(this)
//addEventListener(Event.ENTER_FRAME,removeAlphaMove);
}
}
}
[/sourcecode]

どんな曲線もコントロールできそうだし、なかなかスムーズに動いてよしよし。
っと言ったところで案件がストップ。がっくし。