流体パーティクル(解読用)
miniapp さんの作品「流体パーティクル」の処理を分かりやすく可視化したものです。
// forked from miniapp's 流体パーティクル
/**
* Fluid \ Learning \ Processing 1.0
* http://www.processing.org/learning/topics/fluid.html
*
* via [Flash]流体っぽいのを作ろうと思った | blog ViolentCoding
* http://violentcoding.com/blog/2008/07/26/archives/135
*/
package {
import flash.display.Shape;
import flash.display.Bitmap;
import flash.display.BitmapData;
import flash.display.Sprite;
import flash.display.StageAlign;
import flash.display.StageQuality;
import flash.display.StageScaleMode;
import flash.events.Event;
import flash.events.MouseEvent;
import flash.geom.ColorTransform;
import flash.geom.Rectangle;
import net.hires.debug.Stats;
[SWF(backgroundColor=0x000000, width=465, height=465, frameRate=60)]
public class FluidLine extends Sprite {
public function FluidLine() {
if (stage) init();
else addEventListener(Event.ADDED_TO_STAGE, init);
}
private var pmouseX:Number;
private var pmouseY:Number;
private var canvasWidth:int = 465;
private var canvasHeight:int = 465;
private var mousePressed:Boolean;
private var resolution:int = 50;
private var penSize:int = 40;
private var numCols:int = canvasWidth / resolution;;
private var numRows:int = canvasHeight / resolution;
private var numParticles:int = 500;
private var gridDatasVectors:Vector.<Vector.<GridData>> = new Vector.<Vector.<GridData>>();
private var particles:Vector.<Particle> = new Vector.<Particle>(numParticles, true);
private var pcount:int = 0;
private var arrows:Array = [];
private function init(e:Event = null):void {
removeEventListener(Event.ADDED_TO_STAGE, init);
stage.scaleMode = StageScaleMode.NO_SCALE;
stage.align = StageAlign.TOP_LEFT;
opaqueBackground = 0x0;
stage.addEventListener(MouseEvent.MOUSE_UP, mouseUpHandler);
stage.addEventListener(MouseEvent.MOUSE_DOWN, mouseDownHandler);
stage.quality = StageQuality.LOW;
addChild(new Stats());
for (var i:int = 0; i < numParticles; i++) {
particles[i] = new Particle(Math.random() * canvasWidth, Math.random() * canvasHeight);
}
for (var col:int = 0; col < numCols; ++col) {
gridDatasVectors[col] = new Vector.<GridData>(numRows, true);
arrows[col] = [];
for (var row:int = 0; row < numRows; ++row) {
var gridData:GridData = new GridData(col * resolution, row * resolution, resolution);
gridData.col = col;
gridData.row = row;
gridDatasVectors[col][row] = gridData;
var arrow:Arrow = new Arrow();
addChild(arrow);
arrows[col][row] = arrow;
}
}
var gridView:Shape = new Shape();
gridView.graphics.beginFill(0x808080);
addChild(gridView);
for (col = 0; col <= numCols; ++col) {
gridView.graphics.drawRect(0, col * resolution, canvasWidth, 1);
}
for (row = 0; row <= numRows; ++row) {
gridView.graphics.drawRect(row * resolution, 0, 1, canvasHeight);
}
//隣接するグリッドをセットしていく。
for (col = 0; col < numCols; ++col) {
for (row = 0; row < numRows; ++row) {
gridData = gridDatasVectors[col][row];
if (row > 0) {
var up:GridData = gridDatasVectors[col][row - 1];//上
gridData.up = up;
up.low = gridData;//下
}
if (col > 0) {
var left:GridData = gridDatasVectors[col - 1][row];//左
gridData.left = left;
left.right = gridData;//右
}
if (row > 0 && col > 0) {
var upperLeft:GridData = gridDatasVectors[col - 1][row - 1];
gridData.upperLeft = upperLeft;
upperLeft.lowerRight = gridData;
}
if (row > 0 && col < numCols - 1) {
var upperRight:GridData = gridDatasVectors[col + 1][row - 1];
gridData.upperRight = upperRight;
upperRight.lowerLeft = gridData;
}
}
}
gridDatasVectors.fixed = true;
addEventListener(Event.ENTER_FRAME, draw);
}
private function draw(e:Event):void {
var mouseXvel:Number = mouseX - pmouseX;
var mouseYvel:Number = mouseY - pmouseY;
for each(var gridDatas:Vector.<GridData> in gridDatasVectors) {
for each(var gridData:GridData in gridDatas) {
if (mousePressed) {
updateGridDataVelocity(gridData, mouseXvel, mouseYvel, penSize);
}
updatePressure(gridData);
}
}
graphics.clear();
graphics.lineStyle(1, 0xFFFFFF);
updateParticle();
for each(gridDatas in gridDatasVectors) {
for each(gridData in gridDatas) {
apdateVelocity(gridData);
}
}
pmouseX = mouseX;
pmouseY = mouseY;
}
public function updateParticle():void {
for each(var p:Particle in particles) {
if (p.x >= 0 && p.x < canvasWidth && p.y >= 0 && p.y < canvasHeight) {
var col:int = int(p.x / resolution);//自身が属しているgridDataを見つける
var row:int = int(p.y / resolution);
if (col > numCols - 1) col = numCols - 1;
if (row > numRows - 1) row = numRows - 1;
var gridData:GridData = gridDatasVectors[col][row];
var ax:Number = (p.x % resolution) / resolution;
var ay:Number = (p.y % resolution) / resolution;
p.xvel += (1 - ax) * gridData.xvel * 0.05;
p.yvel += (1 - ay) * gridData.yvel * 0.05;
p.xvel += ax * gridData.right.xvel * 0.05;
p.yvel += ax * gridData.right.yvel * 0.05;
p.xvel += ay * gridData.low.xvel * 0.05;
p.yvel += ay * gridData.low.yvel * 0.05;
p.x += p.xvel;
p.y += p.yvel;
var dx:Number = p.px - p.x;
var dy:Number = p.py - p.y;
var dist:Number = Math.sqrt(dx * dx + dy * dy);
var limit:Number = Math.random() * 0.5;
if (dist > limit) {
graphics.moveTo(p.x, p.y);
graphics.lineTo(p.px, p.py);
}
else {
graphics.moveTo(p.x, p.y);
graphics.lineTo(p.x + limit, p.y + limit);
}
p.px = p.x;
p.py = p.y;
}
else {
p.x = p.px = Math.random() * canvasWidth;
p.y = p.py = Math.random() * canvasHeight;
p.xvel = 0;
p.yvel = 0;
}
p.xvel *= 0.5;
p.yvel *= 0.5;
}
}
/**
* マウスドラッグの処理
* @param gridData
* @param mvelX
* @param mvelY
* @param penSize
*/
public function updateGridDataVelocity(gridData:GridData, mvelX:int, mvelY:int, penSize:Number):void {
var dx:Number = gridData.x - mouseX;
var dy:Number = gridData.y - mouseY;
var dist:Number = Math.sqrt(dy * dy + dx * dx);
if (dist < penSize) {
if (dist < 4) {
dist = penSize;
}
//マウスに近いほど力が強くなるように。
var power:Number = penSize / dist;
gridData.xvel += mvelX * power;
gridData.yvel += mvelY * power;
}
}
public function updatePressure(gridData:GridData):void {
var pressureX:Number = (
gridData.upperLeft.xvel * 0.5 //左上
+ gridData.left.xvel //左
+ gridData.lowerLeft.xvel * 0.5 //左下
- gridData.upperRight.xvel * 0.5 //右上
- gridData.right.xvel //右
- gridData.lowerRight.xvel * 0.5 //右下
);
var pressureY:Number = (
gridData.upperLeft.yvel * 0.5 //左上
+ gridData.up.yvel //上
+ gridData.upperRight.yvel * 0.5 //右上
- gridData.lowerLeft.yvel * 0.5 //左下
- gridData.low.yvel //下
- gridData.lowerRight.yvel * 0.5 //右下
);
gridData.pressure = (pressureX + pressureY) * 0.25;
var arrow:Arrow = arrows[gridData.col][gridData.row];
arrow.x = gridData.x + resolution / 2 >> 0;
arrow.y = gridData.y + resolution / 2 >> 0;
arrow.rotation = Math.atan2(gridData.yvel, gridData.xvel) * 180 / Math.PI;
arrow.scaleX = arrow.scaleY = Math.sqrt(gridData.yvel * gridData.yvel + gridData.xvel * gridData.xvel) / 100
}
public function apdateVelocity(gridData:GridData):void {
gridData.xvel += (
gridData.upperLeft.pressure * 0.5 //左上
+ gridData.left.pressure //左
+ gridData.lowerLeft.pressure * 0.5 //左下
- gridData.upperRight.pressure * 0.5 //右上
- gridData.right.pressure //右
- gridData.lowerRight.pressure * 0.5 //右下
) * 0.25;
gridData.yvel += (
gridData.upperLeft.pressure * 0.5 //左上
+ gridData.up.pressure //上
+ gridData.upperRight.pressure * 0.5 //右上
- gridData.lowerLeft.pressure * 0.5 //左下
- gridData.low.pressure //下
- gridData.lowerRight.pressure * 0.5 //右下
) * 0.25;
gridData.xvel *= 0.99;
gridData.yvel *= 0.99;
}
private function mouseDownHandler(e:Event):void {
mousePressed = true;
}
private function mouseUpHandler(e:Event):void {
mousePressed = false;
}
}
}
import flash.geom.Rectangle;
class BaseGridData {
public var col:int = 0;
public var row:int = 0;
public var x:int = 0;
public var y:int = 0;
public var xvel:Number = 0;
public var yvel:Number = 0;
public var pressure:Number = 0;
public var color:Number = 0;
public var rgb:uint;
public var rectangle:Rectangle;
}
class GridData extends BaseGridData{
public function GridData(x:int, y:int, resolution:Number) {
this.x = x;
this.y = y;
rectangle = new Rectangle(x, y, resolution, resolution)
}
//すべてのグリッドが8方向に隣接したグリッドを持つわけではないので、
//空のデータをセットしておく。
public var upperLeft:BaseGridData = new NullGridData();//左上
public var up:BaseGridData = new NullGridData();//上
public var upperRight:BaseGridData = new NullGridData();//右上
public var left:BaseGridData = new NullGridData();//左
public var right:BaseGridData = new NullGridData();//右
public var lowerLeft:BaseGridData = new NullGridData();//左下
public var low:BaseGridData = new NullGridData();//下
public var lowerRight:BaseGridData = new NullGridData();//右下
}
class NullGridData extends BaseGridData{
}
class Particle {
public function Particle(x:Number, y:Number) {
this.x = px = x;
this.y = py = y;
}
public var x:Number;
public var y:Number;
public var px:Number;
public var py:Number;
public var xvel:Number = 0;
public var yvel:Number = 0;
}
import flash.display.*;
class Arrow extends Sprite
{
function Arrow() {
var s:Shape = new Shape();
s.graphics.beginFill(0xFF0000, 1);
s.graphics.moveTo(2, 4);
s.graphics.lineTo(8, 4);
s.graphics.lineTo(8, 0);
s.graphics.lineTo(20, 7);
s.graphics.lineTo(8, 14);
s.graphics.lineTo(8, 10);
s.graphics.lineTo(2, 10);
s.graphics.lineTo(2, 4);
s.x = -10;
s.y = -7;
addChild(s);
}
}