The engine behind Splitter Flash game – new AS3 prototypes

核心提示：While Guillaume wants to refine a bit the final code before publishing it, here it is Bryce work:Here is my messy attempt at recreating the splitter engine that

While Guillaume wants to refine a bit the final code before publishing it, here it is Bryce work:

Here is my messy attempt at recreating the splitter engine that you posted about on your blog. The code is VERY messy and it doesn’t really work but I decided to send it to you incase it would help at all. The controls are a little funky, you have to move the mouse over to the lower right corner so that the red line is across one of the shapes and click. Sometimes it will (sort of)split it, sometimes it will do nothing. Gravity is disabled at first, hold g to turn it on and release it to turn it off(I added the gravity toggle to try and figure out what was going wrong).

The actionscript resides in two files, one in the timeline and one in the Cutter class

This is the one in the timeline:

import　Box2D.Dynamics.*;
import　Box2D.Collision.*;
import　Box2D.Collision.Shapes.*;
import　Box2D.Dynamics.Joints.*;
import　Box2D.Dynamics.Contacts.*;
import　Box2D.Common.Math.*;
import　Box2d.Common.*;
　
import　flash.events.*;
　
addEventListener(Event.ENTER_FRAME,　update,　false,　0,　true);
stage.addEventListener(MouseEvent.MOUSE_DOWN,　mDown);
stage.addEventListener(MouseEvent.MOUSE_UP,　mUp);
//stage.addEventListener(KeyboardEvent.KEY_DOWN,　kDown);
//stage.addEventListener(KeyboardEvent.KEY_UP,　kUp);
　
var　MouseIsDown:Boolean　=　false;
　
var　m_iterations:int　=　10;
var　m_timeStep:Number　=　1/30;
var　m_physScale:Number　=　50;
　
var　worldAABB:b2AABB　=　new　b2AABB();
worldAABB.lowerBound.Set(-1000.0,　-1000.0);
worldAABB.upperBound.Set(1000.0,　1000.0);
　
//　Define　the　gravity　vector
var　gravity:b2Vec2　=　new　b2Vec2(0.0,　0.0);
　
//　Allow　bodies　to　sleep
var　doSleep:Boolean　=　true;
　
//　Construct　a　world　object
var　m_world　=　new　b2World(worldAABB,　gravity,　doSleep);
　
var　dbgDraw:b2DebugDraw　=　new　b2DebugDraw();
//var　dbgSprite:Sprite　=　new　Sprite();
//m_sprite.addChild(dbgSprite);
dbgDraw.m_sprite　=　this;
dbgDraw.m_drawScale　=　50.0;
dbgDraw.m_fillAlpha　=　0.3;
dbgDraw.m_lineThickness　=　1.0;
dbgDraw.m_drawFlags　=　b2DebugDraw.e_shapeBit　|　b2DebugDraw.e_jointBit;
m_world.SetDebugDraw(dbgDraw);
　
　
var　wallSd:b2PolygonDef　=　new　b2PolygonDef();
var　wallBd:b2BodyDef　=　new　b2BodyDef();
var　wallB:b2Body;
　
//　Left
wallBd.position.Set(-95　/　m_physScale,　360/m_physScale/2);
wallSd.SetAsBox(100/m_physScale,　400/m_physScale/2);
wallB　=　m_world.CreateBody(wallBd);
wallB.CreateShape(wallSd);
wallB.SetMassFromShapes();
//　Right
wallBd.position.Set((640+95)　/　m_physScale,　360/m_physScale/2);
wallB　=　m_world.CreateBody(wallBd);
wallB.CreateShape(wallSd);
wallB.SetMassFromShapes();
//　Top
wallBd.position.Set(640/m_physScale/2,　-95/m_physScale);
wallSd.SetAsBox(680/m_physScale/2,　100/m_physScale);
wallB　=　m_world.CreateBody(wallBd);
wallB.CreateShape(wallSd);
wallB.SetMassFromShapes();
//　Bottom
wallBd.position.Set(640/m_physScale/2,　(360+95)/m_physScale);
wallB　=　m_world.CreateBody(wallBd);
wallB.CreateShape(wallSd);
wallB.SetMassFromShapes();
　
var　body:b2Body;
　
//　Spawn　in　a　bunch　of　crap
for　(var　i　=　0;　i　<　5;　i++){
　var　bodyDef:b2BodyDef　=　new　b2BodyDef();
　//bodyDef.isBullet　=　true;
　var　boxDef:b2PolygonDef　=　new　b2PolygonDef();
　boxDef.density　=　1.0;
　//　Override　the　default　friction.
　boxDef.friction　=　0.3;
　boxDef.restitution　=　0.1;
　boxDef.SetAsBox((Math.random()　*　5　+　10)　/　m_physScale,　(Math.random()　*　5　+　10)　/　m_physScale);
　bodyDef.position.Set((Math.random()　*　400　+　120)　/　m_physScale,　(Math.random()　*　150　+　50)　/　m_physScale);
　bodyDef.angle　=　Math.random()　*　Math.PI;
　body　=　m_world.CreateBody(bodyDef);
　body.CreateShape(boxDef);
　body.SetMassFromShapes();
　
}
/*
for　(i　=　0;　i　<　5;　i++){
　var　bodyDefC:b2BodyDef　=　new　b2BodyDef();
　//bodyDefC.isBullet　=　true;
　var　circDef:b2CircleDef　=　new　b2CircleDef();
　circDef.density　=　1.0;
　circDef.radius　=　(Math.random()　*　5　+　10)　/　m_physScale;
　//　Override　the　default　friction.
　circDef.friction　=　0.3;
　circDef.restitution　=　0.1;
　bodyDefC.position.Set((Math.random()　*　400　+　120)　/　m_physScale,　(Math.random()　*　150　+　50)　/　m_physScale);
　bodyDefC.angle　=　Math.random()　*　Math.PI;
　body　=　m_world.CreateBody(bodyDefC);
　body.CreateShape(circDef);
　body.SetMassFromShapes();
　
}
*/
for　(i　=　0;　i　<　15;　i++){
　var　bodyDefP:b2BodyDef　=　new　b2BodyDef();
　//bodyDefP.isBullet　=　true;
　var　polyDef:b2PolygonDef　=　new　b2PolygonDef();
　if　(Math.random()　>　0.66){
　　polyDef.vertexCount　=　4;
　　polyDef.vertices[0].Set((-10　-Math.random()*10)　/　m_physScale,　(　10　+Math.random()*10)　/　m_physScale);
　　polyDef.vertices[1].Set((　-5　-Math.random()*10)　/　m_physScale,　(-10　-Math.random()*10)　/　m_physScale);
　　polyDef.vertices[2].Set((　　5　+Math.random()*10)　/　m_physScale,　(-10　-Math.random()*10)　/　m_physScale);
　　polyDef.vertices[3].Set((　10　+Math.random()*10)　/　m_physScale,　(　10　+Math.random()*10)　/　m_physScale);
　}
　else　if　(Math.random()　>　0.5){
　　polyDef.vertexCount　=　5;
　　polyDef.vertices[0].Set(0,　(10　+Math.random()*10)　/　m_physScale);
　　polyDef.vertices[2].Set((-5　-Math.random()*10)　/　m_physScale,　(-10　-Math.random()*10)　/　m_physScale);
　　polyDef.vertices[3].Set((　5　+Math.random()*10)　/　m_physScale,　(-10　-Math.random()*10)　/　m_physScale);
　　polyDef.vertices[1].Set((polyDef.vertices[0].x　+　polyDef.vertices[2].x),　(polyDef.vertices[0].y　+　polyDef.vertices[2].y));
　　polyDef.vertices[1].Multiply(Math.random()/2+0.8);
　　polyDef.vertices[4].Set((polyDef.vertices[3].x　+　polyDef.vertices[0].x),　(polyDef.vertices[3].y　+　polyDef.vertices[0].y));
　　polyDef.vertices[4].Multiply(Math.random()/2+0.8);
　}
　else{
　　polyDef.vertexCount　=　3;
　　polyDef.vertices[0].Set(0,　(10　+Math.random()*10)　/　m_physScale);
　　polyDef.vertices[1].Set((-5　-Math.random()*10)　/　m_physScale,　(-10　-Math.random()*10)　/　m_physScale);
　　polyDef.vertices[2].Set((　5　+Math.random()*10)　/　m_physScale,　(-10　-Math.random()*10)　/　m_physScale);
　}
　polyDef.density　=　1.0;
　polyDef.friction　=　0.3;
　polyDef.restitution　=　0.1;
　bodyDefP.position.Set((Math.random()　*　400　+　120)　/　m_physScale,　(Math.random()　*　150　+　50)　/　m_physScale);
　bodyDefP.angle　=　Math.random()　*　Math.PI;
　body　=　m_world.CreateBody(bodyDefP);
　body.CreateShape(polyDef);
　body.SetMassFromShapes();
}
　
function　update(e:Event):void
{
　this.graphics.clear()
　m_world.Step(m_timeStep,　m_iterations);
　
　var　segment:b2Segment　=　new　b2Segment();
　segment.p1.SetV(new　b2Vec2(50　/　m_physScale,　50　/　m_physScale))
　segment.p2.SetV(new　b2Vec2(mouseX　/　m_physScale,　mouseY　/　m_physScale))
　//segment.ExtendForward(worldAABB);
　
　var　lambda　=　[1];
　var　normal:b2Vec2　=　new　b2Vec2();
　var　maxShapes:Number　=　64;
　var　shapes:Array　=　new　Array();
　var　count:Number　=　m_world.Raycast(segment,shapes,maxShapes,false,null);
　
　if　(MouseIsDown)
　{
　　for　(var　i:int　=　0;　i　<　count;　i++)
　　{
　　　if　(shapes[i].GetType()　!=　b2Shape.e_polygonShape)
　　　{
　　　　continue;
　　　}
　
　　　var　b:b2Body　=　shapes[i].GetBody();
　
　　　if　(b.GetMass()　<=　0)
　　　{
　　　　continue;
　　　}
　
　　　var　polyShape:b2PolygonShape　=　shapes[i];
　　　var　pd:Array　=　new　Array(2);
　　　pd[0]　=　new　b2PolygonDef();
　　　pd[0].density　=　1;
　　　pd[1]　=　new　b2PolygonDef();
　　　pd[1].density　=　1;
　
　　　if　(Cutter.SplitShape(polyShape,　segment,　0.1,　pd)　==　0)
　　　{
　　　　b.DestroyShape(shapes[i]);
　　　　b.CreateShape(pd[0]);
　　　　b.SetMassFromShapes();
　　　　b.WakeUp();
　
　　　　var　bd:b2BodyDef　=　new　b2BodyDef();
　　　　bd.position　=　b.GetPosition();
　　　　bd.angle　=　b.GetAngle();
　
　　　　var　newBody:b2Body　=　m_world.CreateBody(bd);
　　　　newBody.CreateShape(pd[1]);
　　　　newBody.SetMassFromShapes();
　　　　newBody.SetAngularVelocity(b.GetAngularVelocity());
　　　　newBody.SetLinearVelocity(b.GetLinearVelocity());
　　　}
　　}
　}
　
　lambda=[1];
　lambda=lambda[0];
　
　this.graphics.lineStyle(1,0xff0000,1);
　this.graphics.moveTo(segment.p1.x　*　m_physScale,　segment.p1.y　*　m_physScale);
　this.graphics.lineTo(　　(segment.p2.x　*　lambda　+　(1-lambda)　*　segment.p1.x)　*　m_physScale,
　　　　　　　　(segment.p2.y　*　lambda　+　(1-lambda)　*　segment.p1.y)　*　m_physScale);
}
　
function　mDown(e:MouseEvent):void
{
　MouseIsDown　=　true;
}
　
function　mUp(e:MouseEvent):void
{
　MouseIsDown　=　false;
}
/*
var　keyToCheck:String　=　"g";
　
function　kDown(e:KeyboardEvent):void
{
　if　(e.charCode　==　keyToCheck.charCodeAt(0))
　{
　　m_world.SetGravity(new　b2Vec2(0,10));
　}
}
　
function　kUpp(e:KeyboardEvent):void
{
　if　(e.charCode　==　keyToChek.charCodeAt(0))
　{
　　m_world.SetGravity(new　b2Vec2(0,0));
　}
}
*/