2016/02/27 codes

最新推荐文章于 2024-10-15 21:06:07 发布

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最新推荐文章于 2024-10-15 21:06:07 发布

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原文链接：http://www.cnblogs.com/whatcanido/p/5223707.html

本文介绍Box2D物理引擎中的碰撞检测与对碰管理实现细节，包括绝对值计算、范围判断、 AABB边界有效性验证等核心数学工具函数，并展示了如何通过哈希表进行对碰对的有效管理。

b2Math.b2Abs = function(a){return a > 0.0 ? a : -a ;};
b2Math.b2AbsV = function(a){var b = new b2Vec2(b2Math.b2Abs(a.x),b2Math.b2Abs(a.y));return b};
b2Math.b2AbsM=function(A){var B=new b2Mat22(0,b2Math.b2AbsV(A.col1),b2Math.b2AbsV(A.col2));return B;};
b2Math.b2Min = function(a,b){return a > b ? a : b;};
b2Math.b2MinV = function(a,b){var c = new b2Vec2(b2Math.b2Min(a.x, b.x),b2Math.b2Min(a.y, b.y));return c;};
b2Math.b2Max = function(a,b){return a > b ? a : b;};
b2Math.b2MaxV = function(a,b){var c = new b2Vec2(b2Math.b2Max(a.x, b.x),b2Math.b2Max(a.y, b.y));return c;};
b2Math.b2Clamp = function(a,low,high){return b2Math.b2Max(low,b2Math.b2Min(a,high));};
b2Math.b2ClampV = function(a,low,high){return b2Math.b2MaxV(low,b2Math.b2MinV(a,high));};
b2Math.b2Swap = function(a,b){var tmp = a[0];a[0] = b[0];b[0] = tmp;};
b2Math.b2Random = function(){return Math.random() * 2 - 1;};
b2Math.b2NextPowerOfTwo = function(x){x|= (x >> 1) & 0x7FFFFFFF;x|= (x >> 2) & 0x3FFFFFFF;x|= (x >> 4) & 0x0FFFFFFF;x|= (x >> 8) &0x00FFFFFF;x|= (x >> 16) & 0x0000FFFF;};
b2Math.b2IsPowerOfTwo = function(x){var result = x > 0 && (x&(x - 1)) == 0;return result;};
b2Math.tempVec2 = new b2Vec2();
b2Math.tempVec3 = new b2Vec2();
b2Math.tempVec4 = new b2Vec2();
b2Math.tempVec5 = new b2Vec2();
b2Math.tempMat = new b2Matt22();
var b2AABB=Class.create();
b2AABB.prototype = {IsValid:function(){
var dX = this.maxVertex.x;
var dY = this.maxVertex.y;
dX = this.maxVertex.x;
dy = this.maxVertex.y;
dX -= this.minVertex.x;
dY -= this.minVertex.y;
var valid = dX > 0.0 && dY > 0.0;
valid = valid && this.minVertex.IsValid() && this.maxVertex.IsValid();
return valid;
},
minVertex :new b2Vec2(),maxVertex : new b2Vec2();
initialize:function(){this.minVertex = new b2Vec2();this.maxVertex = new b2Vec2();}
};
var b2Bound = Class.create();
b2Bound.prototype = {IsLower: function () {
return (this.value & 1) == 1
},
var tempProxyId = this.proxyId;
var tempStabbingCount = this.stabbingCount;
this.value = b.value;
this.proxyId = b.proxyId;
this.stabbingCount = b.stabbingCount;
b.value = tempValue;
b.proxyId = tempProxyId;
b.stabbingCount = tempStabbingCount;
},
proxyId:0,value:0,stabbingCount:0,initialize:function(){}
}
var b2BoundValues = Class.create();
b2BoundValues.prototype = {lowerValues:[0,0],upperValues:[0,0],
initialize:function(){this.lowerValues = [0,0];this.upperValues = [0,0];}}
var b2Pair =Class.create();
b2Pair.prototype = {
SetBuffered:function(){this.status|= b2Pair.e_pairBuffered;},
ClearBuffered:function(){this.status &=~b2Pair.e_pairBuffered;},
IsBuffered:function(){return (this.status & b2Pair.e_pairBuffered) == b2Pair.e_pairBuffered;},
SetRemoved:function(){this.status |= b2Pair.e_pairRemoved;},
ClearRemoved:function(){this.status &=~ b2Pair.e_pairRemoved;},
IsRemoved:function(){return (this.status & b2Pair.e_pairRemoved) == b2Pair.e_pairRemoved;},
SetFinal:function(){this.status |= b2Pair.e_pairFinal ;},
IsFinal:function(){return (this.status & b2Pair.e_pairFinal) == b2Pair.e_pairFinal;},
userData:0,proxyId1:0,proxyId2:0,next:0,status:0,
initialize:function(){}
};
b2Pair.b2_nullPair = b2Settins.USHRT_MAX;
b2Pair.b2_nullProxy = b2Settins.USHRT_MAX;
b2Pair.b2_tableCapacity = b2Settins.b2_maxPairs;
b2Pair.b2_tableMask = b2Pair.b2_tableCapacity - 1;
b2Pair.e_pairBuffered = 0x0001;
b2Pair.e_pairRemoved = 0x0002;
b2Pair.e_pairFinal = 0x0004;
var b2PairCallback = Class.create();
b2PairCallback.prototype = function(){
PairAdded:function(proxyUserData1,proxyUserData2){return null},
PairRemoved:function(pairUserData1,pairUserData2,pairUserData){},
initialize:function(){}
};
var b2BufferedPair = Class.create();
b2BufferedPair.protype = {proxyId1:0,proxyId2:0,initialize:function{}}