Box2D自定义重力

需要给刚体添加一个自定义的属性：m_customGravity，这样就可以动态的修改每一个刚体自定义的重力，查找box2d源码大约在5486行，加上红色的一句代码

b2Island.prototype.Solve = function (step, gravity, allowSleep) {   var i = 0;   var j = 0;   var b;   var joint;   for (i = 0;   i < this.m_bodyCount; ++i) {     b = this.m_bodies[i];     if (b.GetType() != b2Body.b2_dynamicBody) continue;     gravity = b.m_customGravity || gravity;          b.m_linearVelocity.x += step.dt * (gravity.x + b.m_invMass * b.m_force.x);     b.m_linearVelocity.y += step.dt * (gravity.y + b.m_invMass * b.m_force.y);     b.m_angularVelocity += step.dt * b.m_invI * b.m_torque;     b.m_linearVelocity.Multiply(b2Math.Clamp(1.0 - step.dt * b.m_linearDamping, 0.0, 1.0));     b.m_angularVelocity *= b2Math.Clamp(1.0 - step.dt * b.m_angularDamping, 0.0, 1.0);   }..............代码略...........................................................................................};

原标题：Box2D自定义重力

关键词：