Question

所以，我正在尝试创建一个与SFML精灵相关联的Human实体，以及一个Box2D体和夹具。但是我得到了这个错误：

Assertion failed: area > 1.19209289550781250000e-7F, file ...b2PolygonShape.cpp, line 352

所以我做了一些快速的谷歌搜索，发现我的问题在于我的形状不正确的顶点。但是如果我使用Shape.SetAsBox()函数......

，我不明白这是怎么回事

这是我的代码：

#include "../../include/entity/Human.hpp"

Human::Human(unsigned int id, b2World& world, sf::Vector2f pos, sf::Texture* texture)
    : AnimatedEntity(id, world, pos, sf::Vector2i(32, 32), texture)
{
    b2PolygonShape shape;
    shape.SetAsBox((32/2)/SCALE, (32/2)/SCALE);     // Set the size; Box2D takes the half-width/height as params, and then scale.

    b2FixtureDef fixtureDef;
    fixtureDef.density = .8f;
    fixtureDef.friction = .4f;
    fixtureDef.restitution = .2f;
    fixtureDef.shape = &shape;

    e_body->CreateFixture(&fixtureDef);     // Assuming: shape and density are set
}

FTR，SCALE是static const int，其值为30（30px / 1m）。怎么了？

Answer 1

我认为billz的意思是：

(32/2) = 16
16 / 30 = 0

你只需要为SCALE使用浮点而不是int ...

Shape.SetAsBox（）中断言失败？

1 个答案: