Assertion failed : area > 1.19209 - c++

Question

I'm getting this weird error when I run my program that uses Box2D which is really unexpected because it's in a file which is nowhere related to my project(unbuilt folder not linked to my project). I obtained a copy for Box2D for VS12 and built it for my project and setup-ed the project following a tutorial here:https://www.youtube.com/watch?v=kEClRFKyGkw&list=PLSPw4ASQYyymu3PfG9gxywSPghnSMiOAW&index=53
Here's my code:
void Box::init(b2World* world, const glm::vec2& position, const glm::vec2& dimensions)
{
m_dimensions = dimensions;
b2BodyDef boxDef;
boxDef.type = b2_dynamicBody;
boxDef.position.Set(position.x, position.y);
m_body = world->CreateBody(&boxDef);
b2PolygonShape boxShape;
boxShape.SetAsBox(position.x / 2.0f, position.y / 2.0f);
b2FixtureDef fixtureDef;
fixtureDef.shape = &boxShape;
fixtureDef.density = 1.0f;
fixtureDef.friction = 0.3f;
m_fixture = m_body->CreateFixture(&fixtureDef);
}
Where I've called the init():
b2Vec2 gravity(0.0f, -9.8f);
m_world = std::make_unique<b2World>(gravity);
b2BodyDef groundBodyDef;
groundBodyDef.position.Set(0.0f, -10.0f);
b2Body* groundBody = m_world->CreateBody(&groundBodyDef);
b2PolygonShape groundShape;
groundShape.SetAsBox(50.0f, 10.0f);
groundBody->CreateFixture(&groundShape, 0.0f);
Box newBox;
newBox.init(m_world.get(), glm::vec2(0.0f, 14.0f), glm::vec2(15.0f, 15.0f));
m_boxes.push_back(newBox);
A window pop's up as this:
The error printed on my console:
Assertion failed : area > 1.19209 2896e-07F,
path_to_unbuild_box2d\box2d_v2.3.0\box2d\box2d\collision\shapes\b2
polygonshape.cpp, line 422
Here's where the error occur (when I click Retry) line 336 b2Fixture.h:
inline void b2Fixture::GetMassData(b2MassData* massData) const
{
m_shape->ComputeMass(massData, m_density);
}
Problem 1 fixed
boxShape.SetAsBox(dimensions.x / 2.0f, dimensions.y / 2.0f); ///Instead of position.

Answer 1

The line of code that's failing is (as mentioned in the "Assertion failed" message):
b2Assert(area > b2_epsilon);
It means your polygon has a puny size (look at the assertion, the area is less than 1.192092896e-07F, which is the value 0.0000001192092896, which is tiny).
Likely boxShape has the invalid size. Set a breakpoint on the line:
boxShape.SetAsBox(position.x / 2.0f, position.y / 2.0f);
and inspect the value of position. Make sure you're setting the box's dimensions to a sane value. My bet is that you aren't.