c++ - Assertion failed : area > 1.19209 -

i'm getting weird error when run program uses box2d unexpected because it's in file related project(unbuilt folder not linked project). obtained copy box2d vs12 , built project , setup-ed project following tutorial here:https://www.youtube.com/watch?v=keclrfkygkw&list=plspw4asqyyymu3pfg9gxywspghnsmioaw&index=53

here's 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 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 this:

the error printed on 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 error occur (when 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. 

the line of code that's failing is (as mentioned in "assertion failed" message):

b2assert(area > b2_epsilon); 

it means polygon has puny size (look @ assertion, area less 1.192092896e-07f, value 0.0000001192092896, tiny).

likely boxshape has invalid size. set breakpoint on line:

boxshape.setasbox(position.x / 2.0f, position.y / 2.0f); 

and inspect value of position. make sure you're setting box's dimensions sane value. bet aren't.