Chipmunk Physics: cpSpaceShapeQuery

Question

How does the cpSpaceShapeQuery function work? I can not find any doc about it.

Andrea

Answer 1

Yeah... I never got around to documenting that... Sorry. Basically you create a body and shape (neither needs to be added to the space) and use that to query much like the other query functions.

This code snippet makes a copy of a body and shape on the stack and then simulates it out to it's first predicted collision point drawing the path as it goes.

    cpBody body = *(originalBody);  
cpPolyShape shape = *((cpPolyShape *)originalShape);
shape.shape.body = &body;

cpFloat dt = 1.0f/60.0f;
cpVect gravity = space->gravity;

int count = 0;
for(int i=0; i<300; i++){
    cpBodyUpdatePosition(&body, dt);
    cpBodyUpdateVelocity(&body, gravity, 1.0f, dt);

    if(cpSpaceShapeQuery(space, (cpShape *)&shape, NULL, NULL)){
        quads[count%maxQuads] = quad(body.p, body.rot, CGRectMake(0, 2*32, 64, 64), tsize);
        count++;

        break;
    }

    if(i%10==0){
        quads[count%maxQuads] = quad(body.p, body.rot, rect, tsize);
        count++;
    }
}