// written in the D programming language

module samples.Plink;

import chipmunkd.chipmunk;

import samples.ChipmunkDemo;

import std.math;

static cpSpace *space;

// Iterate over all of the bodies and reset the ones that have fallen offscreen.
static void
eachBody(cpBody *_body, void *unused)
{
	if(_body.p.y < -260 || cpfabs(_body.p.x) > 340){
		cpFloat x = frand()*640 - 320;
		_body.p = cpv(x, 260);
	}
}

static void
update(int ticks)
{
	int steps = 1;
	cpFloat dt = 1.0f/60.0f/cast(cpFloat)steps;
	
	for(int i=0; i<steps; i++){
		cpSpaceStep(space, dt);
		cpSpaceEachBody(space, &eachBody, null);
	}
}

enum NUM_VERTS = 5;

static cpSpace *
init()
{
	cpResetShapeIdCounter();
	
	space = cpSpaceNew();
	space.iterations = 5;
	space.gravity = cpv(0, -100);
	
	cpSpaceResizeStaticHash(space, 40.0f, 999);
	cpSpaceResizeActiveHash(space, 30.0f, 2999);
	
	cpBody *_body;
	cpBody *staticBody = &space.staticBody;
	cpShape *shape;
	
	// Create vertexes for a pentagon shape.
	cpVect verts[NUM_VERTS];
	for(int i=0; i<NUM_VERTS; i++){
		cpFloat angle = -2.0f*PI*i/(cast(cpFloat) NUM_VERTS);
		verts[i] = cpv(10.0f*cos(angle), 10.0f*sin(angle));
	}
	
	// Vertexes for a triangle shape.
	enum cpVect tris[] = [
		cpv(-15,-15),
		cpv(  0, 10),
		cpv( 15,-15),
	];

	int foo;
	
	// Create the static triangles.
	foreach(i; 0..9){
		foreach(j; 0..6){
			cpFloat stagger = (j%2)*40;
			cpVect offset;
			offset.x = (i*80) - 320 + stagger;
			offset.y = (j*70) - 240;
			//BUG: crazy fucking dmd codegen bug when optimizing (2.050)
			foo = i;
			
			shape = cpSpaceAddShape(space, cpPolyShapeNew(staticBody, 3, tris.ptr, offset));
			shape.e = 1.0f; shape.u = 1.0f;
			shape.layers = NOT_GRABABLE_MASK;
		}
	}
	
	// Add lots of pentagons.
	for(int i=0; i<300; i++){
		_body = cpSpaceAddBody(space, cpBodyNew(1.0f, cpMomentForPoly(1.0f, NUM_VERTS, verts.ptr, cpvzero)));
		cpFloat x = frand()*640 - 320;
		_body.p = cpv(x, 350);
		
		shape = cpSpaceAddShape(space, cpPolyShapeNew(_body, NUM_VERTS, verts.ptr, cpvzero));
		shape.e = 0.0f; shape.u = 0.4f;
	}
	
	return space;
}

static void
destroy()
{
	cpSpaceFreeChildren(space);
	cpSpaceFree(space);
}

chipmunkDemo Plink = {
	"Plink",
	null,
	&init,
	&update,
	&destroy,
};