// written in the D programming language

module samples.UnsafeOps;

import chipmunkd.chipmunk;

import samples.ChipmunkDemo;

import gameApp;

import std.math;

static cpSpace *space;

enum M_PI = PI;
enum M_PI_2 = PI*0.5f;

enum NUM_CIRCLES = 30;

static cpShape *circles[NUM_CIRCLES];
static cpFloat circleRadius = 30.0f;

static void
update(int ticks)
{
	if(arrowDirection.y){
		circleRadius = cpfmax(10.0f, circleRadius + arrowDirection.y);
		
		for(int i=0; i<NUM_CIRCLES; i++){
			circles[i]._body.m = cpMomentForCircle(1.0f, 0.0f, circleRadius, cpvzero);
			cpCircleShapeSetRadius(circles[i], circleRadius);
		}
	}
	
	int steps = 1;
	cpFloat dt = 1.0f/60.0f/cast(cpFloat)steps;
	
	for(int i=0; i<steps; i++){
		cpSpaceStep(space, dt);
	}
}

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, staticBody = &space.staticBody;
	cpShape *shape;
	
	shape = cpSpaceAddStaticShape(space, cpSegmentShapeNew(staticBody, cpv(-320,-240), cpv(-320,240), 0.0f));
	shape.e = 1.0f; shape.u = 1.0f;
	shape.layers = NOT_GRABABLE_MASK;

	shape = cpSpaceAddStaticShape(space, cpSegmentShapeNew(staticBody, cpv(320,-240), cpv(320,240), 0.0f));
	shape.e = 1.0f; shape.u = 1.0f;
	shape.layers = NOT_GRABABLE_MASK;

	shape = cpSpaceAddStaticShape(space, cpSegmentShapeNew(staticBody, cpv(-320,-240), cpv(320,-240), 0.0f));
	shape.e = 1.0f; shape.u = 1.0f;
	shape.layers = NOT_GRABABLE_MASK;
	
	for(int i=0; i<NUM_CIRCLES; i++){
		_body = cpSpaceAddBody(space, cpBodyNew(1.0f, cpMomentForCircle(1.0f, 0.0f, circleRadius, cpvzero)));
		_body.p = cpvmult(cpv(frand()*2.0f - 1.0f, frand()*2.0f - 1.0f), circleRadius*5.0f);
		
		circles[i] = shape = cpSpaceAddShape(space, cpCircleShapeNew(_body, circleRadius, cpvzero));
		shape.e = 0.0f; shape.u = 1.0f;
	}
	
	//strcat(messageString,
	//	"chipmunk_unsafe.h Contains functions for changing shapes, but they can cause severe stability problems if used incorrectly.\n"
	//	"Shape changes occur as instantaneous changes to position without an accompanying velocity change. USE WITH CAUTION!");
	return space;
}

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

chipmunkDemo UnsafeOps = {
	"Unsafe Operations",
	null,
	&init,
	&update,
	&destroy,
};