// written in the D programming language

module samples.Pump;

import dchip.all;

import samples.ChipmunkDemo;

import gameApp;

import std.math;

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

static cpSpace *space;
static cpConstraint *motor;

enum numBalls = 5;
static cpBody *balls[numBalls];

static void
update(int ticks)
{
    cpFloat coef = (2.0f + arrowDirection.y)/3.0f;
    cpFloat rate = arrowDirection.x*30.0f*coef;

    cpSimpleMotorSetRate(motor, rate);
    motor.maxForce = (rate ? 1000000.0f : 0.0f);

    enum int steps = 2;
    enum cpFloat dt = 1.0f/60.0f/cast(cpFloat)steps;

    for(int i=0; i<steps; i++){
        cpSpaceStep(space, dt);

        for(int j=0; j<numBalls; j++){
            cpBody *ball = balls[j];
            if(ball.p.x > 320.0f){
                ball.v = cpvzero;
                ball.p = cpv(-224.0f, 200.0f);
            }
        }
    }
}

static cpBody *
add_ball(cpVect pos)
{
    cpBody *_body = cpSpaceAddBody(space, cpBodyNew(1.0f, cpMomentForCircle(1.0f, 30, 0, cpvzero)));
    _body.p = pos;

    cpShape *shape = cpSpaceAddShape(space, cpCircleShapeNew(_body, 30, cpvzero));
    shape.e = 0.0f; shape.u = 0.5f;

    return _body;
}

static cpSpace *
init()
{
    space = cpSpaceNew();
    space.gravity = cpv(0, -600);

    cpBody *staticBody = space.staticBody;
    cpShape *shape;

    // beveling all of the line segments slightly helps prevent things from getting stuck on cracks
    shape = cpSpaceAddShape(space, cpSegmentShapeNew(staticBody, cpv(-256,16), cpv(-256,300), 2.0f));
    shape.e = 0.0f; shape.u = 0.5f; shape.layers = 1;
    shape.layers = NOT_GRABABLE_MASK;

    shape = cpSpaceAddShape(space, cpSegmentShapeNew(staticBody, cpv(-256,16), cpv(-192,0), 2.0f));
    shape.e = 0.0f; shape.u = 0.5f; shape.layers = 1;
    shape.layers = NOT_GRABABLE_MASK;

    shape = cpSpaceAddShape(space, cpSegmentShapeNew(staticBody, cpv(-192,0), cpv(-192, -64), 2.0f));
    shape.e = 0.0f; shape.u = 0.5f; shape.layers = 1;
    shape.layers = NOT_GRABABLE_MASK;

    shape = cpSpaceAddShape(space, cpSegmentShapeNew(staticBody, cpv(-128,-64), cpv(-128,144), 2.0f));
    shape.e = 0.0f; shape.u = 0.5f; shape.layers = 1;
    shape.layers = NOT_GRABABLE_MASK;

    shape = cpSpaceAddShape(space, cpSegmentShapeNew(staticBody, cpv(-192,80), cpv(-192,176), 2.0f));
    shape.e = 0.0f; shape.u = 0.5f; shape.layers = 1;
    shape.layers = NOT_GRABABLE_MASK;

    shape = cpSpaceAddShape(space, cpSegmentShapeNew(staticBody, cpv(-192,176), cpv(-128,240), 2.0f));
    shape.e = 0.0f; shape.u = 0.0f; shape.layers = 1;
    shape.layers = NOT_GRABABLE_MASK;

    shape = cpSpaceAddShape(space, cpSegmentShapeNew(staticBody, cpv(-128,144), cpv(192,64), 2.0f));
    shape.e = 0.0f; shape.u = 0.5f; shape.layers = 1;
    shape.layers = NOT_GRABABLE_MASK;

    cpVect verts[] = [
        cpv(-30,-80),
        cpv(-30, 80),
        cpv( 30, 64),
        cpv( 30,-80),
    ];

    cpBody *plunger = cpSpaceAddBody(space, cpBodyNew(1.0f, INFINITY));
    plunger.p = cpv(-160,-80);

    shape = cpSpaceAddShape(space, cpPolyShapeNew(plunger, 4, verts.ptr, cpvzero));
    shape.e = 1.0f; shape.u = 0.5f; shape.layers = 1;

    // add balls to hopper
    for(int i=0; i<numBalls; i++)
        balls[i] = add_ball(cpv(-224 + i,80 + 64*i));

    // add small gear
    cpBody *smallGear = cpSpaceAddBody(space, cpBodyNew(10.0f, cpMomentForCircle(10.0f, 80, 0, cpvzero)));
    smallGear.p = cpv(-160,-160);
    cpBodySetAngle(smallGear, cast(float)-M_PI_2);

    shape = cpSpaceAddShape(space, cpCircleShapeNew(smallGear, 80.0f, cpvzero));
    shape.layers = 0;

    cpSpaceAddConstraint(space, cpPivotJointNew2(staticBody, smallGear, cpv(-160,-160), cpvzero));

    // add big gear
    cpBody *bigGear = cpSpaceAddBody(space, cpBodyNew(40.0f, cpMomentForCircle(40.0f, 160, 0, cpvzero)));
    bigGear.p = cpv(80,-160);
    cpBodySetAngle(bigGear, cast(float)M_PI_2);

    shape = cpSpaceAddShape(space, cpCircleShapeNew(bigGear, 160.0f, cpvzero));
    shape.layers = 0;

    cpSpaceAddConstraint(space, cpPivotJointNew2(staticBody, bigGear, cpv(80,-160), cpvzero));

    // connect the plunger to the small gear.
    cpSpaceAddConstraint(space, cpPinJointNew(smallGear, plunger, cpv(80,0), cpv(0,0)));
    // connect the gears.
    cpSpaceAddConstraint(space, cpGearJointNew(smallGear, bigGear, -M_PI_2, -2.0f));


    // feeder mechanism
    cpFloat bottom = -300.0f;
    cpFloat top = 32.0f;
    cpBody *feeder = cpSpaceAddBody(space, cpBodyNew(1.0f, cpMomentForSegment(1.0f, cpv(-224.0f, bottom), cpv(-224.0f, top))));
    feeder.p = cpv(-224, (bottom + top)/2.0f);

    cpFloat len = top - bottom;
    cpSpaceAddShape(space, cpSegmentShapeNew(feeder, cpv(0.0f, len/2.0f), cpv(0.0f, -len/2.0f), 20.0f));

    cpSpaceAddConstraint(space, cpPivotJointNew2(staticBody, feeder, cpv(-224.0f, bottom), cpv(0.0f, -len/2.0f)));
    cpVect anchr = cpBodyWorld2Local(feeder, cpv(-224.0f, -160.0f));
    cpSpaceAddConstraint(space, cpPinJointNew(feeder, smallGear, anchr, cpv(0.0f, 80.0f)));

    // motorize the second gear
    motor = cpSpaceAddConstraint(space, cpSimpleMotorNew(staticBody, bigGear, 3.0f));

    return space;
}

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

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