py-fizz🔗 i

2.1Basic Gadgets🔗 i

This is just a pretty-looking space for running simulations. There are static walls on all sides, and a cosmetic (wooden) background in the middle. It will dynamically resize if what’s inside doesn’t fit in the default 600x600 space.

Simple bowling ball. High mass.

No parameters on this one. But you can alter its properties with functions like toggle-static, mass, initial-velocity, etc.

Dynamic crate. Falls by default. If you want to use it as a platform, call toggle-static on it to convert it to a static object.

Low mass, circular object.

Floats. (Obeys opposite gravity.)

If it is attached to other objects, it will pull them upward.

Like a regular balloon, but it can be destroyed by clicking on it.

It can also be destroyed if it collides strongly with other objects.

A dynamic object that causes you to lose the game if any of them are destroyed. Useful when building puzzles.

A dynamic object that causes you to win the game if all of them are destroyed. Useful when building puzzles.

A dynamic object that rotates continually. Good for vehicles.

Use negative numbers to make it rotate the other direction.

A dynamic object that rotates continually. It’s pinned to one spot. Good for conveyor belts.

Use negative numbers to make it rotate the other direction.

Makes a see-saw contraption, on one side is a bowling ball with a strong downward starting velocity. On the other side is whatever object you supply.

Note that although this function accepts static, dynamic, cosmetic, or composite objects, it is most exciting when you pass in a dynamic object (or a composite object that contains dynamic objects).

Makes a car. You can control speed and direction with the speed parameter (negative numbers go counter clockwise).

The second parameter controls what object is on top of the car. Passing in a dynamic object is the simplest thing.

If you pass in a static object, the car will be stuck in the air, "pinned" by the static object. Usually not what you want. (Use toggle-static to switch your static object to a dynamic one before passing it into the car function.)

ADVANCED USAGE: If you pass in a composite object, you pust also pass in a join-object as the third parameter. This determines which part of the composite object to connect the wheels to.

Let’s take a moment to see how cool it is to be able to make flying cars...

Makes a dynamic rectangle that looks like a pipe. Good for platforms, walls, falling pipes, etc.

Attaches the given number of balloons to the given object. The length of the balloon string can also be configured.

Creates the given number of motors in a horizontal row. The speed determines three things: the speed (obviously), the direction (negative is counter-clockwise), and the color (blue for counter-clockwise, red for clockwise).

Takes the object and returns a composite object that looks like the original, but is really a bunch of dynamic objects constructed from a sliced up image of the original.

This is how breakable-balloons explode when destroyed.

Note that fragments are computationally expensive. Keep the resolution and the destroy-after parameters low.

Returns a static cannon that shoots the provided object when clicked.

The angle and the power of the shot can be adjusted.

Returns a static treasure chest that turns into the provided object when clicked. Good for puzzles.

An icon of the provided object is displayed above the chest, so the user knows what to anticipate.

3.1Top Level🔗 i

3.2Basic Constructors🔗 i

procedure

(make-staticobject[#:collidercollider])→static?

object:(or/ch:image?cosmetic?layout?physical?)

collider:collider?=circle-collider

procedure

(make-dynamicobject[#:collidercollider])→dynamic?

object:(or/ch:image?cosmetic?layout?physical?)

collider:collider?=circle-collider

procedure

(make-cosmeticobject)→cosmetic?

object:(or/ch:image?cosmetic?layout?)

procedure

(make-pivotobject)→pivot?

object:(or/ch:image?cosmetic?)

3.3Setting Physical Properties of Objects🔗 i

procedure

(motorizespeedobject)→dynamic?

speed:number?

object:dynamic?

procedure

(gravitydirectionobject)→dynamic?

direction:(list/cnumber?number?)

object:dynamic?

procedure

(elasticityamountobject)→dynamic?

amount:number?

object:dynamic?

procedure

(angleamountobject)→dynamic?

amount:number?

object:(or/cdynamic?static?)

procedure

(frictionobject[energyangle])→static?

object:(or/cdynamic?static?)

energy:number?=10000

angle:number?=0

procedure

(ttltimeobject)→dynamic?

time:number?

object:(or/cdynamic?static?cosmetic?)

procedure

(massamountobject)→dynamic?

amount:number?

object:dynamic?

procedure

(initial-velocitydirectionobject)→dynamic?

direction:(list/cnumber?number?)

object:dynamic?

procedure

(toggle-staticobject)→(or/cdynamic?static?)

object:(or/cdynamic?static?)

procedure

(widthobject)→number?

object:(or/cdynamic?static?cosmetic?composite?)

procedure

(heightobject)→number?

object:(or/cdynamic?static?cosmetic?composite?)

3.4Making composite objects🔗 i

The easiest way to make a composite object is to use a spatial layout function: above, beside, or overlay.

These place two objects in a spatial relation to each other.

Additionally, objects can be associated with physical properties: e.g. they might have a joint connecting them. If this is the case, you’ll create the composite object with a two-step process – 1) establish the physical relation ship (e.g. with the spring-joint function), and then place the two objects into a spatial relationship (e.g. with the above function).

(let*([b1(bowling-ball)]

[b2(bowling-ball)]

[b1-with-connection

(pinb1b2)])

(simulate

(aboveb1-with-connectionb2)))

Note that the pin function takes b1 and returns a new version of b1 that has a pin joint relationship to b2. But you still need to place both b1-with-connection and b2 into a relation with each other.

(You’ll get a runtime error if you don’t.)

3.5Runtime Behaviours🔗 i

Collisions can be filtered out based on friction and kinetic energy loss.

3.6Misc🔗 i