grease – Base Classes

class grease.System

Grease system abstract base class. Systems define behaviorial aspects of a World. All systems must define a step() method that is invoked by the world each timestep. User-defined systems are not required to subclass this class.

See an example system from the tutorial.

set_world(world)

Bind the system to a world

step(dt)

Execute a time step for the system. Must be defined by all system classes.

Parameters:

• dt (float) – Time since last step invocation

world

The World this system belongs to

class grease.Renderer

Grease renderer abstract base class. Renderers define the presentation of a World. All renderers must define a draw() method that is invoked by the world when the display needs to be redrawn. User-defined renderers are not required to subclass this class.

See an example renderer from the tutorial.

draw()

Issue drawing commands for this renderer. Must be defined for all renderer classes.

set_world(world)

Bind the system to a world

world

The World this renderer belongs to

Other Base Classes

The following other common base classes can be imported from here for convenience:

• World
• Entity