Spring Classes

Two classes needed: PointMass and Spring

PointMass

Attributes:

Mass

Position

Velocity

Acceleration

Functions:

Clear forces - reset acceleration, at start of frame

Apply force - add its effect to the acceleration, using F=ma

Update - apply current acceleration & velocity

Other features:

Freeze - point will not move on update

Drag - automatically added during update

Code:

• PointMass.h
• PointMass.cpp

Spring

Attributes:

Two PointMasses

Spring constant

Rest length

Functions:

Apply - compute current spring force, and apply it to the two PointMasses

Other features:

Constructor - if no rest length is given, use the current distance between the PointMasses

Draw line - draw an OpenGL line between the two PointMasses

Code:

• Spring.h
• Spring.cpp

Examples:

• spring2.cpp
• springs.cpp

The classes make it easier to build systems of multiple springs

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