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Wired Movies and Sprites

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Constant descriptions

kExpressionContainerAtomType

This atom is used to contain an expression. Expressions are used to describe numeric paramers, sprite and track IDs and indices, Boolean expressions for the case and while statements, and as a special operand type which allows for the nested sub-expressions within expressions. The complete grammar of expressions is described in Appendix  .

The kExpressionContainerAtomType has either a kOperatorAtomType or a kOperandAtomType atom as its only child atom. The parent type of the kExpressionContainerAtomType atom may be any kActionParameter atom associated with a numeric data type, or any of the following: kTargetTrackIndex , kTargetTrackID , kTargetSpriteIndex , kTargetSpriteID , kConditionalAtomType , or kExpressionOperandAtomType .

kOperatorAtomType

This atom is used to describe an operation, such as multiplication or addition, which forms part of an expression. The atom's ID defines which operator it represents. Its parent atom is of type kExpressionContainerAtomType . Its child atoms are of type kOperandAtomType and describe the operands which the operator is applied to. The operator is applied to each of its child kOperandAtomType atoms in order by their atom index. Unary operators must have one kOperandAtomType child atom. Binary operators must have two or more kOperandAtomType child atoms.

kOperandAtomType

This atom is used to describe an operand, such as a constant number, a sprite property, or a variable. Its parent atom type may be of type kExpressionContainerAtomType , in which case the expression consists of only a single operand, or of type kOperatorAtomType in which case its index is used to define its order within the operators operand list. The kOperandAtomType atom contains a single child atom which can be any of the operand atom types.