push / pop operation

Syntax

[ operations ]

Parameters

operations
A sequence of shape operations to execute.

Description

The [ operation pushes the current shape onto the top of the shape stack. It must be matched by a succeeding ] operation, which pops the shape on top of the shape stack and deletes the shape.

Examples

Rotation Example

	Lot --> extrude(15) r(scopeCenter, 0, 22.5, 0) X. r(scopeCenter, 0, 22.5, 0) X. r(scopeCenter, 0, 22.5, 0) X. In this example, the extruded shape is rotated three times and assigned to a new shape (X). The rotations build on each other.
	Lot --> extrude(15) [ r(scopeCenter, 0, 22.5, 0) X. ] [ r(scopeCenter, 0, 22.5, 0) X. ] [ r(scopeCenter, 0, 22.5, 0) X. ] Encapsulating the rotations and create shape operations with a push/pop pair makes all shapes X coincide. The rotations are independent of each other.

House Example


	
	
House -->
    extrude(10)
    comp(f) { top : roofHip(45) Roof. | all = House.}
	
House -->
    [ t(0,10,0) roofHip(45) Roof. ]
    extrude(10)
    comp(f) { top : NIL | all = House. }

Both rules generate the same result. In the second rule, the roof is generated first using push/pop operations.

Translation Example


	
House-->
    Cylinder
    [ t(  0, 0, ' 1) Cylinder ]
    [ t(  0, 0, '-1) Cylinder ]
    [ t(' 1, 0,   0) Cylinder ]
    [ t('-1, 0,   0) Cylinder ]

Cylinder -->
    primitiveCylinder(16, 1, 2)

Cylinder assets are inserted five times. Each scope is translated based on the scope of the initial shape.

Condition Example


Lot -->
    s(1,1,1)
    [ case scope.sx == 1 : primitiveCube() Cube.
      else : primitiveCylinder() Cylinder. ]

Conditional and stochastic statements must not have preceding operations. Use push and pop to encapsulate a case switch.