WorldExpression Class
This class is used to create a world expression, that executes an arbitrary expression. An expression can be executed for the other nodes if they are assigned as child nodes of WorldExpression. The child nodes will inherit transformations (if any) of the world expression and will be transformed relative to the pivot point of WorldExpression.
WorldExpression Class
Members
WorldExpression (const Math::vec3 & size)
Constructor. Creates an arbitrary expression to be executed.Notice
An expression is executed only when its bounding box is in the viewing frustum or when the camera is positioned within this bounding box, so the size is important.
Arguments
- const Math::vec3 & size - Size of the bounding box. This is an optional argument.
void setDistance (float distance)
Sets the distance at which the expression is not executed.Arguments
- float distance - The distance value. If a negative value is specified, 0 will be used instead.
void setIFps (float ifps)
Sets a constant frame duration used to execute the expression. It can be used to decrease the frame rate to get higher performance. 0 means that the expression is executed at the same frame rate as the main application window.Arguments
- float ifps - Frame duration (inverse FPS) in seconds (1/FPS). If a too small value is provided, 1E-6 will be used instead.
int isFunction (const char * name, int num_args)
Returns a value indicating if the given world expression has the function with specified name and number of arguments.Arguments
- const char * name - The name of the function.
- int num_args - The number of arguments.
Return value
1 if the expression exists; otherwise, 0.void setOffset (const Math::vec3 & offset)
Sets an offset of the center of the world expression's bounding box along the X, Y and Z axes.Arguments
- const Math::vec3 & offset - An offset of the expression box center.
const char * getExpression ()
Returns the executable expression.Return value
The executable expression.float getIFps ()
Returns the current constant frame duration used to execute the expression. 0 means that the expression is executed at the same frame rate as the main application window.Return value
Frame duration (inverse FPS) in seconds (1/FPS).Math::vec3 getOffset ()
Returns the offset of the center of the world expression's bounding box along the X, Y and Z axes.Return value
The offset of the expression box center.int setExpression (const char * src)
Sets the arbitrary expression to be executed.Notice
The expression passed as an argument must be wrapped with curly braces {} as they define the world expression scope.
Arguments
- const char * src - An executable expression.
Return value
The expression number.Math::vec3 getSize ()
Returns the current size of the WorldExpression bounding box. The size of the bounding box is important as if the bounding box gets outside the viewing frustum, the expression is not executed.Notice
If the child object transformed according to the expression gets outside the view frustum, but the bounding box is still in the viewing frustum, the playback of the transformation sequence will not stop.
Return value
Size of the bounding box in units.float getDistance ()
Returns the distance at which the expression is not executed.Return value
The distance value.int isCompiled ()
Returns a value indicating if the given expression has been compiled. It is automatically called on world load or after setExpression() is used.Return value
1 if the expression has been compiled; otherwise, 0.void setSize (const Math::vec3 & size)
Sets the size of the WorldExpression bounding box. The size of the bounding box is important as if the bounding box gets outside the viewing frustum, the expression is not executed.Notice
If the child object transformed according to the expression gets outside the view frustum, but the bounding box is still in the viewing frustum, the playback of the transformation sequence will not stop.
Arguments
- const Math::vec3 & size - Size of the bounding box in units.
Last update: 2017-07-03
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