Efficient methods, apparatus and computer program for the evaluation of a graphical programming language

摘要

A system, method and language for compositing or creating images is disclosed. The images typically comprise a plurality of graphical elements each including color and opacity information. The system utilizes operators having the graphical elements as operands in which the operators combine the operands according to a function defined by the operators, the colour information, and the opacity information, to produce new graphical elements. One part of the system includes interpreting the language by parsing and executing a sequence of statements and forming an expression tree the nodes of which comprise the graphical elements. Instructions are then derived from the tree. Another part permits the compositing of opaque graphical elements and associated clipping operations. Bounding box methods are used for locating active areas of graphical elements from the nodes. Manipulation of the expression tree is used to reduce the expected execution time of the compositing commands. An architecture is disclosed for implementing the system. $$