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triangle_strip_filter(display)Filtertriangle_strip_filter(display)

NAME

triangle_strip_filter - convert polygons into triangle strips

DESCRIPTION

Triangle_strip_filter takes as input a display_data object and converts triangle polygons into triangle strips. The goal is to improve rendering speed since many renderers are significantly faster when rendering triangle strips.

Triangle_strip_filter passes lines and non-triangular polygons through to its output display_data. Previously existing triangle strips are also passed through. Triangular polygons are merged together into triangle strips. The length of each triangle strip is variable depending upon the nature of the data. All point data is passed through to the output display data.

SUPERCLASS

adjacency_filter

INSTANCE VARIABLES

max_strip_length the maximum number of triangles in any given triangle strip. If max_strip_length==0, then the strips are of unlimited length.

MESSAGES

max_strip_length= value set the maximum strip length.

max_strip_length? get the maximum strip length.

generate_data! create triangle strips from input data.

EXAMPLE

/* * Create display data (in the form of a "+" consisting of lines, * triangle strips, and polygons. */ display_data new: dd points=( 1,0,0, 2,0,0, 0,1,0, 1,1,0, 2,1,0, 3,1,0, 0,2,0,

1,2,0, 2,2,0, 3,2,0, 1,3,0, 2,3,0 ) polygons=( 3,1,2,4, 3,4,2,5, 4,3,4,8,7, 3,4,5,8, 3,5,8,9, 3,6,9,10, 3,9,11,12, 3,8,11,9 ) lines=( 2,2,6, 4,1,3,7,11 ) triangle_strips=( 3,5,9,6 ) ; /* * Create triangle strips from the polygons */ triangle_strip_filter new: ts data_in= dd output! ;