glesetjoinstyle(3gle) [debian man page]
gleSetJoinStyle(3GLE) GLE gleSetJoinStyle(3GLE) NAME
gleSetJoinStyle, gleGetJoinStyle - Query and Set the GLE join style flags. SYNTAX
void gleSetJoinStyle (int style); int gleGetJoinStyle (void); ARGUMENTS
style bitwise OR of flags DESCRIPTION
Query and set the GLE join style flags. This word is a bitwise OR of the flags described below. The initial join style is TUBE_JN_ANGLE | TUBE_JN_CAP | TUBE_NORM_FACET. Extrusion Join Styles TUBE_JN_RAW Draw polycylinders, polycones, extrusions, etc. with no special treatment of the extrusion ends. TUBE_JN_ANGLE Draw polycylinders, polycones, extrusions, etc. by extending the different segments until they butt into each other with an angular style. TUBE_JN_CUT Draw polycylinders, polycones, extrusions, etc. by joining together the different segments and slicing off the joint at half the angle between the segments. A cap is drawn. Note that the slicing plane runs through the origin of the contour coordinate system. Thus, the amount of slice can be varied by offsetting the contour with respect to the origin. Note that when two segments meet at a shallow angle, the cut join style will potentially shave off a whole lot of the contour, lead- ing to "surprising" results... TUBE_JN_ROUND Joints will be rounded. Strictly speaking, the part of the joint above the origin will be rounded. The part below the origin will come together in an angular join. TUBE_JN_MASK Mask bits. This can be used to mask off the bit field that defines the join style. End Caps TUBE_JN_CAP If this is set, a cap will be drawn at each end of the extrusion. Automatic Normal Vector Generation TUBE_NORM_FACET A normal vector is generated per facet. Useful for having an extrusion have a "faceted" look, such as when extruding a square -- each of the four sides of the square will look flat. TUBE_NORM_EDGE Normal vectors are generated so that they lie along edges. Useful for making angular things look rounded under lighting. For exam- ple, when extruding a hexagon and using this flag, the hexagonal extrusion will look (more like a) smooth perfectly round cylinder, rather than a six-sided shape. TUBE_NORM_PATH_EDGE Normal vectors are generated so that they both lie on edges, and so that they interpolate between neighboring segments. Useful for drawing "spaghetti" -- extrusions that follow a spline path. Because the spline path must be "tessellated" into small straight seg- ments, each segment will look straight unless this flag is set. TUBE_NORM_MASK A mask useful for masking out the "norm" bits. Closed or Open Contours TUBE_CONTOUR_CLOSED If this bit is set, the contour will be treated as a "closed" contour, where the last point connects back up to the first. It is useful to set this flag when drawing closed shapes (such as extruded cylinders, star-shapes, I-Beams, etc. When drawing open extru- sions (e.g. corrugated sheet metal), you DON'T want to set this flag. BUGS
Multiple threads using GLE share a single global join style (although this should be easily fixable because GLE does use a centralized graphics context). SEE ALSO
gleExtrusion, gleTextureMode AUTHOR
Linas Vepstas (linas@linas.org) GLE
3.0 gleSetJoinStyle(3GLE)
Check Out this Related Man Page
gle(3GLE) GLE gle(3GLE) NAME
gle - an introduction to the GLE Tubing & Extrusions Library SYNOPSIS
#include <GL/gle.h> DESCRIPTION
The GLE Tubing and Extrusion Library is a graphics application programming interface (API). The library consists of a number of "C" lan- guage subroutines for drawing tubing and extrusions. The library is distributed in source code form, in a package that includes documenta- tion, a VRML proposal, Makefiles, and full source code and header files. It uses the OpenGL (TM) programming API to perform the actual drawing of the tubing and extrusions. A "sweep" or "extrusion" is a 2D contour (polyline) that is swept or extruded along a 3D path (polyline). For example, sweeping a circle along a straight line will generate a cylinder. Sweeping a circle along a circular path will generate a doughnut (torus). The library also includes a set of utility routines for drawing some of the more common extruded shapes: a polycylinder, a polycone, a gen- eralized torus (circle swept along a helical path), a "helix" (arbitrary contour swept along a helical path) and a "lathe" (arbitrary con- tour swept along a helical path, with torsion used to keep the contour aligned). The most general extrusion supported by this library allows an arbitrary 2D contour to be swept around an arbitrary 3D path. A set of nor- mal vectors can be specified to go along with the contour; the normal vectors determine the appearance of the contour when lighting is turned on. A set of colors and affine matrices can be specified to go along with the 3D path. The colors are used to color along the path. The affine matrices are used to operate on the contour as it is swept along. If no affine matrices are specified, the contour is extruded using the mathematical concept of "parallel translation" or "Gaussian translation". That is, the contour is moved (and drawn) along the extrusion path in a "straight" manner. If there are affine matrices, they are applied to the contour at each extrusion segment before the segment is drawn. The affine matrices allow work in a quasi-non-Euclidean space. They essentially allow the contour to be distorted as it is swept along. The allow the contour to be rotated, translated and rescaled as it is drawn. For example, a rescaling will turn a polycylinder into a poly- cone, since the circle that is being extruded is scaled to a different size at each extrusion vertex. A rotation allows the contour to be spun around while it is being extruded, thus for instance allowing drill-bit type shapes to be drawn. A translation allows the appearance of shearing in real space; that is, taking a contour and displacing it, without otherwise bending it. Note that the affines are 2x3 matri- ces, not 3x4 matrices, since they apply to the 2D contour as it is being extruded. WEB SITE
http://linas.org/gle/index.html SEE ALSO
gleExtrusion, gleHelicoid, gleLathe, glePolyCone, glePolyCylinder, gleScrew, gleSetJoinStyle, gleSpiral, gleSuperExtrusion, gleTextureMode, gleToroid, gleTwistExtrusion, gleTwistExtrusion, gleSuperExtrusion AUTHOR
Linas Vepstas (linas@linas.org) GLE
3.0 gle(3GLE)