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

gleSpiral(3GLE) 							GLE							   gleSpiral(3GLE)

NAME

       gleSpiral - Sweep an arbitrary contour along a helical path.

SYNTAX

       void gleSpiral (int ncp,
		       gleDouble contour[][2],
		       gleDouble cont_normal[][2],
		       gleDouble up[3],
		       gleDouble startRadius,	  /* spiral starts in x-y plane */
		       gleDouble drdTheta,	  /* change in radius per revolution */
		       gleDouble startZ,	  /* starting z value */
		       gleDouble dzdTheta,	  /* change in Z per revolution */
		       gleDouble startXform[2][3], /* starting contour affine xform */
		       gleDouble dXformdTheta[2][3], /* tangent change xform per revoln */
		       gleDouble startTheta,	  /* start angle in x-y plane */
		       gleDouble sweepTheta);	  /* degrees to spiral around */

ARGUMENTS

       ncp	 number of contour points

       contour	 2D contour

       cont_normal
		 2D contour normals

       up	 up vector for contour

       startRadius
		 spiral starts in x-y plane

       drdTheta  change in radius per revolution

       startZ	 starting z value

       dzdTheta  change in Z per revolution

       startXform
		 starting contour affine transformation

       dXformdTheta
		 tangent change xform per revolution

       startTheta
		 start angle in x-y plane

       sweepTheta
		 degrees to spiral around

DESCRIPTION

       Sweep an arbitrary contour along a helical path.

       The axis of the helix lies along the modeling coordinate z-axis.

       An affine transform can be applied as the contour is swept. For most ordinary usage, the affines should be given as NULL.

       The "startXform[][]" is an affine matrix applied to the contour to deform the contour. Thus, "startXform" of the form

	    |  cos     sin    0   |
	    |  -sin    cos    0   |

       will rotate the contour (in the plane of the contour), while

	    |  1    0	 tx   |
	    |  0    1	 ty   |

       will translate the contour, and

	    |  sx    0	  0   |
	    |  0    sy	  0   |

       scales along the two axes of the contour. In particular, note that

	    |  1    0	 0   |
	    |  0    1	 0   |

       is the identity matrix.

       The  "dXformdTheta[][]"	is  a  differential  affine matrix that is integrated while the contour is extruded.  Note that this affine matrix
       lives in the tangent space, and so it should have the form of a generator.  Thus, dx/dt's of the form

	    |  0     r	  0   |
	    |  -r    0	  0   |

       rotate the the contour as it is extruded (r == 0 implies no rotation, r == 2*PI implies that the contour is rotated once, etc.), while

	    |  0    0	 tx   |
	    |  0    0	 ty   |

       translates the contour, and

	    |  sx    0	  0   |
	    |  0    sy	  0   |

       scales it. In particular, note that

	    |  0    0	 0   |
	    |  0    0	 0   |

       is the identity matrix -- i.e. the derivatives are zero, and therefore the integral is a constant.

SEE ALSO

       gleLathe

AUTHOR

       Linas Vepstas (linas@linas.org)

GLE
									3.0							   gleSpiral(3GLE)

Linux and UNIX Man Pages

glesetjoinstyle(3gle) [debian man page]

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