http://www.tienza.es/crux/src/www.jwz.org/xscreensaver/xscreensaver-5.04.tar.gz

[xscreensaver] / hacks / glx / involute.h

diff --git a/hacks/glx/involute.h b/hacks/glx/involute.h
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+++ b/hacks/glx/involute.h
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+/* involute, Copyright (c) 2004-2007 Jamie Zawinski <jwz@jwz.org>
+ *
+ * Permission to use, copy, modify, distribute, and sell this software and its
+ * documentation for any purpose is hereby granted without fee, provided that
+ * the above copyright notice appear in all copies and that both that
+ * copyright notice and this permission notice appear in supporting
+ * documentation.  No representations are made about the suitability of this
+ * software for any purpose.  It is provided "as is" without express or 
+ * implied warranty.
+ *
+ * Utilities for rendering OpenGL gears with involute teeth.
+ */
+
+#ifndef __GEAR_INVOLUTE_H__
+#define __GEAR_INVOLUTE_H__
+
+typedef struct {
+  unsigned long id;          /* unique name */
+  double x, y, z;            /* position */
+  double r;                  /* radius of the gear, at middle of teeth */
+  double th;                 /* rotation (degrees) */
+
+  GLint nteeth;              /* how many teeth */
+  double tooth_w, tooth_h;   /* size of teeth */
+
+  double tooth_slope;       /* 0 for normal right-angle gear; 1 = 45 deg. */
+  double inner_r;            /* radius of the (larger) inside hole */
+  double inner_r2;           /* radius of the (smaller) inside hole, if any */
+  double inner_r3;           /* yet another */
+
+  double thickness;          /* height of the edge */
+  double thickness2;         /* height of the (smaller) inside disc if any */
+  double thickness3;         /* yet another */
+  int spokes;                /* how many spokes inside, if any */
+  int nubs;                  /* how many little nubbly bits, if any */
+  double spoke_thickness;    /* spoke versus hole */
+  double wobble;             /* factory defect! */
+  int motion_blur_p;        /* whether it's spinning too fast to draw */
+  int polygons;              /* how many polys in this gear */
+
+  double ratio;              /* gearing ratio with previous gears */
+  double rpm;                /* approximate revolutions per minute */
+
+  Bool inverted_p;           /* whether this gear has teeth on the inside */
+  Bool base_p;               /* whether this gear begins a new train */
+  int coax_p;                /* whether this is one of a pair of bound gears.
+                                1 for first, 2 for second. */
+  double coax_displacement;  /* distance between gear planes */
+
+  double coax_thickness;     /* thickness of the other gear in the pair */
+
+  enum { INVOLUTE_SMALL, 
+         INVOLUTE_MEDIUM, 
+         INVOLUTE_LARGE } size;        /* Controls complexity of mesh. */
+  GLfloat color[4];
+  GLfloat color2[4];
+
+  GLuint dlist;
+} gear;
+
+/* Render one gear, unrotated at 0,0.
+   Returns the number of polygons.
+ */
+extern int draw_involute_gear (gear *g, Bool wire_p);
+
+/* Draws a much simpler representation of a gear.
+   Returns the number of polygons.
+ */
+extern int draw_involute_schematic (gear *g, Bool wire_p);
+
+/* Which of the gear's inside rings is the biggest? 
+ */
+extern int involute_biggest_ring (gear *g,
+                                  double *posP, double *sizeP,
+                                  double *heightP);
+
+#endif /* __GEAR_INVOLUTE_H__ */