1 files changed, 114 insertions, 0 deletions
diff --git a/hacks/glx/extrusion-screw.c b/hacks/glx/extrusion-screw.c
new file mode 100644
index 0000000..6724476
--- /dev/null
+++ b/hacks/glx/extrusion-screw.c
@@ -0,0 +1,114 @@
+/* 
+ * screw.c
+ * 
+ * FUNCTION:
+ * Draws a screw shape.
+ *
+ * HISTORY:
+ * -- created by Linas Vepstas October 1991
+ * -- heavily modified to draw more texas shapes, Feb 1993, Linas
+ * -- converted to use GLUT -- December 1995, Linas
+ *
+ */
+
+#include "extrusion.h"
+#include <stdlib.h>
+#include <math.h>
+
+/* =========================================================== */
+
+#define SCALE 1.3
+#define CONTOUR(x,y) {					\
+   double ax, ay, alen;					\
+   contour[i][0] = SCALE * (x);				\
+   contour[i][1] = SCALE * (y);				\
+   if (i!=0) {						\
+      ax = contour[i][0] - contour[i-1][0];		\
+      ay = contour[i][1] - contour[i-1][1];		\
+      alen = 1.0 / sqrt (ax*ax + ay*ay);		\
+      ax *= alen;   ay *= alen;				\
+      norms [i-1][0] = ay;				\
+      norms [i-1][1] = -ax;				\
+   }							\
+   i++;							\
+}
+
+#define NUM_PTS (25)
+
+static double contour [NUM_PTS][2];
+static double norms [NUM_PTS][2];
+
+static void init_contour (void)
+{
+   int i;
+
+   /* outline of extrusion */
+   i=0;
+   CONTOUR (1.0, 1.0);
+   CONTOUR (1.0, 2.9);
+   CONTOUR (0.9, 3.0);
+   CONTOUR (-0.9, 3.0);
+   CONTOUR (-1.0, 2.9);
+
+   CONTOUR (-1.0, 1.0);
+   CONTOUR (-2.9, 1.0);
+   CONTOUR (-3.0, 0.9);
+   CONTOUR (-3.0, -0.9);
+   CONTOUR (-2.9, -1.0);
+
+   CONTOUR (-1.0, -1.0);
+   CONTOUR (-1.0, -2.9);
+   CONTOUR (-0.9, -3.0);
+   CONTOUR (0.9, -3.0);
+   CONTOUR (1.0, -2.9);
+
+   CONTOUR (1.0, -1.0);
+   CONTOUR (2.9, -1.0);
+   CONTOUR (3.0, -0.9);
+   CONTOUR (3.0, 0.9);
+   CONTOUR (2.9, 1.0);
+
+   CONTOUR (1.0, 1.0);   /* repeat so that last normal is computed */
+}
+   
+/* =========================================================== */
+
+/* controls shape of object */
+extern float lastx;
+extern float lasty;
+
+void InitStuff_screw (void)
+{
+   int style;
+
+   /* configure the pipeline */
+   style = TUBE_JN_CAP;
+   style |= TUBE_CONTOUR_CLOSED;
+   style |= TUBE_NORM_FACET;
+   style |= TUBE_JN_ANGLE;
+   gleSetJoinStyle (style);
+
+   init_contour();
+}
+
+/* =========================================================== */
+
+void DrawStuff_screw (void) {
+
+   glClear (GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
+   glColor3f (0.5, 0.6, 0.6);
+
+   /* set up some matrices so that the object spins with the mouse */
+   glPushMatrix ();
+   /* glTranslatef (0.0, 0.0, -80.0); */
+   /* glRotatef (130.0, 0.0, 1.0, 0.0); */
+   /* glRotatef (65.0, 1.0, 0.0, 0.0); */
+
+   /* draw the brand and the handle */
+   gleScrew (20, contour, norms, 
+                 NULL, -6.0, 9.0, lasty);
+
+   glPopMatrix ();
+}
+
+/* ===================== END OF FILE ================== */