1 files changed, 148 insertions, 0 deletions
diff --git a/hacks/glx/extrusion-joinoffset.c b/hacks/glx/extrusion-joinoffset.c
new file mode 100644
index 0000000..89a60e2
--- /dev/null
+++ b/hacks/glx/extrusion-joinoffset.c
@@ -0,0 +1,148 @@
+
+/* cylinder drawing demo */
+/* this demo demonstrates the various join styles */
+
+#include "extrusion.h"
+
+/* ------------------------------------------------------- */
+
+/* the arrays in which we will store the polyline */
+#define NPTS 100
+static double points [NPTS][3];
+static float colors [NPTS][3];
+static int idx = 0;
+
+/* some utilities for filling that array */
+#define PSCALE 0.5
+#define PNT(x,y,z) { 			\
+   points[idx][0] = PSCALE * x; 	\
+   points[idx][1] = PSCALE * y; 	\
+   points[idx][2] = PSCALE * z;		\
+   idx ++;				\
+}
+
+#define COL(r,g,b) { 			\
+   colors[idx][0] = r; 			\
+   colors[idx][1] = g; 			\
+   colors[idx][2] = b;			\
+}
+
+/* the arrays in which we will store the contour */
+#define NCONTOUR 100
+static double contour_points [NCONTOUR][2];
+static int cidx = 0;
+
+/* some utilities for filling that array */
+#define C_PNT(x,y) { 			\
+   contour_points[cidx][0] = x;		\
+   contour_points[cidx][1] = y; 	\
+   cidx ++;				\
+}
+
+
+/* ------------------------------------------------------- */
+/* 
+ * Initialize a bent shape with three segments. 
+ * The data format is a polyline.
+ *
+ * NOTE that neither the first, nor the last segment are drawn.
+ * The first & last segment serve only to determine that angle 
+ * at which the endcaps are drawn.
+ */
+
+void InitStuff_joinoffset (void) 
+{
+   COL (0.0, 0.0, 0.0);
+   PNT (16.0, 0.0, 0.0);
+
+   COL (0.2, 0.8, 0.5);
+   PNT (0.0, -16.0, 0.0);
+
+   COL (0.0, 0.8, 0.3);
+   PNT (-16.0, 0.0, 0.0);
+
+   COL (0.8, 0.3, 0.0);
+   PNT (0.0, 16.0, 0.0);
+
+   COL (0.2, 0.3, 0.9);
+   PNT (16.0, 0.0, 0.0);
+
+   COL (0.2, 0.8, 0.5);
+   PNT (0.0, -16.0, 0.0);
+
+   COL (0.0, 0.0, 0.0);
+   PNT (-16.0, 0.0, 0.0);
+
+   C_PNT (-0.8, -0.5);
+   C_PNT (-1.8, 0.0);
+   C_PNT (-1.2, 0.3);
+   C_PNT (-0.7, 0.8);
+   C_PNT (-0.2, 1.3);
+   C_PNT (0.0, 1.6);
+   C_PNT (0.2, 1.3);
+   C_PNT (0.7, 0.8);
+   C_PNT (1.2, 0.3);
+   C_PNT (1.8, 0.0);
+   C_PNT (0.8, -0.5);
+
+   gleSetJoinStyle (TUBE_JN_ANGLE | TUBE_CONTOUR_CLOSED | TUBE_JN_CAP);
+}
+
+static double up_vector[3] = {1.0, 0.0, 0.0};
+
+/* controls shape of object */
+extern float lastx;
+extern float lasty;
+
+/* ------------------------------------------------------- */
+/* draw the extrusion */
+
+void DrawStuff_joinoffset (void) 
+{
+   double moved_contour [NCONTOUR][2];
+   int style, save_style;
+   int i;
+
+   for (i=0; i<cidx; i++) {
+      moved_contour[i][0] = contour_points [i][0];
+      moved_contour[i][1] = contour_points [i][1] + 0.05 * (lasty-200.0);
+   }
+
+   glClear (GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
+
+   /* set up some matrices so that the object spins with the mouse */
+   glPushMatrix ();
+   glScalef (0.5, 0.5, 0.5);
+   glTranslatef (0, 4, 0);
+   /* glTranslatef (0.0, 4.0, -80.0); */
+   /* glRotatef (0.5*lastx, 0.0, 1.0, 0.0); */
+
+   gleExtrusion (cidx, moved_contour, contour_points, up_vector, 
+                 idx, points, colors);
+
+   glPopMatrix ();
+
+
+   /* draw a seond copy, this time with the raw style, to compare
+    * things against */
+   glPushMatrix ();
+   glScalef (0.5, 0.5, 0.5);
+   glTranslatef (0, -4, 0);
+   /* glTranslatef (0.0, -4.0, -80.0); */
+   /* glRotatef (0.5*lastx, 0.0, 1.0, 0.0); */
+
+   save_style = gleGetJoinStyle ();
+   style = save_style;
+   style &= ~TUBE_JN_MASK;
+   style |= TUBE_JN_RAW;
+   gleSetJoinStyle (style);
+
+   gleExtrusion (cidx, moved_contour, contour_points, up_vector, 
+                 idx, points, colors);
+
+   gleSetJoinStyle (save_style);
+   glPopMatrix ();
+
+}
+
+/* ------------------ end of file ----------------------------- */