From http://www.jwz.org/xscreensaver/xscreensaver-5.30.tar.gz

[xscreensaver] / hacks / glx / sphere.c

diff --git a/hacks/glx/sphere.c b/hacks/glx/sphere.c
index eb004b11814a14075f3603cf4fd07e38b3db52dc..ff456cd4316b3ce9a1b5d8ec08d97e62e7614e9e 100644 (file)
--- a/hacks/glx/sphere.c
+++ b/hacks/glx/sphere.c
@@ -1,5 +1,5 @@
 /* sphere, Copyright (c) 2002 Paul Bourke <pbourke@swin.edu.au>,
- *         Copyright (c) 2010 Jamie Zawinski <jwz@jwz.org>
+ *         Copyright (c) 2010-2014 Jamie Zawinski <jwz@jwz.org>
  * Utility function to create a unit sphere in GL.
  *
  * Permission to use, copy, modify, distribute, and sell this software and its
@@ -24,29 +24,32 @@
 # include "config.h"
 #endif
 
-#ifdef HAVE_COCOA
-# include <OpenGL/gl.h>
-#else
+#ifndef HAVE_COCOA
 # include <GL/gl.h>
 #endif
 
+#ifdef HAVE_JWZGLES
+# include "jwzgles.h"
+#endif /* HAVE_JWZGLES */
+
 #include "sphere.h"
 
 typedef struct { GLfloat x, y, z; } XYZ;
 
-int
-unit_sphere (int stacks, int slices, int wire_p)
+static int
+unit_sphere_1 (int stacks, int slices, int wire_p, int half_p)
 {
   int polys = 0;
   int i,j;
   double theta1, theta2, theta3;
   XYZ p, n;
-  XYZ la = { 0, 0, 0 }, lb = { 0, 0, 0 };
+  XYZ la = { 0, -1, 0 }, lb = { 0, -1, 0 };
   XYZ c = {0, 0, 0};  /* center */
   double r = 1.0;     /* radius */
   int stacks2 = stacks * 2;
+  int end = (half_p ? stacks/2 : stacks);
 
-  int mode = (wire_p ? GL_LINE_LOOP : GL_TRIANGLE_STRIP);
+  int mode = (wire_p ? GL_LINE_STRIP : GL_TRIANGLE_STRIP);
 
   int arraysize, out;
   struct { XYZ p; XYZ n; GLfloat s, t; } *array;
@@ -61,7 +64,6 @@ unit_sphere (int stacks, int slices, int wire_p)
   if (! array) abort();
   out = 0;
 
-
   if (slices < 4 || stacks < 2 || r <= 0)
     {
       mode = GL_POINTS;
@@ -69,7 +71,7 @@ unit_sphere (int stacks, int slices, int wire_p)
       goto END;
     }
 
-  for (j = 0; j < stacks; j++)
+  for (j = 0; j < end; j++)
     {
       theta1 = j       * (M_PI+M_PI) / stacks2 - M_PI_2;
       theta2 = (j + 1) * (M_PI+M_PI) / stacks2 - M_PI_2;
@@ -78,7 +80,7 @@ unit_sphere (int stacks, int slices, int wire_p)
         {
           theta3 = i * (M_PI+M_PI) / slices;
 
-          if (wire_p && i != 0)
+          if (wire_p)
             {
               array[out++].p = lb;                             /* vertex */
               array[out++].p = la;                             /* vertex */
@@ -135,3 +137,16 @@ unit_sphere (int stacks, int slices, int wire_p)
 
   return polys;
 }
+
+
+int
+unit_sphere (int stacks, int slices, int wire_p)
+{
+  return unit_sphere_1 (stacks, slices, wire_p, 0);
+}
+
+int
+unit_dome (int stacks, int slices, int wire_p)
+{
+  return unit_sphere_1 (stacks, slices, wire_p, 1);
+}