Original 5.40

1 files changed, 707 insertions, 0 deletions

diff --git a/hacks/glx/discoball.c b/hacks/glx/discoball.c
new file mode 100644
index 0000000..4085c56
--- /dev/null
+++ b/hacks/glx/discoball.c
@@ -0,0 +1,707 @@
+/* discoball, Copyright (c) 2016 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.
+ */
+
+#define DEFAULTS	"*delay:	30000       \n" \
+			"*count:        30          \n" \
+			"*showFPS:      False       \n" \
+			"*wireframe:    False       \n" \
+
+# define release_ball 0
+#undef countof
+#define countof(x) (sizeof((x))/sizeof((*x)))
+
+#include "xlockmore.h"
+#include "normals.h"
+#include "rotator.h"
+#include "gltrackball.h"
+#include <ctype.h>
+
+#ifdef USE_GL /* whole file */
+
+
+#define DEF_SPIN        "False"
+#define DEF_WANDER      "True"
+#define DEF_SPEED       "1.0"
+
+typedef struct tile tile;
+struct tile {
+  XYZ position, normal;
+  GLfloat size, tilt;
+  tile *next;
+};
+
+
+typedef struct {
+  XYZ normal;
+  GLfloat color[4];
+} ray;
+
+typedef struct {
+  GLXContext *glx_context;
+  rotator *rot;
+  GLfloat th;
+  trackball_state *trackball;
+  Bool button_down_p;
+  tile *tiles;
+  int nrays;
+  ray *rays;
+} ball_configuration;
+
+static ball_configuration *bps = NULL;
+
+static Bool do_spin;
+static GLfloat speed;
+static Bool do_wander;
+
+static XrmOptionDescRec opts[] = {
+  { "-spin",   ".spin",   XrmoptionNoArg, "True" },
+  { "+spin",   ".spin",   XrmoptionNoArg, "False" },
+  { "-speed",  ".speed",  XrmoptionSepArg, 0 },
+  { "-wander", ".wander", XrmoptionNoArg, "True" },
+  { "+wander", ".wander", XrmoptionNoArg, "False" }
+};
+
+static argtype vars[] = {
+  {&do_spin,   "spin",   "Spin",   DEF_SPIN,   t_Bool},
+  {&do_wander, "wander", "Wander", DEF_WANDER, t_Bool},
+  {&speed,     "speed",  "Speed",  DEF_SPEED,  t_Float},
+};
+
+ENTRYPOINT ModeSpecOpt ball_opts = {countof(opts), opts, countof(vars), vars, NULL};
+
+
+static XYZ
+normalize (XYZ p)
+{
+  GLfloat d = sqrt(p.x*p.x + p.y*p.y * p.z*p.z);
+  if (d < 0.0000001)
+    p.x = p.y = p.z = 0;
+  else
+    {
+      p.x /= d;
+      p.y /= d;
+      p.z /= d;
+    }
+    
+  return p;
+}
+
+
+static void
+build_texture (ModeInfo *mi)
+{
+  int x, y;
+  int size = 128;
+  int bpl = size * 2;
+  unsigned char *data = malloc (bpl * size);
+
+  for (y = 0; y < size; y++)
+    {
+      for (x = 0; x < size; x++)
+        {
+          unsigned char *c = &data [y * bpl + x * 2];
+          GLfloat X = (x / (GLfloat) (size-1)) - 0.5;
+          GLfloat Y = (y / (GLfloat) (size-1)) - 0.5;
+          X = cos (X * X * 6.2);
+          Y = cos (Y * Y * 6.2);
+          X = X < Y ? X : Y;
+          X *= 0.4;
+          c[0] = 0xFF;
+          c[1] = 0xFF * X;
+        }
+    }
+
+  glTexParameteri (GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
+  glTexParameteri (GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
+  glTexParameteri (GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_REPEAT);
+  glTexParameteri (GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_REPEAT);
+  glTexEnvi (GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_MODULATE);
+  glPixelStorei (GL_UNPACK_ALIGNMENT, 1);
+  check_gl_error ("texture param");
+
+  glTexImage2D (GL_TEXTURE_2D, 0, GL_LUMINANCE_ALPHA, size, size, 0,
+                GL_LUMINANCE_ALPHA, GL_UNSIGNED_BYTE, data);
+  check_gl_error ("light texture");
+  free (data);
+}
+
+
+static int
+draw_rays (ModeInfo *mi)
+{
+  ball_configuration *bp = &bps[MI_SCREEN(mi)];
+  int wire = MI_IS_WIREFRAME(mi);
+  int polys = 0;
+  int i;
+
+  glEnable (GL_TEXTURE_2D);
+  glDisable (GL_LIGHTING);
+  glEnable (GL_BLEND);
+  glDisable (GL_DEPTH_TEST);
+  glBlendFunc (GL_SRC_ALPHA, GL_ONE);
+
+  for (i = 0; i < bp->nrays; i++)
+    {
+      GLfloat x = bp->rays[i].normal.x;
+      GLfloat y = bp->rays[i].normal.y;
+      GLfloat z = bp->rays[i].normal.z;
+      glPushMatrix();
+
+      /* Orient to direction of ray. */
+      glRotatef (-atan2 (x, y)               * (180 / M_PI), 0, 0, 1);
+      glRotatef ( atan2 (z, sqrt(x*x + y*y)) * (180 / M_PI), 1, 0, 0);
+
+      glScalef (5, 5, 10);
+      glTranslatef(0, 0, 1.1);
+      glColor4fv (bp->rays[i].color);
+      glBegin(wire ? GL_LINE_LOOP : GL_QUADS);
+      glTexCoord2f (0, 0); glVertex3f (-0.5, 0, -1);
+      glTexCoord2f (1, 0); glVertex3f ( 0.5, 0, -1);
+      glTexCoord2f (1, 1); glVertex3f ( 0.5, 0,  1);
+      glTexCoord2f (0, 1); glVertex3f (-0.5, 0,  1);
+      glEnd();
+      polys++;
+      glPopMatrix();
+    }
+
+  glDisable (GL_TEXTURE_2D);
+  glEnable (GL_LIGHTING);
+  glDisable (GL_BLEND);
+  glEnable (GL_DEPTH_TEST);
+  glDisable (GL_FOG);
+
+  return polys;
+}
+
+
+static int
+draw_ball_1 (ModeInfo *mi)
+{
+  ball_configuration *bp = &bps[MI_SCREEN(mi)];
+  int wire = MI_IS_WIREFRAME(mi);
+  int polys = 0;
+  tile *t;
+  GLfloat m[4][4];
+
+  glGetFloatv (GL_MODELVIEW_MATRIX, &m[0][0]);
+
+  glFrontFace (GL_CW);
+
+#if 0
+  /* Draw the back rays.
+   */
+  if (! wire)
+    {
+      glPushMatrix();
+      glLoadIdentity();
+      glMultMatrixf (&m[0][0]);
+      glTranslatef(0, 0, -4.1);
+      glRotatef (bp->th, 0, 0, 1);
+      polys += draw_rays (mi);
+      glPopMatrix();
+    }
+  glClear(GL_DEPTH_BUFFER_BIT);
+#endif
+
+
+  /* Instead of rendering polygons for the foam ball substrate, let's
+     just billboard a quad down the middle to mask out the back-facing
+     tiles. */
+  {
+    glPushMatrix();
+    m[0][0] = 1; m[1][0] = 0; m[2][0] = 0;
+    m[0][1] = 0; m[1][1] = 1; m[2][1] = 0;
+    m[0][2] = 0; m[1][2] = 0; m[2][2] = 1;
+    glLoadIdentity();
+    glMultMatrixf (&m[0][0]);
+    glScalef (40, 40, 40);
+    glTranslatef (-0.5, -0.5, -0.01);
+    if (! wire)
+      glDisable (GL_LIGHTING);
+    /* Draw into the depth buffer but not the frame buffer */
+    glColorMask (GL_FALSE, GL_FALSE, GL_FALSE, GL_FALSE);
+    glColor3f (0, 0, 0);
+    glBegin (GL_QUADS);
+    glVertex3f (0, 0, 0);
+    glVertex3f (0, 1, 0);
+    glVertex3f (1, 1, 0);
+    glVertex3f (1, 0, 0);
+    glEnd();
+    polys++;
+    glColorMask (GL_TRUE, GL_TRUE, GL_TRUE, GL_TRUE);
+    if (! wire)
+      glEnable (GL_LIGHTING);
+    glPopMatrix();
+    glColor3f (1, 1, 1);
+  }
+
+  /* Draw all the tiles.
+   */
+  for (t = bp->tiles; t; t = t->next)
+    {
+      GLfloat x = t->normal.x;
+      GLfloat y = t->normal.y;
+      GLfloat z = t->normal.z;
+      GLfloat s = t->size / 2;
+      glPushMatrix();
+
+      /* Move to location of tile. */
+      glTranslatef (t->position.x, t->position.y, t->position.z);
+
+      /* Orient to direction tile is facing. */
+      glRotatef (-atan2 (x, y)               * (180 / M_PI), 0, 0, 1);
+      glRotatef ( atan2 (z, sqrt(x*x + y*y)) * (180 / M_PI), 1, 0, 0);
+
+      glRotatef (t->tilt, 0, 1, 0);
+
+      glScalef (s, s, s);
+      glNormal3f (0, 1, 0);
+      glBegin (wire ? GL_LINE_LOOP : GL_QUADS);
+      glVertex3f (-1, 0, -1);
+      glVertex3f ( 1, 0, -1);
+      glVertex3f ( 1, 0,  1);
+      glVertex3f (-1, 0,  1);
+      glEnd();
+      polys++;
+
+      if (! wire)
+        {
+          GLfloat d = 0.2;
+          glNormal3f (0, 0, -1);
+          glBegin (wire ? GL_LINE_LOOP : GL_QUADS);
+          glVertex3f (-1,  0, -1);
+          glVertex3f (-1, -d, -1);
+          glVertex3f ( 1, -d, -1);
+          glVertex3f ( 1,  0, -1);
+          glEnd();
+          polys++;
+
+          glNormal3f (0, 0, 1);
+          glBegin (wire ? GL_LINE_LOOP : GL_QUADS);
+          glVertex3f ( 1,  0,  1);
+          glVertex3f ( 1, -d,  1);
+          glVertex3f (-1, -d,  1);
+          glVertex3f (-1,  0,  1);
+          glEnd();
+          polys++;
+
+          glNormal3f (1, 0, 0);
+          glBegin (wire ? GL_LINE_LOOP : GL_QUADS);
+          glVertex3f ( 1,  0, -1);
+          glVertex3f ( 1, -d, -1);
+          glVertex3f ( 1, -d,  1);
+          glVertex3f ( 1,  0,  1);
+          glEnd();
+          polys++;
+
+          glNormal3f (-1, 0, 0);
+          glBegin (wire ? GL_LINE_LOOP : GL_QUADS);
+          glVertex3f (-1,  0,  1);
+          glVertex3f (-1, -d,  1);
+          glVertex3f (-1, -d, -1);
+          glVertex3f (-1,  0, -1);
+          glEnd();
+          polys++;
+        }
+
+      glPopMatrix();
+    }
+
+  /* Draw the front rays.
+   */
+  if (! wire)
+    {
+      glPushMatrix();
+      glLoadIdentity();
+      glMultMatrixf (&m[0][0]);
+      glTranslatef(0, 0, 4.1);
+      glRotatef (-bp->th, 0, 0, 1);
+      polys += draw_rays (mi);
+      glPopMatrix();
+    }
+
+  return polys;
+}
+
+
+static GLfloat
+vector_angle (XYZ a, XYZ b)
+{
+  double La = sqrt (a.x*a.x + a.y*a.y + a.z*a.z);
+  double Lb = sqrt (b.x*b.x + b.y*b.y + b.z*b.z);
+  double cc, angle;
+
+  if (La == 0 || Lb == 0) return 0;
+  if (a.x == b.x && a.y == b.y && a.z == b.z) return 0;
+
+  /* dot product of two vectors is defined as:
+       La * Lb * cos(angle between vectors)
+     and is also defined as:
+       ax*bx + ay*by + az*bz
+     so:
+      La * Lb * cos(angle) = ax*bx + ay*by + az*bz
+      cos(angle)  = (ax*bx + ay*by + az*bz) / (La * Lb)
+      angle = acos ((ax*bx + ay*by + az*bz) / (La * Lb));
+  */
+  cc = (a.x*b.x + a.y*b.y + a.z*b.z) / (La * Lb);
+  if (cc > 1) cc = 1;  /* avoid fp rounding error (1.000001 => sqrt error) */
+  angle = acos (cc);
+
+  return (angle);
+}
+
+
+#undef RANDSIGN
+#define RANDSIGN() ((random() & 1) ? 1 : -1)
+
+#undef BELLRAND
+#define BELLRAND(n) ((frand((n)) + frand((n)) + frand((n))) / 3)
+
+static void
+build_ball (ModeInfo *mi)
+{
+  ball_configuration *bp = &bps[MI_SCREEN(mi)];
+  int rows = MI_COUNT (mi);
+
+  GLfloat tile_size = M_PI / rows;
+  GLfloat th0, th1;
+
+  struct { XYZ position; GLfloat strength; } dents[5];
+  int dent_count = random() % countof(dents);
+  int i;
+  for (i = 0; i < dent_count; i++)
+    {
+      GLfloat dist;
+      dents[i].position.x = RANDSIGN() * (2 - BELLRAND(0.2));
+      dents[i].position.y = RANDSIGN() * (2 - BELLRAND(0.2));
+      dents[i].position.z = RANDSIGN() * (2 - BELLRAND(0.2));
+      dist = sqrt (dents[i].position.x * dents[i].position.x +
+                   dents[i].position.y * dents[i].position.y +
+                   dents[i].position.z * dents[i].position.z);
+      dents[i].strength = dist - (1 - BELLRAND(0.3));
+      dents[i].strength = dist - (1 - BELLRAND(0.3));
+    }
+
+
+  for (th1 = M_PI/2; th1 > -(M_PI/2 + tile_size/2); th1 -= tile_size)
+    {
+      GLfloat x  = cos (th1);
+      GLfloat y  = sin (th1);
+      GLfloat x0 = cos (th1 - tile_size/2);
+      GLfloat x1 = cos (th1 + tile_size/2);
+      GLfloat circ0 = M_PI * x0 * 2;
+      GLfloat circ1 = M_PI * x1 * 2;
+      GLfloat circ  = (circ0 < circ1 ? circ0 : circ1);
+      int row_tiles = floor ((circ < 0 ? 0 : circ) / tile_size);
+      GLfloat spacing;
+      GLfloat dropsy = 0.13 + frand(0.04);
+
+      if (row_tiles <= 0) row_tiles = 1;
+      spacing = M_PI*2 / row_tiles;
+
+      for (th0 = 0; th0 < M_PI*2; th0 += spacing)
+        {
+          tile *t = (tile *) calloc (1, sizeof(*t));
+          t->size = tile_size * 0.85;
+          t->position.x = cos (th0) * x;
+          t->position.y = sin (th0) * x;
+          t->position.z = y;
+
+          t->normal = t->position;
+
+          /* Apply pressure on position from the dents. */
+          for (i = 0; i < dent_count; i++)
+            {
+              GLfloat dist;
+              XYZ direction;
+
+              if (! (random() % 150))	/* Drop tiles randomly */
+                {
+                  free (t);
+                  goto SKIP;
+                }
+
+              direction.x = t->position.x - dents[i].position.x;
+              direction.y = t->position.y - dents[i].position.y;
+              direction.z = t->position.z - dents[i].position.z;
+              dist = sqrt (direction.x * direction.x +
+                           direction.y * direction.y +
+                           direction.z * direction.z);
+              if (dist < dents[i].strength)
+                {
+                  GLfloat s = 1 - (dents[i].strength - dist) * 0.66;
+                  XYZ n2 = t->normal;
+                  GLfloat angle = vector_angle (t->position, dents[i].position);
+
+                  /* Drop out the tiles near the apex of the dent. */
+                  if (angle < dropsy)
+                    {
+                      free (t);
+                      goto SKIP;
+                    }
+
+                  t->position.x *= s;
+                  t->position.y *= s;
+                  t->position.z *= s;
+
+                  direction = normalize (direction);
+                  n2.x -= direction.x;
+                  n2.y -= direction.y;
+                  n2.z -= direction.z;
+
+                  t->normal.x = (t->normal.x + n2.x) / 2;
+                  t->normal.y = (t->normal.y + n2.y) / 2;
+                  t->normal.z = (t->normal.z + n2.z) / 2;
+                }
+            }
+
+          /* Skew the direction the tile is facing slightly. */
+          t->normal.x += 0.12 - frand(0.06);
+          t->normal.y += 0.12 - frand(0.06);
+          t->normal.z += 0.12 - frand(0.06);
+          t->tilt = 4 - BELLRAND(8);
+
+          t->next = bp->tiles;
+          bp->tiles = t;
+        SKIP: ;
+        }
+    }
+
+  bp->nrays = 5 + BELLRAND(10);
+  bp->rays = (ray *) calloc (bp->nrays, sizeof(*bp->rays));
+  for (i = 0; i < bp->nrays; i++)
+    {
+      GLfloat th = frand(M_PI * 2);
+      bp->rays[i].normal.x = cos (th);
+      bp->rays[i].normal.y = sin (th);
+      bp->rays[i].normal.z = 1;
+      bp->rays[i].normal = normalize (bp->rays[i].normal);
+      bp->rays[i].color[0] = 0.9 + frand(0.1);
+      bp->rays[i].color[1] = 0.6 + frand(0.4);
+      bp->rays[i].color[2] = 0.6 + frand(0.2);
+      bp->rays[i].color[3] = 1;
+    }
+}
+
+
+/* Window management, etc
+ */
+ENTRYPOINT void
+reshape_ball (ModeInfo *mi, int width, int height)
+{
+  GLfloat h = (GLfloat) height / (GLfloat) width;
+  int y = 0;
+
+  if (width > height * 5) {   /* tiny window: show middle */
+    height = width * 9/16;
+    y = -height/2;
+    h = height / (GLfloat) width;
+  }
+
+  glViewport (0, y, (GLint) width, (GLint) height);
+
+  glMatrixMode(GL_PROJECTION);
+  glLoadIdentity();
+  gluPerspective (30.0, 1/h, 1.0, 100.0);
+
+  glMatrixMode(GL_MODELVIEW);
+  glLoadIdentity();
+  gluLookAt( 0.0, 0.0, 30.0,
+             0.0, 0.0, 0.0,
+             0.0, 1.0, 0.0);
+
+# ifdef HAVE_MOBILE	/* Keep it the same relative size when rotated. */
+  {
+    int o = (int) current_device_rotation();
+    if (o != 0 && o != 180 && o != -180)
+      glScalef (1/h, 1/h, 1/h);
+  }
+# endif
+
+  glClear(GL_COLOR_BUFFER_BIT);
+}
+
+
+ENTRYPOINT Bool
+ball_handle_event (ModeInfo *mi, XEvent *event)
+{
+  ball_configuration *bp = &bps[MI_SCREEN(mi)];
+
+  if (gltrackball_event_handler (event, bp->trackball,
+                                 MI_WIDTH (mi), MI_HEIGHT (mi),
+                                 &bp->button_down_p))
+    return True;
+
+  return False;
+}
+
+
+ENTRYPOINT void 
+init_ball (ModeInfo *mi)
+{
+  ball_configuration *bp;
+  int wire = MI_IS_WIREFRAME(mi);
+
+  MI_INIT (mi, bps);
+
+  bp = &bps[MI_SCREEN(mi)];
+
+  bp->glx_context = init_GL(mi);
+
+  if (! wire)
+    build_texture (mi);
+
+  reshape_ball (mi, MI_WIDTH(mi), MI_HEIGHT(mi));
+
+  bp->th = 180 - frand(360);
+
+  if (MI_COUNT(mi) < 10)
+    MI_COUNT(mi) = 10;
+  if (MI_COUNT(mi) > 200)
+    MI_COUNT(mi) = 200;
+
+  {
+    double spin_speed   = 0.1;
+    double wander_speed = 0.003;
+    double spin_accel   = 1;
+
+    bp->rot = make_rotator (do_spin ? spin_speed : 0,
+                            do_spin ? spin_speed : 0,
+                            do_spin ? spin_speed : 0,
+                            spin_accel,
+                            do_wander ? wander_speed : 0,
+                            False);
+    bp->trackball = gltrackball_init (True);
+  }
+
+  build_ball (mi);
+
+  if (!wire)
+    {
+      GLfloat color[4] = {0.5, 0.5, 0.5, 1};
+      GLfloat cspec[4] = {1, 1, 1, 1};
+      static const GLfloat shiny = 10;
+
+      static GLfloat pos0[4] = { 0.5, -1, -0.5, 0};
+      static GLfloat pos1[4] = {-0.75, -1, 0, 0};
+      static GLfloat amb[4] = {0, 0, 0, 1};
+      static GLfloat dif[4] = {1, 1, 1, 1};
+      static GLfloat spc[4] = {1, 1, 1, 1};
+
+      glEnable(GL_LIGHTING);
+      glEnable(GL_LIGHT0);
+      glEnable(GL_LIGHT1);
+      glEnable(GL_DEPTH_TEST);
+      glEnable(GL_CULL_FACE);
+
+      color[0] += frand(0.2);
+      color[1] += frand(0.2);
+      color[2] += frand(0.2);
+
+      cspec[0] -= frand(0.2);
+      cspec[1] -= frand(0.2);
+      cspec[2] -= frand(0.2);
+
+      glLightfv(GL_LIGHT0, GL_POSITION, pos0);
+      glLightfv(GL_LIGHT0, GL_AMBIENT,  amb);
+      glLightfv(GL_LIGHT0, GL_DIFFUSE,  dif);
+      glLightfv(GL_LIGHT0, GL_SPECULAR, spc);
+
+      glLightfv(GL_LIGHT1, GL_POSITION, pos1);
+      glLightfv(GL_LIGHT1, GL_AMBIENT,  amb);
+      glLightfv(GL_LIGHT1, GL_DIFFUSE,  dif);
+      glLightfv(GL_LIGHT1, GL_SPECULAR, spc);
+
+      glMaterialfv (GL_FRONT, GL_AMBIENT_AND_DIFFUSE, color);
+      glMaterialfv (GL_FRONT, GL_SPECULAR,  cspec);
+      glMateriali  (GL_FRONT, GL_SHININESS, shiny);
+    }
+}
+
+
+ENTRYPOINT void
+draw_ball (ModeInfo *mi)
+{
+  ball_configuration *bp = &bps[MI_SCREEN(mi)];
+  Display *dpy = MI_DISPLAY(mi);
+  Window window = MI_WINDOW(mi);
+
+  if (!bp->glx_context)
+    return;
+
+  glXMakeCurrent(MI_DISPLAY(mi), MI_WINDOW(mi), *(bp->glx_context));
+
+  glShadeModel(GL_SMOOTH);
+
+  glEnable(GL_DEPTH_TEST);
+  glEnable(GL_NORMALIZE);
+  glEnable(GL_CULL_FACE);
+
+  glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
+
+  glPushMatrix ();
+
+  glRotatef(current_device_rotation(), 0, 0, 1);
+
+  {
+    double x, y, z;
+    get_position (bp->rot, &x, &y, &z, !bp->button_down_p);
+    glTranslatef((x - 0.5) * 6,
+                 (y - 0.5) * 6,
+                 (z - 0.5) * 2);
+
+    gltrackball_rotate (bp->trackball);
+
+    get_rotation (bp->rot, &x, &y, &z, !bp->button_down_p);
+    glRotatef (x * 360, 1.0, 0.0, 0.0);
+    glRotatef (y * 360, 0.0, 1.0, 0.0);
+    glRotatef (z * 360, 0.0, 0.0, 1.0);
+  }
+
+  mi->polygon_count = 0;
+
+  glRotatef (50, 1, 0, 0);
+
+  glScalef (4, 4, 4);
+  glRotatef (bp->th, 0, 0, 1);
+  if (! bp->button_down_p)
+    {
+      bp->th += (bp->th > 0 ? speed : -speed);
+      while (bp->th >  360) bp->th -= 360;
+      while (bp->th < -360) bp->th += 360;
+    }
+
+  mi->polygon_count += draw_ball_1 (mi);
+  glPopMatrix ();
+
+  if (mi->fps_p) do_fps (mi);
+  glFinish();
+
+  glXSwapBuffers(dpy, window);
+}
+
+
+ENTRYPOINT void
+free_ball (ModeInfo *mi)
+{
+  ball_configuration *bp = &bps[MI_SCREEN(mi)];
+  while (bp->tiles)
+    {
+      tile *t = bp->tiles->next;
+      free (bp->tiles);
+      bp->tiles = t;
+    }
+  free (bp->rays);
+}
+
+XSCREENSAVER_MODULE_2 ("Discoball", discoball, ball)
+
+#endif /* USE_GL */