http://packetstormsecurity.org/UNIX/admin/xscreensaver-3.29.tar.gz

[xscreensaver] / hacks / glx / moebius.c

diff --git a/hacks/glx/moebius.c b/hacks/glx/moebius.c
index b388a116d0b8eec7340611f2367a734bf428e81d..bb08482006fd548d15f9a43d34f3ed300f1f8f61 100644 (file)
--- a/hacks/glx/moebius.c
+++ b/hacks/glx/moebius.c
@@ -82,9 +82,11 @@ static const char sccsid[] = "@(#)moebius.c  4.08 97/01/04 xlockmore";
 # define PROGCLASS                     "Moebius"
 # define HACK_INIT                     init_moebius
 # define HACK_DRAW                     draw_moebius
-# define moebius_opts                  xlockmore_opts
+# define HACK_RESHAPE          reshape_moebius
+# define moebius_opts          xlockmore_opts
 # define DEFAULTS                      "*cycles:               1       \n"                     \
                                                        "*delay:                20000   \n"                     \
+                                                       "*showFPS:      False   \n"                     \
                                                        "*wireframe:    False   \n"
 # include "xlockmore.h"                /* from the xscreensaver distribution */
 #else /* !STANDALONE */
@@ -151,6 +153,12 @@ typedef struct {
        GLfloat     ant_position;
        int         AreObjectsDefined[2];
        GLXContext *glx_context;
+
+  GLfloat rotx, roty, rotz;       /* current object rotation */
+  GLfloat dx, dy, dz;             /* current rotational velocity */
+  GLfloat ddx, ddy, ddz;          /* current rotational acceleration */
+  GLfloat d_max;                          /* max velocity */
+
 } moebiusstruct;
 
 static float front_shininess[] =
@@ -550,8 +558,8 @@ draw_moebius_strip(ModeInfo * mi)
 #undef MoebiusDivisions
 #undef MoebiusTransversals
 
-static void
-reshape(ModeInfo * mi, int width, int height)
+void
+reshape_moebius(ModeInfo * mi, int width, int height)
 {
        moebiusstruct *mp = &moebius[MI_SCREEN(mi)];
 
@@ -614,6 +622,79 @@ pinit(void)
        glMaterialfv(GL_FRONT_AND_BACK, GL_SPECULAR, front_specular);
 }
 
+
+
+/* lifted from lament.c */
+#define RAND(n) ((long) ((random() & 0x7fffffff) % ((long) (n))))
+#define RANDSIGN() ((random() & 1) ? 1 : -1)
+
+static void
+rotate(GLfloat *pos, GLfloat *v, GLfloat *dv, GLfloat max_v)
+{
+  double ppos = *pos;
+
+  /* tick position */
+  if (ppos < 0)
+    ppos = -(ppos + *v);
+  else
+    ppos += *v;
+
+  if (ppos > 1.0)
+    ppos -= 1.0;
+  else if (ppos < 0)
+    ppos += 1.0;
+
+  if (ppos < 0) abort();
+  if (ppos > 1.0) abort();
+  *pos = (*pos > 0 ? ppos : -ppos);
+
+  /* accelerate */
+  *v += *dv;
+
+  /* clamp velocity */
+  if (*v > max_v || *v < -max_v)
+    {
+      *dv = -*dv;
+    }
+  /* If it stops, start it going in the other direction. */
+  else if (*v < 0)
+    {
+      if (random() % 4)
+       {
+         *v = 0;
+
+         /* keep going in the same direction */
+         if (random() % 2)
+           *dv = 0;
+         else if (*dv < 0)
+           *dv = -*dv;
+       }
+      else
+       {
+         /* reverse gears */
+         *v = -*v;
+         *dv = -*dv;
+         *pos = -*pos;
+       }
+    }
+
+  /* Alter direction of rotational acceleration randomly. */
+  if (! (random() % 120))
+    *dv = -*dv;
+
+  /* Change acceleration very occasionally. */
+  if (! (random() % 200))
+    {
+      if (*dv == 0)
+       *dv = 0.00001;
+      else if (random() & 1)
+       *dv *= 1.2;
+      else
+       *dv *= 0.8;
+    }
+}
+
+
 void
 init_moebius(ModeInfo * mi)
 {
@@ -629,9 +710,28 @@ init_moebius(ModeInfo * mi)
        mp->step = NRAND(90);
        mp->ant_position = NRAND(90);
 
+    mp->rotx = frand(1.0) * RANDSIGN();
+    mp->roty = frand(1.0) * RANDSIGN();
+    mp->rotz = frand(1.0) * RANDSIGN();
+
+    /* bell curve from 0-1.5 degrees, avg 0.75 */
+    mp->dx = (frand(1) + frand(1) + frand(1)) / (360*2);
+    mp->dy = (frand(1) + frand(1) + frand(1)) / (360*2);
+    mp->dz = (frand(1) + frand(1) + frand(1)) / (360*2);
+
+    mp->d_max = mp->dx * 2;
+
+    mp->ddx = 0.00006 + frand(0.00003);
+    mp->ddy = 0.00006 + frand(0.00003);
+    mp->ddz = 0.00006 + frand(0.00003);
+
+    mp->ddx = 0.00001;
+    mp->ddy = 0.00001;
+    mp->ddz = 0.00001;
+
        if ((mp->glx_context = init_GL(mi)) != NULL) {
 
-               reshape(mi, MI_WIDTH(mi), MI_HEIGHT(mi));
+               reshape_moebius(mi, MI_WIDTH(mi), MI_HEIGHT(mi));
                glDrawBuffer(GL_BACK);
                if (!glIsList(objects))
                        objects = glGenLists(3);
@@ -666,14 +766,28 @@ draw_moebius(ModeInfo * mi)
                glScalef(Scale4Iconic * mp->WindH / mp->WindW, Scale4Iconic, Scale4Iconic);
        }
 
+    {
+      GLfloat x = mp->rotx;
+      GLfloat y = mp->roty;
+      GLfloat z = mp->rotz;
+      if (x < 0) x = 1 - (x + 1);
+      if (y < 0) y = 1 - (y + 1);
+      if (z < 0) z = 1 - (z + 1);
+      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);
+    }
+
        /* moebius */
-       glRotatef(mp->step * 100, 1, 0, 0);
-       glRotatef(mp->step * 95, 0, 1, 0);
-       glRotatef(mp->step * 90, 0, 0, 1);
        draw_moebius_strip(mi);
 
        glPopMatrix();
 
+    rotate(&mp->rotx, &mp->dx, &mp->ddx, mp->d_max);
+    rotate(&mp->roty, &mp->dy, &mp->ddy, mp->d_max);
+    rotate(&mp->rotz, &mp->dz, &mp->ddz, mp->d_max);
+
+    if (mi->fps_p) do_fps (mi);
        glFlush();
 
        glXSwapBuffers(display, window);