http://packetstormsecurity.org/UNIX/admin/xscreensaver-3.31.tar.gz

[xscreensaver] / hacks / nerverot.c

diff --git a/hacks/nerverot.c b/hacks/nerverot.c
index 39f33479185112a346c428127d283773cede1d8c..16bd267040e822e70fcb58088f1cedab6b3f7451 100644 (file)
--- a/hacks/nerverot.c
+++ b/hacks/nerverot.c
@@ -1,6 +1,6 @@
-/* nerverot, nervous rotation of random thingies, v1.2
+/* nerverot, nervous rotation of random thingies, v1.3
  * by Dan Bornstein, danfuzz@milk.com
- * Copyright (c) 2000 Dan Bornstein.
+ * Copyright (c) 2000-2001 Dan Bornstein. All rights reserved.
  *
  * Permission to use, copy, modify, distribute, and sell this software and its
  * documentation for any purpose is hereby granted without fee, provided that
@@ -39,6 +39,9 @@ static int requestedBlotCount;
 /* delay (usec) between iterations */
 int delay;
 
+/* max iterations per model */
+int maxIters;
+
 /* variability of xoff/yoff per iteration (0..1) */
 static FLOAT nervousness;
 
@@ -366,11 +369,15 @@ static void setupBlotsCylinder (void)
 static void setupBlotsSquiggle (void)
 {
     FLOAT x, y, z, xv, yv, zv, len;
+    int minCoor, maxCoor;
     int n;
 
     blotCount = requestedBlotCount;
     blots = calloc (sizeof (Blot), blotCount);
 
+    maxCoor = (int) (RAND_FLOAT_01 * 5) + 1;
+    minCoor = -maxCoor;
+
     x = RAND_FLOAT_PM1;
     y = RAND_FLOAT_PM1;
     z = RAND_FLOAT_PM1;
@@ -402,9 +409,9 @@ static void setupBlotsSquiggle (void)
            newy = y + yv * 0.1;
            newz = z + zv * 0.1;
 
-           if (   (newx >= -1) && (newx <= 1)
-               && (newy >= -1) && (newy <= 1)
-               && (newz >= -1) && (newz <= 1))
+           if (   (newx >= minCoor) && (newx <= maxCoor)
+               && (newy >= minCoor) && (newy <= maxCoor)
+               && (newz >= minCoor) && (newz <= maxCoor))
            {
                break;
            }
@@ -448,6 +455,66 @@ static void setupBlotsCubeCorners (void)
 
 
 
+/* set up the initial array of blots to be randomly distributed
+ * on the surface of a tetrahedron */
+static void setupBlotsTetrahedron (void)
+{
+    /* table of corners of the tetrahedron */
+    static FLOAT cor[4][3] = { {  0.0,   1.0,  0.0 },
+                              { -0.75, -0.5, -0.433013 },
+                              {  0.0,  -0.5,  0.866025 },
+                              {  0.75, -0.5, -0.433013 } };
+
+    int n, c;
+
+    /* derive blotsPerSurface from blotCount, but then do the reverse
+     * since roundoff may have changed blotCount */
+    int blotsPerSurface = requestedBlotCount / 4;
+
+    blotCount = blotsPerSurface * 4;
+    blots = calloc (sizeof (Blot), blotCount);
+
+    for (n = 0; n < blotCount; n += 4)
+    {
+       /* pick a random point on a unit right triangle */
+       FLOAT rawx = RAND_FLOAT_01;
+       FLOAT rawy = RAND_FLOAT_01;
+
+       if ((rawx + rawy) > 1)
+       {
+           /* swap coords into place */
+           FLOAT t = 1.0 - rawx;
+           rawx = 1.0 - rawy;
+           rawy = t;
+       }
+
+       /* translate the point to be on each of the surfaces */
+       for (c = 0; c < 4; c++)
+       {
+           FLOAT x, y, z;
+           
+           int c1 = (c + 1) % 4;
+           int c2 = (c + 2) % 4;
+           
+           x = (cor[c1][0] - cor[c][0]) * rawx + 
+               (cor[c2][0] - cor[c][0]) * rawy + 
+               cor[c][0];
+
+           y = (cor[c1][1] - cor[c][1]) * rawx + 
+               (cor[c2][1] - cor[c][1]) * rawy + 
+               cor[c][1];
+
+           z = (cor[c1][2] - cor[c][2]) * rawx + 
+               (cor[c2][2] - cor[c][2]) * rawy + 
+               cor[c][2];
+
+           initBlot (&blots[n + c], x, y, z);
+       }
+    }
+}
+
+
+
 /* forward declaration for recursive use immediately below */
 static void setupBlots (void);
 
@@ -558,7 +625,7 @@ static void freeBlots (void)
 /* set up the initial arrays of blots */
 static void setupBlots (void)
 {
-    int which = RAND_FLOAT_01 * 7;
+    int which = RAND_FLOAT_01 * 8;
 
     freeBlots ();
 
@@ -580,7 +647,10 @@ static void setupBlots (void)
            setupBlotsCubeCorners ();
            break;
        case 5:
+           setupBlotsTetrahedron ();
+           break;
        case 6:
+       case 7:
            setupBlotsDuo ();
            break;
     }
@@ -699,7 +769,7 @@ static void setup (void)
     lightY = lightYTarget = RAND_FLOAT_PM1;
     lightZ = lightZTarget = RAND_FLOAT_PM1;
 
-    itersTillNext = RAND_FLOAT_01 * 1234;
+    itersTillNext = RAND_FLOAT_01 * maxIters;
 }
 
 
@@ -801,7 +871,7 @@ static void updateWithFeeling (void)
     itersTillNext--;
     if (itersTillNext < 0)
     {
-       itersTillNext = RAND_FLOAT_01 * 1234;
+       itersTillNext = RAND_FLOAT_01 * maxIters;
        setupBlots ();
        setupSegs ();
        renderSegs ();
@@ -983,6 +1053,7 @@ char *defaults [] = {
     "*count:           250",
     "*colors:          4",
     "*delay:           10000",
+    "*maxIters:                1200",
     "*doubleBuffer:    false",
     "*eventChance:      0.2",
     "*iterAmt:          0.01",
@@ -1000,6 +1071,7 @@ XrmOptionDescRec options [] = {
   { "-count",            ".count",          XrmoptionSepArg, 0 },
   { "-colors",           ".colors",         XrmoptionSepArg, 0 },
   { "-delay",            ".delay",          XrmoptionSepArg, 0 },
+  { "-max-iters",        ".maxIters",       XrmoptionSepArg, 0 },
   { "-db",               ".doubleBuffer",   XrmoptionNoArg,  "true" },
   { "-no-db",            ".doubleBuffer",   XrmoptionNoArg,  "false" },
   { "-event-chance",     ".eventChance",    XrmoptionSepArg, 0 },
@@ -1026,6 +1098,13 @@ static void initParams (void)
        problems = 1;
     }
     
+    maxIters = get_integer_resource ("maxIters", "Integer");
+    if (maxIters < 0)
+    {
+       fprintf (stderr, "error: maxIters must be at least 0\n");
+       problems = 1;
+    }
+    
     doubleBuffer = get_boolean_resource ("doubleBuffer", "Boolean");
 
     requestedBlotCount = get_integer_resource ("count", "Count");