/* Create and return a new gear sized for placement next to or on top of
the given parent gear (if any.) Returns 0 if out of memory.
*/
static gear *
new_gear (ModeInfo *mi, gear *parent, Bool coaxial_p)
{
pinion_configuration *pp = &pps[MI_SCREEN(mi)];
gear *g = (gear *) calloc (1, sizeof (*g));
int loop_count = 0;
static unsigned long id = 0; /* only used in debugging output */
if (!g) return 0;
if (coaxial_p && !parent) abort();
g->id = ++id;
g->coax_displacement = pp->plane_displacement;
while (1)
{
loop_count++;
if (loop_count > 1000)
/* The only time we loop in here is when making a coaxial gear, and
trying to pick a radius that is either significantly larger or
smaller than its parent. That shouldn't be hard, so something
must be really wrong if we can't do that in only a few tries.
*/
abort();
/* Pick the size of the teeth.
*/
if (parent && !coaxial_p) /* adjascent gears need matching teeth */
{
g->tooth_w = parent->tooth_w;
g->tooth_h = parent->tooth_h;
g->thickness = parent->thickness;
g->thickness2 = parent->thickness2;
g->thickness3 = parent->thickness3;
}
else /* gears that begin trains get any size they want */
{
double scale = (1.0 + BELLRAND(4.0)) * gear_size;
g->tooth_w = 0.007 * scale;
g->tooth_h = 0.005 * scale;
g->thickness = g->tooth_h * (0.1 + BELLRAND(1.5));
g->thickness2 = g->thickness / 4;
g->thickness3 = g->thickness;
}
/* Pick the number of teeth, and thus, the radius.
*/
{
double c;
AGAIN:
g->nteeth = 3 + (random() % 97); /* from 3 to 100 teeth */
if (g->nteeth < 7 && (random() % 5) != 0)
goto AGAIN; /* Let's make very small tooth-counts more rare */
c = g->nteeth * g->tooth_w * 2; /* circumference = teeth + gaps */
g->r = c / (M_PI * 2); /* c = 2 pi r */
}
/* Are we done now?
*/
if (! coaxial_p) break; /* yes */
if (g->nteeth == parent->nteeth) continue; /* ugly */
if (g->r < parent->r * 0.6) break; /* g much smaller than parent */
if (parent->r < g->r * 0.6) break; /* g much larger than parent */
}
/* g->tooth_slope = (parent ? -parent->tooth_slope : 4); */
/* Colorize
*/
g->color[0] = 0.5 + frand(0.5);
g->color[1] = 0.5 + frand(0.5);
g->color[2] = 0.5 + frand(0.5);
g->color[3] = 1.0;
g->color2[0] = g->color[0] * 0.85;
g->color2[1] = g->color[1] * 0.85;
g->color2[2] = g->color[2] * 0.85;
g->color2[3] = g->color[3];
/* Decide on shape of gear interior:
- just a ring with teeth;
- that, plus a thinner in-set "plate" in the middle;
- that, plus a thin raised "lip" on the inner plate;
- or, a wide lip (really, a thicker third inner plate.)
*/
if ((random() % 10) == 0)
{
/* inner_r can go all the way in; there's no inset disc. */
g->inner_r = (g->r * 0.1) + frand((g->r - g->tooth_h/2) * 0.8);
g->inner_r2 = 0;
g->inner_r3 = 0;
}
else
{
/* inner_r doesn't go in very far; inner_r2 is an inset disc. */
g->inner_r = (g->r * 0.5) + frand((g->r - g->tooth_h) * 0.4);
g->inner_r2 = (g->r * 0.1) + frand(g->inner_r * 0.5);
g->inner_r3 = 0;
if (g->inner_r2 > (g->r * 0.2))
{
int nn = (random() % 10);
if (nn <= 2)
g->inner_r3 = (g->r * 0.1) + frand(g->inner_r2 * 0.2);
else if (nn <= 7 && g->inner_r2 >= 0.1)
g->inner_r3 = g->inner_r2 - 0.01;
}
}
/* Coaxial gears need to have the same innermost hole size (for the axle.)
Use whichever of the two is smaller. (Modifies parent.)
*/
if (coaxial_p)
{
double hole1 = (g->inner_r3 ? g->inner_r3 :
g->inner_r2 ? g->inner_r2 :
g->inner_r);
double hole2 = (parent->inner_r3 ? parent->inner_r3 :
parent->inner_r2 ? parent->inner_r2 :
parent->inner_r);
double hole = (hole1 < hole2 ? hole1 : hole2);
if (hole <= 0) abort();
if (g->inner_r3) g->inner_r3 = hole;
else if (g->inner_r2) g->inner_r2 = hole;
else g->inner_r = hole;
if (parent->inner_r3) parent->inner_r3 = hole;
else if (parent->inner_r2) parent->inner_r2 = hole;
else parent->inner_r = hole;
}
/* If we have three discs, sometimes make the middle disc be spokes.
*/
if (g->inner_r3 && ((random() % 5) == 0))
{
g->spokes = 2 + BELLRAND (5);
g->spoke_thickness = 1 + frand(7.0);
if (g->spokes == 2 && g->spoke_thickness < 2)
g->spoke_thickness += 1;
}
/* Sometimes add little nubbly bits, if there is room.
*/
if (g->nteeth > 5)
{
double size = 0;
involute_biggest_ring (g, 0, &size, 0);
if (size > g->r * 0.2 && (random() % 5) == 0)
{
g->nubs = 1 + (random() % 16);
if (g->nubs > 8) g->nubs = 1;
}
}
if (g->inner_r3 > g->inner_r2) abort();
if (g->inner_r2 > g->inner_r) abort();
if (g->inner_r > g->r) abort();
/* Decide how complex the polygon model should be.
*/
{
double pix = g->tooth_h * MI_HEIGHT(mi); /* approx. tooth size in pixels */
if (pix <= 2.5) g->size = INVOLUTE_SMALL;
else if (pix <= 3.5) g->size = INVOLUTE_MEDIUM;
else g->size = INVOLUTE_LARGE;
}
g->base_p = !parent;
return g;
}
/* Create and return a new gear sized for placement next to or on top of
the given parent gear (if any.) Returns 0 if out of memory.
[Mostly lifted from pinion.c]
*/
static gear *
new_gear (ModeInfo *mi, gear *parent)
{
gears_configuration *bp = &bps[MI_SCREEN(mi)];
gear *g = (gear *) calloc (1, sizeof (*g));
static unsigned long id = 0; /* only used in debugging output */
if (!g) return 0;
g->id = ++id;
/* Pick the size of the teeth.
*/
if (parent) /* adjascent gears need matching teeth */
{
g->tooth_w = parent->tooth_w;
g->tooth_h = parent->tooth_h;
g->tooth_slope = -parent->tooth_slope;
}
else /* gears that begin trains get any size they want */
{
g->tooth_w = 0.007 * (1.0 + BELLRAND(4.0));
g->tooth_h = 0.005 * (1.0 + BELLRAND(8.0));
/*
g->tooth_slope = ((random() % 8)
? 0
: 0.5 + BELLRAND(1));
*/
}
/* Pick the number of teeth, and thus, the radius.
*/
{
double c;
if (!parent || bp->ngears > 4)
g->nteeth = 5 + BELLRAND (20);
else
g->nteeth = parent->nteeth * (0.5 + BELLRAND(2));
c = g->nteeth * g->tooth_w * 2; /* circumference = teeth + gaps */
g->r = c / (M_PI * 2); /* c = 2 pi r */
}
g->thickness = g->tooth_w + frand (g->r);
g->thickness2 = g->thickness * 0.7;
g->thickness3 = g->thickness;
/* Colorize
*/
g->color[0] = 0.5 + frand(0.5);
g->color[1] = 0.5 + frand(0.5);
g->color[2] = 0.5 + frand(0.5);
g->color[3] = 1.0;
g->color2[0] = g->color[0] * 0.85;
g->color2[1] = g->color[1] * 0.85;
g->color2[2] = g->color[2] * 0.85;
g->color2[3] = g->color[3];
/* Decide on shape of gear interior:
- just a ring with teeth;
- that, plus a thinner in-set "plate" in the middle;
- that, plus a thin raised "lip" on the inner plate;
- or, a wide lip (really, a thicker third inner plate.)
*/
if ((random() % 10) == 0)
{
/* inner_r can go all the way in; there's no inset disc. */
g->inner_r = (g->r * 0.1) + frand((g->r - g->tooth_h/2) * 0.8);
g->inner_r2 = 0;
g->inner_r3 = 0;
}
else
{
/* inner_r doesn't go in very far; inner_r2 is an inset disc. */
g->inner_r = (g->r * 0.5) + frand((g->r - g->tooth_h) * 0.4);
g->inner_r2 = (g->r * 0.1) + frand(g->inner_r * 0.5);
g->inner_r3 = 0;
if (g->inner_r2 > (g->r * 0.2))
{
int nn = (random() % 10);
if (nn <= 2)
g->inner_r3 = (g->r * 0.1) + frand(g->inner_r2 * 0.2);
else if (nn <= 7 && g->inner_r2 >= 0.1)
g->inner_r3 = g->inner_r2 - 0.01;
}
}
/* If we have three discs, sometimes make the middle disc be spokes.
*/
if (g->inner_r3 && ((random() % 5) == 0))
{
g->spokes = 2 + BELLRAND (5);
g->spoke_thickness = 1 + frand(7.0);
if (g->spokes == 2 && g->spoke_thickness < 2)
g->spoke_thickness += 1;
}
/* Sometimes add little nubbly bits, if there is room.
*/
if (g->nteeth > 5)
{
double size = 0;
involute_biggest_ring (g, 0, &size, 0);
if (size > g->r * 0.2 && (random() % 5) == 0)
{
g->nubs = 1 + (random() % 16);
if (g->nubs > 8) g->nubs = 1;
}
}
if (g->inner_r3 > g->inner_r2) abort();
if (g->inner_r2 > g->inner_r) abort();
if (g->inner_r > g->r) abort();
/* Decide how complex the polygon model should be.
*/
{
double pix = g->tooth_h * MI_HEIGHT(mi); /* approx. tooth size in pixels */
if (pix <= 2.5) g->size = INVOLUTE_SMALL;
else if (pix <= 3.5) g->size = INVOLUTE_MEDIUM;
else g->size = INVOLUTE_LARGE;
}
g->base_p = !parent;
return g;
}