Revision: 37463
http://brlcad.svn.sourceforge.net/brlcad/?rev=37463&view=rev
Author: brlcad
Date: 2010-01-29 12:56:10 +0000 (Fri, 29 Jan 2010)
Log Message:
-----------
horay for multitasking productivity during seminars. rename rt_mk_ell() and
rt_ell4() to static make_ellipse() and make_ellipse4() routines.
Modified Paths:
--------------
brlcad/trunk/src/librt/primitives/eto/eto.c
Modified: brlcad/trunk/src/librt/primitives/eto/eto.c
===================================================================
--- brlcad/trunk/src/librt/primitives/eto/eto.c 2010-01-29 00:01:19 UTC (rev
37462)
+++ brlcad/trunk/src/librt/primitives/eto/eto.c 2010-01-29 12:56:10 UTC (rev
37463)
@@ -724,6 +724,118 @@
/**
+ * M A K E _ E L L I P S E 4
+ *
+ * Approximate one fourth (1st quadrant) of an ellipse with line
+ * segments. The initial single segment is broken at the point
+ * farthest from the ellipse if that point is not aleady within the
+ * distance and normal error tolerances. The two resulting segments
+ * are passed recursively to this routine until each segment is within
+ * tolerance.
+ */
+HIDDEN int
+make_ellipse4(struct rt_pt_node *pts, fastf_t a, fastf_t b, fastf_t dtol,
fastf_t ntol)
+{
+ fastf_t dist, intr, m, theta0, theta1;
+ int n;
+ point_t mpt, p0, p1;
+ vect_t norm_line, norm_ell;
+ struct rt_pt_node *new, *rt_ptalloc(void);
+
+ /* endpoints of segment approximating ellipse */
+ VMOVE(p0, pts->p);
+ VMOVE(p1, pts->next->p);
+ /* slope and intercept of segment */
+ m = (p1[X] - p0[X]) / (p1[Y] - p0[Y]);
+ intr = p0[X] - m * p0[Y];
+ /* point on ellipse with max dist between ellipse and line */
+ mpt[Y] = a / sqrt(b*b / (m*m*a*a) + 1);
+ mpt[X] = b * sqrt(1 - mpt[Y] * mpt[Y] / (a*a));
+ mpt[Z] = 0;
+ /* max distance between that point and line */
+ dist = fabs(m * mpt[Y] - mpt[X] + intr) / sqrt(m * m + 1);
+ /* angles between normal of line and of ellipse at line endpoints */
+ VSET(norm_line, m, -1., 0.);
+ VSET(norm_ell, b * b * p0[Y], a * a * p0[X], 0.);
+ VUNITIZE(norm_line);
+ VUNITIZE(norm_ell);
+ theta0 = fabs(acos(VDOT(norm_line, norm_ell)));
+ VSET(norm_ell, b * b * p1[Y], a * a * p1[X], 0.);
+ VUNITIZE(norm_ell);
+ theta1 = fabs(acos(VDOT(norm_line, norm_ell)));
+ /* split segment at widest point if not within error tolerances */
+ if (dist > dtol || theta0 > ntol || theta1 > ntol) {
+ /* split segment */
+ new = rt_ptalloc();
+ VMOVE(new->p, mpt);
+ new->next = pts->next;
+ pts->next = new;
+ /* keep track of number of pts added */
+ n = 1;
+ /* recurse on first new segment */
+ n += make_ellipse4(pts, a, b, dtol, ntol);
+ /* recurse on second new segment */
+ n += make_ellipse4(new, a, b, dtol, ntol);
+ } else
+ n = 0;
+ return(n);
+}
+
+
+/**
+ * M A K E _ E L L I P S E
+ *
+ * Return pointer an array of points approximating an ellipse with
+ * semi-major and semi-minor axes a and b. The line segments fall
+ * within the normal and distance tolerances of ntol and dtol.
+ */
+HIDDEN point_t *
+make_ellipse(int *n, fastf_t a, fastf_t b, fastf_t dtol, fastf_t ntol)
+{
+ int i;
+ point_t *ell;
+ struct rt_pt_node *ell_quad, *oldpos, *pos, *rt_ptalloc(void);
+
+ ell_quad = rt_ptalloc();
+ VSET(ell_quad->p, b, 0., 0.);
+ ell_quad->next = rt_ptalloc();
+ VSET(ell_quad->next->p, 0., a, 0.);
+ ell_quad->next->next = NULL;
+
+ *n = make_ellipse4(ell_quad, a, b, dtol, ntol);
+ ell = (point_t *)bu_malloc(4*(*n+1)*sizeof(point_t), "make_ellipse pts");
+
+ /* put 1st quad of ellipse into an array */
+ pos = ell_quad;
+ for (i = 0; i < *n+2; i++) {
+ VMOVE(ell[i], pos->p);
+ oldpos = pos;
+ pos = pos->next;
+ bu_free((char *)oldpos, "rt_pt_node");
+ }
+ /* mirror 1st quad to make 2nd */
+ for (i = (*n+1)+1; i < 2*(*n+1); i++) {
+ VMOVE(ell[i], ell[(*n*2+2)-i]);
+ ell[i][X] = -ell[i][X];
+ }
+ /* mirror 2nd quad to make 3rd */
+ for (i = 2*(*n+1); i < 3*(*n+1); i++) {
+ VMOVE(ell[i], ell[i-(*n*2+2)]);
+ ell[i][X] = -ell[i][X];
+ ell[i][Y] = -ell[i][Y];
+ }
+ /* mirror 3rd quad to make 4th */
+ for (i = 3*(*n+1); i < 4*(*n+1); i++) {
+ VMOVE(ell[i], ell[i-(*n*2+2)]);
+ ell[i][X] = -ell[i][X];
+ ell[i][Y] = -ell[i][Y];
+ }
+ *n = 4*(*n + 1);
+ return(ell);
+}
+
+
+/**
* R T _ E T O _ P L O T
*
* The ETO has the following input fields:
@@ -743,7 +855,6 @@
int i, j, npts, nells;
point_t *ell; /* array of ellipse points */
point_t Ell_V; /* vertex of an ellipse */
- point_t *rt_mk_ell();
struct rt_eto_internal *tip;
vect_t Au, Bu, Nu, Cp, Dp, Xu;
@@ -797,7 +908,7 @@
ntol = bn_pi;
/* (x, y) coords for an ellipse */
- ell = rt_mk_ell(&npts, a, b, dtol, ntol);
+ ell = make_ellipse(&npts, a, b, dtol, ntol);
/* generate coordinate axes */
VMOVE(Nu, tip->eto_N);
VUNITIZE(Nu); /* z axis of coord sys */
@@ -870,120 +981,6 @@
/**
- * R T _ E L L 4
- *
- * Approximate one fourth (1st quadrant) of an ellipse with line
- * segments. The initial single segment is broken at the point
- * farthest from the ellipse if that point is not aleady within the
- * distance and normal error tolerances. The two resulting segments
- * are passed recursively to this routine until each segment is within
- * tolerance.
- */
-int
-rt_ell4(struct rt_pt_node *pts, fastf_t a, fastf_t b, fastf_t dtol, fastf_t
ntol)
-{
- fastf_t dist, intr, m, theta0, theta1;
- int n;
- point_t mpt, p0, p1;
- vect_t norm_line, norm_ell;
- struct rt_pt_node *new, *rt_ptalloc(void);
-
- /* endpoints of segment approximating ellipse */
- VMOVE(p0, pts->p);
- VMOVE(p1, pts->next->p);
- /* slope and intercept of segment */
- m = (p1[X] - p0[X]) / (p1[Y] - p0[Y]);
- intr = p0[X] - m * p0[Y];
- /* point on ellipse with max dist between ellipse and line */
- mpt[Y] = a / sqrt(b*b / (m*m*a*a) + 1);
- mpt[X] = b * sqrt(1 - mpt[Y] * mpt[Y] / (a*a));
- mpt[Z] = 0;
- /* max distance between that point and line */
- dist = fabs(m * mpt[Y] - mpt[X] + intr) / sqrt(m * m + 1);
- /* angles between normal of line and of ellipse at line endpoints */
- VSET(norm_line, m, -1., 0.);
- VSET(norm_ell, b * b * p0[Y], a * a * p0[X], 0.);
- VUNITIZE(norm_line);
- VUNITIZE(norm_ell);
- theta0 = fabs(acos(VDOT(norm_line, norm_ell)));
- VSET(norm_ell, b * b * p1[Y], a * a * p1[X], 0.);
- VUNITIZE(norm_ell);
- theta1 = fabs(acos(VDOT(norm_line, norm_ell)));
- /* split segment at widest point if not within error tolerances */
- if (dist > dtol || theta0 > ntol || theta1 > ntol) {
- /* split segment */
- new = rt_ptalloc();
- VMOVE(new->p, mpt);
- new->next = pts->next;
- pts->next = new;
- /* keep track of number of pts added */
- n = 1;
- /* recurse on first new segment */
- n += rt_ell4(pts, a, b, dtol, ntol);
- /* recurse on second new segment */
- n += rt_ell4(new, a, b, dtol, ntol);
- } else
- n = 0;
- return(n);
-}
-
-
-/**
- * R T _ M K _ E L L
- *
- * Return pointer an array of points approximating an ellipse with
- * semi-major and semi-minor axes a and b. The line segments fall
- * within the normal and distance tolerances of ntol and dtol.
- */
-point_t *
-rt_mk_ell(n, a, b, dtol, ntol)
- int *n;
- fastf_t a, b, dtol, ntol;
-{
- int i;
- point_t *ell;
- struct rt_pt_node *ell_quad, *oldpos, *pos, *rt_ptalloc(void);
-
- ell_quad = rt_ptalloc();
- VSET(ell_quad->p, b, 0., 0.);
- ell_quad->next = rt_ptalloc();
- VSET(ell_quad->next->p, 0., a, 0.);
- ell_quad->next->next = NULL;
-
- *n = rt_ell4(ell_quad, a, b, dtol, ntol);
- ell = (point_t *)bu_malloc(4*(*n+1)*sizeof(point_t), "rt_mk_ell pts");
-
- /* put 1st quad of ellipse into an array */
- pos = ell_quad;
- for (i = 0; i < *n+2; i++) {
- VMOVE(ell[i], pos->p);
- oldpos = pos;
- pos = pos->next;
- bu_free((char *)oldpos, "rt_pt_node");
- }
- /* mirror 1st quad to make 2nd */
- for (i = (*n+1)+1; i < 2*(*n+1); i++) {
- VMOVE(ell[i], ell[(*n*2+2)-i]);
- ell[i][X] = -ell[i][X];
- }
- /* mirror 2nd quad to make 3rd */
- for (i = 2*(*n+1); i < 3*(*n+1); i++) {
- VMOVE(ell[i], ell[i-(*n*2+2)]);
- ell[i][X] = -ell[i][X];
- ell[i][Y] = -ell[i][Y];
- }
- /* mirror 3rd quad to make 4th */
- for (i = 3*(*n+1); i < 4*(*n+1); i++) {
- VMOVE(ell[i], ell[i-(*n*2+2)]);
- ell[i][X] = -ell[i][X];
- ell[i][Y] = -ell[i][Y];
- }
- *n = 4*(*n + 1);
- return(ell);
-}
-
-
-/**
* R T _ E T O _ T E S S
*/
int
@@ -995,7 +992,6 @@
int i, j, nfaces, npts, nells;
point_t *ell = NULL; /* array of ellipse points */
point_t Ell_V; /* vertex of an ellipse */
- point_t *rt_mk_ell();
struct rt_eto_internal *tip;
struct shell *s;
struct vertex **verts = NULL;
@@ -1055,7 +1051,7 @@
ntol = bn_pi;
/* (x, y) coords for an ellipse */
- ell = rt_mk_ell(&npts, a, b, dtol, ntol);
+ ell = make_ellipse(&npts, a, b, dtol, ntol);
/* generate coordinate axes */
VMOVE(Nu, tip->eto_N);
VUNITIZE(Nu); /* z axis of coord sys */
@@ -1176,7 +1172,7 @@
nmg_region_a(*r, tol);
failure:
- bu_free((char *)ell, "rt_mk_ell pts");
+ bu_free((char *)ell, "make_ellipse pts");
bu_free((char *)eto_ells, "ells[]");
bu_free((char *)verts, "rt_eto_tess *verts[]");
bu_free((char *)faces, "rt_eto_tess *faces[]");
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