*
* This file contains the OpenGL side; computation of the polyhedra themselves
* is in "polyhedra.c".
- *
- * KNOWN BUG:
- *
- * The normals are wrong (inverted) on some faces of some of the duals
- * (e.g., "Rhombicosacron".) I can't figure out how to tell when the
- * normal should be pointing the other way.
*/
#include <X11/Intrinsic.h>
#define countof(x) (sizeof((x))/sizeof((*x)))
#include "xlockmore.h"
+#include <GL/glu.h>
+
+#include "glxfonts.h"
+#include "normals.h"
#include "polyhedra.h"
#include "colors.h"
#include "rotator.h"
\f
-typedef struct {
- double x,y,z;
-} XYZ;
-
-static void
-normalize (XYZ *p)
-{
- double length;
- length = sqrt (p->x * p->x +
- p->y * p->y +
- p->z * p->z);
- if (length != 0)
- {
- p->x /= length;
- p->y /= length;
- p->z /= length;
- }
- else
- {
- p->x = 0;
- p->y = 0;
- p->z = 0;
- }
-}
-
-/* Calculate the unit normal at p given two other points p1,p2 on the
- surface. The normal points in the direction of p1 crossproduct p2
+/* Calculate the normals at each vertex of a face, and use the sum to
+ decide which normal to assign to the entire face. This also solves
+ problems caused by nonconvex faces, in most (but not all) cases.
*/
-static XYZ
-calc_normal (XYZ p, XYZ p1, XYZ p2)
-{
- XYZ n, pa, pb;
- pa.x = p1.x - p.x;
- pa.y = p1.y - p.y;
- pa.z = p1.z - p.z;
- pb.x = p2.x - p.x;
- pb.y = p2.y - p.y;
- pb.z = p2.z - p.z;
- n.x = pa.y * pb.z - pa.z * pb.y;
- n.y = pa.z * pb.x - pa.x * pb.z;
- n.z = pa.x * pb.y - pa.y * pb.x;
- normalize (&n);
- return (n);
-}
-
-
static void
-do_normal(GLfloat x1, GLfloat y1, GLfloat z1,
- GLfloat x2, GLfloat y2, GLfloat z2,
- GLfloat x3, GLfloat y3, GLfloat z3)
+kludge_normal (int n, const int *indices, const point *points)
{
- XYZ p1, p2, p3, p;
- p1.x = x1; p1.y = y1; p1.z = z1;
- p2.x = x2; p2.y = y2; p2.z = z2;
- p3.x = x3; p3.y = y3; p3.z = z3;
+ XYZ normal = { 0, 0, 0 };
+ XYZ p;
+ int i;
- p = calc_normal (p1, p2, p3);
+ for (i = 0; i < n; ++i) {
+ int i1 = indices[i];
+ int i2 = indices[(i + 1) % n];
+ int i3 = indices[(i + 2) % n];
+ XYZ p1, p2, p3;
- glNormal3f (p.x, p.y, p.z);
+ p1.x = points[i1].x; p1.y = points[i1].y; p1.z = points[i1].z;
+ p2.x = points[i2].x; p2.y = points[i2].y; p2.z = points[i2].z;
+ p3.x = points[i3].x; p3.y = points[i3].y; p3.z = points[i3].z;
-#ifdef DEBUG
- /* Draw a line in the direction of this face's normal. */
- {
- glPushMatrix();
- glTranslatef ((x1 + x2 + x3) / 3,
- (y1 + y2 + y3) / 3,
- (z1 + z2 + z3) / 3);
- glScalef (0.5, 0.5, 0.5);
- glBegin(GL_LINE_LOOP);
- glVertex3f(0, 0, 0);
- glVertex3f(p.x, p.y, p.z);
- glEnd();
- glPopMatrix();
+ p = calc_normal (p1, p2, p3);
+ normal.x += p.x;
+ normal.y += p.y;
+ normal.z += p.z;
}
-#endif /* DEBUG */
-}
-static void
-load_font (ModeInfo *mi, char *res, XFontStruct **fontP, GLuint *dlistP)
-{
- const char *font = get_string_resource (res, "Font");
- XFontStruct *f;
- Font id;
- int first, last;
-
- if (!font) font = "-*-times-bold-r-normal-*-180-*";
-
- f = XLoadQueryFont(mi->dpy, font);
- if (!f) f = XLoadQueryFont(mi->dpy, "fixed");
-
- id = f->fid;
- first = f->min_char_or_byte2;
- last = f->max_char_or_byte2;
-
- clear_gl_error ();
- *dlistP = glGenLists ((GLuint) last+1);
- check_gl_error ("glGenLists");
- glXUseXFont(id, first, last-first+1, *dlistP + first);
- check_gl_error ("glXUseXFont");
-
- *fontP = f;
+ /*normalize(&normal);*/
+ if (normal.x == 0 && normal.y == 0 && normal.z == 0) {
+ glNormal3f (p.x, p.y, p.z);
+ } else {
+ glNormal3f (normal.x, normal.y, normal.z);
+ }
}
load_fonts (ModeInfo *mi)
{
polyhedra_configuration *bp = &bps[MI_SCREEN(mi)];
- load_font (mi, "titleFont", &bp->xfont1, &bp->font1_dlist);
- load_font (mi, "titleFont2", &bp->xfont2, &bp->font2_dlist);
- load_font (mi, "titleFont3", &bp->xfont3, &bp->font3_dlist);
+ load_font (mi->dpy, "titleFont", &bp->xfont1, &bp->font1_dlist);
+ load_font (mi->dpy, "titleFont2", &bp->xfont2, &bp->font2_dlist);
+ load_font (mi->dpy, "titleFont3", &bp->xfont3, &bp->font3_dlist);
}
-static int
-string_width (XFontStruct *f, const char *c)
-{
- int w = 0;
- while (*c)
- {
- int cc = *((unsigned char *) c);
- w += (f->per_char
- ? f->per_char[cc-f->min_char_or_byte2].rbearing
- : f->min_bounds.rbearing);
- c++;
- }
- return w;
-}
-
-static void
-print_title_string (ModeInfo *mi, const char *string,
- GLfloat x, GLfloat y,
- XFontStruct *font, int font_dlist)
-{
- GLfloat line_height = font->ascent + font->descent;
- GLfloat sub_shift = (line_height * 0.3);
- int cw = string_width (font, "m");
- int tabs = cw * 7;
-
- y -= line_height;
-
- glPushAttrib (GL_TRANSFORM_BIT | /* for matrix contents */
- GL_ENABLE_BIT); /* for various glDisable calls */
- glDisable (GL_LIGHTING);
- glDisable (GL_DEPTH_TEST);
- {
- glMatrixMode(GL_PROJECTION);
- glPushMatrix();
- {
- glLoadIdentity();
-
- glMatrixMode(GL_MODELVIEW);
- glPushMatrix();
- {
- int i;
- int x2 = x;
- Bool sub_p = False;
- glLoadIdentity();
-
- gluOrtho2D (0, mi->xgwa.width, 0, mi->xgwa.height);
-
- glColor3f (0.8, 0.8, 0);
-
- glRasterPos2f (x, y);
- for (i = 0; i < strlen(string); i++)
- {
- char c = string[i];
- if (c == '\n')
- {
- glRasterPos2f (x, (y -= line_height));
- x2 = x;
- }
- else if (c == '\t')
- {
- x2 -= x;
- x2 = ((x2 + tabs) / tabs) * tabs; /* tab to tab stop */
- x2 += x;
- glRasterPos2f (x2, y);
- }
- else if (c == '[' && (isdigit (string[i+1])))
- {
- sub_p = True;
- glRasterPos2f (x2, (y -= sub_shift));
- }
- else if (c == ']' && sub_p)
- {
- sub_p = False;
- glRasterPos2f (x2, (y += sub_shift));
- }
- else
- {
- glCallList (font_dlist + (int)(c));
- x2 += (font->per_char
- ? font->per_char[c - font->min_char_or_byte2].width
- : font->min_bounds.width);
- }
- }
- }
- glPopMatrix();
- }
- glMatrixMode(GL_PROJECTION);
- glPopMatrix();
- }
- glPopAttrib();
-
- glMatrixMode(GL_MODELVIEW);
-}
-
static void
startup_blurb (ModeInfo *mi)
{
polyhedra_configuration *bp = &bps[MI_SCREEN(mi)];
const char *s = "Computing polyhedra...";
- print_title_string (mi, s,
- mi->xgwa.width - (string_width (bp->xfont1, s) + 40),
- 10 + bp->xfont1->ascent + bp->xfont1->descent,
- bp->xfont1, bp->font1_dlist);
+ glColor3f (0.8, 0.8, 0);
+ print_gl_string (mi->dpy, bp->xfont1, bp->font1_dlist,
+ mi->xgwa.width, mi->xgwa.height,
+ mi->xgwa.width - (string_width (bp->xfont1, s) + 40),
+ mi->xgwa.height - 10,
+ s);
glFinish();
glXSwapBuffers(MI_DISPLAY(mi), MI_WINDOW(mi));
}
polyhedra_configuration *bp = &bps[MI_SCREEN(mi)];
if (event->xany.type == ButtonPress &&
- event->xbutton.button & Button1)
+ event->xbutton.button == Button1)
{
bp->button_down_p = True;
gltrackball_start (bp->trackball,
return True;
}
else if (event->xany.type == ButtonRelease &&
- event->xbutton.button & Button1)
+ event->xbutton.button == Button1)
{
bp->button_down_p = False;
return True;
}
+ else if (event->xany.type == ButtonPress &&
+ (event->xbutton.button == Button4 ||
+ event->xbutton.button == Button5))
+ {
+ gltrackball_mousewheel (bp->trackball, event->xbutton.button, 10,
+ !!event->xbutton.state);
+ return True;
+ }
else if (event->xany.type == KeyPress)
{
KeySym keysym;
else
f = bp->xfont3, fl = bp->font3_dlist; /* tiny font */
- print_title_string (mi, label,
- 10, mi->xgwa.height - 10,
- f, fl);
+ glColor3f (0.8, 0.8, 0);
+ print_gl_string (mi->dpy, f, fl,
+ mi->xgwa.width, mi->xgwa.height,
+ 10, mi->xgwa.height - 10,
+ label);
}
}
glEndList ();
}
+static void
+tess_error (GLenum errorCode)
+{
+ fprintf (stderr, "%s: tesselation error: %s\n",
+ progname, gluErrorString(errorCode));
+ exit (0);
+}
+
static void
new_polyhedron (ModeInfo *mi)
{
static GLfloat bcolor[4] = {0.0, 0.0, 0.0, 1.0};
int i;
+ /* Use the GLU polygon tesselator so that nonconvex faces are displayed
+ correctly (e.g., for the "pentagrammic concave deltohedron").
+ */
+ GLUtesselator *tobj = gluNewTess();
+ gluTessCallback (tobj, GLU_TESS_BEGIN, (void (*) (void)) &glBegin);
+ gluTessCallback (tobj, GLU_TESS_END, (void (*) (void)) &glEnd);
+ gluTessCallback (tobj, GLU_TESS_VERTEX, (void (*) (void)) &glVertex3dv);
+ gluTessCallback (tobj, GLU_TESS_ERROR, (void (*) (void)) &tess_error);
+
mi->polygon_count = 0;
bp->ncolors = 128;
glMaterialfv (GL_FRONT_AND_BACK, GL_AMBIENT_AND_DIFFUSE, bcolor);
}
- do_normal (p->points[f->points[0]].x,
- p->points[f->points[0]].y,
- p->points[f->points[0]].z,
- p->points[f->points[1]].x,
- p->points[f->points[1]].y,
- p->points[f->points[1]].z,
- p->points[f->points[2]].x,
- p->points[f->points[2]].y,
- p->points[f->points[2]].z);
-
- glBegin (wire ? GL_LINE_LOOP :
- f->npoints == 3 ? GL_TRIANGLES :
- f->npoints == 4 ? GL_QUADS :
- GL_POLYGON);
+ kludge_normal (f->npoints, f->points, p->points);
+
+ gluTessBeginPolygon (tobj, 0);
+ gluTessBeginContour (tobj);
for (j = 0; j < f->npoints; j++)
{
point *pp = &p->points[f->points[j]];
- glVertex3f (pp->x, pp->y, pp->z);
+ gluTessVertex (tobj, &pp->x, &pp->x);
}
- glEnd();
+ gluTessEndContour (tobj);
+ gluTessEndPolygon (tobj);
}
glEndList ();
mi->polygon_count += p->nfaces;
+ gluDeleteTess (tobj);
}
glEnable(GL_DEPTH_TEST);
/* glEnable(GL_CULL_FACE); */
+ /* We need two-sided lighting for polyhedra where both sides of
+ a face are simultaneously visible (e.g., the "X-hemi-Y-hedrons".)
+ */
+ glLightModeli(GL_LIGHT_MODEL_TWO_SIDE, GL_TRUE);
+
glLightfv(GL_LIGHT0, GL_POSITION, pos);
glLightfv(GL_LIGHT0, GL_AMBIENT, amb);
glLightfv(GL_LIGHT0, GL_DIFFUSE, dif);