/* -*- Mode: C; tab-width: 4 -*- */
/* moebius --- Moebius Strip II, an Escher-like GL scene with ants. */
#if !defined( lint ) && !defined( SABER )
static const char sccsid[] = "@(#)moebius.c 4.08 97/01/04 xlockmore";
#endif
#undef DEBUG_LISTS
/*-
* Permission to use, copy, modify, and distribute this software and its
* documentation for any purpose and without fee is hereby granted,
* provided that the above copyright notice appear in all copies and that
* both that copyright notice and this permission notice appear in
* supporting documentation.
*
* This file is provided AS IS with no warranties of any kind. The author
* shall have no liability with respect to the infringement of copyrights,
* trade secrets or any patents by this file or any part thereof. In no
* event will the author be liable for any lost revenue or profits or
* other special, indirect and consequential damages.
*
* The RotateAroundU() routine was adapted from the book
* "Computer Graphics Principles and Practice
* Foley - vanDam - Feiner - Hughes
* Second Edition" Pag. 227, exercise 5.15.
*
* This mode shows some interesting scenes that are impossible OR very
* wierd to build in the real universe. Much of the scenes are inspirated
* on Mauritz Cornelis Escher's works which derivated the mode's name.
* M.C. Escher (1898-1972) was a dutch artist and many people prefer to
* say he was a mathematician.
*
* Thanks goes to Brian Paul for making it possible and inexpensive to use
* OpenGL at home.
*
* Since I'm not a native English speaker, my apologies for any grammatical
* mistake.
*
* My e-mail address is
* m-vianna@usa.net
*
* Marcelo F. Vianna (Jun-01-1997)
*
* Revision History:
* 01-Jan-98: Mode separated from escher and renamed
* 08-Jun-97: New scene implemented: "Impossible Cage" based in a M.C. Escher's
* painting with the same name (quite similar). The first GL mode
* to use texture mapping.
* The "Impossible Cage" scene doesn't use DEPTH BUFFER, the
* wood planks are drawn consistently using GL_CULL_FACE, and
* the painter's algorithm is used to sort the planks.
* Marcelo F. Vianna.
* 07-Jun-97: Speed ups in Moebius Strip using GL_CULL_FACE.
* Marcelo F. Vianna.
* 03-Jun-97: Initial Release (Only one scene: "Moebius Strip")
* The Moebius Strip scene was inspirated in a M.C. Escher's
* painting named Moebius Strip II in wich ants walk across a
* Moebius Strip path, sometimes meeting each other and sometimes
* being in "opposite faces" (note that the moebius strip has
* only one face and one edge).
* Marcelo F. Vianna.
*
*/
/*-
* Texture mapping is only available on RGBA contexts, Mono and color index
* visuals DO NOT support texture mapping in OpenGL.
*
* BUT Mesa do implements RGBA contexts in pseudo color visuals, so texture
* mapping shuld work on PseudoColor, DirectColor, TrueColor using Mesa. Mono
* is not officially supported for both OpenGL and Mesa, but seems to not crash
* Mesa.
*
* In real OpenGL, PseudoColor DO NOT support texture map (as far as I know).
*/
#include <X11/Intrinsic.h>
#ifdef STANDALONE
#define PROGCLASS "Moebius"
#define HACK_INIT init_moebius
#define HACK_DRAW draw_moebius
#define moebius_opts xlockmore_opts
#define DEFAULTS "*delay: 1000 \n"
#include "xlockmore.h" /* from the xscreensaver distribution */
#else /* !STANDALONE */
#include "xlock.h" /* from the xlockmore distribution */
#include "vis.h"
#endif /* !STANDALONE */
#ifdef MODE_moebius
#include <GL/glu.h>
#include "e_textures.h"
#define DEF_SOLIDMOEBIUS "False"
#define DEF_NOANTS "False"
static int solidmoebius;
static int noants;
static XrmOptionDescRec opts[] =
{
{"-solidmoebius", ".moebius.solidmoebius", XrmoptionNoArg, (caddr_t) "on"},
{"+solidmoebius", ".moebius.solidmoebius", XrmoptionNoArg, (caddr_t) "off"},
{"-noants", ".moebius.noants", XrmoptionNoArg, (caddr_t) "on"},
{"+noants", ".moebius.noants", XrmoptionNoArg, (caddr_t) "off"}
};
static argtype vars[] =
{
{(caddr_t *) & solidmoebius, "solidmoebius", "Solidmoebius", DEF_SOLIDMOEBIUS, t_Bool},
{(caddr_t *) & noants, "noants", "Noants", DEF_NOANTS, t_Bool}
};
static OptionStruct desc[] =
{
{"-/+solidmoebius", "select between a SOLID or a NET Moebius Strip"},
{"-/+noants", "turn on/off walking ants"}
};
ModeSpecOpt moebius_opts =
{sizeof opts / sizeof opts[0], opts, sizeof vars / sizeof vars[0], vars, desc};
#ifdef USE_MODULES
ModStruct moebius_description =
{"moebius", "init_moebius", "draw_moebius", "release_moebius",
"draw_moebius", "change_moebius", NULL, &moebius_opts,
1000, 1, 1, 1, 4, 1.0, "",
"Shows Moebius Strip II, an Escher-like GL scene with ants", 0, NULL};
#endif
#define Scale4Window 0.3
#define Scale4Iconic 0.4
#define sqr(A) ((A)*(A))
#ifndef Pi
#define Pi M_PI
#endif
/*************************************************************************/
typedef struct {
GLint WindH, WindW;
GLfloat step;
GLfloat ant_position;
int AreObjectsDefined[2];
GLXContext *glx_context;
} moebiusstruct;
static float front_shininess[] =
{60.0};
static float front_specular[] =
{0.7, 0.7, 0.7, 1.0};
static float ambient[] =
{0.0, 0.0, 0.0, 1.0};
static float diffuse[] =
{1.0, 1.0, 1.0, 1.0};
static float position0[] =
{1.0, 1.0, 1.0, 0.0};
static float position1[] =
{-1.0, -1.0, 1.0, 0.0};
static float lmodel_ambient[] =
{0.5, 0.5, 0.5, 1.0};
static float lmodel_twoside[] =
{GL_TRUE};
static float MaterialRed[] =
{0.7, 0.0, 0.0, 1.0};
static float MaterialGreen[] =
{0.1, 0.5, 0.2, 1.0};
static float MaterialBlue[] =
{0.0, 0.0, 0.7, 1.0};
static float MaterialCyan[] =
{0.2, 0.5, 0.7, 1.0};
static float MaterialYellow[] =
{0.7, 0.7, 0.0, 1.0};
static float MaterialMagenta[] =
{0.6, 0.2, 0.5, 1.0};
static float MaterialWhite[] =
{0.7, 0.7, 0.7, 1.0};
static float MaterialGray[] =
{0.2, 0.2, 0.2, 1.0};
static float MaterialGray5[] =
{0.5, 0.5, 0.5, 1.0};
static float MaterialGray6[] =
{0.6, 0.6, 0.6, 1.0};
static float MaterialGray8[] =
{0.8, 0.8, 0.8, 1.0};
static moebiusstruct *moebius = NULL;
static GLuint objects;
#define NUM_SCENES 2
#define ObjMoebiusStrip 0
#define ObjAntBody 1
static void
mySphere(float radius)
{
GLUquadricObj *quadObj;
quadObj = gluNewQuadric();
gluQuadricDrawStyle(quadObj, (GLenum) GLU_FILL);
gluSphere(quadObj, radius, 16, 16);
gluDeleteQuadric(quadObj);
}
static void
myCone(float radius)
{
GLUquadricObj *quadObj;
quadObj = gluNewQuadric();
gluQuadricDrawStyle(quadObj, (GLenum) GLU_FILL);
gluCylinder(quadObj, radius, 0, radius * 3, 8, 1);
gluDeleteQuadric(quadObj);
}
static void
draw_moebius_ant(moebiusstruct * mp, float *Material, int mono)
{
static float ant_step = 0;
float cos1 = cos(ant_step);
float cos2 = cos(ant_step + 2 * Pi / 3);
float cos3 = cos(ant_step + 4 * Pi / 3);
float sin1 = sin(ant_step);
float sin2 = sin(ant_step + 2 * Pi / 3);
float sin3 = sin(ant_step + 4 * Pi / 3);
if (mono)
glMaterialfv(GL_FRONT_AND_BACK, GL_DIFFUSE, MaterialGray5);
else
glMaterialfv(GL_FRONT_AND_BACK, GL_DIFFUSE, Material);
if (!mp->AreObjectsDefined[ObjAntBody]) {
glNewList(objects + ObjAntBody, GL_COMPILE_AND_EXECUTE);
glEnable(GL_CULL_FACE);
glPushMatrix();
glScalef(1, 1.3, 1);
mySphere(0.18);
glScalef(1, 1 / 1.3, 1);
glTranslatef(0.00, 0.30, 0.00);
mySphere(0.2);
glTranslatef(-0.05, 0.17, 0.05);
glRotatef(-90, 1, 0, 0);
glRotatef(-25, 0, 1, 0);
myCone(0.05);
glTranslatef(0.00, 0.10, 0.00);
myCone(0.05);
glRotatef(25, 0, 1, 0);
glRotatef(90, 1, 0, 0);
glScalef(1, 1.3, 1);
glTranslatef(0.15, -0.65, 0.05);
mySphere(0.25);
glScalef(1, 1 / 1.3, 1);
glPopMatrix();
glDisable(GL_CULL_FACE);
glEndList();
mp->AreObjectsDefined[ObjAntBody] = 1;
#ifdef DEBUG_LISTS
(void) printf("Ant drawn SLOWLY\n");
#endif
} else {
glCallList(objects + ObjAntBody);
#ifdef DEBUG_LISTS
(void) printf("Ant drawn quickly\n");
#endif
}
glDisable(GL_LIGHTING);
/* ANTENNAS */
glBegin(GL_LINES);
if (mono)
glColor3fv(MaterialGray5);
else
glColor3fv(Material);
glVertex3f(0.00, 0.30, 0.00);
glColor3fv(MaterialGray);
glVertex3f(0.40, 0.70, 0.40);
if (mono)
glColor3fv(MaterialGray5);
else
glColor3fv(Material);
glVertex3f(0.00, 0.30, 0.00);
glColor3fv(MaterialGray);
glVertex3f(0.40, 0.70, -0.40);
glEnd();
glBegin(GL_POINTS);
if (mono)
glColor3fv(MaterialGray6);
else
glColor3fv(MaterialRed);
glVertex3f(0.40, 0.70, 0.40);
glVertex3f(0.40, 0.70, -0.40);
glEnd();
/* LEFT-FRONT ARM */
glBegin(GL_LINE_STRIP);
if (mono)
glColor3fv(MaterialGray5);
else
glColor3fv(Material);
glVertex3f(0.00, 0.05, 0.18);
glVertex3f(0.35 + 0.05 * cos1, 0.15, 0.25);
glColor3fv(MaterialGray);
glVertex3f(-0.20 + 0.05 * cos1, 0.25 + 0.1 * sin1, 0.45);
glEnd();
/* LEFT-CENTER ARM */
glBegin(GL_LINE_STRIP);
if (mono)
glColor3fv(MaterialGray5);
else
glColor3fv(Material);
glVertex3f(0.00, 0.00, 0.18);
glVertex3f(0.35 + 0.05 * cos2, 0.00, 0.25);
glColor3fv(MaterialGray);
glVertex3f(-0.20 + 0.05 * cos2, 0.00 + 0.1 * sin2, 0.45);
glEnd();
/* LEFT-BACK ARM */
glBegin(GL_LINE_STRIP);
if (mono)
glColor3fv(MaterialGray5);
else
glColor3fv(Material);
glVertex3f(0.00, -0.05, 0.18);
glVertex3f(0.35 + 0.05 * cos3, -0.15, 0.25);
glColor3fv(MaterialGray);
glVertex3f(-0.20 + 0.05 * cos3, -0.25 + 0.1 * sin3, 0.45);
glEnd();
/* RIGHT-FRONT ARM */
glBegin(GL_LINE_STRIP);
if (mono)
glColor3fv(MaterialGray5);
else
glColor3fv(Material);
glVertex3f(0.00, 0.05, -0.18);
glVertex3f(0.35 - 0.05 * sin1, 0.15, -0.25);
glColor3fv(MaterialGray);
glVertex3f(-0.20 - 0.05 * sin1, 0.25 + 0.1 * cos1, -0.45);
glEnd();
/* RIGHT-CENTER ARM */
glBegin(GL_LINE_STRIP);
if (mono)
glColor3fv(MaterialGray5);
else
glColor3fv(Material);
glVertex3f(0.00, 0.00, -0.18);
glVertex3f(0.35 - 0.05 * sin2, 0.00, -0.25);
glColor3fv(MaterialGray);
glVertex3f(-0.20 - 0.05 * sin2, 0.00 + 0.1 * cos2, -0.45);
glEnd();
/* RIGHT-BACK ARM */
glBegin(GL_LINE_STRIP);
if (mono)
glColor3fv(MaterialGray5);
else
glColor3fv(Material);
glVertex3f(0.00, -0.05, -0.18);
glVertex3f(0.35 - 0.05 * sin3, -0.15, -0.25);
glColor3fv(MaterialGray);
glVertex3f(-0.20 - 0.05 * sin3, -0.25 + 0.1 * cos3, -0.45);
glEnd();
glBegin(GL_POINTS);
if (mono)
glColor3fv(MaterialGray8);
else
glColor3fv(MaterialMagenta);
glVertex3f(-0.20 + 0.05 * cos1, 0.25 + 0.1 * sin1, 0.45);
glVertex3f(-0.20 + 0.05 * cos2, 0.00 + 0.1 * sin2, 0.45);
glVertex3f(-0.20 + 0.05 * cos3, -0.25 + 0.1 * sin3, 0.45);
glVertex3f(-0.20 - 0.05 * sin1, 0.25 + 0.1 * cos1, -0.45);
glVertex3f(-0.20 - 0.05 * sin2, 0.00 + 0.1 * cos2, -0.45);
glVertex3f(-0.20 - 0.05 * sin3, -0.25 + 0.1 * cos3, -0.45);
glEnd();
glEnable(GL_LIGHTING);
ant_step += 0.3;
}
static void
RotateAaroundU(float Ax, float Ay, float Az,
float Ux, float Uy, float Uz,
float *Cx, float *Cy, float *Cz,
float Theta)
{
float cosO = cos(Theta);
float sinO = sin(Theta);
float one_cosO = 1 - cosO;
float Ux2 = sqr(Ux);
float Uy2 = sqr(Uy);
float Uz2 = sqr(Uz);
float UxUy = Ux * Uy;
float UxUz = Ux * Uz;
float UyUz = Uy * Uz;
*Cx = (Ux2 + cosO * (1 - Ux2)) * Ax + (UxUy * one_cosO - Uz * sinO) * Ay + (UxUz * one_cosO + Uy * sinO) * Az;
*Cy = (UxUy * one_cosO + Uz * sinO) * Ax + (Uy2 + cosO * (1 - Uy2)) * Ay + (UyUz * one_cosO - Ux * sinO) * Az;
*Cz = (UxUz * one_cosO - Uy * sinO) * Ax + (UyUz * one_cosO + Ux * sinO) * Ay + (Uz2 + cosO * (1 - Uz2)) * Az;
}
#define MoebiusDivisions 40
#define MoebiusTransversals 4
static void
draw_moebius_strip(ModeInfo * mi)
{
GLfloat Phi, Theta;
GLfloat cPhi, sPhi;
moebiusstruct *mp = &moebius[MI_SCREEN(mi)];
int i, j;
int mono = MI_IS_MONO(mi);
float Cx, Cy, Cz;
if (!mp->AreObjectsDefined[ObjMoebiusStrip]) {
glNewList(objects + ObjMoebiusStrip, GL_COMPILE_AND_EXECUTE);
if (solidmoebius) {
glBegin(GL_QUAD_STRIP);
Phi = 0;
i = 0;
while (i < (MoebiusDivisions * 2 + 1)) {
Theta = Phi / 2;
cPhi = cos(Phi);
sPhi = sin(Phi);
i++;
if (mono)
glMaterialfv(GL_FRONT_AND_BACK, GL_DIFFUSE, MaterialWhite);
else if (i % 2)
glMaterialfv(GL_FRONT_AND_BACK, GL_DIFFUSE, MaterialRed);
else
glMaterialfv(GL_FRONT_AND_BACK, GL_DIFFUSE, MaterialGray);
RotateAaroundU(cPhi, sPhi, 0, -sPhi, cPhi, 0, &Cx, &Cy, &Cz, Theta);
glNormal3f(Cx, Cy, Cz);
RotateAaroundU(0, 0, 1, -sPhi, cPhi, 0, &Cx, &Cy, &Cz, Theta);
glVertex3f(cPhi * 3 + Cx, sPhi * 3 + Cy, +Cz);
glVertex3f(cPhi * 3 - Cx, sPhi * 3 - Cy, -Cz);
Phi += Pi / MoebiusDivisions;
}
glEnd();
} else {
for (j = -MoebiusTransversals; j < MoebiusTransversals; j++) {
glPolygonMode(GL_FRONT_AND_BACK, GL_LINE);
glBegin(GL_QUAD_STRIP);
Phi = 0;
i = 0;
while (i < (MoebiusDivisions * 2 + 1)) {
Theta = Phi / 2;
cPhi = cos(Phi);
sPhi = sin(Phi);
RotateAaroundU(cPhi, sPhi, 0, -sPhi, cPhi, 0, &Cx, &Cy, &Cz, Theta);
glNormal3f(Cx, Cy, Cz);
RotateAaroundU(0, 0, 1, -sPhi, cPhi, 0, &Cx, &Cy, &Cz, Theta);
j++;
if (j == MoebiusTransversals || mono)
glMaterialfv(GL_FRONT_AND_BACK, GL_DIFFUSE, MaterialWhite);
else if (i % 2)
glMaterialfv(GL_FRONT_AND_BACK, GL_DIFFUSE, MaterialRed);
else
glMaterialfv(GL_FRONT_AND_BACK, GL_DIFFUSE, MaterialGray);
glVertex3f(cPhi * 3 + Cx / MoebiusTransversals * j, sPhi * 3 + Cy / MoebiusTransversals * j, +Cz / MoebiusTransversals * j);
j--;
if (j == -MoebiusTransversals || mono)
glMaterialfv(GL_FRONT_AND_BACK, GL_DIFFUSE, MaterialWhite);
else if (i % 2)
glMaterialfv(GL_FRONT_AND_BACK, GL_DIFFUSE, MaterialRed);
else
glMaterialfv(GL_FRONT_AND_BACK, GL_DIFFUSE, MaterialGray);
glVertex3f(cPhi * 3 + Cx / MoebiusTransversals * j, sPhi * 3 + Cy / MoebiusTransversals * j, +Cz / MoebiusTransversals * j);
Phi += Pi / MoebiusDivisions;
i++;
}
glEnd();
}
glPolygonMode(GL_FRONT_AND_BACK, GL_FILL);
}
glEndList();
mp->AreObjectsDefined[ObjMoebiusStrip] = 1;
#ifdef DEBUG_LISTS
(void) printf("Strip drawn SLOWLY\n");
#endif
} else {
glCallList(objects + ObjMoebiusStrip);
#ifdef DEBUG_LISTS
(void) printf("Strip drawn quickly\n");
#endif
}
if (!noants) {
/* DRAW BLUE ANT */
glPushMatrix();
glRotatef(mp->ant_position + 180, 0, 0, 1);
glTranslatef(3, 0, 0);
glRotatef(mp->ant_position / 2 + 90, 0, 1, 0);
glTranslatef(0.28, 0, -0.45);
draw_moebius_ant(mp, MaterialYellow, mono);
glPopMatrix();
/* DRAW YELLOW ANT */
glPushMatrix();
glRotatef(mp->ant_position, 0, 0, 1);
glTranslatef(3, 0, 0);
glRotatef(mp->ant_position / 2, 0, 1, 0);
glTranslatef(0.28, 0, -0.45);
draw_moebius_ant(mp, MaterialBlue, mono);
glPopMatrix();
/* DRAW GREEN ANT */
glPushMatrix();
glRotatef(-mp->ant_position, 0, 0, 1);
glTranslatef(3, 0, 0);
glRotatef(-mp->ant_position / 2, 0, 1, 0);
glTranslatef(0.28, 0, 0.45);
glRotatef(180, 1, 0, 0);
draw_moebius_ant(mp, MaterialGreen, mono);
glPopMatrix();
/* DRAW CYAN ANT */
glPushMatrix();
glRotatef(-mp->ant_position + 180, 0, 0, 1);
glTranslatef(3, 0, 0);
glRotatef(-mp->ant_position / 2 + 90, 0, 1, 0);
glTranslatef(0.28, 0, 0.45);
glRotatef(180, 1, 0, 0);
draw_moebius_ant(mp, MaterialCyan, mono);
glPopMatrix();
}
mp->ant_position += 1;
}
#undef MoebiusDivisions
#undef MoebiusTransversals
static void
reshape(ModeInfo * mi, int width, int height)
{
moebiusstruct *mp = &moebius[MI_SCREEN(mi)];
glViewport(0, 0, mp->WindW = (GLint) width, mp->WindH = (GLint) height);
glMatrixMode(GL_PROJECTION);
glLoadIdentity();
glFrustum(-1.0, 1.0, -1.0, 1.0, 5.0, 15.0);
glMatrixMode(GL_MODELVIEW);
if (width >= 1024) {
glLineWidth(3);
glPointSize(3);
} else if (width >= 512) {
glLineWidth(2);
glPointSize(2);
} else {
glLineWidth(1);
glPointSize(1);
}
mp->AreObjectsDefined[ObjMoebiusStrip] = 0;
mp->AreObjectsDefined[ObjAntBody] = 0;
}
static void
pinit(void)
{
glClearDepth(1.0);
glClearColor(0.0, 0.0, 0.0, 1.0);
glLightfv(GL_LIGHT0, GL_AMBIENT, ambient);
glLightfv(GL_LIGHT0, GL_DIFFUSE, diffuse);
glLightfv(GL_LIGHT0, GL_POSITION, position0);
glLightfv(GL_LIGHT1, GL_AMBIENT, ambient);
glLightfv(GL_LIGHT1, GL_DIFFUSE, diffuse);
glLightfv(GL_LIGHT1, GL_POSITION, position1);
glLightModelfv(GL_LIGHT_MODEL_AMBIENT, lmodel_ambient);
glLightModelfv(GL_LIGHT_MODEL_TWO_SIDE, lmodel_twoside);
glEnable(GL_LIGHTING);
glEnable(GL_LIGHT0);
glEnable(GL_LIGHT1);
glEnable(GL_NORMALIZE);
glFrontFace(GL_CCW);
glCullFace(GL_BACK);
/* moebius */
glShadeModel(GL_SMOOTH);
glEnable(GL_DEPTH_TEST);
glDisable(GL_TEXTURE_2D);
glDisable(GL_CULL_FACE);
glPixelStorei(GL_UNPACK_ALIGNMENT, 1);
gluBuild2DMipmaps(GL_TEXTURE_2D, 3, WoodTextureWidth, WoodTextureHeight,
GL_RGB, GL_UNSIGNED_BYTE, WoodTextureData);
glTexEnvf(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_MODULATE);
glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_REPEAT);
glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_REPEAT);
glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
glMaterialfv(GL_FRONT_AND_BACK, GL_SHININESS, front_shininess);
glMaterialfv(GL_FRONT_AND_BACK, GL_SPECULAR, front_specular);
}
void
init_moebius(ModeInfo * mi)
{
int screen = MI_SCREEN(mi);
moebiusstruct *mp;
if (moebius == NULL) {
if ((moebius = (moebiusstruct *) calloc(MI_NUM_SCREENS(mi),
sizeof (moebiusstruct))) == NULL)
return;
}
mp = &moebius[screen];
mp->step = NRAND(90);
mp->ant_position = NRAND(90);
if ((mp->glx_context = init_GL(mi)) != NULL) {
reshape(mi, MI_WIDTH(mi), MI_HEIGHT(mi));
glDrawBuffer(GL_BACK);
if (!glIsList(objects))
objects = glGenLists(3);
pinit();
} else {
MI_CLEARWINDOW(mi);
}
}
void
draw_moebius(ModeInfo * mi)
{
moebiusstruct *mp = &moebius[MI_SCREEN(mi)];
Display *display = MI_DISPLAY(mi);
Window window = MI_WINDOW(mi);
MI_IS_DRAWN(mi) = True;
if (!mp->glx_context)
return;
glXMakeCurrent(display, window, *(mp->glx_context));
glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
glPushMatrix();
glTranslatef(0.0, 0.0, -10.0);
if (!MI_IS_ICONIC(mi)) {
glScalef(Scale4Window * mp->WindH / mp->WindW, Scale4Window, Scale4Window);
} else {
glScalef(Scale4Iconic * mp->WindH / mp->WindW, Scale4Iconic, Scale4Iconic);
}
/* 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();
glFlush();
glXSwapBuffers(display, window);
mp->step += 0.025;
}
void
change_moebius(ModeInfo * mi)
{
moebiusstruct *mp = &moebius[MI_SCREEN(mi)];
if (!mp->glx_context)
return;
glXMakeCurrent(MI_DISPLAY(mi), MI_WINDOW(mi), *(mp->glx_context));
pinit();
}
void
release_moebius(ModeInfo * mi)
{
if (moebius != NULL) {
(void) free((void *) moebius);
moebius = NULL;
}
if (glIsList(objects)) {
glDeleteLists(objects, 3);
}
FreeAllGL(mi);
}
#endif
