/* -*- Mode: C; tab-width: 4 -*- */ /* stairs --- Infinite Stairs, and Escher-like scene. */ #if !defined( lint ) && !defined( SABER ) static const char sccsid[] = "@(#)stairs.c 5.01 2001/03/01 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. * * This mode shows some interesting scenes that are impossible OR very * weird to build in the real universe. Much of the scenes are inspirated * on Mauritz Cornelis stairs'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 * mistakes. * * My e-mail address is * mfvianna@centroin.com.br * * Marcelo F. Vianna (Jun-01-1997) * * Revision History: * 01-Mar-2001: Added FPS stuff - Eric Lassauge <lassauge AT users.sourceforge.net> * 01-Nov-2000: Allocation checks * 07-Jan-1998: This would be a scene for the escher mode, but now escher mode * was splitted in different modes for each scene. This is the * initial release and is not working yet. * 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). */ #ifdef VMS #include <X11/Intrinsic.h> #endif #ifdef STANDALONE #define MODE_stairs #define PROGCLASS "stairs" #define HACK_INIT init_stairs #define HACK_DRAW draw_stairs #define stairs_opts xlockmore_opts #define DEFAULTS "*delay: 200000 \n" #include "xlockmore.h" /* from the xscreensaver distribution */ #else /* !STANDALONE */ #include "xlock.h" /* from the xlockmore distribution */ #include "visgl.h" #endif /* !STANDALONE */ #ifdef MODE_stairs #include <GL/glu.h> #include "e_textures.h" ModeSpecOpt stairs_opts = {0, (XrmOptionDescRec *) NULL, 0, (argtype *) NULL, (OptionStruct *) NULL}; #ifdef USE_MODULES ModStruct stairs_description = {"stairs", "init_stairs", "draw_stairs", "release_stairs", "draw_stairs", "change_stairs", (char *) NULL, &stairs_opts, 1000, 1, 1, 1, 4, 1.0, "", "Shows Infinite Stairs, an Escher-like scene", 0, NULL}; #endif #define Scale4Window 0.3 #define Scale4Iconic 0.4 #define sqr(A) ((A)*(A)) #ifndef Pi #define Pi M_PI #endif #if 0 #define ObjSphere 0 #define MaxObj 1 #endif /*************************************************************************/ typedef struct { GLint WindH, WindW; GLfloat step; Bool direction; #if 0 Bool AreObjectsDefined[MaxObj]; #endif int sphere_position; GLXContext *glx_context; } stairsstruct; 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}; #if 0 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 MaterialMagenta[] = {0.6, 0.2, 0.5, 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}; #endif static float MaterialYellow[] = {0.7, 0.7, 0.0, 1.0}; static float MaterialWhite[] = {0.7, 0.7, 0.7, 1.0}; static float positions[] = { -2.5, 4.0, 0.0, /* First one is FUDGED :) */ -3.0, 3.25, 1.0, -3.0, 4.4, 1.5, -3.0, 3.05, 2.0, -3.0, 4.2, 2.5, -3.0, 2.85, 3.0, -2.5, 4.0, 3.0, -2.0, 2.75, 3.0, -1.5, 3.9, 3.0, -1.0, 2.65, 3.0, -0.5, 3.8, 3.0, 0.0, 2.55, 3.0, 0.5, 3.7, 3.0, 1.0, 2.45, 3.0, 1.5, 3.6, 3.0, 2.0, 2.35, 3.0, 2.0, 3.5, 2.5, 2.0, 2.25, 2.0, 2.0, 3.4, 1.5, 2.0, 2.15, 1.0, 2.0, 3.3, 0.5, 2.0, 2.05, 0.0, 2.0, 3.2, -0.5, 2.0, 1.95, -1.0, 2.0, 3.1, -1.5, 2.0, 1.85, -2.0, 1.5, 2.9, -2.0, 1.0, 1.65, -2.0, 0.5, 2.7, -2.0, 0.0, 1.55, -2.0, -0.5, 2.5, -2.0, -1.0, 1.45, -2.0, }; #define NPOSITIONS ((sizeof positions) / (sizeof positions[0])) static stairsstruct *stairs = (stairsstruct *) NULL; #if 0 static GLuint objects = 0; #endif #define PlankWidth 3.0 #define PlankHeight 0.35 #define PlankThickness 0.15 static Bool mySphere(float radius) { GLUquadricObj *quadObj; if ((quadObj = gluNewQuadric()) == 0) return False; gluQuadricDrawStyle(quadObj, (GLenum) GLU_FILL); gluSphere(quadObj, radius, 16, 16); gluDeleteQuadric(quadObj); return True; } static void draw_block(GLfloat width, GLfloat height, GLfloat thickness) { glBegin(GL_QUADS); glNormal3f(0, 0, 1); glTexCoord2f(0, 0); glVertex3f(-width, -height, thickness); glTexCoord2f(1, 0); glVertex3f(width, -height, thickness); glTexCoord2f(1, 1); glVertex3f(width, height, thickness); glTexCoord2f(0, 1); glVertex3f(-width, height, thickness); glNormal3f(0, 0, -1); glTexCoord2f(0, 0); glVertex3f(-width, height, -thickness); glTexCoord2f(1, 0); glVertex3f(width, height, -thickness); glTexCoord2f(1, 1); glVertex3f(width, -height, -thickness); glTexCoord2f(0, 1); glVertex3f(-width, -height, -thickness); glNormal3f(0, 1, 0); glTexCoord2f(0, 0); glVertex3f(-width, height, thickness); glTexCoord2f(1, 0); glVertex3f(width, height, thickness); glTexCoord2f(1, 1); glVertex3f(width, height, -thickness); glTexCoord2f(0, 1); glVertex3f(-width, height, -thickness); glNormal3f(0, -1, 0); glTexCoord2f(0, 0); glVertex3f(-width, -height, -thickness); glTexCoord2f(1, 0); glVertex3f(width, -height, -thickness); glTexCoord2f(1, 1); glVertex3f(width, -height, thickness); glTexCoord2f(0, 1); glVertex3f(-width, -height, thickness); glNormal3f(1, 0, 0); glTexCoord2f(0, 0); glVertex3f(width, -height, thickness); glTexCoord2f(1, 0); glVertex3f(width, -height, -thickness); glTexCoord2f(1, 1); glVertex3f(width, height, -thickness); glTexCoord2f(0, 1); glVertex3f(width, height, thickness); glNormal3f(-1, 0, 0); glTexCoord2f(0, 0); glVertex3f(-width, height, thickness); glTexCoord2f(1, 0); glVertex3f(-width, height, -thickness); glTexCoord2f(1, 1); glVertex3f(-width, -height, -thickness); glTexCoord2f(0, 1); glVertex3f(-width, -height, thickness); glEnd(); } static Bool draw_stairs_internal(ModeInfo * mi) { stairsstruct *sp = &stairs[MI_SCREEN(mi)]; GLfloat X; glPushMatrix(); glPushMatrix(); glTranslatef(-3.0, 0.1, 2.0); for (X = 0; X < 2; X++) { draw_block(0.5, 2.7 + 0.1 * X, 0.5); glTranslatef(0.0, 0.1, -1.0); } glPopMatrix(); glTranslatef(-3.0, 0.0, 3.0); glPushMatrix(); for (X = 0; X < 6; X++) { draw_block(0.5, 2.6 - 0.1 * X, 0.5); glTranslatef(1.0, -0.1, 0.0); } glTranslatef(-1.0, -0.9, -1.0); for (X = 0; X < 5; X++) { draw_block(0.5, 3.0 - 0.1 * X, 0.5); glTranslatef(0.0, 0.0, -1.0); } glTranslatef(-1.0, -1.1, 1.0); for (X = 0; X < 3; X++) { draw_block(0.5, 3.5 - 0.1 * X, 0.5); glTranslatef(-1.0, -0.1, 0.0); } glPopMatrix(); glPopMatrix(); glPushMatrix(); glMaterialfv(GL_FRONT_AND_BACK, GL_DIFFUSE, MaterialYellow); glTranslatef((GLfloat) positions[sp->sphere_position], (GLfloat) positions[sp->sphere_position + 1], (GLfloat) positions[sp->sphere_position + 2]); /* FUDGE sphere_position soo its not so obvious */ if (!mySphere((sp->sphere_position == 0) ? 0.48 : 0.5)) return False; glPopMatrix(); sp->sphere_position += 3; if (sp->sphere_position >= (int) NPOSITIONS) sp->sphere_position = 0; return True; } static void reshape(ModeInfo * mi, int width, int height) { stairsstruct *sp = &stairs[MI_SCREEN(mi)]; int i; glViewport(0, 0, sp->WindW = (GLint) width, sp->WindH = (GLint) height); glMatrixMode(GL_PROJECTION); glLoadIdentity(); glFrustum(-1.0, 1.0, -1.0, 1.0, 5.0, 15.0); glMatrixMode(GL_MODELVIEW); i = width / 512 + 1; glLineWidth(i); glPointSize(i); } 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); glMaterialfv(GL_FRONT_AND_BACK, GL_DIFFUSE, MaterialWhite); glShadeModel(GL_FLAT); glEnable(GL_DEPTH_TEST); glEnable(GL_TEXTURE_2D); glEnable(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 release_stairs(ModeInfo * mi) { if (stairs != NULL) { #if 0 int screen; for (screen = 0; screen < MI_NUM_SCREENS(mi); screen++) { stairsstruct *sp = &stairs[screen]; if (sp->glx_context) { if (glIsList(objects)) { glDeleteLists(objects, MaxObj); objects = 0; } } } #endif free(stairs); stairs = (stairsstruct *) NULL; } FreeAllGL(mi); } void init_stairs(ModeInfo * mi) { stairsstruct *sp; if (stairs == NULL) { if ((stairs = (stairsstruct *) calloc(MI_NUM_SCREENS(mi), sizeof (stairsstruct))) == NULL) return; } sp = &stairs[MI_SCREEN(mi)]; sp->step = 0.0; sp->direction = LRAND() & 1; sp->sphere_position = NRAND(NPOSITIONS / 3) * 3; if ((sp->glx_context = init_GL(mi)) != NULL) { reshape(mi, MI_WIDTH(mi), MI_HEIGHT(mi)); glDrawBuffer(GL_BACK); #if 0 if (!glIsList(objects)) if ((objects = glGenLists(MaxObj)) == 0) { MI_CLEARWINDOW(mi); } #endif pinit(); } else { MI_CLEARWINDOW(mi); } } void draw_stairs(ModeInfo * mi) { Display *display = MI_DISPLAY(mi); Window window = MI_WINDOW(mi); stairsstruct *sp; if (stairs == NULL) return; sp = &stairs[MI_SCREEN(mi)]; MI_IS_DRAWN(mi) = True; if (!sp->glx_context) return; glXMakeCurrent(display, window, *(sp->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 * sp->WindH / sp->WindW, Scale4Window, Scale4Window); } else { glScalef(Scale4Iconic * sp->WindH / sp->WindW, Scale4Iconic, Scale4Iconic); } glRotatef(44.5, 1, 0, 0); glRotatef(50 + ((sp->direction) ? 1 : -1) * ((sp->step * 100 > 120) ? sp->step * 100 - 120 : 0), 0, 1, 0); if (sp->step * 100 >= 360 + 120) { /* stop showing secrets */ sp->step = 0; sp->direction = LRAND() & 1; } if (!draw_stairs_internal(mi)) { release_stairs(mi); return; } glPopMatrix(); if (MI_IS_FPS(mi)) do_fps (mi); glFlush(); glXSwapBuffers(display, window); sp->step += 0.025; } void change_stairs(ModeInfo * mi) { stairsstruct *sp; if (stairs == NULL) return; sp = &stairs[MI_SCREEN(mi)]; if (!sp->glx_context) return; glXMakeCurrent(MI_DISPLAY(mi), MI_WINDOW(mi), *(sp->glx_context)); pinit(); } #endif