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author | Simon Rettberg | 2018-10-16 10:08:48 +0200 |
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committer | Simon Rettberg | 2018-10-16 10:08:48 +0200 |
commit | d3a98cf6cbc3bd0b9efc570f58e8812c03931c18 (patch) | |
tree | cbddf8e50f35a9c6e878a5bfe3c6d625d99e12ba /hacks/glx/cage.c | |
download | xscreensaver-d3a98cf6cbc3bd0b9efc570f58e8812c03931c18.tar.gz xscreensaver-d3a98cf6cbc3bd0b9efc570f58e8812c03931c18.tar.xz xscreensaver-d3a98cf6cbc3bd0b9efc570f58e8812c03931c18.zip |
Original 5.40
Diffstat (limited to 'hacks/glx/cage.c')
-rw-r--r-- | hacks/glx/cage.c | 480 |
1 files changed, 480 insertions, 0 deletions
diff --git a/hacks/glx/cage.c b/hacks/glx/cage.c new file mode 100644 index 0000000..66f48aa --- /dev/null +++ b/hacks/glx/cage.c @@ -0,0 +1,480 @@ +/* -*- Mode: C; tab-width: 4 -*- */ +/* cage --- the Impossible Cage, an Escher like scene. */ + +#if 0 +static const char sccsid[] = "@(#)cage.c 5.01 2001/03/01 xlockmore"; +#endif + +/*- + * 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 + * mistakes. + * + * My e-mail address is + * mfvianna@centroin.com.br + * + * Marcelo F. Vianna (Jun-01-1997) + * + * Revision History: + * 05-Apr-2002: Removed all gllist uses (fix some bug with nvidia driver) + * 01-Mar-2001: Added FPS stuff E.Lassauge <lassauge@mail.dotcom.fr> + * 01-Nov-2000: Allocation checks + * 01-Jan-1998: Mode separated from escher and renamed + * 08-Jun-1997: 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-1997: Speed ups in Moebius Strip using GL_CULL_FACE. + * Marcelo F. Vianna. + * 03-Jun-1997: 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). + */ + +#ifdef STANDALONE +# define MODE_cage +# define DEFAULTS "*delay: 25000 \n" \ + "*showFPS: False \n" \ + "*wireframe: False \n" \ + "*suppressRotationAnimation: True\n" \ + +# define free_cage 0 +# define release_cage 0 +# define cage_handle_event xlockmore_no_events +# include "xlockmore.h" /* from the xscreensaver distribution */ +#else /* !STANDALONE */ +# include "xlock.h" /* from the xlockmore distribution */ +#endif /* !STANDALONE */ + +#ifdef MODE_cage + +#if 0 +#include "e_textures.h" +#else +#include "ximage-loader.h" +#include "images/gen/wood_png.h" +#endif + +ENTRYPOINT ModeSpecOpt cage_opts = +{0, (XrmOptionDescRec *) NULL, 0, (argtype *) NULL, (OptionStruct *) NULL}; + +#ifdef USE_MODULES +ModStruct cage_description = +{"cage", "init_cage", "draw_cage", NULL, + "draw_cage", "change_cage", (char *) NULL, &cage_opts, + 25000, 1, 1, 1, 1.0, 4, "", + "Shows the Impossible Cage, an Escher-like GL scene", 0, NULL}; + +#endif + +#define Scale4Window 0.3 +#define Scale4Iconic 0.4 + +#define sqr(A) ((A)*(A)) + +#ifndef Pi +#define Pi M_PI +#endif + +#define ObjWoodPlank 0 +#define MaxObj 1 + +/*************************************************************************/ + +typedef struct { + GLint WindH, WindW; + GLfloat step; + GLXContext *glx_context; +} cagestruct; + +static const float front_shininess[] = {60.0}; +static const float front_specular[] = {0.7, 0.7, 0.7, 1.0}; +static const float ambient[] = {0.0, 0.0, 0.0, 1.0}; +static const float diffuse[] = {1.0, 1.0, 1.0, 1.0}; +static const float position0[] = {1.0, 1.0, 1.0, 0.0}; +static const float position1[] = {-1.0, -1.0, 1.0, 0.0}; +static const float lmodel_ambient[] = {0.5, 0.5, 0.5, 1.0}; +static const float lmodel_twoside[] = {GL_TRUE}; + +static const float MaterialWhite[] = {0.7, 0.7, 0.7, 1.0}; + +static cagestruct *cage = (cagestruct *) NULL; + +#define PlankWidth 3.0 +#define PlankHeight 0.35 +#define PlankThickness 0.15 + +static Bool +draw_woodplank(ModeInfo *mi, cagestruct * cp, int wire) +{ + glBegin(wire ? GL_LINES : GL_QUADS); + glNormal3f(0, 0, 1); + glTexCoord2f(0, 0); + glVertex3f(-PlankWidth, -PlankHeight, PlankThickness); + glTexCoord2f(1, 0); + glVertex3f(PlankWidth, -PlankHeight, PlankThickness); + glTexCoord2f(1, 1); + glVertex3f(PlankWidth, PlankHeight, PlankThickness); + glTexCoord2f(0, 1); + glVertex3f(-PlankWidth, PlankHeight, PlankThickness); + mi->polygon_count++; + glNormal3f(0, 0, -1); + glTexCoord2f(0, 0); + glVertex3f(-PlankWidth, PlankHeight, -PlankThickness); + glTexCoord2f(1, 0); + glVertex3f(PlankWidth, PlankHeight, -PlankThickness); + glTexCoord2f(1, 1); + glVertex3f(PlankWidth, -PlankHeight, -PlankThickness); + glTexCoord2f(0, 1); + glVertex3f(-PlankWidth, -PlankHeight, -PlankThickness); + mi->polygon_count++; + glNormal3f(0, 1, 0); + glTexCoord2f(0, 0); + glVertex3f(-PlankWidth, PlankHeight, PlankThickness); + glTexCoord2f(1, 0); + glVertex3f(PlankWidth, PlankHeight, PlankThickness); + glTexCoord2f(1, 1); + glVertex3f(PlankWidth, PlankHeight, -PlankThickness); + glTexCoord2f(0, 1); + glVertex3f(-PlankWidth, PlankHeight, -PlankThickness); + mi->polygon_count++; + glNormal3f(0, -1, 0); + glTexCoord2f(0, 0); + glVertex3f(-PlankWidth, -PlankHeight, -PlankThickness); + glTexCoord2f(1, 0); + glVertex3f(PlankWidth, -PlankHeight, -PlankThickness); + glTexCoord2f(1, 1); + glVertex3f(PlankWidth, -PlankHeight, PlankThickness); + glTexCoord2f(0, 1); + glVertex3f(-PlankWidth, -PlankHeight, PlankThickness); + mi->polygon_count++; + glNormal3f(1, 0, 0); + glTexCoord2f(0, 0); + glVertex3f(PlankWidth, -PlankHeight, PlankThickness); + glTexCoord2f(1, 0); + glVertex3f(PlankWidth, -PlankHeight, -PlankThickness); + glTexCoord2f(1, 1); + glVertex3f(PlankWidth, PlankHeight, -PlankThickness); + glTexCoord2f(0, 1); + glVertex3f(PlankWidth, PlankHeight, PlankThickness); + mi->polygon_count++; + glNormal3f(-1, 0, 0); + glTexCoord2f(0, 0); + glVertex3f(-PlankWidth, PlankHeight, PlankThickness); + glTexCoord2f(1, 0); + glVertex3f(-PlankWidth, PlankHeight, -PlankThickness); + glTexCoord2f(1, 1); + glVertex3f(-PlankWidth, -PlankHeight, -PlankThickness); + glTexCoord2f(0, 1); + glVertex3f(-PlankWidth, -PlankHeight, PlankThickness); + mi->polygon_count++; + glEnd(); + + return True; +} + +static Bool +draw_impossiblecage(ModeInfo *mi, cagestruct * cp, int wire) +{ + glPushMatrix(); + glRotatef(90, 0, 1, 0); + glTranslatef(0.0, PlankHeight - PlankWidth, -PlankThickness - PlankWidth); + if (!draw_woodplank(mi, cp, wire)) + return False; + glPopMatrix(); + glPushMatrix(); + glRotatef(90, 0, 0, 1); + glTranslatef(0.0, PlankHeight - PlankWidth, PlankWidth - PlankThickness); + if (!draw_woodplank(mi, cp, wire)) + return False; + glPopMatrix(); + glPushMatrix(); + glRotatef(90, 0, 1, 0); + glTranslatef(0.0, PlankWidth - PlankHeight, -PlankThickness - PlankWidth); + if (!draw_woodplank(mi, cp, wire)) + return False; + glPopMatrix(); + glPushMatrix(); + glTranslatef(0.0, PlankWidth - PlankHeight, 3 * PlankThickness - PlankWidth); + if (!draw_woodplank(mi, cp, wire)) + return False; + glPopMatrix(); + glPushMatrix(); + glRotatef(90, 0, 0, 1); + glTranslatef(0.0, PlankWidth - PlankHeight, PlankWidth - PlankThickness); + if (!draw_woodplank(mi, cp, wire)) + return False; + glPopMatrix(); + glPushMatrix(); + glTranslatef(0.0, PlankWidth - PlankHeight, PlankWidth - 3 * PlankThickness); + if (!draw_woodplank(mi, cp, wire)) + return False; + glPopMatrix(); + glPushMatrix(); + glTranslatef(0.0, PlankHeight - PlankWidth, 3 * PlankThickness - PlankWidth); + if (!draw_woodplank(mi, cp, wire)) + return False; + glPopMatrix(); + glPushMatrix(); + glRotatef(90, 0, 0, 1); + glTranslatef(0.0, PlankHeight - PlankWidth, PlankThickness - PlankWidth); + if (!draw_woodplank(mi, cp, wire)) + return False; + glPopMatrix(); + glPushMatrix(); + glTranslatef(0.0, PlankHeight - PlankWidth, PlankWidth - 3 * PlankThickness); + if (!draw_woodplank(mi, cp, wire)) + return False; + glPopMatrix(); + glPushMatrix(); + glRotatef(90, 0, 1, 0); + glTranslatef(0.0, PlankHeight - PlankWidth, PlankWidth + PlankThickness); + if (!draw_woodplank(mi, cp, wire)) + return False; + glPopMatrix(); + glPushMatrix(); + glRotatef(90, 0, 0, 1); + glTranslatef(0.0, PlankWidth - PlankHeight, PlankThickness - PlankWidth); + if (!draw_woodplank(mi, cp, wire)) + return False; + glPopMatrix(); + glPushMatrix(); + glRotatef(90, 0, 1, 0); + glTranslatef(0.0, PlankWidth - PlankHeight, PlankWidth + PlankThickness); + if (!draw_woodplank(mi, cp, wire)) + return False; + glPopMatrix(); + return True; +} + +static void +reshape_cage(ModeInfo * mi, int width, int height) +{ + cagestruct *cp = &cage[MI_SCREEN(mi)]; + int i; + int y = 0; + + if (width > height * 5) { /* tiny window: show middle */ + height = width * 9/16; + y = -height/2; + } + + glViewport(0, y, cp->WindW = (GLint) width, cp->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(ModeInfo *mi) +{ + /* int status; */ + + if (MI_IS_WIREFRAME(mi)) + return; + + 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); + + /* cage */ + glMaterialfv(GL_FRONT_AND_BACK, GL_DIFFUSE, MaterialWhite); + glShadeModel(GL_FLAT); + glDisable(GL_DEPTH_TEST); + glEnable(GL_TEXTURE_2D); + glEnable(GL_CULL_FACE); + + glPixelStorei(GL_UNPACK_ALIGNMENT, 1); + +#if 0 + clear_gl_error(); + if (MI_IS_MONO(mi)) + status = 0; + else + status = gluBuild2DMipmaps(GL_TEXTURE_2D, 3, + WoodTextureWidth, WoodTextureHeight, + GL_RGB, GL_UNSIGNED_BYTE, WoodTextureData); + if (status) + { + const char *s = (char *) gluErrorString (status); + fprintf (stderr, "%s: error mipmapping texture: %s\n", + progname, (s ? s : "(unknown)")); + exit (1); + } + check_gl_error("mipmapping"); +#else + { + XImage *img = image_data_to_ximage (mi->dpy, mi->xgwa.visual, + wood_png, sizeof(wood_png)); + glTexImage2D (GL_TEXTURE_2D, 0, GL_RGBA, + img->width, img->height, 0, + GL_RGBA, GL_UNSIGNED_BYTE, img->data); + check_gl_error("texture"); + XDestroyImage (img); + } +#endif + + 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); +} + +ENTRYPOINT void +init_cage (ModeInfo * mi) +{ + cagestruct *cp; + + MI_INIT (mi, cage); + cp = &cage[MI_SCREEN(mi)]; + + cp->step = NRAND(90); + if ((cp->glx_context = init_GL(mi)) != NULL) { + + reshape_cage(mi, MI_WIDTH(mi), MI_HEIGHT(mi)); + glDrawBuffer(GL_BACK); + pinit(mi); + } else { + MI_CLEARWINDOW(mi); + } +} + +ENTRYPOINT void +draw_cage (ModeInfo * mi) +{ + Display *display = MI_DISPLAY(mi); + Window window = MI_WINDOW(mi); + cagestruct *cp; + + if (cage == NULL) + return; + cp = &cage[MI_SCREEN(mi)]; + + MI_IS_DRAWN(mi) = True; + if (!cp->glx_context) + return; + + mi->polygon_count = 0; + glXMakeCurrent(display, window, *(cp->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 * cp->WindH / cp->WindW, Scale4Window, Scale4Window); + } else { + glScalef(Scale4Iconic * cp->WindH / cp->WindW, Scale4Iconic, Scale4Iconic); + } + +# ifdef HAVE_MOBILE /* Keep it the same relative size when rotated. */ + { + int o = (int) current_device_rotation(); + GLfloat h = MI_HEIGHT(mi) / (GLfloat) MI_WIDTH(mi); + if (o != 0 && o != 180 && o != -180) { + glScalef (1/h, h, 1/h); /* #### not quite right */ + h = 1.7; + glScalef (h, h, h); + } + } +# endif + + /* cage */ + glRotatef(cp->step * 100, 0, 0, 1); + glRotatef(25 + cos(cp->step * 5) * 6, 1, 0, 0); + glRotatef(204.5 - sin(cp->step * 5) * 8, 0, 1, 0); + if (!draw_impossiblecage(mi, cp, MI_IS_WIREFRAME(mi))) { + MI_ABORT(mi); + return; + } + + glPopMatrix(); + if (MI_IS_FPS(mi)) do_fps (mi); + glFlush(); + + glXSwapBuffers(display, window); + + cp->step += 0.025; +} + +#ifndef STANDALONE +ENTRYPOINT void +change_cage (ModeInfo * mi) +{ + cagestruct *cp = &cage[MI_SCREEN(mi)]; + + if (!cp->glx_context) + return; + + glXMakeCurrent(MI_DISPLAY(mi), MI_WINDOW(mi), *(cp->glx_context)); + pinit(mi); +} +#endif /* !STANDALONE */ + +XSCREENSAVER_MODULE ("Cage", cage) + +#endif |