/* -*- Mode: C; tab-width: 4 -*- */ /* gears --- 3D gear wheels */ #if !defined( lint ) && !defined( SABER ) static const char sccsid[] = "@(#)gears.c 5.00 2000/11/01 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. * * Revision History: * 01-Nov-2000: Allocation checks * 10-May-1997: Compatible with xscreensaver * 22-Mar-1997: Added support for -mono mode, and monochrome X servers. * Ed Mackey, emackey@netaxs.com * 13-Mar-1997: Memory leak fix by Tom Schmidt * 1996: "written" by Danny Sung * Based on 3-D gear wheels by Brian Paul which is in the public domain. */ /*- * PURIFY 3.0a on SunOS4 reports an unitialized memory read on each of * the glCallList() functions below when using MesaGL 2.1. This has * been fixed in MesaGL 2.2 and later releases. */ /*- * due to a Bug/feature in VMS X11/Intrinsic.h has to be placed before xlock. * otherwise caddr_t is not defined correctly */ #include #ifdef STANDALONE #define PROGCLASS "Gears" #define HACK_INIT init_gears #define HACK_DRAW draw_gears #define gears_opts xlockmore_opts #define DEFAULTS "*delay: 1000 \n" \ "*cycles: 2 \n" \ "*wireframe: False \n" #include "xlockmore.h" /* from the xscreensaver distribution */ #else /* !STANDALONE */ #include "xlock.h" /* from the xlockmore distribution */ #include "vis.h" #endif /* !STANDALONE */ #ifdef MODE_cage ModeSpecOpt gears_opts = {0, NULL, 0, NULL, NULL}; #ifdef USE_MODULES ModStruct gears_description = {"gears", "init_gears", "draw_gears", "release_gears", "draw_gears", "init_gears", NULL, &gears_opts, 1000, 1, 2, 1, 4, 1.0, "", "Shows GL's gears", 0, NULL}; #endif typedef struct { GLfloat view_rotx, view_roty, view_rotz; GLuint gear1, gear2, gear3; GLfloat angle; GLXContext *glx_context; Window window; } gearsstruct; static gearsstruct *gears = NULL; /*- * Draw a gear wheel. You'll probably want to call this function when * building a display list since we do a lot of trig here. * * Input: inner_radius - radius of hole at center * outer_radius - radius at center of teeth * width - width of gear * teeth - number of teeth * tooth_depth - depth of tooth * wire - true for wireframe mode */ static void gear(GLfloat inner_radius, GLfloat outer_radius, GLfloat width, GLint teeth, GLfloat tooth_depth, Bool wire) { GLint i; GLfloat r0, r1, r2; GLfloat angle, da; GLfloat u, v, len; r0 = inner_radius; r1 = outer_radius - tooth_depth / 2.0; r2 = outer_radius + tooth_depth / 2.0; da = 2.0 * M_PI / teeth / 4.0; glShadeModel(GL_FLAT); /* This subroutine got kind of messy when I added all the checks * for wireframe mode. A much cleaner solution that I sometimes * use is to have a variable hold the value GL_LINE_LOOP when * in wireframe mode, or hold the value GL_POLYGON otherwise. * Then I just call glBegin(that_variable), give my polygon * coordinates, and glEnd(). Pretty neat eh? Too bad I couldn't * integrate that trick here. * --Ed. */ if (!wire) glNormal3f(0.0, 0.0, 1.0); /* draw front face */ if (!wire) glBegin(GL_QUAD_STRIP); for (i = 0; i <= teeth; i++) { if (wire) glBegin(GL_LINES); angle = i * 2.0 * M_PI / teeth; glVertex3f(r0 * cos(angle), r0 * sin(angle), width * 0.5); glVertex3f(r1 * cos(angle), r1 * sin(angle), width * 0.5); if (!wire) { glVertex3f(r0 * cos(angle), r0 * sin(angle), width * 0.5); glVertex3f(r1 * cos(angle + 3 * da), r1 * sin(angle + 3 * da), width * 0.5); } else { glVertex3f(r1 * cos(angle + 3 * da), r1 * sin(angle + 3 * da), width * 0.5); glVertex3f(r1 * cos(angle + 4 * da), r1 * sin(angle + 4 * da), width * 0.5); glEnd(); } } if (!wire) glEnd(); /* draw front sides of teeth */ if (!wire) glBegin(GL_QUADS); da = 2.0 * M_PI / teeth / 4.0; for (i = 0; i < teeth; i++) { angle = i * 2.0 * M_PI / teeth; if (wire) glBegin(GL_LINE_LOOP); glVertex3f(r1 * cos(angle), r1 * sin(angle), width * 0.5); glVertex3f(r2 * cos(angle + da), r2 * sin(angle + da), width * 0.5); glVertex3f(r2 * cos(angle + 2 * da), r2 * sin(angle + 2 * da), width * 0.5); glVertex3f(r1 * cos(angle + 3 * da), r1 * sin(angle + 3 * da), width * 0.5); if (wire) glEnd(); } if (!wire) glEnd(); if (!wire) glNormal3f(0.0, 0.0, -1.0); /* draw back face */ if (!wire) glBegin(GL_QUAD_STRIP); for (i = 0; i <= teeth; i++) { angle = i * 2.0 * M_PI / teeth; if (wire) glBegin(GL_LINES); glVertex3f(r1 * cos(angle), r1 * sin(angle), -width * 0.5); glVertex3f(r0 * cos(angle), r0 * sin(angle), -width * 0.5); if (!wire) { glVertex3f(r1 * cos(angle + 3 * da), r1 * sin(angle + 3 * da), -width * 0.5); glVertex3f(r0 * cos(angle), r0 * sin(angle), -width * 0.5); } else { glVertex3f(r1 * cos(angle + 3 * da), r1 * sin(angle + 3 * da), -width * 0.5); glVertex3f(r1 * cos(angle + 4 * da), r1 * sin(angle + 4 * da), -width * 0.5); glEnd(); } } if (!wire) glEnd(); /* draw back sides of teeth */ if (!wire) glBegin(GL_QUADS); da = 2.0 * M_PI / teeth / 4.0; for (i = 0; i < teeth; i++) { angle = i * 2.0 * M_PI / teeth; if (wire) glBegin(GL_LINE_LOOP); glVertex3f(r1 * cos(angle + 3 * da), r1 * sin(angle + 3 * da), -width * 0.5); glVertex3f(r2 * cos(angle + 2 * da), r2 * sin(angle + 2 * da), -width * 0.5); glVertex3f(r2 * cos(angle + da), r2 * sin(angle + da), -width * 0.5); glVertex3f(r1 * cos(angle), r1 * sin(angle), -width * 0.5); if (wire) glEnd(); } if (!wire) glEnd(); /* draw outward faces of teeth */ if (!wire) glBegin(GL_QUAD_STRIP); for (i = 0; i < teeth; i++) { angle = i * 2.0 * M_PI / teeth; if (wire) glBegin(GL_LINES); glVertex3f(r1 * cos(angle), r1 * sin(angle), width * 0.5); glVertex3f(r1 * cos(angle), r1 * sin(angle), -width * 0.5); u = r2 * cos(angle + da) - r1 * cos(angle); v = r2 * sin(angle + da) - r1 * sin(angle); len = sqrt(u * u + v * v); u /= len; v /= len; glNormal3f(v, -u, 0.0); glVertex3f(r2 * cos(angle + da), r2 * sin(angle + da), width * 0.5); glVertex3f(r2 * cos(angle + da), r2 * sin(angle + da), -width * 0.5); glNormal3f(cos(angle), sin(angle), 0.0); glVertex3f(r2 * cos(angle + 2 * da), r2 * sin(angle + 2 * da), width * 0.5); glVertex3f(r2 * cos(angle + 2 * da), r2 * sin(angle + 2 * da), -width * 0.5); u = r1 * cos(angle + 3 * da) - r2 * cos(angle + 2 * da); v = r1 * sin(angle + 3 * da) - r2 * sin(angle + 2 * da); glNormal3f(v, -u, 0.0); glVertex3f(r1 * cos(angle + 3 * da), r1 * sin(angle + 3 * da), width * 0.5); glVertex3f(r1 * cos(angle + 3 * da), r1 * sin(angle + 3 * da), -width * 0.5); glNormal3f(cos(angle), sin(angle), 0.0); if (wire) glEnd(); } if (!wire) { glVertex3f(r1 * cos(0.0), r1 * sin(0.0), width * 0.5); glVertex3f(r1 * cos(0.0), r1 * sin(0.0), -width * 0.5); glEnd(); } if (!wire) glShadeModel(GL_SMOOTH); /* draw inside radius cylinder */ if (!wire) glBegin(GL_QUAD_STRIP); for (i = 0; i <= teeth; i++) { angle = i * 2.0 * M_PI / teeth; if (wire) glBegin(GL_LINES); glNormal3f(-cos(angle), -sin(angle), 0.0); glVertex3f(r0 * cos(angle), r0 * sin(angle), -width * 0.5); glVertex3f(r0 * cos(angle), r0 * sin(angle), width * 0.5); if (wire) { glVertex3f(r0 * cos(angle), r0 * sin(angle), -width * 0.5); glVertex3f(r0 * cos(angle + 4 * da), r0 * sin(angle + 4 * da), -width * 0.5); glVertex3f(r0 * cos(angle), r0 * sin(angle), width * 0.5); glVertex3f(r0 * cos(angle + 4 * da), r0 * sin(angle + 4 * da), width * 0.5); glEnd(); } } if (!wire) glEnd(); } static void draw(ModeInfo * mi) { gearsstruct *gp = &gears[MI_SCREEN(mi)]; int wire = MI_IS_WIREFRAME(mi); if (!wire) { glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT); } else { glClear(GL_COLOR_BUFFER_BIT); } glPushMatrix(); glRotatef(gp->view_rotx, 1.0, 0.0, 0.0); glRotatef(gp->view_roty, 0.0, 1.0, 0.0); glRotatef(gp->view_rotz, 0.0, 0.0, 1.0); glPushMatrix(); glTranslatef(-3.0, -2.0, 0.0); glRotatef(gp->angle, 0.0, 0.0, 1.0); /* PURIFY 4.0.1 reports an unitialized memory read on the next line when using * MesaGL 2.2 and -mono. This has been fixed in MesaGL 2.3 and later. */ glCallList(gp->gear1); glPopMatrix(); glPushMatrix(); glTranslatef(3.1, -2.0, 0.0); glRotatef(-2.0 * gp->angle - 9.0, 0.0, 0.0, 1.0); glCallList(gp->gear2); glPopMatrix(); glPushMatrix(); glTranslatef(-3.1, 4.2, 0.0); glRotatef(-2.0 * gp->angle - 25.0, 0.0, 0.0, 1.0); glCallList(gp->gear3); glPopMatrix(); glPopMatrix(); } /* new window size or exposure */ static void reshape(int width, int height) { GLfloat h = (GLfloat) height / (GLfloat) width; glViewport(0, 0, (GLint) width, (GLint) height); glMatrixMode(GL_PROJECTION); glLoadIdentity(); glFrustum(-1.0, 1.0, -h, h, 5.0, 60.0); glMatrixMode(GL_MODELVIEW); glLoadIdentity(); glTranslatef(0.0, 0.0, -40.0); /* The depth buffer will be cleared, if needed, before the * next frame. Right now we just want to black the screen. */ glClear(GL_COLOR_BUFFER_BIT); } static void free_gears(Display *display, gearsstruct *gp) { if (gp->glx_context) { /* Display lists MUST be freed while their glXContext is current. */ glXMakeCurrent(display, gp->window, *(gp->glx_context)); if (glIsList(gp->gear1)) { glDeleteLists(gp->gear1, 1); gp->gear1 = 0; } if (glIsList(gp->gear2)) { glDeleteLists(gp->gear2, 1); gp->gear2 = 0; } if (glIsList(gp->gear3)) { glDeleteLists(gp->gear3, 1); gp->gear3 = 0; } gp->glx_context = NULL; } } static Bool pinit(ModeInfo * mi) { gearsstruct *gp = &gears[MI_SCREEN(mi)]; static GLfloat pos[4] = {5.0, 5.0, 10.0, 1.0}; static GLfloat red[4] = {0.8, 0.1, 0.0, 1.0}; static GLfloat green[4] = {0.0, 0.8, 0.2, 1.0}; static GLfloat blue[4] = {0.2, 0.2, 1.0, 1.0}; static GLfloat gray[4] = {0.5, 0.5, 0.5, 1.0}; static GLfloat white[4] = {1.0, 1.0, 1.0, 1.0}; int wire = MI_IS_WIREFRAME(mi); int mono = MI_IS_MONO(mi); if (!wire) { glLightfv(GL_LIGHT0, GL_POSITION, pos); glEnable(GL_CULL_FACE); glEnable(GL_LIGHTING); glEnable(GL_LIGHT0); glEnable(GL_DEPTH_TEST); } /* make the gears */ if ((gp->gear1 = glGenLists(1)) == 0) { free_gears(MI_DISPLAY(mi), gp); return False; } glNewList(gp->gear1, GL_COMPILE); if (glGetError() != GL_NO_ERROR) { free_gears(MI_DISPLAY(mi), gp); return False; } if (wire) { if (mono) glColor4fv(white); else glColor4fv(red); } else { if (mono) glMaterialfv(GL_FRONT, GL_AMBIENT_AND_DIFFUSE, gray); else glMaterialfv(GL_FRONT, GL_AMBIENT_AND_DIFFUSE, red); } gear(1.0, 4.0, 1.0, 20, 0.7, wire); glEndList(); if ((gp->gear2 = glGenLists(1)) == 0) { free_gears(MI_DISPLAY(mi), gp); return False; } glNewList(gp->gear2, GL_COMPILE); if (glGetError() != GL_NO_ERROR) { free_gears(MI_DISPLAY(mi), gp); return False; } if (wire) { if (mono) glColor4fv(white); else glColor4fv(green); } else { if (mono) glMaterialfv(GL_FRONT, GL_AMBIENT_AND_DIFFUSE, gray); else glMaterialfv(GL_FRONT, GL_AMBIENT_AND_DIFFUSE, green); } gear(0.5, 2.0, 2.0, 10, 0.7, wire); glEndList(); if ((gp->gear3 = glGenLists(1)) == 0) { free_gears(MI_DISPLAY(mi), gp); return False; } glNewList(gp->gear3, GL_COMPILE); if (glGetError() != GL_NO_ERROR) { free_gears(MI_DISPLAY(mi), gp); return False; } if (wire) { if (mono) glColor4fv(white); else glColor4fv(blue); } else { if (mono) glMaterialfv(GL_FRONT, GL_AMBIENT_AND_DIFFUSE, gray); else glMaterialfv(GL_FRONT, GL_AMBIENT_AND_DIFFUSE, blue); } gear(1.3, 2.0, 0.5, 10, 0.7, wire); glEndList(); if (!wire) glEnable(GL_NORMALIZE); return True; } void init_gears(ModeInfo * mi) { /*Colormap cmap; */ /* Boolean rgba, doublebuffer, cmap_installed; */ gearsstruct *gp; if (gears == NULL) { if ((gears = (gearsstruct *) calloc(MI_NUM_SCREENS(mi), sizeof (gearsstruct))) == NULL) return; } gp = &gears[MI_SCREEN(mi)]; gp->window = MI_WINDOW(mi); gp->view_rotx = NRAND(360); gp->view_roty = NRAND(360); gp->view_rotz = NRAND(360); gp->angle = NRAND(360); if ((gp->glx_context = init_GL(mi)) != NULL) { reshape(MI_WIDTH(mi), MI_HEIGHT(mi)); glDrawBuffer(GL_BACK); if (!pinit(mi)) { MI_CLEARWINDOW(mi); } } else { MI_CLEARWINDOW(mi); } } void draw_gears(ModeInfo * mi) { Display *display = MI_DISPLAY(mi); Window window = MI_WINDOW(mi); int angle_incr = MI_CYCLES(mi) ? MI_CYCLES(mi) : 2; int rot_incr = MI_COUNT(mi) ? MI_COUNT(mi) : 1; gearsstruct *gp; if (gears == NULL) return; gp = &gears[MI_SCREEN(mi)]; MI_IS_DRAWN(mi) = True; if (!gp->glx_context) return; glXMakeCurrent(display, window, *(gp->glx_context)); draw(mi); /* let's do something so we don't get bored */ gp->angle = (int) (gp->angle + angle_incr) % 360; gp->view_rotx = (int) (gp->view_rotx + rot_incr) % 360; gp->view_roty = (int) (gp->view_roty + rot_incr) % 360; gp->view_rotz = (int) (gp->view_rotz + rot_incr) % 360; glFinish(); glXSwapBuffers(display, window); } void release_gears(ModeInfo * mi) { if (gears != NULL) { int screen; for (screen = 0; screen < MI_NUM_SCREENS(mi); screen++) free_gears(MI_DISPLAY(mi), &gears[screen]); (void) free((void *) gears); gears = NULL; } FreeAllGL(mi); } /*********************************************************/ #endif