progs/xdemos/xfont.c

   1 /* $Id: xfont.c,v 1.3 1999/11/05 08:12:46 brianp Exp $ */
   2
   3 /*
   4  * Mesa 3-D graphics library
   5  *
   6  * Copyright (C) 1999  Brian Paul   All Rights Reserved.
   7  *
   8  * Permission is hereby granted, free of charge, to any person obtaining a
   9  * copy of this software and associated documentation files (the "Software"),
  10  * to deal in the Software without restriction, including without limitation
  11  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
  12  * and/or sell copies of the Software, and to permit persons to whom the
  13  * Software is furnished to do so, subject to the following conditions:
  14  *
  15  * The above copyright notice and this permission notice shall be included
  16  * in all copies or substantial portions of the Software.
  17  *
  18  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
  19  * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  20  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
  21  * BRIAN PAUL BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN
  22  * AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
  23  * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  24  */
  25
  26
  27 /*
  28  * Example of using glXUseXFont().
  29  * 5 November 1999
  30  * Brian Paul
  31  */
  32
  33
  34 #include <GL/gl.h>
  35 #include <GL/glx.h>
  36 #include <stdio.h>
  37 #include <stdlib.h>
  38 #include <string.h>
  39
  40
  41 static const char *ProgramName = "xfont";
  42
  43 static const char *FontName = "fixed";
  44
  45 static GLuint FontBase = 0;
  46
  47
  48
  49 static void redraw( Display *dpy, Window w )
  50 {
  51    static const char *text = "This is glXUseXFont()";
  52
  53    glClear( GL_COLOR_BUFFER_BIT );
  54
  55    /* triangle */
  56    glColor3f( 0.2, 0.2, 1.0 );
  57    glBegin(GL_TRIANGLES);
  58    glVertex2f( 0, 0.8 );
  59    glVertex2f( -0.8, -0.7 );
  60    glVertex2f( 0.8, -0.7 );
  61    glEnd();
  62
  63    /* text */
  64    glColor3f( 1, 1, 1 );
  65    glRasterPos2f(-0.8, 0);
  66    glListBase(FontBase);
  67    glCallLists(strlen(text), GL_UNSIGNED_BYTE, (GLubyte *) text);
  68
  69    glXSwapBuffers( dpy, w );
  70 }
  71
  72
  73
  74 static void resize( unsigned int width, unsigned int height )
  75 {
  76    glViewport( 0, 0, width, height );
  77    glMatrixMode( GL_PROJECTION );
  78    glLoadIdentity();
  79    glOrtho( -1.0, 1.0, -1.0, 1.0, -1.0, 1.0 );
  80 }
  81
  82
  83
  84 static void setup_font( Display *dpy )
  85 {
  86     XFontStruct *fontInfo;
  87     Font id;
  88     unsigned int first, last;
  89
  90     fontInfo = XLoadQueryFont(dpy, FontName);
  91     if (!fontInfo) {
  92         printf("Error: font %s not found\n", FontName);
  93         exit(0);
  94     }
  95
  96     id = fontInfo->fid;
  97     first = fontInfo->min_char_or_byte2;
  98     last = fontInfo->max_char_or_byte2;
  99
 100     FontBase = glGenLists((GLuint) last + 1);
 101     if (!FontBase) {
 102         printf("Error: unable to allocate display lists\n");
 103         exit(0);
 104     }
 105     glXUseXFont(id, first, last - first + 1, FontBase + first);
 106 }
 107
 108 static Window make_rgb_db_window( Display *dpy, int xpos, int ypos,
 109                                   unsigned int width, unsigned int height )
 110 {
 111    int attrib[] = { GLX_RGBA,
 112                     GLX_RED_SIZE, 1,
 113                     GLX_GREEN_SIZE, 1,
 114                     GLX_BLUE_SIZE, 1,
 115                     GLX_DOUBLEBUFFER,
 116                     None };
 117    int scrnum;
 118    XSetWindowAttributes attr;
 119    unsigned long mask;
 120    Window root;
 121    Window win;
 122    GLXContext ctx;
 123    XVisualInfo *visinfo;
 124
 125    scrnum = DefaultScreen( dpy );
 126    root = RootWindow( dpy, scrnum );
 127
 128    visinfo = glXChooseVisual( dpy, scrnum, attrib );
 129    if (!visinfo) {
 130       printf("Error: couldn't get an RGB, Double-buffered visual\n");
 131       exit(1);
 132    }
 133
 134    /* window attributes */
 135    attr.background_pixel = 0;
 136    attr.border_pixel = 0;
 137    attr.colormap = XCreateColormap( dpy, root, visinfo->visual, AllocNone);
 138    attr.event_mask = StructureNotifyMask | ExposureMask | KeyPressMask;
 139    mask = CWBackPixel | CWBorderPixel | CWColormap | CWEventMask;
 140
 141    win = XCreateWindow( dpy, root, 0, 0, width, height,
 142                         0, visinfo->depth, InputOutput,
 143                         visinfo->visual, mask, &attr );
 144
 145    {
 146       XSizeHints sizehints;
 147       sizehints.x = xpos;
 148       sizehints.y = ypos;
 149       sizehints.width  = width;
 150       sizehints.height = height;
 151       sizehints.flags = USSize | USPosition;
 152       XSetNormalHints(dpy, win, &sizehints);
 153       XSetStandardProperties(dpy, win, ProgramName, ProgramName,
 154                               None, (char **)NULL, 0, &sizehints);
 155    }
 156
 157
 158    ctx = glXCreateContext( dpy, visinfo, NULL, True );
 159
 160    glXMakeCurrent( dpy, win, ctx );
 161
 162    return win;
 163 }
 164
 165
 166 static void event_loop( Display *dpy )
 167 {
 168    XEvent event;
 169
 170    while (1) {
 171       XNextEvent( dpy, &event );
 172
 173       switch (event.type) {
 174          case Expose:
 175             redraw( dpy, event.xany.window );
 176             break;
 177          case ConfigureNotify:
 178             resize( event.xconfigure.width, event.xconfigure.height );
 179             break;
 180          case KeyPress:
 181             exit(0);
 182          default:
 183             ;  /* no-op */
 184       }
 185    }
 186 }
 187
 188
 189
 190 int main( int argc, char *argv[] )
 191 {
 192    Display *dpy;
 193    Window win;
 194
 195    dpy = XOpenDisplay(NULL);
 196
 197    win = make_rgb_db_window( dpy, 0, 0, 300, 300 );
 198    setup_font( dpy );
 199
 200    glShadeModel( GL_FLAT );
 201    glClearColor( 0.5, 0.5, 1.0, 1.0 );
 202
 203    XMapWindow( dpy, win );
 204
 205    event_loop( dpy );
 206    return 0;
 207 }