progs/egl/xegl_tri.c

   1 /*
   2  * Copyright (C) 2008  Brian Paul   All Rights Reserved.
   3  *
   4  * Permission is hereby granted, free of charge, to any person obtaining a
   5  * copy of this software and associated documentation files (the "Software"),
   6  * to deal in the Software without restriction, including without limitation
   7  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
   8  * and/or sell copies of the Software, and to permit persons to whom the
   9  * Software is furnished to do so, subject to the following conditions:
  10  *
  11  * The above copyright notice and this permission notice shall be included
  12  * in all copies or substantial portions of the Software.
  13  *
  14  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
  15  * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  16  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
  17  * BRIAN PAUL BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN
  18  * AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
  19  * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  20  */
  21
  22 /*
  23  * Draw a triangle with X/EGL.
  24  * Brian Paul
  25  * 3 June 2008
  26  */
  27
  28
  29 #include <assert.h>
  30 #include <math.h>
  31 #include <stdlib.h>
  32 #include <stdio.h>
  33 #include <string.h>
  34 #include <X11/Xlib.h>
  35 #include <X11/Xutil.h>
  36 #include <X11/keysym.h>
  37 #include <GL/gl.h>  /* using full OpenGL for now */
  38 #include <GLES/egl.h>
  39
  40
  41 static GLfloat view_rotx = 0.0, view_roty = 0.0, view_rotz = 0.0;
  42
  43
  44 static void
  45 draw(void)
  46 {
  47    static const GLfloat verts[3][2] = {
  48       { -1, -1 },
  49       {  1, -1 },
  50       {  0,  1 }
  51    };
  52    static const GLfloat colors[3][3] = {
  53       { 1, 0, 0 },
  54       { 0, 1, 0 },
  55       { 0, 0, 1 }
  56    };
  57
  58    glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
  59
  60    glPushMatrix();
  61    glRotatef(view_rotx, 1, 0, 0);
  62    glRotatef(view_roty, 0, 1, 0);
  63    glRotatef(view_rotz, 0, 0, 1);
  64
  65    {
  66       glVertexPointer(2, GL_FLOAT, 0, verts);
  67       glColorPointer(3, GL_FLOAT, 0, colors);
  68       glEnableClientState(GL_VERTEX_ARRAY);
  69       glEnableClientState(GL_COLOR_ARRAY);
  70
  71       glDrawArrays(GL_TRIANGLES, 0, 3);
  72
  73       glDisableClientState(GL_VERTEX_ARRAY);
  74       glDisableClientState(GL_COLOR_ARRAY);
  75    }
  76
  77    glPopMatrix();
  78 }
  79
  80
  81 /* new window size or exposure */
  82 static void
  83 reshape(int width, int height)
  84 {
  85    GLfloat ar = (GLfloat) width / (GLfloat) height;
  86
  87    glViewport(0, 0, (GLint) width, (GLint) height);
  88
  89    glMatrixMode(GL_PROJECTION);
  90    glLoadIdentity();
  91    glFrustum(-ar, ar, -1, 1, 5.0, 60.0);
  92
  93    glMatrixMode(GL_MODELVIEW);
  94    glLoadIdentity();
  95    glTranslatef(0.0, 0.0, -10.0);
  96 }
  97
  98
  99 static void
 100 init(void)
 101 {
 102    glClearColor(0.4, 0.4, 0.4, 0.0);
 103 }
 104
 105
 106 /*
 107  * Create an RGB, double-buffered X window.
 108  * Return the window and context handles.
 109  */
 110 static void
 111 make_x_window(Display *x_dpy, EGLDisplay egl_dpy,
 112               const char *name,
 113               int x, int y, int width, int height,
 114               Window *winRet,
 115               EGLContext *ctxRet,
 116               EGLSurface *surfRet)
 117 {
 118    static const EGLint attribs[] = {
 119       EGL_RED_SIZE, 1,
 120       EGL_GREEN_SIZE, 1,
 121       EGL_BLUE_SIZE, 1,
 122       EGL_DEPTH_SIZE, 1,
 123       EGL_NONE
 124    };
 125
 126    int scrnum;
 127    XSetWindowAttributes attr;
 128    unsigned long mask;
 129    Window root;
 130    Window win;
 131    XVisualInfo *visInfo, visTemplate;
 132    int num_visuals;
 133    EGLContext ctx;
 134    EGLConfig config;
 135    EGLint num_configs;
 136    EGLint vid;
 137
 138    scrnum = DefaultScreen( x_dpy );
 139    root = RootWindow( x_dpy, scrnum );
 140
 141    if (!eglChooseConfig( egl_dpy, attribs, &config, 1, &num_configs)) {
 142       printf("Error: couldn't get an EGL visual config\n");
 143       exit(1);
 144    }
 145
 146    assert(config);
 147    assert(num_configs > 0);
 148
 149    if (!eglGetConfigAttrib(egl_dpy, config, EGL_NATIVE_VISUAL_ID, &vid)) {
 150       printf("Error: eglGetConfigAttrib() failed\n");
 151       exit(1);
 152    }
 153
 154    /* The X window visual must match the EGL config */
 155    visTemplate.visualid = vid;
 156    visInfo = XGetVisualInfo(x_dpy, VisualIDMask, &visTemplate, &num_visuals);
 157    if (!visInfo) {
 158       printf("Error: couldn't get X visual\n");
 159       exit(1);
 160    }
 161
 162    /* window attributes */
 163    attr.background_pixel = 0;
 164    attr.border_pixel = 0;
 165    attr.colormap = XCreateColormap( x_dpy, root, visInfo->visual, AllocNone);
 166    attr.event_mask = StructureNotifyMask | ExposureMask | KeyPressMask;
 167    mask = CWBackPixel | CWBorderPixel | CWColormap | CWEventMask;
 168
 169    win = XCreateWindow( x_dpy, root, 0, 0, width, height,
 170                         0, visInfo->depth, InputOutput,
 171                         visInfo->visual, mask, &attr );
 172
 173    /* set hints and properties */
 174    {
 175       XSizeHints sizehints;
 176       sizehints.x = x;
 177       sizehints.y = y;
 178       sizehints.width  = width;
 179       sizehints.height = height;
 180       sizehints.flags = USSize | USPosition;
 181       XSetNormalHints(x_dpy, win, &sizehints);
 182       XSetStandardProperties(x_dpy, win, name, name,
 183                               None, (char **)NULL, 0, &sizehints);
 184    }
 185
 186    eglBindAPI(EGL_OPENGL_API);
 187
 188    ctx = eglCreateContext(egl_dpy, config, EGL_NO_CONTEXT, NULL );
 189    if (!ctx) {
 190       printf("Error: glXCreateContext failed\n");
 191       exit(1);
 192    }
 193
 194    *surfRet = eglCreateWindowSurface(egl_dpy, config, win, NULL);
 195
 196    if (!*surfRet) {
 197       printf("Error: eglCreateWindowSurface failed\n");
 198       exit(1);
 199    }
 200
 201    XFree(visInfo);
 202
 203    *winRet = win;
 204    *ctxRet = ctx;
 205 }
 206
 207
 208 static void
 209 event_loop(Display *dpy, Window win,
 210            EGLDisplay egl_dpy, EGLSurface egl_surf)
 211 {
 212    while (1) {
 213       int redraw = 0;
 214       XEvent event;
 215
 216       XNextEvent(dpy, &event);
 217
 218       switch (event.type) {
 219       case Expose:
 220          redraw = 1;
 221          break;
 222       case ConfigureNotify:
 223          reshape(event.xconfigure.width, event.xconfigure.height);
 224          break;
 225       case KeyPress:
 226          {
 227             char buffer[10];
 228             int r, code;
 229             code = XLookupKeysym(&event.xkey, 0);
 230             if (code == XK_Left) {
 231                view_roty += 5.0;
 232             }
 233             else if (code == XK_Right) {
 234                view_roty -= 5.0;
 235             }
 236             else if (code == XK_Up) {
 237                view_rotx += 5.0;
 238             }
 239             else if (code == XK_Down) {
 240                view_rotx -= 5.0;
 241             }
 242             else {
 243                r = XLookupString(&event.xkey, buffer, sizeof(buffer),
 244                                  NULL, NULL);
 245                if (buffer[0] == 27) {
 246                   /* escape */
 247                   return;
 248                }
 249             }
 250          }
 251          redraw = 1;
 252          break;
 253       default:
 254          ; /*no-op*/
 255       }
 256
 257       if (redraw) {
 258          draw();
 259          eglSwapBuffers(egl_dpy, egl_surf);
 260       }
 261    }
 262 }
 263
 264
 265 static void
 266 usage(void)
 267 {
 268    printf("Usage:\n");
 269    printf("  -display <displayname>  set the display to run on\n");
 270    printf("  -info                   display OpenGL renderer info\n");
 271 }
 272
 273
 274 int
 275 main(int argc, char *argv[])
 276 {
 277    const int winWidth = 300, winHeight = 300;
 278    Display *x_dpy;
 279    Window win;
 280    EGLSurface egl_surf;
 281    EGLContext egl_ctx;
 282    EGLDisplay egl_dpy;
 283    char *dpyName = NULL;
 284    GLboolean printInfo = GL_FALSE;
 285    EGLint egl_major, egl_minor;
 286    int i;
 287    const char *s;
 288
 289    for (i = 1; i < argc; i++) {
 290       if (strcmp(argv[i], "-display") == 0) {
 291          dpyName = argv[i+1];
 292          i++;
 293       }
 294       else if (strcmp(argv[i], "-info") == 0) {
 295          printInfo = GL_TRUE;
 296       }
 297       else {
 298          usage();
 299          return -1;
 300       }
 301    }
 302
 303    x_dpy = XOpenDisplay(dpyName);
 304    if (!x_dpy) {
 305       printf("Error: couldn't open display %s\n",
 306              dpyName ? dpyName : getenv("DISPLAY"));
 307       return -1;
 308    }
 309
 310    egl_dpy = eglGetDisplay(x_dpy);
 311    if (!egl_dpy) {
 312       printf("Error: eglGetDisplay() failed\n");
 313       return -1;
 314    }
 315
 316    if (!eglInitialize(egl_dpy, &egl_major, &egl_minor)) {
 317       printf("Error: eglInitialize() failed\n");
 318       return -1;
 319    }
 320
 321    s = eglQueryString(egl_dpy, EGL_VERSION);
 322    printf("EGL_VERSION = %s\n", s);
 323
 324    make_x_window(x_dpy, egl_dpy,
 325                  "xegl_tri", 0, 0, winWidth, winHeight,
 326                  &win, &egl_ctx, &egl_surf);
 327
 328    XMapWindow(x_dpy, win);
 329    if (!eglMakeCurrent(egl_dpy, egl_surf, egl_surf, egl_ctx)) {
 330       printf("Error: eglMakeCurrent() failed\n");
 331       return -1;
 332    }
 333
 334    if (printInfo) {
 335       printf("GL_RENDERER   = %s\n", (char *) glGetString(GL_RENDERER));
 336       printf("GL_VERSION    = %s\n", (char *) glGetString(GL_VERSION));
 337       printf("GL_VENDOR     = %s\n", (char *) glGetString(GL_VENDOR));
 338    }
 339
 340    init();
 341
 342    /* Set initial projection/viewing transformation.
 343     * We can't be sure we'll get a ConfigureNotify event when the window
 344     * first appears.
 345     */
 346    reshape(winWidth, winHeight);
 347
 348    event_loop(x_dpy, win, egl_dpy, egl_surf);
 349
 350    eglDestroyContext(egl_dpy, egl_ctx);
 351    eglDestroySurface(egl_dpy, egl_surf);
 352    eglTerminate(egl_dpy);
 353
 354
 355    XDestroyWindow(x_dpy, win);
 356    XCloseDisplay(x_dpy);
 357
 358    return 0;
 359 }