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_RENDERABLE_TYPE, EGL_OPENGL_BIT,
 124       EGL_NONE
 125    };
 126
 127    int scrnum;
 128    XSetWindowAttributes attr;
 129    unsigned long mask;
 130    Window root;
 131    Window win;
 132    XVisualInfo *visInfo, visTemplate;
 133    int num_visuals;
 134    EGLContext ctx;
 135    EGLConfig config;
 136    EGLint num_configs;
 137    EGLint vid;
 138
 139    scrnum = DefaultScreen( x_dpy );
 140    root = RootWindow( x_dpy, scrnum );
 141
 142    if (!eglChooseConfig( egl_dpy, attribs, &config, 1, &num_configs) ||
 143        !num_configs) {
 144       printf("Error: couldn't get an EGL visual config\n");
 145       exit(1);
 146    }
 147
 148    assert(config);
 149    assert(num_configs > 0);
 150
 151    if (!eglGetConfigAttrib(egl_dpy, config, EGL_NATIVE_VISUAL_ID, &vid)) {
 152       printf("Error: eglGetConfigAttrib() failed\n");
 153       exit(1);
 154    }
 155
 156    /* The X window visual must match the EGL config */
 157    visTemplate.visualid = vid;
 158    visInfo = XGetVisualInfo(x_dpy, VisualIDMask, &visTemplate, &num_visuals);
 159    if (!visInfo) {
 160       printf("Error: couldn't get X visual\n");
 161       exit(1);
 162    }
 163
 164    /* window attributes */
 165    attr.background_pixel = 0;
 166    attr.border_pixel = 0;
 167    attr.colormap = XCreateColormap( x_dpy, root, visInfo->visual, AllocNone);
 168    attr.event_mask = StructureNotifyMask | ExposureMask | KeyPressMask;
 169    mask = CWBackPixel | CWBorderPixel | CWColormap | CWEventMask;
 170
 171    win = XCreateWindow( x_dpy, root, 0, 0, width, height,
 172                         0, visInfo->depth, InputOutput,
 173                         visInfo->visual, mask, &attr );
 174
 175    /* set hints and properties */
 176    {
 177       XSizeHints sizehints;
 178       sizehints.x = x;
 179       sizehints.y = y;
 180       sizehints.width  = width;
 181       sizehints.height = height;
 182       sizehints.flags = USSize | USPosition;
 183       XSetNormalHints(x_dpy, win, &sizehints);
 184       XSetStandardProperties(x_dpy, win, name, name,
 185                               None, (char **)NULL, 0, &sizehints);
 186    }
 187
 188    eglBindAPI(EGL_OPENGL_API);
 189
 190    ctx = eglCreateContext(egl_dpy, config, EGL_NO_CONTEXT, NULL );
 191    if (!ctx) {
 192       printf("Error: glXCreateContext failed\n");
 193       exit(1);
 194    }
 195
 196    *surfRet = eglCreateWindowSurface(egl_dpy, config, win, NULL);
 197
 198    if (!*surfRet) {
 199       printf("Error: eglCreateWindowSurface failed\n");
 200       exit(1);
 201    }
 202
 203    XFree(visInfo);
 204
 205    *winRet = win;
 206    *ctxRet = ctx;
 207 }
 208
 209
 210 static void
 211 event_loop(Display *dpy, Window win,
 212            EGLDisplay egl_dpy, EGLSurface egl_surf)
 213 {
 214    while (1) {
 215       int redraw = 0;
 216       XEvent event;
 217
 218       XNextEvent(dpy, &event);
 219
 220       switch (event.type) {
 221       case Expose:
 222          redraw = 1;
 223          break;
 224       case ConfigureNotify:
 225          reshape(event.xconfigure.width, event.xconfigure.height);
 226          break;
 227       case KeyPress:
 228          {
 229             char buffer[10];
 230             int r, code;
 231             code = XLookupKeysym(&event.xkey, 0);
 232             if (code == XK_Left) {
 233                view_roty += 5.0;
 234             }
 235             else if (code == XK_Right) {
 236                view_roty -= 5.0;
 237             }
 238             else if (code == XK_Up) {
 239                view_rotx += 5.0;
 240             }
 241             else if (code == XK_Down) {
 242                view_rotx -= 5.0;
 243             }
 244             else {
 245                r = XLookupString(&event.xkey, buffer, sizeof(buffer),
 246                                  NULL, NULL);
 247                if (buffer[0] == 27) {
 248                   /* escape */
 249                   return;
 250                }
 251             }
 252          }
 253          redraw = 1;
 254          break;
 255       default:
 256          ; /*no-op*/
 257       }
 258
 259       if (redraw) {
 260          draw();
 261          eglSwapBuffers(egl_dpy, egl_surf);
 262       }
 263    }
 264 }
 265
 266
 267 static void
 268 usage(void)
 269 {
 270    printf("Usage:\n");
 271    printf("  -display <displayname>  set the display to run on\n");
 272    printf("  -info                   display OpenGL renderer info\n");
 273 }
 274
 275
 276 int
 277 main(int argc, char *argv[])
 278 {
 279    const int winWidth = 300, winHeight = 300;
 280    Display *x_dpy;
 281    Window win;
 282    EGLSurface egl_surf;
 283    EGLContext egl_ctx;
 284    EGLDisplay egl_dpy;
 285    char *dpyName = NULL;
 286    GLboolean printInfo = GL_FALSE;
 287    EGLint egl_major, egl_minor;
 288    int i;
 289    const char *s;
 290
 291    for (i = 1; i < argc; i++) {
 292       if (strcmp(argv[i], "-display") == 0) {
 293          dpyName = argv[i+1];
 294          i++;
 295       }
 296       else if (strcmp(argv[i], "-info") == 0) {
 297          printInfo = GL_TRUE;
 298       }
 299       else {
 300          usage();
 301          return -1;
 302       }
 303    }
 304
 305    x_dpy = XOpenDisplay(dpyName);
 306    if (!x_dpy) {
 307       printf("Error: couldn't open display %s\n",
 308              dpyName ? dpyName : getenv("DISPLAY"));
 309       return -1;
 310    }
 311
 312    egl_dpy = eglGetDisplay(x_dpy);
 313    if (!egl_dpy) {
 314       printf("Error: eglGetDisplay() failed\n");
 315       return -1;
 316    }
 317
 318    if (!eglInitialize(egl_dpy, &egl_major, &egl_minor)) {
 319       printf("Error: eglInitialize() failed\n");
 320       return -1;
 321    }
 322
 323    s = eglQueryString(egl_dpy, EGL_VERSION);
 324    printf("EGL_VERSION = %s\n", s);
 325
 326    make_x_window(x_dpy, egl_dpy,
 327                  "xegl_tri", 0, 0, winWidth, winHeight,
 328                  &win, &egl_ctx, &egl_surf);
 329
 330    XMapWindow(x_dpy, win);
 331    if (!eglMakeCurrent(egl_dpy, egl_surf, egl_surf, egl_ctx)) {
 332       printf("Error: eglMakeCurrent() failed\n");
 333       return -1;
 334    }
 335
 336    if (printInfo) {
 337       printf("GL_RENDERER   = %s\n", (char *) glGetString(GL_RENDERER));
 338       printf("GL_VERSION    = %s\n", (char *) glGetString(GL_VERSION));
 339       printf("GL_VENDOR     = %s\n", (char *) glGetString(GL_VENDOR));
 340    }
 341
 342    init();
 343
 344    /* Set initial projection/viewing transformation.
 345     * We can't be sure we'll get a ConfigureNotify event when the window
 346     * first appears.
 347     */
 348    reshape(winWidth, winHeight);
 349
 350    event_loop(x_dpy, win, egl_dpy, egl_surf);
 351
 352    eglDestroyContext(egl_dpy, egl_ctx);
 353    eglDestroySurface(egl_dpy, egl_surf);
 354    eglTerminate(egl_dpy);
 355
 356
 357    XDestroyWindow(x_dpy, win);
 358    XCloseDisplay(x_dpy);
 359
 360    return 0;
 361 }