/*
 * Copyright (C) 2008  Tunsgten Graphics,Inc.   All Rights Reserved.
 */

/*
 * List OpenGL ES extensions.
 * Print ES 1 or ES 2 extensions depending on which library we're
 * linked with: libGLESv1_CM.so vs libGLESv2.so
 */

#define GL_GLEXT_PROTOTYPES

#include <assert.h>
#include <math.h>
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <X11/Xlib.h>
#include <X11/Xutil.h>
#include <X11/keysym.h>
#include <GLES/gl.h>
#include <GLES/glext.h>
#include <EGL/egl.h>


/*
 * Print a list of extensions, with word-wrapping.
 */
static void
print_extension_list(const char *ext)
{
   const char *indentString = "    ";
   const int indent = 4;
   const int max = 79;
   int width, i, j;

   if (!ext || !ext[0])
      return;

   width = indent;
   printf(indentString);
   i = j = 0;
   while (1) {
      if (ext[j] == ' ' || ext[j] == 0) {
         /* found end of an extension name */
         const int len = j - i;
         if (width + len > max) {
            /* start a new line */
            printf("\n");
            width = indent;
            printf(indentString);
         }
         /* print the extension name between ext[i] and ext[j] */
         while (i < j) {
            printf("%c", ext[i]);
            i++;
         }
         /* either we're all done, or we'll continue with next extension */
         width += len + 1;
         if (ext[j] == 0) {
            break;
         }
         else {
            i++;
            j++;
            if (ext[j] == 0)
               break;
            printf(", ");
            width += 2;
         }
      }
      j++;
   }
   printf("\n");
}


static void
info(EGLDisplay egl_dpy)
{
   const char *s;

   s = eglQueryString(egl_dpy, EGL_VERSION);
   printf("EGL_VERSION = %s\n", s);

   s = eglQueryString(egl_dpy, EGL_VENDOR);
   printf("EGL_VENDOR = %s\n", s);

   s = eglQueryString(egl_dpy, EGL_EXTENSIONS);
   printf("EGL_EXTENSIONS = %s\n", s);

   s = eglQueryString(egl_dpy, EGL_CLIENT_APIS);
   printf("EGL_CLIENT_APIS = %s\n", s);

   printf("GL_VERSION: %s\n", (char *) glGetString(GL_VERSION));
   printf("GL_RENDERER: %s\n", (char *) glGetString(GL_RENDERER));
   printf("GL_EXTENSIONS:\n");
   print_extension_list((char *) glGetString(GL_EXTENSIONS));
}


/*
 * Create an RGB, double-buffered X window.
 * Return the window and context handles.
 */
static void
make_x_window(Display *x_dpy, EGLDisplay egl_dpy,
              const char *name,
              int x, int y, int width, int height,
              Window *winRet,
              EGLContext *ctxRet,
              EGLSurface *surfRet)
{
   static const EGLint attribs[] = {
      EGL_RED_SIZE, 1,
      EGL_GREEN_SIZE, 1,
      EGL_BLUE_SIZE, 1,
      EGL_NONE
   };

   int scrnum;
   XSetWindowAttributes attr;
   unsigned long mask;
   Window root;
   Window win;
   XVisualInfo *visInfo, visTemplate;
   int num_visuals;
   EGLContext ctx;
   EGLConfig config;
   EGLint num_configs;
   EGLint vid;

   scrnum = DefaultScreen( x_dpy );
   root = RootWindow( x_dpy, scrnum );

   if (!eglChooseConfig( egl_dpy, attribs, &config, 1, &num_configs)) {
      printf("Error: couldn't get an EGL visual config\n");
      exit(1);
   }

   assert(config);
   assert(num_configs > 0);

   if (!eglGetConfigAttrib(egl_dpy, config, EGL_NATIVE_VISUAL_ID, &vid)) {
      printf("Error: eglGetConfigAttrib() failed\n");
      exit(1);
   }

   /* The X window visual must match the EGL config */
   visTemplate.visualid = vid;
   visInfo = XGetVisualInfo(x_dpy, VisualIDMask, &visTemplate, &num_visuals);
   if (!visInfo) {
      printf("Error: couldn't get X visual\n");
      exit(1);
   }

   /* window attributes */
   attr.background_pixel = 0;
   attr.border_pixel = 0;
   attr.colormap = XCreateColormap( x_dpy, root, visInfo->visual, AllocNone);
   attr.event_mask = StructureNotifyMask | ExposureMask | KeyPressMask;
   mask = CWBackPixel | CWBorderPixel | CWColormap | CWEventMask;

   win = XCreateWindow( x_dpy, root, 0, 0, width, height,
		        0, visInfo->depth, InputOutput,
		        visInfo->visual, mask, &attr );

   /* set hints and properties */
   {
      XSizeHints sizehints;
      sizehints.x = x;
      sizehints.y = y;
      sizehints.width  = width;
      sizehints.height = height;
      sizehints.flags = USSize | USPosition;
      XSetNormalHints(x_dpy, win, &sizehints);
      XSetStandardProperties(x_dpy, win, name, name,
                              None, (char **)NULL, 0, &sizehints);
   }

   eglBindAPI(EGL_OPENGL_ES_API);

   ctx = eglCreateContext(egl_dpy, config, EGL_NO_CONTEXT, NULL );
   if (!ctx) {
      printf("Error: eglCreateContext failed\n");
      exit(1);
   }

   *surfRet = eglCreateWindowSurface(egl_dpy, config, win, NULL);

   if (!*surfRet) {
      printf("Error: eglCreateWindowSurface failed\n");
      exit(1);
   }

   XFree(visInfo);

   *winRet = win;
   *ctxRet = ctx;
}


static void
usage(void)
{
   printf("Usage:\n");
   printf("  -display <displayname>  set the display to run on\n");
}
 

int
main(int argc, char *argv[])
{
   const int winWidth = 400, winHeight = 300;
   Display *x_dpy;
   Window win;
   EGLSurface egl_surf;
   EGLContext egl_ctx;
   EGLDisplay egl_dpy;
   char *dpyName = NULL;
   EGLint egl_major, egl_minor;
   int i;

   for (i = 1; i < argc; i++) {
      if (strcmp(argv[i], "-display") == 0) {
         dpyName = argv[i+1];
         i++;
      }
      else {
         usage();
         return -1;
      }
   }

   x_dpy = XOpenDisplay(dpyName);
   if (!x_dpy) {
      printf("Error: couldn't open display %s\n",
	     dpyName ? dpyName : getenv("DISPLAY"));
      return -1;
   }

   egl_dpy = eglGetDisplay(x_dpy);
   if (!egl_dpy) {
      printf("Error: eglGetDisplay() failed\n");
      return -1;
   }

   if (!eglInitialize(egl_dpy, &egl_major, &egl_minor)) {
      printf("Error: eglInitialize() failed\n");
      return -1;
   }

   make_x_window(x_dpy, egl_dpy,
                 "ES info", 0, 0, winWidth, winHeight,
                 &win, &egl_ctx, &egl_surf);

   /*XMapWindow(x_dpy, win);*/
   if (!eglMakeCurrent(egl_dpy, egl_surf, egl_surf, egl_ctx)) {
      printf("Error: eglMakeCurrent() failed\n");
      return -1;
   }

   info(egl_dpy);

   eglDestroyContext(egl_dpy, egl_ctx);
   eglDestroySurface(egl_dpy, egl_surf);
   eglTerminate(egl_dpy);


   XDestroyWindow(x_dpy, win);
   XCloseDisplay(x_dpy);

   return 0;
}