rne-triangle.cpp

/*
 * If not stated otherwise in this file or this component's Licenses.txt file the
 * following copyright and licenses apply:
 *
 * Copyright 2018 RDK Management
 * Copyright 2005-2018 John Robinson
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
/*
 * Copyright © 2010 Intel Corporation
 * Copyright © 2011 Benjamin Franzke
 * Copyright © 2012-2013 Collabora, Ltd.
 *
 * Permission is hereby granted, free of charge, to any person obtaining a
 * copy of this software and associated documentation files (the "Software"),
 * to deal in the Software without restriction, including without limitation
 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
 * and/or sell copies of the Software, and to permit persons to whom the
 * Software is furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice (including the next
 * paragraph) shall be included in all copies or substantial portions of the
 * Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
 * DEALINGS IN THE SOFTWARE.
 */
#include <stdlib.h>
#include <stdio.h>
#include <memory.h>
#include <assert.h>
#include <errno.h>
#include <unistd.h>
#include <signal.h>
#include <termios.h>
#include <sys/mman.h>
#include <sys/time.h>
 
#include <EGL/egl.h>
#include <EGL/eglext.h>
 
#include <GLES2/gl2.h>
#include <GLES2/gl2ext.h>
 
#include <xkbcommon/xkbcommon.h>
 
#include "wayland-client.h"
#include "wayland-egl.h"
#include "simpleshell-client-protocol.h"
 
#define UNUSED(x) ((void)x)
 
#if !defined (XKB_KEYMAP_COMPILE_NO_FLAGS)
#define XKB_KEYMAP_COMPILE_NO_FLAGS XKB_MAP_COMPILE_NO_FLAGS
#endif
 
static void registryHandleGlobal(void *data, 
                                 struct wl_registry *registry, uint32_t id,
                                           const char *interface, uint32_t version);
static void registryHandleGlobalRemove(void *data, 
                                       struct wl_registry *registry,
                                                      uint32_t name);
 
static const struct wl_registry_listener registryListener = 
{
        registryHandleGlobal,
        registryHandleGlobalRemove
};
 
static void shellSurfaceId(void *data,
                           struct wl_simple_shell *wl_simple_shell,
                           struct wl_surface *surface,
                           uint32_t surfaceId);
static void shellSurfaceCreated(void *data,
                                struct wl_simple_shell *wl_simple_shell,
                                uint32_t surfaceId,
                                const char *name);
static void shellSurfaceDestroyed(void *data,
                                  struct wl_simple_shell *wl_simple_shell,
                                  uint32_t surfaceId,
                                  const char *name);
static void shellSurfaceStatus(void *data,
                               struct wl_simple_shell *wl_simple_shell,
                               uint32_t surfaceId,
                               const char *name,
                               uint32_t visible,
                               int32_t x,
                               int32_t y,
                               int32_t width,
                               int32_t height,
                               wl_fixed_t opacity,
                               wl_fixed_t zorder);
static void shellGetSurfacesDone(void *data,
                                 struct wl_simple_shell *wl_simple_shell);
 
static const struct wl_simple_shell_listener shellListener = 
{
   shellSurfaceId,
   shellSurfaceCreated,
   shellSurfaceDestroyed,
   shellSurfaceStatus,
   shellGetSurfacesDone
};
 
typedef enum _InputState
{
   InputState_main,
   InputState_attribute,
} InputState;
 
typedef enum _Attribute
{
   Attribute_position,
   Attribute_size,
   Attribute_visibility,
   Attribute_opacity,
   Attribute_zorder
} Attribute;
 
typedef struct _AppCtx
{
   struct wl_display *display;
   struct wl_registry *registry;
   struct wl_shm *shm;
   struct wl_compositor *compositor;
   struct wl_simple_shell *shell;
   struct wl_seat *seat;
   struct wl_keyboard *keyboard;
   struct wl_pointer *pointer;
   struct wl_touch *touch;
   struct wl_surface *surface;
   struct wl_output *output;
   struct wl_egl_window *native;
   struct wl_callback *frameCallback;
 
   struct xkb_context *xkbCtx;
   struct xkb_keymap *xkbKeymap;
   struct xkb_state *xkbState;
   xkb_mod_index_t modAlt;
   xkb_mod_index_t modCtrl;
 
   EGLDisplay eglDisplay;
   EGLConfig eglConfig;
   EGLSurface eglSurfaceWindow;
   EGLContext eglContext;   
   EGLImageKHR eglImage;
   EGLNativePixmapType eglPixmap;
 
   bool getShell;
   InputState inputState;
   Attribute attribute;
   
   int planeX;
   int planeY;
   int planeWidth;
   int planeHeight;
 
   uint32_t surfaceIdOther;
   uint32_t surfaceIdCurrent;
   float surfaceOpacity;
   float surfaceZOrder;
   bool surfaceVisible;   
   int surfaceX;
   int surfaceY;
   int surfaceWidth;
   int surfaceHeight;
   
   int surfaceDX;
   int surfaceDY;
   int surfaceDWidth;
   int surfaceDHeight;
 
        struct 
        {
                GLuint rotation_uniform;
                GLuint pos;
                GLuint col;
        } gl;
        long long startTime;
        long long currTime;
        bool noAnimation;
        bool needRedraw;
        bool verboseLog;
        int pointerX, pointerY;
} AppCtx;
 
 
static void processInput( AppCtx *ctx, uint32_t sym );
static void drawFrame( AppCtx *ctx );
static bool setupEGL( AppCtx *ctx );
static void termEGL( AppCtx *ctx );
static bool createSurface( AppCtx *ctx );
static void resizeSurface( AppCtx *ctx, int dx, int dy, int width, int height );
static void destroySurface( AppCtx *ctx );
static bool setupGL( AppCtx *ctx );
static bool renderGL( AppCtx *ctx );
 
int g_running= 0;
int g_log= 0;
 
static void signalHandler(int signum)
{
   printf("signalHandler: signum %d\n", signum);
        g_running = 0;
}
 
static long long currentTimeMillis()
{
   long long timeMillis;
   struct timeval tv;   
 
   gettimeofday(&tv, NULL);
   timeMillis = tv.tv_sec * 1000 + tv.tv_usec / 1000;
   
   return timeMillis;
}
 
static void shmFormat(void *data, struct wl_shm *wl_shm, uint32_t format)
{
   AppCtx *ctx = (AppCtx*)data;
 
   printf("shm format: %X\n", format);
}
 
struct wl_shm_listener shmListener = {
        shmFormat
};
 
static void keyboardKeymap( void *data, struct wl_keyboard *keyboard, uint32_t format, int32_t fd, uint32_t size )
{
   AppCtx *ctx= (AppCtx*)data;
 
   if ( format == WL_KEYBOARD_KEYMAP_FORMAT_XKB_V1 )
   {
      void *map= mmap( 0, size, PROT_READ, MAP_SHARED, fd, 0 );
      if ( map != MAP_FAILED )
      {
         if ( !ctx->xkbCtx )
         {
            ctx->xkbCtx= xkb_context_new( XKB_CONTEXT_NO_FLAGS );
         }
         else
         {
            printf("error: xkb_context_new failed\n");
         }
         if ( ctx->xkbCtx )
         {
            if ( ctx->xkbKeymap )
            {
               xkb_keymap_unref( ctx->xkbKeymap );
               ctx->xkbKeymap= 0;
            }
            ctx->xkbKeymap= xkb_keymap_new_from_string( ctx->xkbCtx, (char*)map, XKB_KEYMAP_FORMAT_TEXT_V1, XKB_KEYMAP_COMPILE_NO_FLAGS);
            if ( !ctx->xkbKeymap )
            {
               printf("error: xkb_keymap_new_from_string failed\n");
            }
            if ( ctx->xkbState )
            {
               xkb_state_unref( ctx->xkbState );
               ctx->xkbState= 0;
            }
            ctx->xkbState= xkb_state_new( ctx->xkbKeymap );
            if ( !ctx->xkbState )
            {
               printf("error: xkb_state_new failed\n");
            }
            if ( ctx->xkbKeymap )
            {
               ctx->modAlt= xkb_keymap_mod_get_index( ctx->xkbKeymap, XKB_MOD_NAME_ALT );
               ctx->modCtrl= xkb_keymap_mod_get_index( ctx->xkbKeymap, XKB_MOD_NAME_CTRL );
            }
            munmap( map, size );
         }
      }
   }
 
   close( fd );
}
 
static void keyboardEnter( void *data, struct wl_keyboard *keyboard, uint32_t serial,
                           struct wl_surface *surface, struct wl_array *keys )
{
   UNUSED(data);
   UNUSED(keyboard);
   UNUSED(serial);
   UNUSED(keys);
 
   printf("keyboard enter surface %p\n", surface );
}
 
static void keyboardLeave( void *data, struct wl_keyboard *keyboard, uint32_t serial, struct wl_surface *surface )
{
   UNUSED(data);
   UNUSED(keyboard);
   UNUSED(serial);
 
   printf("keyboard leave surface %p\n", surface );
}
 
static void keyboardKey( void *data, struct wl_keyboard *keyboard, uint32_t serial,
                         uint32_t time, uint32_t key, uint32_t state )
{
   AppCtx *ctx= (AppCtx*)data;
   UNUSED(keyboard);
   UNUSED(serial);
   xkb_keycode_t keyCode;
   uint32_t sym;
 
   if ( ctx->xkbState )
   {
      // As per wayland protocol for XKB_V1 map, we must add 8 to the key code
      keyCode= key+8;
 
      sym= xkb_state_key_get_one_sym( ctx->xkbState, keyCode );
 
      if ( ctx->verboseLog )
      {
         int ctrl= 0;
         int alt= 0;
 
         if ( xkb_state_mod_index_is_active( ctx->xkbState, ctx->modCtrl, XKB_STATE_MODS_DEPRESSED) == 1 )
         {
            ctrl= 1;
         }
 
         if ( xkb_state_mod_index_is_active( ctx->xkbState, ctx->modAlt, XKB_STATE_MODS_DEPRESSED) == 1 )
         {
            alt= 1;
         }
 
         printf("keyboardKey: sym %X state %s ctrl %d alt %d time %u\n",
                sym, (state == WL_KEYBOARD_KEY_STATE_PRESSED ? "Down" : "Up"), ctrl, alt, time);
      }
 
      if ( state == WL_KEYBOARD_KEY_STATE_PRESSED )
      {
         processInput( ctx, sym );
      }
   }
}
 
static void keyboardModifiers( void *data, struct wl_keyboard *keyboard, uint32_t serial,
                               uint32_t mods_depressed, uint32_t mods_latched,
                               uint32_t mods_locked, uint32_t group )
{
   AppCtx *ctx= (AppCtx*)data;
   if ( ctx->xkbState )
   {
      xkb_state_update_mask( ctx->xkbState, mods_depressed, mods_latched, mods_locked, 0, 0, group );
   }
}
 
static void keyboardRepeatInfo( void *data, struct wl_keyboard *keyboard, int32_t rate, int32_t delay )
{
   UNUSED(data);
   UNUSED(keyboard);
   UNUSED(rate);
   UNUSED(delay);
}
 
static const struct wl_keyboard_listener keyboardListener= {
   keyboardKeymap,
   keyboardEnter,
   keyboardLeave,
   keyboardKey,
   keyboardModifiers,
   keyboardRepeatInfo
};
 
static void pointerEnter( void* data, struct wl_pointer *pointer, uint32_t serial,
                          struct wl_surface *surface, wl_fixed_t sx, wl_fixed_t sy )
{
   UNUSED(pointer);
   UNUSED(serial);
   AppCtx *ctx= (AppCtx*)data;
   int x, y;
 
   x= wl_fixed_to_int( sx );
   y= wl_fixed_to_int( sy );
 
   ctx->pointerX= x;
   ctx->pointerY= y;
 
   printf("pointer enter surface %p (%d,%d)\n", surface, x, y );
}
 
static void pointerLeave( void* data, struct wl_pointer *pointer, uint32_t serial, struct wl_surface *surface )
{
   UNUSED(data);
   UNUSED(pointer);
   UNUSED(serial);
 
   printf("pointer leave surface %p\n", surface );
}
 
static void pointerMotion( void *data, struct wl_pointer *pointer, uint32_t time, wl_fixed_t sx, wl_fixed_t sy )
{
   UNUSED(pointer);
   AppCtx *ctx= (AppCtx*)data;
   int x, y;
 
   x= wl_fixed_to_int( sx );
   y= wl_fixed_to_int( sy );
 
   ctx->pointerX= x;
   ctx->pointerY= y;
 
   if ( ctx->verboseLog )
   {
      printf("pointer motion surface (%d,%d) time %u\n", x, y, time );
   }
}
 
static void pointerButton( void *data, struct wl_pointer *pointer, uint32_t serial,
                           uint32_t time, uint32_t button, uint32_t state )
{
   UNUSED(pointer);
   UNUSED(serial);
   AppCtx *ctx= (AppCtx*)data;
 
   printf("pointer button %u state %u (%d, %d)\n", button, state, ctx->pointerX, ctx->pointerY);
   ctx->verboseLog= (state == WL_POINTER_BUTTON_STATE_PRESSED);
}
 
static void pointerAxis( void *data, struct wl_pointer *pointer, uint32_t time,
                         uint32_t axis, wl_fixed_t value )
{
   UNUSED(data);
   UNUSED(pointer);
   UNUSED(time);
   int v;
 
   v= wl_fixed_to_int( value );
   printf("pointer axis %u value %d\n", axis, v);
}
 
static const struct wl_pointer_listener pointerListener = {
   pointerEnter,
   pointerLeave,
   pointerMotion,
   pointerButton,
   pointerAxis
};
 
static void seatCapabilities( void *data, struct wl_seat *seat, uint32_t capabilities )
{
        AppCtx *ctx = (AppCtx*)data;
 
   printf("seat %p caps: %X\n", seat, capabilities );
   
   if ( capabilities & WL_SEAT_CAPABILITY_KEYBOARD )
   {
      printf("  seat has keyboard\n");
      ctx->keyboard= wl_seat_get_keyboard( ctx->seat );
      printf("  keyboard %p\n", ctx->keyboard );
      wl_keyboard_add_listener( ctx->keyboard, &keyboardListener, ctx );
   }
   if ( capabilities & WL_SEAT_CAPABILITY_POINTER )
   {
      printf("  seat has pointer\n");
      ctx->pointer= wl_seat_get_pointer( ctx->seat );
      printf("  pointer %p\n", ctx->pointer );
      wl_pointer_add_listener( ctx->pointer, &pointerListener, ctx );
   }
   if ( capabilities & WL_SEAT_CAPABILITY_TOUCH )
   {
      printf("  seat has touch\n");
      ctx->touch= wl_seat_get_touch( ctx->seat );
      printf("  touch %p\n", ctx->touch );
   }   
}
 
static void seatName( void *data, struct wl_seat *seat, const char *name )
{
        AppCtx *ctx = (AppCtx*)data;
   printf("seat %p name: %s\n", seat, name);
}
 
static const struct wl_seat_listener seatListener = {
   seatCapabilities,
   seatName 
};
 
static void outputGeometry( void *data, struct wl_output *output, int32_t x, int32_t y,
                            int32_t physical_width, int32_t physical_height, int32_t subpixel,
                            const char *make, const char *model, int32_t transform )
{
   UNUSED(data);
   UNUSED(output);
   UNUSED(x);
   UNUSED(y);
   UNUSED(physical_width);
   UNUSED(physical_height);
   UNUSED(subpixel);
   UNUSED(make);
   UNUSED(model);
   UNUSED(transform);
}
 
static void outputMode( void *data, struct wl_output *output, uint32_t flags,
                        int32_t width, int32_t height, int32_t refresh )
{
        AppCtx *ctx = (AppCtx*)data;
 
   if ( flags & WL_OUTPUT_MODE_CURRENT )
   {
      if ( (width !=  ctx->planeWidth) || (height != ctx->planeHeight) )
      {
         ctx->planeWidth= width;
         ctx->planeHeight= height;
         if ( ctx->verboseLog )
         {
            printf("outputMode: resize egl window to (%d,%d)\n", ctx->planeWidth, ctx->planeHeight );
         }
         resizeSurface( ctx, 0, 0, ctx->planeWidth, ctx->planeHeight);
      }
   }
}
 
static void outputDone( void *data, struct wl_output *output )
{
   UNUSED(data);
   UNUSED(output);
}
 
static void outputScale( void *data, struct wl_output *output, int32_t factor )
{
   UNUSED(data);
   UNUSED(output);
   UNUSED(factor);
}
 
static const struct wl_output_listener outputListener = {
   outputGeometry,
   outputMode,
   outputDone,
   outputScale
};
 
static void registryHandleGlobal(void *data, 
                                 struct wl_registry *registry, uint32_t id,
                                           const char *interface, uint32_t version)
{
        AppCtx *ctx = (AppCtx*)data;
        int len;
 
   printf("rne-triangle: registry: id %d interface (%s) version %d\n", id, interface, version );
 
   len= strlen(interface);
   if ( (len==6) && !strncmp(interface, "wl_shm", len)) {
      ctx->shm= (struct wl_shm*)wl_registry_bind(registry, id, &wl_shm_interface, 1);
      printf("shm %p\n", ctx->shm);
                wl_shm_add_listener(ctx->shm, &shmListener, ctx);
   }
   else if ( (len==13) && !strncmp(interface, "wl_compositor", len) ) {
      ctx->compositor= (struct wl_compositor*)wl_registry_bind(registry, id, &wl_compositor_interface, 1);
      printf("compositor %p\n", ctx->compositor);
   } 
   else if ( (len==7) && !strncmp(interface, "wl_seat", len) ) {
      ctx->seat= (struct wl_seat*)wl_registry_bind(registry, id, &wl_seat_interface, 4);
      printf("seat %p\n", ctx->seat);
                wl_seat_add_listener(ctx->seat, &seatListener, ctx);
   }
   else if ( (len==9) && !strncmp(interface, "wl_output", len) ) {
      ctx->output= (struct wl_output*)wl_registry_bind(registry, id, &wl_output_interface, 2);
      printf("output %p\n", ctx->output);
      wl_output_add_listener(ctx->output, &outputListener, ctx);
   }
   else if ( (len==15) && !strncmp(interface, "wl_simple_shell", len) ) {
      if ( ctx->getShell ) {
         ctx->shell= (struct wl_simple_shell*)wl_registry_bind(registry, id, &wl_simple_shell_interface, 1);      
         printf("shell %p\n", ctx->shell );
         wl_simple_shell_add_listener(ctx->shell, &shellListener, ctx);
      }
   }
}
 
static void registryHandleGlobalRemove(void *data, 
                                       struct wl_registry *registry,
                                                      uint32_t name)
{
}
 
static void shellSurfaceId(void *data,
                           struct wl_simple_shell *wl_simple_shell,
                           struct wl_surface *surface,
                           uint32_t surfaceId)
{
        AppCtx *ctx = (AppCtx*)data;
   char name[32];
  
        sprintf( name, "rne-triangle-surface-%x", surfaceId );
   printf("shell: surface created: %p id %x\n", surface, surfaceId);
        wl_simple_shell_set_name( ctx->shell, surfaceId, name );
}
                           
static void shellSurfaceCreated(void *data,
                                struct wl_simple_shell *wl_simple_shell,
                                uint32_t surfaceId,
                                const char *name)
{
        AppCtx *ctx = (AppCtx*)data;
 
   printf("shell: surface created: %x name: %s\n", surfaceId, name);
   ctx->surfaceIdOther= ctx->surfaceIdCurrent;
   ctx->surfaceIdCurrent= surfaceId;   
   wl_simple_shell_get_status( ctx->shell, ctx->surfaceIdCurrent );
   printf("shell: surfaceCurrent: %x surfaceOther: %x\n", ctx->surfaceIdCurrent, ctx->surfaceIdOther);
}
 
static void shellSurfaceDestroyed(void *data,
                                  struct wl_simple_shell *wl_simple_shell,
                                  uint32_t surfaceId,
                                  const char *name)
{
        AppCtx *ctx = (AppCtx*)data;
        
   printf("shell: surface destroyed: %x name: %s\n", surfaceId, name);
   
   if ( ctx->surfaceIdCurrent == surfaceId )
   {
      ctx->surfaceIdCurrent= ctx->surfaceIdOther;
      ctx->surfaceIdOther= 0;
      wl_simple_shell_get_status( ctx->shell, ctx->surfaceIdCurrent );
   }
   if ( ctx->surfaceIdOther == surfaceId )
   {
      ctx->surfaceIdOther= 0;
   }
   printf("shell: surfaceCurrent: %x surfaceOther: %x\n", ctx->surfaceIdCurrent, ctx->surfaceIdOther);
}
                                  
static void shellSurfaceStatus(void *data,
                               struct wl_simple_shell *wl_simple_shell,
                               uint32_t surfaceId,
                               const char *name,
                               uint32_t visible,
                               int32_t x,
                               int32_t y,
                               int32_t width,
                               int32_t height,
                               wl_fixed_t opacity,
                               wl_fixed_t zorder)
{
        AppCtx *ctx = (AppCtx*)data;
 
   printf("shell: surface: %x name: %s\n", surfaceId, name);
   printf("shell: position (%d,%d,%d,%d) visible %d opacity %f zorder %f\n",
           x, y, width, height, visible, wl_fixed_to_double(opacity), wl_fixed_to_double(zorder) );
 
   ctx->surfaceVisible= visible;
   ctx->surfaceX= x;
   ctx->surfaceY= y;
   ctx->surfaceWidth= width;
   ctx->surfaceHeight= height;
   ctx->surfaceOpacity= wl_fixed_to_double(opacity);
   ctx->surfaceZOrder= wl_fixed_to_double(zorder);   
}                               
 
static void shellGetSurfacesDone(void *data,
                                 struct wl_simple_shell *wl_simple_shell)
{
        AppCtx *ctx = (AppCtx*)data;
        printf("shell: get all surfaces done\n");
}                                        
 
#define NON_BLOCKING_ENABLED (0)
#define NON_BLOCKING_DISABLED (1)
 
static void setBlockingMode(int blockingState )  
{  
   struct termios ttystate;
   int mask, bits;  
 
   mask= (blockingState == NON_BLOCKING_ENABLED) ? ~(ICANON|ECHO) : -1;
   bits= (blockingState == NON_BLOCKING_ENABLED) ? 0 : (ICANON|ECHO);
 
   // Obtain the current terminal state and alter the attributes to achieve 
   // the requested blocking behaviour
   tcgetattr(STDIN_FILENO, &ttystate);  
 
   ttystate.c_lflag= ((ttystate.c_lflag & mask) | bits);  
 
   if (blockingState == NON_BLOCKING_ENABLED)  
   {  
       ttystate.c_cc[VMIN]= 1;  
   }  
 
   tcsetattr(STDIN_FILENO, TCSANOW, &ttystate);   
}
 
static bool isKeyHit()
{
   bool keyHit= false;
   fd_set fdset;
   struct timeval tval;
 
   // do a non-blocking check to see if any keys
   // are ready to read from stdin
   tval.tv_sec= 0;
   tval.tv_usec= 0;
   FD_ZERO(&fdset);
   FD_SET(STDIN_FILENO, &fdset);
   select(STDIN_FILENO+1, &fdset, NULL, NULL, &tval);
 
   keyHit= FD_ISSET(STDIN_FILENO, &fdset);
 
   return keyHit;
}
 
static void adjustAttribute( AppCtx *ctx, uint32_t sym )
{
   switch( ctx->attribute )
   {
      case Attribute_position:
         switch( sym )
         {
            case XKB_KEY_Up:
               --ctx->surfaceDY;
               break;
            case XKB_KEY_Down:
               ++ctx->surfaceDY;
               break;
            case XKB_KEY_Right:
               ++ctx->surfaceDX;
               break;
            case XKB_KEY_Left:
               --ctx->surfaceDX;
               break;
         }
         break;
      case Attribute_size:
         switch( sym )
         {
            case XKB_KEY_Up:
               --ctx->surfaceDHeight;
               break;
            case XKB_KEY_Down:
               ++ctx->surfaceDHeight;
               break;
            case XKB_KEY_Right:
               ++ctx->surfaceDWidth;
               break;
            case XKB_KEY_Left:
               --ctx->surfaceDWidth;
               break;
         }
         break;
      case Attribute_visibility:
         switch( sym )
         {
            case XKB_KEY_Up:
            case XKB_KEY_Right:
            case XKB_KEY_Down:
            case XKB_KEY_Left:
               ctx->surfaceVisible= !ctx->surfaceVisible;
               wl_simple_shell_set_visible( ctx->shell, ctx->surfaceIdCurrent, (ctx->surfaceVisible ? 1 : 0) );
               break;
         }
         break;
      case Attribute_opacity:
         switch( sym )
         {
            case XKB_KEY_Up:
            case XKB_KEY_Right:
               ctx->surfaceOpacity += 0.1;
               if ( ctx->surfaceOpacity > 1.0 )
               {
                  ctx->surfaceOpacity= 1.0;
               }
               wl_simple_shell_set_opacity( ctx->shell, ctx->surfaceIdCurrent, wl_fixed_from_double(ctx->surfaceOpacity) );
               break;
            case XKB_KEY_Down:
            case XKB_KEY_Left:
               ctx->surfaceOpacity -= 0.1;
               if ( ctx->surfaceOpacity < 0.0 )
               {
                  ctx->surfaceOpacity= 0.0;
               }
               wl_simple_shell_set_opacity( ctx->shell, ctx->surfaceIdCurrent, wl_fixed_from_double(ctx->surfaceOpacity) );
               break;
         }
         break;
      case Attribute_zorder:
         switch( sym )
         {
            case XKB_KEY_Up:
            case XKB_KEY_Right:
               ctx->surfaceZOrder += 0.1;
               if ( ctx->surfaceZOrder > 1.0 )
               {
                  ctx->surfaceZOrder= 1.0;
               }
               wl_simple_shell_set_zorder( ctx->shell, ctx->surfaceIdCurrent, wl_fixed_from_double(ctx->surfaceZOrder) );
               break;
            case XKB_KEY_Down:
            case XKB_KEY_Left:
               ctx->surfaceZOrder -= 0.1;
               if ( ctx->surfaceZOrder < 0.0 )
               {
                  ctx->surfaceZOrder= 0.0;
               }
               wl_simple_shell_set_zorder( ctx->shell, ctx->surfaceIdCurrent, wl_fixed_from_double(ctx->surfaceZOrder) );
               break;
         }
         break;
   }
}
 
static void processInputMain( AppCtx *ctx, uint32_t sym )
{
   switch( sym )
   {
      case XKB_KEY_Left:
      case XKB_KEY_Up:
      case XKB_KEY_Right:
      case XKB_KEY_Down:
         if ( ctx->surfaceIdCurrent )
         {
            adjustAttribute( ctx, sym );
         }
         break;
      case XKB_KEY_a:
         ctx->inputState= InputState_attribute;
         printf("attribute: (p) osition, (s) ize, (v) isible, (o) pacity, (z) order (x) back to main\n");
         break;
      case XKB_KEY_s:
         if ( ctx->surfaceIdCurrent )
         {
            wl_simple_shell_get_status( ctx->shell, ctx->surfaceIdCurrent );
         }
         break;
      case XKB_KEY_n:
         if ( ctx->surfaceIdOther )
         {
            uint32_t temp= ctx->surfaceIdCurrent;
            ctx->surfaceIdCurrent= ctx->surfaceIdOther;
            ctx->surfaceIdOther= temp;
            printf("shell: surfaceCurrent: %x surfaceOther: %x\n", ctx->surfaceIdCurrent, ctx->surfaceIdOther);
            wl_simple_shell_get_status( ctx->shell, ctx->surfaceIdCurrent );
         }
         break;
      case XKB_KEY_l:
         if ( ctx->shell )
         {
             printf("get all surfaces:\n");
             wl_simple_shell_get_surfaces( ctx->shell );
         }
         break;
      case XKB_KEY_r:
         ctx->planeWidth= (ctx->planeWidth == 1280) ? 640 : 1280;
         ctx->planeHeight= (ctx->planeHeight == 720) ? 360 : 720;
         printf("resize egl window to (%d,%d)\n", ctx->planeWidth, ctx->planeHeight );
         resizeSurface( ctx, 0, 0, ctx->planeWidth, ctx->planeHeight);
         break;
   }
}
 
static void processInputAttribute( AppCtx *ctx, uint32_t sym )
{
   switch( sym )
   {
      case XKB_KEY_p:
         ctx->attribute= Attribute_position;
         break;
      case XKB_KEY_s:
         ctx->attribute= Attribute_size;
         break;
      case XKB_KEY_v:
         ctx->attribute= Attribute_visibility;
         break;
      case XKB_KEY_o:
         ctx->attribute= Attribute_opacity;
         break;
      case XKB_KEY_z:
         ctx->attribute= Attribute_zorder;
         break;
      default:
      case 'x':
         break;
   }
   ctx->inputState= InputState_main;
}
 
static void processInput( AppCtx *ctx, uint32_t sym )
{
   switch( ctx->inputState )
   {
      case InputState_main:
         processInputMain( ctx, sym );
         break;
      case InputState_attribute:
         processInputAttribute( ctx, sym );
         break;
   }
}
 
static void showUsage()
{
   printf("usage:\n");
   printf(" rne_triangle [options]\n" );
   printf("where [options] are:\n" );
   printf("  --delay <delay> : render loop delay\n" );
   printf("  --shell : use wl_simple_shell protocol\n" );
   printf("  --display <name> : wayland display to connect to\n" );
   printf("  --noframe : don't pace rendering with frame requests\n" );
   printf("  --noanimate : don't use animation\n" );
   printf("  -? : show usage\n" );
   printf("\n" );
}
 
static void redraw( void *data, struct wl_callback *callback, uint32_t time )
{
   AppCtx *ctx= (AppCtx*)data;
 
   if ( g_log ) printf("redraw: time %u\n", time);
   wl_callback_destroy( callback );
 
   ctx->needRedraw= true;
}
 
static struct wl_callback_listener frameListener=
{
   redraw
};
 
static void drawFrame( AppCtx *ctx )
{
   if ( ctx->surfaceDX || ctx->surfaceDY || ctx->surfaceDWidth || ctx->surfaceDHeight )
   {
      ctx->surfaceX += ctx->surfaceDX;
      ctx->surfaceY += ctx->surfaceDY;
      ctx->surfaceWidth += ctx->surfaceDWidth;
      ctx->surfaceHeight += ctx->surfaceDHeight;
      
      wl_simple_shell_set_geometry( ctx->shell, ctx->surfaceIdCurrent, 
                                    ctx->surfaceX, ctx->surfaceY, ctx->surfaceWidth, ctx->surfaceHeight );
   }
   
   renderGL(ctx);
   
   ctx->frameCallback= wl_surface_frame( ctx->surface );
   wl_callback_add_listener( ctx->frameCallback, &frameListener, ctx );
   
   eglSwapBuffers(ctx->eglDisplay, ctx->eglSurfaceWindow);
}
 
#define NUM_EVENTS (20)
int main( int argc, char** argv)
{
   int nRC= 0;
   AppCtx ctx;
        struct sigaction sigint;
   struct wl_display *display= 0;
   struct wl_registry *registry= 0;
   int count;
   int delay= 16667;
   const char *display_name= 0;
   bool paceRendering= true;
   EGLBoolean swapok;
 
   printf("rne_triangle: v1.0\n" );
 
   memset( &ctx, 0, sizeof(AppCtx) );
 
   for( int i= 1; i < argc; ++i )
   {
      if ( !strcmp( (const char*)argv[i], "--delay") )
      {
         printf("got delay: i %d argc %d\n", i, argc );
         if ( i+1 < argc )
         {
            int v= atoi(argv[++i]);
            printf("v=%d\n", v);
            if ( v > 0 )
            {
               delay= v;
               printf("using delay=%d\n", delay );
            }
         }
      }
      else if (!strcmp( (const char*)argv[i], "--shell" ) )
      {
         ctx.getShell= true;
      }
      else if ( !strcmp( (const char*)argv[i], "--display") )
      {
         if ( i+1 < argc )
         {
            ++i;
            display_name= argv[i];
         }
      }
      else if (!strcmp( (const char*)argv[i], "--noframe" ) )
      {
         paceRendering= false;
      }
      else if (!strcmp( (const char*)argv[i], "--log" ) )
      {
         g_log= true;
      }
      else if (!strcmp( (const char*)argv[i], "--noanimate" ) )
      {
         ctx.noAnimation= true;
      }
      else if ( !strcmp( (const char*)argv[i], "-?" ) )
      {
         showUsage();
         goto exit;
      }
   }
 
   ctx.startTime= currentTimeMillis();
   
   if ( display_name )
   {
      printf("calling wl_display_connect for display name %s\n", display_name);
   }
   else
   {
      printf("calling wl_display_connect for default display\n");
   }
   display= wl_display_connect(display_name);
   printf("wl_display_connect: display=%p\n", display);
   if ( !display )
   {
      printf("error: unable to connect to primary display\n");
      nRC= -1;
      goto exit;
   }
 
   printf("calling wl_display_get_registry\n");
   registry= wl_display_get_registry(display);
   printf("wl_display_get_registry: registry=%p\n", registry);
   if ( !registry )
   {
      printf("error: unable to get display registry\n");
      nRC= -2;
      goto exit;
   }
 
   ctx.display= display;
   ctx.registry= registry;
   ctx.planeX= 0;
   ctx.planeY= 0;
   ctx.planeWidth= 1280;
   ctx.planeHeight= 720;
   wl_registry_add_listener(registry, &registryListener, &ctx);
   
   wl_display_roundtrip(ctx.display);
   
   setupEGL(&ctx);
 
   ctx.surfaceWidth= 1280;
   ctx.surfaceHeight= 720;
   ctx.surfaceX= 0;
   ctx.surfaceY= 0;
 
   createSurface(&ctx);
   
   setupGL(&ctx);
   
   if ( paceRendering )
   {
      drawFrame(&ctx);
   }
  
        sigint.sa_handler = signalHandler;
        sigemptyset(&sigint.sa_mask);
        sigint.sa_flags = SA_RESETHAND;
        sigaction(SIGINT, &sigint, NULL);
 
   setBlockingMode(NON_BLOCKING_ENABLED);
 
   ctx.inputState= InputState_main;
   ctx.attribute= Attribute_position;
   
   g_running= 1;
   while( g_running )
   {
      if ( wl_display_dispatch( ctx.display ) == -1 )
      {
         break;
      }
 
      if ( !paceRendering )
      {
         if ( delay > 0 )
         {
            usleep(delay);
         }
         renderGL(&ctx);
         eglSwapBuffers(ctx.eglDisplay, ctx.eglSurfaceWindow);
      }
      else if ( ctx.needRedraw )
      {
         ctx.needRedraw= false;
         drawFrame(&ctx);
      }
 
      if ( ctx.getShell )
      {      
         if ( isKeyHit() )
         {
            uint32_t sym= XKB_KEY_NoSymbol;
            int c= fgetc(stdin);
            switch( c )
            {
               case 0x1B:
                  c= fgetc(stdin);
                  if ( c == 0x5B )
                  {
                     c= fgetc(stdin);
                     switch( c )
                     {
                        case 0x41: //UP
                           sym= XKB_KEY_Up;
                           break;
                        case 0x42: //DOWN
                           sym= XKB_KEY_Down;
                           break;
                        case 0x43: //RIGHT
                           sym= XKB_KEY_Right;
                           break;
                        case 0x44: // LEFT
                           sym= XKB_KEY_Left;
                           break;
                     }
                  }
                  break;
               default:
                  sym= c;
                  break;
            }
            processInput(&ctx, sym);
            
            // Prevent keys from building up while held down
            tcflush(STDIN_FILENO,TCIFLUSH);
         }
         else
         {
            if ( ctx.surfaceDX || ctx.surfaceDY || ctx.surfaceDWidth || ctx.surfaceDHeight )
            {
              // Key has been released - reset deltas
              ctx.surfaceDX= ctx.surfaceDY= ctx.surfaceDWidth= ctx.surfaceDHeight= 0;         
            }
         }
      }
   }   
 
exit:
 
   printf("rne_triangle: exiting...\n");
 
   setBlockingMode(NON_BLOCKING_DISABLED);
   
   if ( ctx.compositor )
   {
      wl_compositor_destroy( ctx.compositor );
      ctx.compositor= 0;
   }
   
   if ( ctx.shell )
   {
      wl_simple_shell_destroy( ctx.shell );
      ctx.shell= 0;
   }
   
   termEGL(&ctx);
 
   if ( ctx.xkbState )
   {
      xkb_state_unref( ctx.xkbState );
      ctx.xkbState= 0;
   }
 
   if ( ctx.xkbKeymap )
   {
      xkb_keymap_unref( ctx.xkbKeymap );
      ctx.xkbKeymap= 0;
   }
 
   if ( ctx.xkbCtx )
   {
      xkb_context_unref( ctx.xkbCtx );
      ctx.xkbCtx= 0;
   }
 
   if ( ctx.pointer )
   {
      wl_pointer_destroy(ctx.pointer);
      ctx.pointer= 0;
   }
 
   if ( ctx.keyboard )
   {
     wl_keyboard_destroy(ctx.keyboard);
     ctx.keyboard= 0;
   }
 
   if ( ctx.seat )
   {
      wl_seat_destroy(ctx.seat);
      ctx.seat= 0;
   }
 
   if ( ctx.output )
   {
      wl_output_destroy(ctx.output);
      ctx.output= 0;
   }
 
   if ( registry )
   {
      wl_registry_destroy(registry);
      registry= 0;
   }
   
   if ( display )
   {
      wl_display_disconnect(display);
      display= 0;
   }
   
   printf("rne_triangle: exit\n");
      
   return nRC;
}
 
#define RED_SIZE (8)
#define GREEN_SIZE (8)
#define BLUE_SIZE (8)
#define ALPHA_SIZE (8)
#define DEPTH_SIZE (0)
 
static bool setupEGL( AppCtx *ctx )
{
   bool result= false;
   EGLint major, minor;
   EGLBoolean b;
   EGLint configCount;
   EGLConfig *eglConfigs= 0;
   EGLint attr[32];
   EGLint redSize, greenSize, blueSize, alphaSize, depthSize;
   EGLint ctxAttrib[3];
   int i;
 
   /*
    * Get default EGL display
    */
   ctx->eglDisplay = eglGetDisplay((NativeDisplayType)ctx->display);
   printf("eglDisplay=%p\n", ctx->eglDisplay );
   if ( ctx->eglDisplay == EGL_NO_DISPLAY )
   {
      printf("error: EGL not available\n" );
      goto exit;
   }
    
   /*
    * Initialize display
    */
   b= eglInitialize( ctx->eglDisplay, &major, &minor );
   if ( !b )
   {
      printf("error: unable to initialize EGL display\n" );
      goto exit;
   }
   printf("eglInitiialize: major: %d minor: %d\n", major, minor );
    
   /*
    * Get number of available configurations
    */
   b= eglGetConfigs( ctx->eglDisplay, NULL, 0, &configCount );
   if ( !b )
   {
      printf("error: unable to get count of EGL configurations: %X\n", eglGetError() );
      goto exit;
   }
   printf("Number of EGL configurations: %d\n", configCount );
    
   eglConfigs= (EGLConfig*)malloc( configCount*sizeof(EGLConfig) );
   if ( !eglConfigs )
   {
      printf("error: unable to alloc memory for EGL configurations\n");
      goto exit;
   }
    
   i= 0;
   attr[i++]= EGL_RED_SIZE;
   attr[i++]= RED_SIZE;
   attr[i++]= EGL_GREEN_SIZE;
   attr[i++]= GREEN_SIZE;
   attr[i++]= EGL_BLUE_SIZE;
   attr[i++]= BLUE_SIZE;
   attr[i++]= EGL_DEPTH_SIZE;
   attr[i++]= DEPTH_SIZE;
   attr[i++]= EGL_STENCIL_SIZE;
   attr[i++]= 0;
   attr[i++]= EGL_SURFACE_TYPE;
   attr[i++]= EGL_WINDOW_BIT;
   attr[i++]= EGL_RENDERABLE_TYPE;
   attr[i++]= EGL_OPENGL_ES2_BIT;
   attr[i++]= EGL_NONE;
    
   /*
    * Get a list of configurations that meet or exceed our requirements
    */
   b= eglChooseConfig( ctx->eglDisplay, attr, eglConfigs, configCount, &configCount );
   if ( !b )
   {
      printf("error: eglChooseConfig failed: %X\n", eglGetError() );
      goto exit;
   }
   printf("eglChooseConfig: matching configurations: %d\n", configCount );
    
   /*
    * Choose a suitable configuration
    */
   for( i= 0; i < configCount; ++i )
   {
      eglGetConfigAttrib( ctx->eglDisplay, eglConfigs[i], EGL_RED_SIZE, &redSize );
      eglGetConfigAttrib( ctx->eglDisplay, eglConfigs[i], EGL_GREEN_SIZE, &greenSize );
      eglGetConfigAttrib( ctx->eglDisplay, eglConfigs[i], EGL_BLUE_SIZE, &blueSize );
      eglGetConfigAttrib( ctx->eglDisplay, eglConfigs[i], EGL_ALPHA_SIZE, &alphaSize );
      eglGetConfigAttrib( ctx->eglDisplay, eglConfigs[i], EGL_DEPTH_SIZE, &depthSize );
 
      printf("config %d: red: %d green: %d blue: %d alpha: %d depth: %d\n",
              i, redSize, greenSize, blueSize, alphaSize, depthSize );
      if ( (redSize == RED_SIZE) &&
           (greenSize == GREEN_SIZE) &&
           (blueSize == BLUE_SIZE) &&
           (alphaSize == ALPHA_SIZE) &&
           (depthSize >= DEPTH_SIZE) )
      {
         printf( "choosing config %d\n", i);
         break;
      }
   }
   if ( i == configCount )
   {
      printf("error: no suitable configuration available\n");
      goto exit;
   }
   ctx->eglConfig= eglConfigs[i];
 
   ctxAttrib[0]= EGL_CONTEXT_CLIENT_VERSION;
   ctxAttrib[1]= 2; // ES2
   ctxAttrib[2]= EGL_NONE;
    
   /*
    * Create an EGL context
    */
   ctx->eglContext= eglCreateContext( ctx->eglDisplay, ctx->eglConfig, EGL_NO_CONTEXT, ctxAttrib );
   if ( ctx->eglContext == EGL_NO_CONTEXT )
   {
      printf( "eglCreateContext failed: %X\n", eglGetError() );
      goto exit;
   }
   printf("eglCreateContext: eglContext %p\n", ctx->eglContext );
 
   result= true;
    
exit:
 
   if ( eglConfigs )
   {
      free( eglConfigs );
      eglConfigs= 0;
   }
 
   return result;       
}
 
static void termEGL( AppCtx *ctx )
{
   if ( ctx->display )
   {
      eglMakeCurrent( ctx->eglDisplay, EGL_NO_SURFACE, EGL_NO_SURFACE, EGL_NO_CONTEXT );
      
      destroySurface( ctx );
      
      eglTerminate( ctx->eglDisplay );
      eglReleaseThread();
   }
}
 
static bool createSurface( AppCtx *ctx )
{
   bool result= false;
   EGLBoolean b;
 
   ctx->surface= wl_compositor_create_surface(ctx->compositor);
   printf("surface=%p\n", ctx->surface);   
   if ( !ctx->surface )
   {
      printf("error: unable to create wayland surface\n");
      goto exit;
   }
 
   ctx->native= wl_egl_window_create(ctx->surface, ctx->planeWidth, ctx->planeHeight);
   if ( !ctx->native )
   {
      printf("error: unable to create wl_egl_window\n");
      goto exit;
   }
   printf("wl_egl_window %p\n", ctx->native);
   
   /*
    * Create a window surface
    */
   ctx->eglSurfaceWindow= eglCreateWindowSurface( ctx->eglDisplay,
                                                  ctx->eglConfig,
                                                  (EGLNativeWindowType)ctx->native,
                                                  NULL );
   if ( ctx->eglSurfaceWindow == EGL_NO_SURFACE )
   {
      printf("eglCreateWindowSurface: A: error %X\n", eglGetError() );
      ctx->eglSurfaceWindow= eglCreateWindowSurface( ctx->eglDisplay,
                                                     ctx->eglConfig,
                                                     (EGLNativeWindowType)NULL,
                                                     NULL );
      if ( ctx->eglSurfaceWindow == EGL_NO_SURFACE )
      {
         printf("eglCreateWindowSurface: B: error %X\n", eglGetError() );
         goto exit;
      }
   }
   printf("eglCreateWindowSurface: eglSurfaceWindow %p\n", ctx->eglSurfaceWindow );                                         
 
   /*
    * Establish EGL context for this thread
    */
   b= eglMakeCurrent( ctx->eglDisplay, ctx->eglSurfaceWindow, ctx->eglSurfaceWindow, ctx->eglContext );
   if ( !b )
   {
      printf("error: eglMakeCurrent failed: %X\n", eglGetError() );
      goto exit;
   }
    
   eglSwapInterval( ctx->eglDisplay, 1 );
 
exit:
 
   return result;
}
 
static void destroySurface( AppCtx *ctx )
{
   if ( ctx->eglSurfaceWindow )
   {
      eglDestroySurface( ctx->eglDisplay, ctx->eglSurfaceWindow );
      
      wl_egl_window_destroy( ctx->native );   
   }
   if ( ctx->surface )
   {
      wl_surface_destroy( ctx->surface );
      ctx->surface= 0;
   }
}
 
static void resizeSurface( AppCtx *ctx, int dx, int dy, int width, int height )
{
   wl_egl_window_resize( ctx->native, width, height, dx, dy );
}
 
static const char *vert_shader_text =
        "uniform mat4 rotation;\n"
        "attribute vec4 pos;\n"
        "attribute vec4 color;\n"
        "varying vec4 v_color;\n"
        "void main() {\n"
        "  gl_Position = rotation * pos;\n"
        "  v_color = color;\n"
        "}\n";
 
static const char *frag_shader_text =
        "precision mediump float;\n"
        "varying vec4 v_color;\n"
        "void main() {\n"
        "  gl_FragColor = v_color;\n"
        "}\n";
 
static GLuint createShader(AppCtx *ctx, GLenum shaderType, const char *shaderSource )
{
   GLuint shader= 0;
   GLint shaderStatus;
   GLsizei length;
   char logText[1000];
   
   shader= glCreateShader( shaderType );
   if ( shader )
   {
      glShaderSource( shader, 1, (const char **)&shaderSource, NULL );
      glCompileShader( shader );
      glGetShaderiv( shader, GL_COMPILE_STATUS, &shaderStatus );
      if ( !shaderStatus )
      {
         glGetShaderInfoLog( shader, sizeof(logText), &length, logText );
         printf("Error compiling %s shader: %*s\n",
                ((shaderType == GL_VERTEX_SHADER) ? "vertex" : "fragment"),
                length,
                logText );
      }
   }
   
   return shader;
}
 
static bool setupGL( AppCtx *ctx )
{
   bool result= false;
        GLuint frag, vert;
        GLuint program;
        GLint status;
 
        frag= createShader(ctx, GL_FRAGMENT_SHADER, frag_shader_text);
        vert= createShader(ctx, GL_VERTEX_SHADER, vert_shader_text);
 
        program= glCreateProgram();
        glAttachShader(program, frag);
        glAttachShader(program, vert);
        glLinkProgram(program);
 
        glGetProgramiv(program, GL_LINK_STATUS, &status);
        if (!status) 
        {
                char log[1000];
                GLsizei len;
                glGetProgramInfoLog(program, 1000, &len, log);
                fprintf(stderr, "Error: linking:\n%*s\n", len, log);
                goto exit;
        }
 
        glUseProgram(program);
 
        ctx->gl.pos= 0;
        ctx->gl.col= 1;
 
        glBindAttribLocation(program, ctx->gl.pos, "pos");
        glBindAttribLocation(program, ctx->gl.col, "color");
        glLinkProgram(program);
 
        ctx->gl.rotation_uniform= glGetUniformLocation(program, "rotation");
                
exit:
   return result;               
}
 
static bool renderGL( AppCtx *ctx )
{
   static const GLfloat verts[3][2] = {
      { -0.5, -0.5 },
      {  0.5, -0.5 },
      {  0,    0.5 }
   };
   static const GLfloat colors[3][4] = {
      { 1, 0, 0, 1.0 },
      { 0, 1, 0, 1.0 },
      { 0, 0, 1, 1.0 }
   };
   GLfloat angle;
   GLfloat rotation[4][4] = {
      { 1, 0, 0, 0 },
      { 0, 1, 0, 0 },
      { 0, 0, 1, 0 },
      { 0, 0, 0, 1 }
   };
   static const uint32_t speed_div = 5;
   EGLint rect[4];
 
   glViewport( 0, 0, ctx->planeWidth, ctx->planeHeight );
   glClearColor(0.0f, 0.0f, 0.0f, 0.0f);
   glClear(GL_COLOR_BUFFER_BIT);
 
   ctx->currTime= currentTimeMillis();
 
   angle = ctx->noAnimation ? 0.0 : ((ctx->currTime-ctx->startTime) / speed_div) % 360 * M_PI / 180.0;
   rotation[0][0] =  cos(angle);
   rotation[0][2] =  sin(angle);
   rotation[2][0] = -sin(angle);
   rotation[2][2] =  cos(angle);
 
   glUniformMatrix4fv(ctx->gl.rotation_uniform, 1, GL_FALSE, (GLfloat *) rotation);
 
   glVertexAttribPointer(ctx->gl.pos, 2, GL_FLOAT, GL_FALSE, 0, verts);
   glVertexAttribPointer(ctx->gl.col, 4, GL_FLOAT, GL_FALSE, 0, colors);
   glEnableVertexAttribArray(ctx->gl.pos);
   glEnableVertexAttribArray(ctx->gl.col);
 
   glDrawArrays(GL_TRIANGLES, 0, 3);
 
   glDisableVertexAttribArray(ctx->gl.pos);
   glDisableVertexAttribArray(ctx->gl.col);
   
   GLenum err= glGetError();
   if ( err != GL_NO_ERROR )
   {
      printf( "renderGL: glGetError() = %X\n", err );
   }
}