progs/es1/screen/tri.c

/*
 * Copyright (C) 2009 Chia-I Wu <olv@0xlab.org>
 *
 * Based on egltri by
 * Copyright (C) 1999-2001  Brian Paul   All Rights Reserved.
 * Copyright (C) 2008  Brian Paul   All Rights Reserved.
 * Copyright (C) 2008  Jakob Bornecrantz   All Rights Reserved.
 *
 * 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 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
 * BRIAN PAUL 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 <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <GLES/gl.h>
#include "winsys.h"

static GLfloat view_rotx = 0.0, view_roty = 0.0, view_rotz = 0.0;

static void tri_init()
{
   glClearColor(0.4, 0.4, 0.4, 0.0);
}

static void tri_reshape(int width, int height)
{
   GLfloat ar = (GLfloat) width / (GLfloat) height;

   glViewport(0, 0, (GLint) width, (GLint) height);

   glMatrixMode(GL_PROJECTION);
   glLoadIdentity();
   glFrustumf(-ar, ar, -1, 1, 5.0, 60.0);

   glMatrixMode(GL_MODELVIEW);
   glLoadIdentity();
   glTranslatef(0.0, 0.0, -10.0);
}

static void tri_draw(void *data)
{
   static const GLfloat verts[3][2] = {
      { -1, -1 },
      {  1, -1 },
      {  0,  1 }
   };
   static const GLfloat colors[3][4] = {
      { 1, 0, 0, 1 },
      { 0, 1, 0, 1 },
      { 0, 0, 1, 1 }
   };

   glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);

   glPushMatrix();
   glRotatef(view_rotx, 1, 0, 0);
   glRotatef(view_roty, 0, 1, 0);
   glRotatef(view_rotz, 0, 0, 1);

   {
      glVertexPointer(2, GL_FLOAT, 0, verts);
      glColorPointer(4, GL_FLOAT, 0, colors);
      glEnableClientState(GL_VERTEX_ARRAY);
      glEnableClientState(GL_COLOR_ARRAY);

      glDrawArrays(GL_TRIANGLES, 0, 3);

      glDisableClientState(GL_VERTEX_ARRAY);
      glDisableClientState(GL_COLOR_ARRAY);
   }

   glPopMatrix();
}

static void tri_run(void)
{
   winsysRun(3.0, tri_draw, NULL);
}

int main(int argc, char *argv[])
{
   EGLint width, height;
   GLboolean printInfo = GL_FALSE;
   int i;

   /* parse cmd line args */
   for (i = 1; i < argc; i++) {
      if (strcmp(argv[i], "-info") == 0) {
         printInfo = GL_TRUE;
      }
      else {
         printf("Warning: unknown parameter: %s\n", argv[i]);
      }
   }

   if (!winsysInitScreen())
      exit(1);
   winsysQueryScreenSize(&width, &height);

   if (printInfo) {
      printf("GL_RENDERER   = %s\n", (char *) glGetString(GL_RENDERER));
      printf("GL_VERSION    = %s\n", (char *) glGetString(GL_VERSION));
      printf("GL_VENDOR     = %s\n", (char *) glGetString(GL_VENDOR));
      printf("GL_EXTENSIONS = %s\n", (char *) glGetString(GL_EXTENSIONS));
   }

   tri_init();
   tri_reshape(width, height);
   tri_run();

   winsysFiniScreen();

   return 0;
}