mipmap.cpp

OPENGL2.0用于ARM11 3D处理

/*
 * License Applicability. Except to the extent portions of this file are
 * made subject to an alternative license as permitted in the SGI Free
 * Software License B, Version 1.1 (the "License"), the contents of this
 * file are subject only to the provisions of the License. You may not use
 * this file except in compliance with the License. You may obtain a copy
 * of the License at Silicon Graphics, Inc., attn: Legal Services, 1600
 * Amphitheatre Parkway, Mountain View, CA 94043-1351, or at:
 * 
 * http://oss.sgi.com/projects/FreeB
 * 
 * Note that, as provided in the License, the Software is distributed on an
 * "AS IS" basis, with ALL EXPRESS AND IMPLIED WARRANTIES AND CONDITIONS
 * DISCLAIMED, INCLUDING, WITHOUT LIMITATION, ANY IMPLIED WARRANTIES AND
 * CONDITIONS OF MERCHANTABILITY, SATISFACTORY QUALITY, FITNESS FOR A
 * PARTICULAR PURPOSE, AND NON-INFRINGEMENT.
 * 
 * Original Code. The Original Code is: OpenGL Sample Implementation,
 * Version 1.2.1, released January 26, 2000, developed by Silicon Graphics,
 * Inc. The Original Code is Copyright (c) 1991-2000 Silicon Graphics, Inc.
 * Copyright in any portions created by third parties is as indicated
 * elsewhere herein. All Rights Reserved.
 * 
 * Additional Notice Provisions: The application programming interfaces
 * established by SGI in conjunction with the Original Code are The
 * OpenGL(R) Graphics System: A Specification (Version 1.2.1), released
 * April 1, 1999; The OpenGL(R) Graphics System Utility Library (Version
 * 1.3), released November 4, 1998; and OpenGL(R) Graphics with the X
 * Window System(R) (Version 1.3), released October 19, 1998. This software
 * was created using the OpenGL(R) version 1.2.1 Sample Implementation
 * published by SGI, but has not been independently verified as being
 * compliant with the OpenGL(R) version 1.2.1 Specification.
 *
 */

/*  mipmap.c
 *  This program demonstrates using mipmaps for texture maps.
 *  To overtly show the effect of mipmaps, each mipmap reduction
 *  level has a solidly colored, contrasting texture image.
 *  Thus, the quadrilateral which is drawn is drawn with several
 *  different colors.
 */
#include "stdafx.h"
#include <stdlib.h>
#include <stdio.h>

#include <gles/gles.h>
#include <math.h>

static void display(void);
static void reshape(int w,int h);
static void init(void);

GLubyte mipmapImage32[32][32][4];
GLubyte mipmapImage16[16][16][4];
GLubyte mipmapImage8[8][8][4];
GLubyte mipmapImage4[4][4][4];
GLubyte mipmapImage2[2][2][4];
GLubyte mipmapImage1[1][1][4];

static GLuint texName;

void makeImages(void)
{
   int i, j;
    
   for (i = 0; i < 32; i++) {
      for (j = 0; j < 32; j++) {
         mipmapImage32[i][j][0] = 255;
         mipmapImage32[i][j][1] = 255;
         mipmapImage32[i][j][2] = 0;
         mipmapImage32[i][j][3] = 255;
      }
   }
   for (i = 0; i < 16; i++) {
      for (j = 0; j < 16; j++) {
         mipmapImage16[i][j][0] = 255;
         mipmapImage16[i][j][1] = 0;
         mipmapImage16[i][j][2] = 255;
         mipmapImage16[i][j][3] = 255;
      }
   }
   for (i = 0; i < 8; i++) {
      for (j = 0; j < 8; j++) {
         mipmapImage8[i][j][0] = 255;
         mipmapImage8[i][j][1] = 0;
         mipmapImage8[i][j][2] = 0;
         mipmapImage8[i][j][3] = 255;
      }
   }
   for (i = 0; i < 4; i++) {
      for (j = 0; j < 4; j++) {
         mipmapImage4[i][j][0] = 0;
         mipmapImage4[i][j][1] = 255;
         mipmapImage4[i][j][2] = 0;
         mipmapImage4[i][j][3] = 255;
      }
   }
   for (i = 0; i < 2; i++) {
      for (j = 0; j < 2; j++) {
         mipmapImage2[i][j][0] = 0;
         mipmapImage2[i][j][1] = 0;
         mipmapImage2[i][j][2] = 255;
         mipmapImage2[i][j][3] = 255;
      }
   }
   mipmapImage1[0][0][0] = 255;
   mipmapImage1[0][0][1] = 255;
   mipmapImage1[0][0][2] = 255;
   mipmapImage1[0][0][3] = 255;
}

static void init(void)
{    
   static const GLfloat v[] = {
       -2.0, -1.0, 0.0,
       -2.0, 1.0, 0.0,
       2000.0, -1.0, -6000.0,
       2000.0, 1.0, -6000.0,
   };
   static const GLfloat t[] = {
       0.0, 0.0,
       0.0, 8.0,
       8.0, 0.0,
       8.0, 8.0,
   };

   glEnable(GL_DEPTH_TEST);
   glShadeModel(GL_FLAT);

   glTranslatef(0.0, 0.0, -3.6f);
   makeImages();
   glPixelStorei(GL_UNPACK_ALIGNMENT, 1);

   glGenTextures(1, &texName);
   glBindTexture(GL_TEXTURE_2D, texName);

   glTexParameterx(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_REPEAT);
   glTexParameterx(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_REPEAT);
   glTexParameterx(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
   glTexParameterx(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, 
                   GL_NEAREST_MIPMAP_NEAREST);
   glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, 32, 32, 0,
                GL_RGBA, GL_UNSIGNED_BYTE, mipmapImage32);
   glTexImage2D(GL_TEXTURE_2D, 1, GL_RGBA, 16, 16, 0,
                GL_RGBA, GL_UNSIGNED_BYTE, mipmapImage16);
   glTexImage2D(GL_TEXTURE_2D, 2, GL_RGBA, 8, 8, 0,
                GL_RGBA, GL_UNSIGNED_BYTE, mipmapImage8);
   glTexImage2D(GL_TEXTURE_2D, 3, GL_RGBA, 4, 4, 0,
                GL_RGBA, GL_UNSIGNED_BYTE, mipmapImage4);
   glTexImage2D(GL_TEXTURE_2D, 4, GL_RGBA, 2, 2, 0,
                GL_RGBA, GL_UNSIGNED_BYTE, mipmapImage2);
   glTexImage2D(GL_TEXTURE_2D, 5, GL_RGBA, 1, 1, 0,
                GL_RGBA, GL_UNSIGNED_BYTE, mipmapImage1);

   glTexEnvf(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_DECAL);
   glEnable(GL_TEXTURE_2D);
   glVertexPointer(3, GL_FLOAT, 0, v);
   glTexCoordPointer(2, GL_FLOAT, 0, t);

   glEnableClientState(GL_VERTEX_ARRAY);
   glEnableClientState(GL_TEXTURE_COORD_ARRAY);
}


void MipmapRender()
{
   glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
   glBindTexture(GL_TEXTURE_2D, texName);
   glDrawArrays(GL_TRIANGLE_STRIP, 0, 4);
   glFlush();
}

static void reshape(int w, int h)
{
	glViewport (0, 0, (GLsizei) w, (GLsizei) h);
	glMatrixMode (GL_PROJECTION);
	glLoadIdentity();
	glFrustumf(-1.5f, 1.5f, -1.5f,1.5f, 1.0f, 30000.0f);
	glMatrixMode(GL_MODELVIEW);
	glLoadIdentity();
   
   
}

int MipmapDemo()
{
	
	init ();
    reshape(WINDOW_WIDTH, WINDOW_HEIGHT);



   return 1; 
}

int MipmapDeinit()
{
	return 1;
}