1
2/* Copyright (c) Mark J. Kilgard, 1994. */
3
4/*
5 * (c) Copyright 1993, Silicon Graphics, Inc.
6 * ALL RIGHTS RESERVED
7 * Permission to use, copy, modify, and distribute this software for
8 * any purpose and without fee is hereby granted, provided that the above
9 * copyright notice appear in all copies and that both the copyright notice
10 * and this permission notice appear in supporting documentation, and that
11 * the name of Silicon Graphics, Inc. not be used in advertising
12 * or publicity pertaining to distribution of the software without specific,
13 * written prior permission.
14 *
15 * THE MATERIAL EMBODIED ON THIS SOFTWARE IS PROVIDED TO YOU "AS-IS"
16 * AND WITHOUT WARRANTY OF ANY KIND, EXPRESS, IMPLIED OR OTHERWISE,
17 * INCLUDING WITHOUT LIMITATION, ANY WARRANTY OF MERCHANTABILITY OR
18 * FITNESS FOR A PARTICULAR PURPOSE.  IN NO EVENT SHALL SILICON
19 * GRAPHICS, INC.  BE LIABLE TO YOU OR ANYONE ELSE FOR ANY DIRECT,
20 * SPECIAL, INCIDENTAL, INDIRECT OR CONSEQUENTIAL DAMAGES OF ANY
21 * KIND, OR ANY DAMAGES WHATSOEVER, INCLUDING WITHOUT LIMITATION,
22 * LOSS OF PROFIT, LOSS OF USE, SAVINGS OR REVENUE, OR THE CLAIMS OF
23 * THIRD PARTIES, WHETHER OR NOT SILICON GRAPHICS, INC.  HAS BEEN
24 * ADVISED OF THE POSSIBILITY OF SUCH LOSS, HOWEVER CAUSED AND ON
25 * ANY THEORY OF LIABILITY, ARISING OUT OF OR IN CONNECTION WITH THE
26 * POSSESSION, USE OR PERFORMANCE OF THIS SOFTWARE.
27 *
28 * US Government Users Restricted Rights
29 * Use, duplication, or disclosure by the Government is subject to
30 * restrictions set forth in FAR 52.227.19(c)(2) or subparagraph
31 * (c)(1)(ii) of the Rights in Technical Data and Computer Software
32 * clause at DFARS 252.227-7013 and/or in similar or successor
33 * clauses in the FAR or the DOD or NASA FAR Supplement.
34 * Unpublished-- rights reserved under the copyright laws of the
35 * United States.  Contractor/manufacturer is Silicon Graphics,
36 * Inc., 2011 N.  Shoreline Blvd., Mountain View, CA 94039-7311.
37 *
38 * OpenGL(TM) is a trademark of Silicon Graphics, Inc.
39 */
40/*  mipmap.c
41 *  This program demonstrates using mipmaps for texture maps.
42 *  To overtly show the effect of mipmaps, each mipmap reduction
43 *  level has a solidly colored, contrasting texture image.
44 *  Thus, the quadrilateral which is drawn is drawn with several
45 *  different colors.
46 */
47#include <stdlib.h>
48#include "glut_wrap.h"
49
50GLubyte mipmapImage32[32][32][3];
51GLubyte mipmapImage16[16][16][3];
52GLubyte mipmapImage8[8][8][3];
53GLubyte mipmapImage4[4][4][3];
54GLubyte mipmapImage2[2][2][3];
55GLubyte mipmapImage1[1][1][3];
56
57static void makeImages(void)
58{
59    int i, j;
60
61    for (i = 0; i < 32; i++) {
62	for (j = 0; j < 32; j++) {
63	    mipmapImage32[i][j][0] = 255;
64	    mipmapImage32[i][j][1] = 255;
65	    mipmapImage32[i][j][2] = 0;
66	}
67    }
68    for (i = 0; i < 16; i++) {
69	for (j = 0; j < 16; j++) {
70	    mipmapImage16[i][j][0] = 255;
71	    mipmapImage16[i][j][1] = 0;
72	    mipmapImage16[i][j][2] = 255;
73	}
74    }
75    for (i = 0; i < 8; i++) {
76	for (j = 0; j < 8; j++) {
77	    mipmapImage8[i][j][0] = 255;
78	    mipmapImage8[i][j][1] = 0;
79	    mipmapImage8[i][j][2] = 0;
80	}
81    }
82    for (i = 0; i < 4; i++) {
83	for (j = 0; j < 4; j++) {
84	    mipmapImage4[i][j][0] = 0;
85	    mipmapImage4[i][j][1] = 255;
86	    mipmapImage4[i][j][2] = 0;
87	}
88    }
89    for (i = 0; i < 2; i++) {
90	for (j = 0; j < 2; j++) {
91	    mipmapImage2[i][j][0] = 0;
92	    mipmapImage2[i][j][1] = 0;
93	    mipmapImage2[i][j][2] = 255;
94	}
95    }
96    mipmapImage1[0][0][0] = 255;
97    mipmapImage1[0][0][1] = 255;
98    mipmapImage1[0][0][2] = 255;
99}
100
101static void myinit(void)
102{
103    glEnable(GL_DEPTH_TEST);
104    glDepthFunc(GL_LESS);
105    glShadeModel(GL_FLAT);
106
107    glTranslatef(0.0, 0.0, -3.6);
108    makeImages();
109    glPixelStorei(GL_UNPACK_ALIGNMENT, 1);
110    glTexImage2D(GL_TEXTURE_2D, 0, 3, 32, 32, 0,
111		 GL_RGB, GL_UNSIGNED_BYTE, &mipmapImage32[0][0][0]);
112    glTexImage2D(GL_TEXTURE_2D, 1, 3, 16, 16, 0,
113		 GL_RGB, GL_UNSIGNED_BYTE, &mipmapImage16[0][0][0]);
114    glTexImage2D(GL_TEXTURE_2D, 2, 3, 8, 8, 0,
115		 GL_RGB, GL_UNSIGNED_BYTE, &mipmapImage8[0][0][0]);
116    glTexImage2D(GL_TEXTURE_2D, 3, 3, 4, 4, 0,
117		 GL_RGB, GL_UNSIGNED_BYTE, &mipmapImage4[0][0][0]);
118    glTexImage2D(GL_TEXTURE_2D, 4, 3, 2, 2, 0,
119		 GL_RGB, GL_UNSIGNED_BYTE, &mipmapImage2[0][0][0]);
120    glTexImage2D(GL_TEXTURE_2D, 5, 3, 1, 1, 0,
121		 GL_RGB, GL_UNSIGNED_BYTE, &mipmapImage1[0][0][0]);
122    glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_REPEAT);
123    glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_REPEAT);
124    glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
125    glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER,
126	GL_NEAREST_MIPMAP_NEAREST);
127    glTexEnvf(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_DECAL);
128    glEnable(GL_TEXTURE_2D);
129}
130
131static void display(void)
132{
133    glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
134    glBegin(GL_QUADS);
135    glTexCoord2f(0.0, 0.0); glVertex3f(-2.0, -1.0, 0.0);
136    glTexCoord2f(0.0, 8.0); glVertex3f(-2.0, 1.0, 0.0);
137    glTexCoord2f(8.0, 8.0); glVertex3f(2000.0, 1.0, -6000.0);
138    glTexCoord2f(8.0, 0.0); glVertex3f(2000.0, -1.0, -6000.0);
139    glEnd();
140    glFlush();
141}
142
143static void myReshape(int w, int h)
144{
145    glViewport(0, 0, w, h);
146    glMatrixMode(GL_PROJECTION);
147    glLoadIdentity();
148    gluPerspective(60.0, 1.0*(GLfloat)w/(GLfloat)h, 1.0, 30000.0);
149    glMatrixMode(GL_MODELVIEW);
150    glLoadIdentity();
151}
152
153static void
154key(unsigned char k, int x, int y)
155{
156  switch (k) {
157  case 27:  /* Escape */
158    exit(0);
159    break;
160  default:
161    return;
162  }
163  glutPostRedisplay();
164}
165
166int main(int argc, char** argv)
167{
168    glutInit(&argc, argv);
169    glutInitDisplayMode (GLUT_SINGLE | GLUT_RGB | GLUT_DEPTH);
170    glutInitWindowSize (500, 500);
171    glutCreateWindow (argv[0]);
172    myinit();
173    glutReshapeFunc (myReshape);
174    glutDisplayFunc(display);
175    glutKeyboardFunc(key);
176    glutMainLoop();
177    return 0;             /* ANSI C requires main to return int. */
178}
179