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34 * Unpublished-- rights reserved under the copyright laws of the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/*  texturesurf.c
41 *  This program uses evaluators to generate a curved
42 *  surface and automatically generated texture coordinates.
43 */
44
45#include <stdlib.h>
46#include "glut_wrap.h"
47#include <math.h>
48
49GLfloat ctrlpoints[4][4][3] = {
50    {{ -1.5, -1.5, 4.0}, { -0.5, -1.5, 2.0},
51	{0.5, -1.5, -1.0}, {1.5, -1.5, 2.0}},
52    {{ -1.5, -0.5, 1.0}, { -0.5, -0.5, 3.0},
53	{0.5, -0.5, 0.0}, {1.5, -0.5, -1.0}},
54    {{ -1.5, 0.5, 4.0}, { -0.5, 0.5, 0.0},
55	{0.5, 0.5, 3.0}, {1.5, 0.5, 4.0}},
56    {{ -1.5, 1.5, -2.0}, { -0.5, 1.5, -2.0},
57	{0.5, 1.5, 0.0}, {1.5, 1.5, -1.0}}
58};
59
60GLfloat texpts[2][2][2] = {{{0.0, 0.0}, {0.0, 1.0}},
61			{{1.0, 0.0}, {1.0, 1.0}}};
62
63static void display(void)
64{
65    glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
66    glColor3f(1.0, 1.0, 1.0);
67    glEvalMesh2(GL_FILL, 0, 20, 0, 20);
68    glFlush();
69}
70
71#define	imageWidth 64
72#define	imageHeight 64
73GLubyte image[3*imageWidth*imageHeight];
74
75static void makeImage(void)
76{
77    int i, j;
78    float ti, tj;
79
80    for (i = 0; i < imageWidth; i++) {
81	ti = 2.0*3.14159265*i/imageWidth;
82	for (j = 0; j < imageHeight; j++) {
83	    tj = 2.0*3.14159265*j/imageHeight;
84
85	    image[3*(imageHeight*i+j)] = (GLubyte) 127*(1.0+sin(ti));
86	    image[3*(imageHeight*i+j)+1] = (GLubyte) 127*(1.0+cos(2*tj));
87	    image[3*(imageHeight*i+j)+2] = (GLubyte) 127*(1.0+cos(ti+tj));
88	}
89    }
90}
91
92static void myinit(void)
93{
94    glMap2f(GL_MAP2_VERTEX_3, 0, 1, 3, 4,
95	    0, 1, 12, 4, &ctrlpoints[0][0][0]);
96    glMap2f(GL_MAP2_TEXTURE_COORD_2, 0, 1, 2, 2,
97	    0, 1, 4, 2, &texpts[0][0][0]);
98    glEnable(GL_MAP2_TEXTURE_COORD_2);
99    glEnable(GL_MAP2_VERTEX_3);
100    glMapGrid2f(20, 0.0, 1.0, 20, 0.0, 1.0);
101    makeImage();
102    glTexEnvf(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_DECAL);
103    glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_REPEAT);
104    glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_REPEAT);
105    glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
106    glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
107    glTexImage2D(GL_TEXTURE_2D, 0, 3, imageWidth, imageHeight, 0,
108		 GL_RGB, GL_UNSIGNED_BYTE, image);
109    glEnable(GL_TEXTURE_2D);
110    glEnable(GL_DEPTH_TEST);
111    glEnable(GL_NORMALIZE);
112    glShadeModel (GL_FLAT);
113}
114
115static void myReshape(int w, int h)
116{
117    glViewport(0, 0, w, h);
118    glMatrixMode(GL_PROJECTION);
119    glLoadIdentity();
120    if (w <= h)
121	glOrtho(-4.0, 4.0, -4.0*(GLfloat)h/(GLfloat)w,
122	    4.0*(GLfloat)h/(GLfloat)w, -4.0, 4.0);
123    else
124	glOrtho(-4.0*(GLfloat)w/(GLfloat)h,
125	    4.0*(GLfloat)w/(GLfloat)h, -4.0, 4.0, -4.0, 4.0);
126    glMatrixMode(GL_MODELVIEW);
127    glLoadIdentity();
128    glRotatef(85.0, 1.0, 1.0, 1.0);
129}
130
131static void
132key(unsigned char k, int x, int y)
133{
134  switch (k) {
135  case 27:  /* Escape */
136    exit(0);
137    break;
138  default:
139    return;
140  }
141  glutPostRedisplay();
142}
143
144int main(int argc, char** argv)
145{
146    glutInit(&argc, argv);
147    glutInitDisplayMode (GLUT_SINGLE | GLUT_RGB | GLUT_DEPTH);
148    glutCreateWindow (argv[0]);
149    myinit();
150    glutReshapeFunc (myReshape);
151    glutDisplayFunc(display);
152    glutKeyboardFunc(key);
153    glutMainLoop();
154    return 0;             /* ANSI C requires main to return int. */
155}
156