1/*
2 * Copyright (c) 1993-1997, Silicon Graphics, Inc.
3 * ALL RIGHTS RESERVED
4 * Permission to use, copy, modify, and distribute this software for
5 * any purpose and without fee is hereby granted, provided that the above
6 * copyright notice appear in all copies and that both the copyright notice
7 * and this permission notice appear in supporting documentation, and that
8 * the name of Silicon Graphics, Inc. not be used in advertising
9 * or publicity pertaining to distribution of the software without specific,
10 * written prior permission.
11 *
12 * THE MATERIAL EMBODIED ON THIS SOFTWARE IS PROVIDED TO YOU "AS-IS"
13 * AND WITHOUT WARRANTY OF ANY KIND, EXPRESS, IMPLIED OR OTHERWISE,
14 * INCLUDING WITHOUT LIMITATION, ANY WARRANTY OF MERCHANTABILITY OR
15 * FITNESS FOR A PARTICULAR PURPOSE.  IN NO EVENT SHALL SILICON
16 * GRAPHICS, INC.  BE LIABLE TO YOU OR ANYONE ELSE FOR ANY DIRECT,
17 * SPECIAL, INCIDENTAL, INDIRECT OR CONSEQUENTIAL DAMAGES OF ANY
18 * KIND, OR ANY DAMAGES WHATSOEVER, INCLUDING WITHOUT LIMITATION,
19 * LOSS OF PROFIT, LOSS OF USE, SAVINGS OR REVENUE, OR THE CLAIMS OF
20 * THIRD PARTIES, WHETHER OR NOT SILICON GRAPHICS, INC.  HAS BEEN
21 * ADVISED OF THE POSSIBILITY OF SUCH LOSS, HOWEVER CAUSED AND ON
22 * ANY THEORY OF LIABILITY, ARISING OUT OF OR IN CONNECTION WITH THE
23 * POSSESSION, USE OR PERFORMANCE OF THIS SOFTWARE.
24 *
25 * US Government Users Restricted Rights
26 * Use, duplication, or disclosure by the Government is subject to
27 * restrictions set forth in FAR 52.227.19(c)(2) or subparagraph
28 * (c)(1)(ii) of the Rights in Technical Data and Computer Software
29 * clause at DFARS 252.227-7013 and/or in similar or successor
30 * clauses in the FAR or the DOD or NASA FAR Supplement.
31 * Unpublished-- rights reserved under the copyright laws of the
32 * United States.  Contractor/manufacturer is Silicon Graphics,
33 * Inc., 2011 N.  Shoreline Blvd., Mountain View, CA 94039-7311.
34 *
35 * OpenGL(R) is a registered trademark of Silicon Graphics, Inc.
36 */
37
38/*
39 *  aargb.c
40 *  This program draws shows how to draw anti-aliased lines. It draws
41 *  two diagonal lines to form an X; when 'r' is typed in the window,
42 *  the lines are rotated in opposite directions.
43 */
44#include "glut_wrap.h"
45#include <stdlib.h>
46#include <stdio.h>
47
48static float rotAngle = 0.;
49
50/*  Initialize antialiasing for RGBA mode, including alpha
51 *  blending, hint, and line width.  Print out implementation
52 *  specific info on line width granularity and width.
53 */
54static void init(void)
55{
56   GLfloat values[2];
57   glGetFloatv (GL_LINE_WIDTH_GRANULARITY, values);
58   printf ("GL_LINE_WIDTH_GRANULARITY value is %3.1f\n", values[0]);
59
60   glGetFloatv (GL_LINE_WIDTH_RANGE, values);
61   printf ("GL_LINE_WIDTH_RANGE values are %3.1f %3.1f\n",
62      values[0], values[1]);
63
64   glEnable (GL_LINE_SMOOTH);
65   glEnable (GL_BLEND);
66   glBlendFunc (GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
67   glHint (GL_LINE_SMOOTH_HINT, GL_DONT_CARE);
68   glLineWidth (1.5);
69
70   glClearColor(0.0, 0.0, 0.0, 0.0);
71}
72
73/* Draw 2 diagonal lines to form an X
74 */
75static void display(void)
76{
77   glClear(GL_COLOR_BUFFER_BIT);
78
79   glColor3f (0.0, 1.0, 0.0);
80   glPushMatrix();
81   glRotatef(-rotAngle, 0.0, 0.0, 0.1);
82   glBegin (GL_LINES);
83      glVertex2f (-0.5, 0.5);
84      glVertex2f (0.5, -0.5);
85   glEnd ();
86   glPopMatrix();
87
88   glColor3f (0.0, 0.0, 1.0);
89   glPushMatrix();
90   glRotatef(rotAngle, 0.0, 0.0, 0.1);
91   glBegin (GL_LINES);
92      glVertex2f (0.5, 0.5);
93      glVertex2f (-0.5, -0.5);
94   glEnd ();
95   glPopMatrix();
96
97   glFlush();
98}
99
100static void reshape(int w, int h)
101{
102   glViewport(0, 0, w, h);
103   glMatrixMode(GL_PROJECTION);
104   glLoadIdentity();
105   if (w <= h)
106      gluOrtho2D (-1.0, 1.0,
107         -1.0*(GLfloat)h/(GLfloat)w, 1.0*(GLfloat)h/(GLfloat)w);
108   else
109      gluOrtho2D (-1.0*(GLfloat)w/(GLfloat)h,
110         1.0*(GLfloat)w/(GLfloat)h, -1.0, 1.0);
111   glMatrixMode(GL_MODELVIEW);
112   glLoadIdentity();
113}
114
115/* ARGSUSED1 */
116static void keyboard(unsigned char key, int x, int y)
117{
118   switch (key) {
119      case 'r':
120      case 'R':
121         rotAngle += 20.;
122         if (rotAngle >= 360.) rotAngle = 0.;
123         glutPostRedisplay();
124         break;
125      case 27:  /*  Escape Key  */
126         exit(0);
127         break;
128      default:
129         break;
130    }
131}
132
133/*  Main Loop
134 *  Open window with initial window size, title bar,
135 *  RGBA display mode, and handle input events.
136 */
137int main(int argc, char** argv)
138{
139   glutInit(&argc, argv);
140   glutInitDisplayMode (GLUT_SINGLE | GLUT_RGB);
141   glutInitWindowSize (200, 200);
142   glutCreateWindow (argv[0]);
143   init();
144   glutReshapeFunc (reshape);
145   glutKeyboardFunc (keyboard);
146   glutDisplayFunc (display);
147   glutMainLoop();
148   return 0;
149}
150