line-smooth.c revision 32001f49 
1/*
2 * Copyright (c) 1991, 1992, 1993 Silicon Graphics, Inc.
3 *
4 * Permission to use, copy, modify, distribute, and sell this software and
5 * its documentation for any purpose is hereby granted without fee, provided
6 * that (i) the above copyright notices and this permission notice appear in
7 * all copies of the software and related documentation, and (ii) the name of
8 * Silicon Graphics may not be used in any advertising or
9 * publicity relating to the software without the specific, prior written
10 * permission of Silicon Graphics.
11 *
12 * THE SOFTWARE IS PROVIDED "AS-IS" AND WITHOUT WARRANTY OF
13 * ANY KIND,
14 * EXPRESS, IMPLIED OR OTHERWISE, INCLUDING WITHOUT LIMITATION, ANY
15 * WARRANTY OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE.
16 *
17 * IN NO EVENT SHALL SILICON GRAPHICS BE LIABLE FOR
18 * ANY SPECIAL, INCIDENTAL, INDIRECT OR CONSEQUENTIAL DAMAGES OF ANY KIND,
19 * OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS,
20 * WHETHER OR NOT ADVISED OF THE POSSIBILITY OF DAMAGE, AND ON ANY THEORY OF
21 * LIABILITY, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE
22 * OF THIS SOFTWARE.
23 */
24
25#include <math.h>
26#include <stdio.h>
27#include <string.h>
28#include <stdlib.h>
29#include <GL/glew.h>
30#include "glut_wrap.h"
31
32
33#define CI_OFFSET_1 16
34#define CI_OFFSET_2 32
35
36
37GLenum doubleBuffer;
38GLboolean smooth = GL_TRUE;
39GLboolean flat = GL_TRUE;
40GLfloat width = 1.0;
41
42
43static void Init(void)
44{
45   float range[2], aarange[2];
46   fprintf(stderr, "GL_RENDERER   = %s\n", (char *) glGetString(GL_RENDERER));
47   fprintf(stderr, "GL_VERSION    = %s\n", (char *) glGetString(GL_VERSION));
48   fprintf(stderr, "GL_VENDOR     = %s\n", (char *) glGetString(GL_VENDOR));
49   fflush(stderr);
50   glGetFloatv(GL_LINE_WIDTH_RANGE, aarange);
51   glGetFloatv(GL_ALIASED_LINE_WIDTH_RANGE, range);
52   printf("Non-AA line width range: %f .. %f\n", range[0], range[1]);
53   printf("AA line width range: %f .. %f\n", aarange[0], aarange[1]);
54   fflush(stdout);
55}
56
57
58static void Reshape(int width, int height)
59{
60   glViewport(0, 0, (GLint)width, (GLint)height);
61   glMatrixMode(GL_PROJECTION);
62   glLoadIdentity();
63   glOrtho(-1.0, 1.0, -1.0, 1.0, -0.5, 1000.0);
64   glMatrixMode(GL_MODELVIEW);
65   glLoadIdentity();
66   glTranslatef(0, 0, -30);
67}
68
69static void Key(unsigned char key, int x, int y)
70{
71   switch (key) {
72   case 'f':
73      flat = !flat;
74      break;
75   case 'w':
76      width -= 0.5;
77      if (width < 0.5)
78         width = 0.5;
79      break;
80   case 'W':
81      width += 0.5;
82      break;
83   case 's':
84      smooth = !smooth;
85      break;
86   case 27:
87      exit(1);
88   default:
89      return;
90   }
91   printf("LineWidth: %g  FlatShade: %d\n", width, flat);
92   glutPostRedisplay();
93}
94
95
96static void Draw(void)
97{
98   float a;
99
100   glClear(GL_COLOR_BUFFER_BIT);
101
102   glLineWidth(width);
103
104   if (smooth) {
105      glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
106      glEnable(GL_BLEND);
107      glEnable(GL_LINE_SMOOTH);
108   }
109
110   glShadeModel(flat ? GL_FLAT : GL_SMOOTH);
111
112   glBegin(GL_LINES);
113   for (a = 0; a < 3.14159; a += 0.2) {
114      float x = .9 * cos(a);
115      float y = .9 * sin(a);
116
117      glColor3f(1, 0, 1);
118      glVertex2f(-x, -y);
119      glColor3f(1, 1, 1);
120      glVertex2f( x,  y);
121   }
122   glEnd();
123
124   glDisable(GL_LINE_SMOOTH);
125   glDisable(GL_BLEND);
126
127   glFlush();
128
129   if (doubleBuffer) {
130      glutSwapBuffers();
131   }
132}
133
134static GLenum Args(int argc, char **argv)
135{
136   GLint i;
137
138   doubleBuffer = GL_FALSE;
139
140   for (i = 1; i < argc; i++) {
141      if (strcmp(argv[i], "-sb") == 0) {
142         doubleBuffer = GL_FALSE;
143      } else if (strcmp(argv[i], "-db") == 0) {
144         doubleBuffer = GL_TRUE;
145      } else {
146         fprintf(stderr, "%s (Bad option).\n", argv[i]);
147         return GL_FALSE;
148      }
149   }
150   return GL_TRUE;
151}
152
153
154int main(int argc, char **argv)
155{
156   GLenum type;
157
158   glutInit(&argc, argv);
159
160   if (Args(argc, argv) == GL_FALSE) {
161      exit(1);
162   }
163
164   glutInitWindowPosition(0, 0); glutInitWindowSize( 250, 250);
165
166   type = GLUT_RGB;
167   type |= (doubleBuffer) ? GLUT_DOUBLE : GLUT_SINGLE;
168   glutInitDisplayMode(type);
169
170   if (glutCreateWindow(argv[0]) == GL_FALSE) {
171      exit(1);
172   }
173
174   Init();
175
176   glutReshapeFunc(Reshape);
177   glutKeyboardFunc(Key);
178   glutDisplayFunc(Draw);
179   glutMainLoop();
180   return 0;
181}
182