1/*
2 * Copyright © 2008 Intel Corporation
3 *
4 * Permission is hereby granted, free of charge, to any person obtaining a
5 * copy of this software and associated documentation files (the "Software"),
6 * to deal in the Software without restriction, including without limitation
7 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
8 * and/or sell copies of the Software, and to permit persons to whom the
9 * Software is furnished to do so, subject to the following conditions:
10 *
11 * The above copyright notice and this permission notice (including the next
12 * paragraph) shall be included in all copies or substantial portions of the
13 * Software.
14 *
15 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
16 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
17 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
18 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
19 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
20 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
21 * IN THE SOFTWARE.
22 *
23 * Authors:
24 *    Eric Anholt <eric@anholt.net>
25 *
26 */
27
28#include <stdlib.h>
29#include <GL/glew.h>
30#include "glut_wrap.h"
31
32static int win_width, win_height;
33
34#if 0
35static void
36line(GLfloat x1, GLfloat y1, GLfloat x2, GLfloat y2)
37{
38	glBegin(GL_LINES);
39	glVertex2f(x1, y1);
40	glVertex2f(x2, y2);
41	glEnd();
42}
43#endif
44
45static void
46line3(GLfloat x1, GLfloat y1, GLfloat z1, GLfloat x2, GLfloat y2, GLfloat z2)
47{
48	glBegin(GL_LINES);
49	glVertex3f(x1, y1, z1);
50	glVertex3f(x2, y2, z2);
51	glEnd();
52}
53
54static void
55display(void)
56{
57	glPolygonMode(GL_FRONT_AND_BACK, GL_LINE);
58
59	glClearColor(0.0, 0.0, 0.0, 0.0);
60	glClear(GL_COLOR_BUFFER_BIT);
61
62	glColor3f(1.0, 0.0, 0.0);
63	/* clipped along xmin */
64	glBegin(GL_TRIANGLES);
65	glVertex2f(-20, win_height / 2 - 20);
66	glVertex2f(20, win_height / 2);
67	glVertex2f(-20, win_height / 2 + 20);
68	glEnd();
69
70	glColor3f(0.0, 1.0, 0.0);
71	/* clipped along ymax */
72	glBegin(GL_TRIANGLES);
73	glVertex2f(win_height / 2 - 20, win_height + 20);
74	glVertex2f(win_height / 2,      win_height - 20);
75	glVertex2f(win_height / 2 + 20, win_height + 20);
76	glEnd();
77
78	glColor3f(0.0, 0.0, 1.0);
79	/* clipped along xmax */
80	glBegin(GL_TRIANGLES);
81	glVertex2f(win_height + 20, win_height / 2 - 20);
82	glVertex2f(win_height - 20, win_height / 2);
83	glVertex2f(win_height + 20, win_height / 2 + 20);
84	glEnd();
85
86	glColor3f(1.0, 1.0, 1.0);
87	/* clipped along ymin */
88	glBegin(GL_TRIANGLES);
89	glVertex2f(win_height / 2 - 20, -20);
90	glVertex2f(win_height / 2,       20);
91	glVertex2f(win_height / 2 + 20, -20);
92	glEnd();
93
94	/* clipped along near */
95	glColor3f(1.0, 0.0, 1.0);
96	glBegin(GL_TRIANGLES);
97	glVertex3f(win_width / 2 - 20, win_height / 2 - 20,  0.5);
98	glVertex3f(win_width / 2 - 40, win_height / 2,      -0.5);
99	glVertex3f(win_width / 2 - 20, win_height / 2 + 20,  0.5);
100	glEnd();
101
102	/* clipped along far */
103	glColor3f(0.0, 1.0, 1.0);
104	glBegin(GL_TRIANGLES);
105	glVertex3f(win_width / 2 + 20, win_height / 2 - 20, 0.5);
106	glVertex3f(win_width / 2 + 40, win_height / 2,      1.5);
107	glVertex3f(win_width / 2 + 20, win_height / 2 + 20, 0.5);
108	glEnd();
109
110	/* entirely clipped along near/far */
111	glColor3f(.5, .5, .5);
112	glBegin(GL_TRIANGLES);
113	glVertex3f(win_width / 2 - 20, win_height / 2 + 20, -0.5);
114	glVertex3f(win_width / 2,      win_height / 2 + 40, -0.5);
115	glVertex3f(win_width / 2 + 20, win_height / 2 + 20, -0.5);
116	glEnd();
117
118	glBegin(GL_TRIANGLES);
119	glVertex3f(win_width / 2 - 20, win_height / 2 - 20, 1.5);
120	glVertex3f(win_width / 2,      win_height / 2 - 40, 1.5);
121	glVertex3f(win_width / 2 + 20, win_height / 2 - 20, 1.5);
122	glEnd();
123
124	glColor3f(.5, .5, .5);
125	line3(win_width / 2, win_height / 2 - 20, 1.5,
126	      win_width / 2, win_height / 2 + 20, 1.5);
127
128	glColor3f(1.0, 1.0, 0.0);
129	/* clipped along both x and y limits */
130	glBegin(GL_TRIANGLES); /* xmin, ymin */
131	glVertex2f(-5, 20);
132	glVertex2f(20, 20);
133	glVertex2f(20, -5);
134	glEnd();
135	glBegin(GL_TRIANGLES); /* xmin, ymax */
136	glVertex2f(-5, win_height - 20);
137	glVertex2f(20, win_height - 20);
138	glVertex2f(20, win_height + 5);
139	glEnd();
140	glBegin(GL_TRIANGLES); /* xmax, ymax */
141	glVertex2f(win_width - 20, win_height + 5);
142	glVertex2f(win_width - 20, win_height - 20);
143	glVertex2f(win_width + 5,  win_height - 20);
144	glEnd();
145	glBegin(GL_TRIANGLES); /* xmax, ymin */
146	glVertex2f(win_width + 5, 20);
147	glVertex2f(win_width - 20, 20);
148	glVertex2f(win_width - 20, -5);
149	glEnd();
150
151	glutSwapBuffers();
152}
153
154static void
155reshape(int width, int height)
156{
157	win_width = width;
158	win_height = height;
159	glViewport(0, 0, width, height);
160
161	glMatrixMode(GL_PROJECTION);
162	glLoadIdentity();
163	glOrtho(0, win_width, 0, win_height, 0.0, -1.0);
164
165	glMatrixMode(GL_MODELVIEW);
166	glLoadIdentity();
167	glTranslatef(.25, .25, 0);
168}
169
170static void key( unsigned char key, int x, int y )
171{
172	(void) x;
173	(void) y;
174
175	switch (key) {
176	case 27: /* esc */
177		exit(0);
178		break;
179	}
180
181	glutPostRedisplay();
182}
183
184static void
185init(void)
186{
187}
188
189int
190main(int argc, char *argv[])
191{
192	win_width = 200;
193	win_height = 200;
194
195	glutInit(&argc, argv);
196	glutInitWindowPosition(0, 0);
197	glutInitWindowSize(win_width, win_height);
198	glutInitDisplayMode(GLUT_RGB | GLUT_DOUBLE | GLUT_DEPTH);
199	glutCreateWindow(argv[0]);
200        glewInit();
201	glutReshapeFunc(reshape);
202	glutKeyboardFunc(key);
203	glutDisplayFunc(display);
204
205	init();
206
207	glutMainLoop();
208	return 0;
209}
210