/usr/share/doc/ruby-opengl/examples/RedBook/select.rb is in ruby-opengl 0.60.1+dfsg2-1~wheezy1.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 | #
# Copyright (c) 1993-1997, Silicon Graphics, Inc.
# ALL RIGHTS RESERVED
# Permission to use, copy, modify, and distribute this software for
# any purpose and without fee is hereby granted, provided that the above
# copyright notice appear in all copies and that both the copyright notice
# and this permission notice appear in supporting documentation, and that
# the name of Silicon Graphics, Inc. not be used in advertising
# or publicity pertaining to distribution of the software without specific,
# written prior permission.
#
# THE MATERIAL EMBODIED ON THIS SOFTWARE IS PROVIDED TO YOU "AS-IS"
# AND WITHOUT WARRANTY OF ANY KIND, EXPRESS, IMPLIED OR OTHERWISE,
# INCLUDING WITHOUT LIMITATION, ANY WARRANTY OF MERCHANTABILITY OR
# FITNESS FOR A PARTICULAR PURPOSE. IN NO EVENT SHALL SILICON
# GRAPHICS, INC. BE LIABLE TO YOU OR ANYONE ELSE FOR ANY DIRECT,
# SPECIAL, INCIDENTAL, INDIRECT OR CONSEQUENTIAL DAMAGES OF ANY
# KIND, OR ANY DAMAGES WHATSOEVER, INCLUDING WITHOUT LIMITATION,
# LOSS OF PROFIT, LOSS OF USE, SAVINGS OR REVENUE, OR THE CLAIMS OF
# THIRD PARTIES, WHETHER OR NOT SILICON GRAPHICS, INC. HAS BEEN
# ADVISED OF THE POSSIBILITY OF SUCH LOSS, HOWEVER CAUSED AND ON
# ANY THEORY OF LIABILITY, ARISING OUT OF OR IN CONNECTION WITH THE
# POSSESSION, USE OR PERFORMANCE OF THIS SOFTWARE.
#
# US Government Users Restricted Rights
# Use, duplication, or disclosure by the Government is subject to
# restrictions set forth in FAR 52.227.19(c)(2) or subparagraph
# (c)(1)(ii) of the Rights in Technical Data and Computer Software
# clause at DFARS 252.227-7013 and/or in similar or successor
# clauses in the FAR or the DOD or NASA FAR Supplement.
# Unpublished-- rights reserved under the copyright laws of the
# United States. Contractor/manufacturer is Silicon Graphics,
# Inc., 2011 N. Shoreline Blvd., Mountain View, CA 94039-7311.
#
# OpenGL(R) is a registered trademark of Silicon Graphics, Inc.
#
#
# select.c
# This is an illustration of the selection mode and
# name stack, which detects whether objects which collide
# with a viewing volume. First, four triangles and a
# rectangular box representing a viewing volume are drawn
# (drawScene routine). The green triangle and yellow
# triangles appear to lie within the viewing volume, but
# the red triangle appears to lie outside it. Then the
# selection mode is entered (selectObjects routine).
# Drawing to the screen ceases. To see if any collisions
# occur, the four triangles are called. In this example,
# the green triangle causes one hit with the name 1, and
# the yellow triangles cause one hit with the name 3.
require 'opengl'
include Gl,Glu,Glut
# draw a triangle with vertices at (x1, y1), (x2, y2)
# and (x3, y3) at z units away from the origin.
def drawTriangle(x1, y1, x2, y2, x3, y3, z)
glBegin(GL_TRIANGLES)
glVertex(x1, y1, z)
glVertex(x2, y2, z)
glVertex(x3, y3, z)
glEnd()
end
# draw a rectangular box with these outer x, y, and z values
def drawViewVolume(x1, x2, y1, y2, z1, z2)
glColor(1.0, 1.0, 1.0)
glBegin(GL_LINE_LOOP)
glVertex(x1, y1, -z1)
glVertex(x2, y1, -z1)
glVertex(x2, y2, -z1)
glVertex(x1, y2, -z1)
glEnd()
glBegin(GL_LINE_LOOP)
glVertex(x1, y1, -z2)
glVertex(x2, y1, -z2)
glVertex(x2, y2, -z2)
glVertex(x1, y2, -z2)
glEnd()
glBegin(GL_LINES)# 4 lines
glVertex(x1, y1, -z1)
glVertex(x1, y1, -z2)
glVertex(x1, y2, -z1)
glVertex(x1, y2, -z2)
glVertex(x2, y1, -z1)
glVertex(x2, y1, -z2)
glVertex(x2, y2, -z1)
glVertex(x2, y2, -z2)
glEnd()
end
# drawScene draws 4 triangles and a wire frame
# which represents the viewing volume.
def drawScene()
glMatrixMode(GL_PROJECTION)
glLoadIdentity()
gluPerspective(40.0, 4.0/3.0, 1.0, 100.0)
glMatrixMode(GL_MODELVIEW)
glLoadIdentity()
gluLookAt(7.5, 7.5, 12.5, 2.5, 2.5, -5.0, 0.0, 1.0, 0.0)
glColor(0.0, 1.0, 0.0)# green triangle
drawTriangle(2.0, 2.0, 3.0, 2.0, 2.5, 3.0, -5.0)
glColor(1.0, 0.0, 0.0)# red triangle
drawTriangle(2.0, 7.0, 3.0, 7.0, 2.5, 8.0, -5.0)
glColor(1.0, 1.0, 0.0)# yellow triangles
drawTriangle(2.0, 2.0, 3.0, 2.0, 2.5, 3.0, 0.0)
drawTriangle(2.0, 2.0, 3.0, 2.0, 2.5, 3.0, -10.0)
drawViewVolume(0.0, 5.0, 0.0, 5.0, 0.0, 10.0)
end
# processHits prints out the contents of the selection array
def processHits(hits, buffer)
printf("hits = %d\n", hits)
ptr = buffer.unpack("I*")
p = 0
for i in 0...hits # for each hit
names = ptr[p]
printf(" number of names for hit = %d\n", names); p+=1
printf(" z1 is %g", ptr[p].to_f/0xffffffff); p+=1
printf(" z2 is %g\n", ptr[p].to_f/0xffffffff); p+=1
printf(" the name is ")
for j in 0...names # for each name
printf("%d ", ptr[p]); p+=1
end
printf("\n")
end
end
# selectObjects "draws" the triangles in selection mode,
# assigning names for the triangles. Note that the third
# and fourth triangles share one name, so that if either
# or both triangles intersects the viewing/clipping volume,
# only one hit will be registered.
BUFSIZE=512
def selectObjects
selectBuf = glSelectBuffer(BUFSIZE)
glRenderMode(GL_SELECT)
glInitNames()
glPushName(0)
glPushMatrix()
glMatrixMode(GL_PROJECTION)
glLoadIdentity()
glOrtho(0.0, 5.0, 0.0, 5.0, 0.0, 10.0)
glMatrixMode(GL_MODELVIEW)
glLoadIdentity()
glLoadName(1)
drawTriangle(2.0, 2.0, 3.0, 2.0, 2.5, 3.0, -5.0)
glLoadName(2)
drawTriangle(2.0, 7.0, 3.0, 7.0, 2.5, 8.0, -5.0)
glLoadName(3)
drawTriangle(2.0, 2.0, 3.0, 2.0, 2.5, 3.0, 0.0)
drawTriangle(2.0, 2.0, 3.0, 2.0, 2.5, 3.0, -10.0)
glPopMatrix()
glFlush()
hits = glRenderMode(GL_RENDER)
processHits(hits, selectBuf)
end
def init
glEnable(GL_DEPTH_TEST)
glShadeModel(GL_FLAT)
end
display = proc do
glClearColor(0.0, 0.0, 0.0, 0.0)
glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT)
drawScene()
selectObjects()
glFlush()
end
keyboard = proc do |key, x, y|
case (key)
when ?\e
exit(0)
end
end
# Main Loop
GLUT.Init
glutInitDisplayMode(GLUT_SINGLE | GLUT_RGB | GLUT_DEPTH)
glutInitWindowSize(500, 500)
glutInitWindowPosition(100, 100)
glutCreateWindow $0
init()
glutDisplayFunc(display)
glutKeyboardFunc(keyboard)
glutMainLoop()
|