Demo 62 of 68 in category RedBook
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# texture3d.tcl
#
# An example of the OpenGL red book modified to work with Tcl3D.
# The original C sources are Copyright (c) 1993-2003, Silicon Graphics, Inc.
# The Tcl3D sources are Copyright (c) 2005-2022, Paul Obermeier.
# See file LICENSE for complete license information.
#
# This program demonstrates using a three-dimensional texture.
# It creates a 3D texture and then renders two rectangles
# with different texture coordinates to obtain different
# "slices" of the 3D texture.
package require tcl3d
set iWidth 16
set iHeight 16
set iDepth 16
set image [tcl3dVector GLubyte [expr $iDepth*$iHeight*$iWidth*3]]
# Font to be used in the Tk listbox.
set listFont {-family {Courier} -size 10}
# Show errors occuring in the Togl callbacks.
proc bgerror { msg } {
tk_messageBox -icon error -type ok -message "Error: $msg\n\n$::errorInfo"
exit
}
# Print info message into widget a the bottom of the window.
proc PrintInfo { msg } {
if { [winfo exists .fr.info] } {
.fr.info configure -text $msg
}
}
# Create a 16x16x16x3 array with different color values in
# each array element [r, g, b]. Values range from 0 to 255.
#
proc makeImage {} {
for { set s 0 } { $s < 16 } { incr s } {
for { set t 0 } { $t < 16 } { incr t } {
for { set r 0 } { $r < 16 } { incr r } {
set ind [expr {((($r*$::iDepth + $t) * $::iHeight) +$s)*3}]
$::image set [expr {$ind + 0}] [expr {$s * 17}]
$::image set [expr {$ind + 1}] [expr {$t * 17}]
$::image set [expr {$ind + 2}] [expr {$r * 17}]
}
}
}
}
proc CreateCallback { toglwin } {
glClearColor 0.0 0.0 0.0 0.0
glShadeModel GL_FLAT
glEnable GL_DEPTH_TEST
makeImage
glPixelStorei GL_UNPACK_ALIGNMENT 1
set texName [tcl3dVector GLuint 1]
glGenTextures 1 $texName
glBindTexture GL_TEXTURE_3D [$texName get 0]
glTexParameteri GL_TEXTURE_3D GL_TEXTURE_WRAP_S $::GL_CLAMP
glTexParameteri GL_TEXTURE_3D GL_TEXTURE_WRAP_T $::GL_CLAMP
glTexParameteri GL_TEXTURE_3D GL_TEXTURE_WRAP_R $::GL_CLAMP
glTexParameteri GL_TEXTURE_3D GL_TEXTURE_MAG_FILTER $::GL_NEAREST
glTexParameteri GL_TEXTURE_3D GL_TEXTURE_MIN_FILTER $::GL_NEAREST
glTexImage3D GL_TEXTURE_3D 0 $::GL_RGB $::iWidth $::iHeight \
$::iDepth 0 GL_RGB GL_UNSIGNED_BYTE $::image
glEnable GL_TEXTURE_3D
}
proc DisplayCallback { toglwin } {
glClear [expr $::GL_COLOR_BUFFER_BIT | $::GL_DEPTH_BUFFER_BIT]
# Viewport command is not really needed, but has been inserted for
# Mac OSX. Presentation framework (Tk) does not send a reshape event,
# when switching from one demo to another.
glViewport 0 0 [$toglwin width] [$toglwin height]
glBegin GL_QUADS
glTexCoord3f 0.0 0.0 0.0 ; glVertex3f -2.25 -1.0 0.0
glTexCoord3f 0.0 1.0 0.0 ; glVertex3f -2.25 1.0 0.0
glTexCoord3f 1.0 1.0 1.0 ; glVertex3f -0.25 1.0 0.0
glTexCoord3f 1.0 0.0 1.0 ; glVertex3f -0.25 -1.0 0.0
glTexCoord3f 0.0 0.0 1.0 ; glVertex3f 0.25 -1.0 0.0
glTexCoord3f 0.0 1.0 1.0 ; glVertex3f 0.25 1.0 0.0
glTexCoord3f 1.0 1.0 0.0 ; glVertex3f 2.25 1.0 0.0
glTexCoord3f 1.0 0.0 0.0 ; glVertex3f 2.25 -1.0 0.0
glEnd
glFlush
$toglwin swapbuffers
}
proc ReshapeCallback { toglwin { w -1 } { h -1 } } {
set w [$toglwin width]
set h [$toglwin height]
glViewport 0 0 $w $h
glMatrixMode GL_PROJECTION
glLoadIdentity
gluPerspective 60.0 [expr double($w)/double($h)] 1.0 30.0
glMatrixMode GL_MODELVIEW
glLoadIdentity
glTranslatef 0.0 0.0 -4.0
}
frame .fr
pack .fr -expand 1 -fill both
togl .fr.toglwin -width 400 -height 400 -double true -depth true \
-createcommand CreateCallback \
-reshapecommand ReshapeCallback \
-displaycommand DisplayCallback
listbox .fr.usage -font $::listFont -height 1
label .fr.info
grid .fr.toglwin -row 0 -column 0 -sticky news
grid .fr.usage -row 1 -column 0 -sticky news
grid .fr.info -row 2 -column 0 -sticky news
grid rowconfigure .fr 0 -weight 1
grid columnconfigure .fr 0 -weight 1
wm title . "Tcl3D demo: OpenGL Red Book example texture3d"
bind . <Key-Escape> "exit"
.fr.usage insert end "Key-Escape Exit"
.fr.usage configure -state disabled
PrintInfo [tcl3dOglGetInfoString]
if { ! [tcl3dOglHaveVersion 1 2] } {
tk_messageBox -icon warning -type ok -title "Invalid OpenGL version" \
-message [format "Feature needs OpenGL >= 1.2. Only have %s" \
[glGetString GL_VERSION]]
}
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