Demo 36 of 68 in category RedBook
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# mipmap.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 mipmaps for texture maps.
# To overtly show the effect of mipmaps, each mipmap reduction
# level has a solidly colored, contrasting texture image.
# Thus, the quadrilateral which is drawn is drawn with several
# different colors.
package require tcl3d
set mipmapImage32 [tcl3dVector GLubyte [expr 32*32*4]]
set mipmapImage16 [tcl3dVector GLubyte [expr 16*16*4]]
set mipmapImage8 [tcl3dVector GLubyte [expr 8*8*4]]
set mipmapImage4 [tcl3dVector GLubyte [expr 4*4*4]]
set mipmapImage2 [tcl3dVector GLubyte [expr 2*2*4]]
set mipmapImage1 [tcl3dVector GLubyte [expr 1*1*4]]
# 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
}
}
proc makeImages {} {
for { set i 0 } { $i < 32 } { incr i } {
for { set j 0 } { $j < 32 } { incr j } {
$::mipmapImage32 set [expr $i*32*4 + $j*4 + 0] 255
$::mipmapImage32 set [expr $i*32*4 + $j*4 + 1] 255
$::mipmapImage32 set [expr $i*32*4 + $j*4 + 2] 0
$::mipmapImage32 set [expr $i*32*4 + $j*4 + 3] 255
}
}
for { set i 0 } { $i < 16 } { incr i } {
for { set j 0 } { $j < 16 } { incr j } {
$::mipmapImage16 set [expr $i*16*4 + $j*4 + 0] 255
$::mipmapImage16 set [expr $i*16*4 + $j*4 + 1] 0
$::mipmapImage16 set [expr $i*16*4 + $j*4 + 2] 255
$::mipmapImage16 set [expr $i*16*4 + $j*4 + 3] 255
}
}
for { set i 0 } { $i < 8 } { incr i } {
for { set j 0 } { $j < 8 } { incr j } {
$::mipmapImage8 set [expr $i*8*4 + $j*4 + 0] 255
$::mipmapImage8 set [expr $i*8*4 + $j*4 + 1] 0
$::mipmapImage8 set [expr $i*8*4 + $j*4 + 2] 0
$::mipmapImage8 set [expr $i*8*4 + $j*4 + 3] 255
}
}
for { set i 0 } { $i < 4 } { incr i } {
for { set j 0 } { $j < 4 } { incr j } {
$::mipmapImage4 set [expr $i*4*4 + $j*4 + 0] 0
$::mipmapImage4 set [expr $i*4*4 + $j*4 + 1] 255
$::mipmapImage4 set [expr $i*4*4 + $j*4 + 2] 0
$::mipmapImage4 set [expr $i*4*4 + $j*4 + 3] 255
}
}
for { set i 0 } { $i < 2 } { incr i } {
for { set j 0 } { $j < 2 } { incr j } {
$::mipmapImage2 set [expr $i*2*4 + $j*4 + 0] 0
$::mipmapImage2 set [expr $i*2*4 + $j*4 + 1] 0
$::mipmapImage2 set [expr $i*2*4 + $j*4 + 2] 255
$::mipmapImage2 set [expr $i*2*4 + $j*4 + 3] 255
}
}
$::mipmapImage1 set 0 255
$::mipmapImage1 set 1 255
$::mipmapImage1 set 2 255
$::mipmapImage1 set 3 255
}
proc CreateCallback { toglwin } {
glEnable GL_DEPTH_TEST
glShadeModel GL_FLAT
glTranslatef 0.0 0.0 -3.6
makeImages
glPixelStorei GL_UNPACK_ALIGNMENT 1
set ::texName [tcl3dVector GLuint 1]
glGenTextures 1 $::texName
glBindTexture GL_TEXTURE_2D [$::texName get 0]
glTexParameteri GL_TEXTURE_2D GL_TEXTURE_WRAP_S $::GL_REPEAT
glTexParameteri GL_TEXTURE_2D GL_TEXTURE_WRAP_T $::GL_REPEAT
glTexParameteri GL_TEXTURE_2D GL_TEXTURE_MAG_FILTER $::GL_NEAREST
glTexParameteri GL_TEXTURE_2D GL_TEXTURE_MIN_FILTER \
$::GL_NEAREST_MIPMAP_NEAREST
glTexImage2D GL_TEXTURE_2D 0 $::GL_RGBA 32 32 0 \
GL_RGBA GL_UNSIGNED_BYTE $::mipmapImage32
glTexImage2D GL_TEXTURE_2D 1 $::GL_RGBA 16 16 0 \
GL_RGBA GL_UNSIGNED_BYTE $::mipmapImage16
glTexImage2D GL_TEXTURE_2D 2 $::GL_RGBA 8 8 0 \
GL_RGBA GL_UNSIGNED_BYTE $::mipmapImage8
glTexImage2D GL_TEXTURE_2D 3 $::GL_RGBA 4 4 0 \
GL_RGBA GL_UNSIGNED_BYTE $::mipmapImage4
glTexImage2D GL_TEXTURE_2D 4 $::GL_RGBA 2 2 0 \
GL_RGBA GL_UNSIGNED_BYTE $::mipmapImage2
glTexImage2D GL_TEXTURE_2D 5 $::GL_RGBA 1 1 0 \
GL_RGBA GL_UNSIGNED_BYTE $::mipmapImage1
glTexEnvf GL_TEXTURE_ENV GL_TEXTURE_ENV_MODE $::GL_DECAL
glEnable GL_TEXTURE_2D
}
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] [$toglwin height]
glBindTexture GL_TEXTURE_2D [$::texName get 0]
glBegin GL_QUADS
glTexCoord2f 0.0 0.0 ; glVertex3f -2.0 -1.0 0.0
glTexCoord2f 0.0 8.0 ; glVertex3f -2.0 1.0 0.0
glTexCoord2f 8.0 8.0 ; glVertex3f 2000.0 1.0 -6000.0
glTexCoord2f 8.0 0.0 ; glVertex3f 2000.0 -1.0 -6000.0
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 30000.0
glMatrixMode GL_MODELVIEW
glLoadIdentity
}
frame .fr
pack .fr -expand 1 -fill both
togl .fr.toglwin -width 500 -height 500 -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 mipmap"
bind . <Key-Escape> "exit"
.fr.usage insert end "Key-Escape Exit"
.fr.usage configure -state disabled
PrintInfo [tcl3dOglGetInfoString]
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