Demo 63 of 68 in category RedBook
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# texturesurf.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 uses evaluators to generate a curved
# surface and automatically generated texture coordinates.
package require tcl3d
set ctrlpoints {
{{ -1.5 -1.5 4.0} { -0.5 -1.5 2.0}
{0.5 -1.5 -1.0} {1.5 -1.5 2.0}}
{{ -1.5 -0.5 1.0} { -0.5 -0.5 3.0}
{0.5 -0.5 0.0} {1.5 -0.5 -1.0}}
{{ -1.5 0.5 4.0} { -0.5 0.5 0.0}
{0.5 0.5 3.0} {1.5 0.5 4.0}}
{{ -1.5 1.5 -2.0} { -0.5 1.5 -2.0}
{0.5 1.5 0.0} {1.5 1.5 -1.0}}
}
set texpts {{{0.0 0.0} {0.0 1.0}}
{{1.0 0.0} {1.0 1.0}}}
set imageWidth 64
set imageHeight 64
set imgVec [tcl3dVector GLubyte [expr 3*$imageWidth*$imageHeight]]
# 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 makeImage {} {
set TWO_PI [expr {2.0*3.14159265}]
for { set i 0 } { $i < $::imageWidth } { incr i } {
set ti [expr {$TWO_PI * $i / $::imageWidth}]
for { set j 0 } { $j < $::imageHeight } { incr j } {
set tj [expr {$TWO_PI * $j / $::imageHeight}]
set ind [expr {3 * ($::imageHeight*$i + $j)}]
$::imgVec set [expr {$ind+0}] [expr {int (127*(1.0+sin($ti)))}]
$::imgVec set [expr {$ind+1}] [expr {int (127*(1.0+cos(2*$tj)))}]
$::imgVec set [expr {$ind+2}] [expr {int (127*(1.0+cos($ti+$tj)))}]
}
}
}
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]
glColor3f 1.0 1.0 1.0
glEvalMesh2 GL_FILL 0 20 0 20
glFlush
$toglwin swapbuffers
}
proc CreateCallback { toglwin } {
glMap2f GL_MAP2_VERTEX_3 0 1 3 4 \
0 1 12 4 [join [join $::ctrlpoints]]
glMap2f GL_MAP2_TEXTURE_COORD_2 0 1 2 2 \
0 1 4 2 [join [join $::texpts]]
glEnable GL_MAP2_TEXTURE_COORD_2
glEnable GL_MAP2_VERTEX_3
glMapGrid2f 20 0.0 1.0 20 0.0 1.0
makeImage
glTexEnvf GL_TEXTURE_ENV GL_TEXTURE_ENV_MODE $::GL_DECAL
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
glTexImage2D GL_TEXTURE_2D 0 $::GL_RGB $::imageWidth $::imageHeight 0 \
GL_RGB GL_UNSIGNED_BYTE $::imgVec
glEnable GL_TEXTURE_2D
glEnable GL_DEPTH_TEST
glShadeModel GL_FLAT
}
proc ReshapeCallback { toglwin { w -1 } { h -1 } } {
set w [$toglwin width]
set h [$toglwin height]
glViewport 0 0 $w $h
glMatrixMode GL_PROJECTION
glLoadIdentity
if { $w <= $h } {
glOrtho -4.0 4.0 \
[expr -4.0*double($h)/double($w)] \
[expr 4.0*double($h)/double($w)] \
-4.0 4.0
} else {
glOrtho [expr -4.0*double($w)/double($h)] \
[expr 4.0*double($w)/double($h)] \
-4.0 4.0 -4.0 4.0
}
glMatrixMode GL_MODELVIEW
glLoadIdentity
glRotatef 85.0 1.0 1.0 1.0
}
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 texturesurf"
bind . <Key-Escape> "exit"
.fr.usage insert end "Key-Escape Exit"
.fr.usage configure -state disabled
PrintInfo [tcl3dOglGetInfoString]
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