OUTPUT BUFFER:
# texgen.c # # 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, Paul Obermeier. # See file LICENSE for complete license information. # # This program draws a texture mapped teapot with # automatically generated texture coordinates. The # texture is rendered as stripes on the teapot. # Initially, the object is drawn with texture coordinates # based upon the object coordinates of the vertex # and distance from the plane x = 0. Pressing the 'e' # key changes the coordinate generation to eye coordinates # of the vertex. Pressing the 'o' key switches it back # to the object coordinates. Pressing the 's' key # changes the plane to a slanted one (x + y + z = 0). # Pressing the 'x' key switches it back to x = 0. package require tcl3d 0.4.0 set stripeImageWidth 32 set stripeImage [tcl3dVector GLubyte [expr 4*$stripeImageWidth]] # 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 makeStripeImage {} { for { set j 0 } { $j < $::stripeImageWidth } { incr j } { set r [expr ($j<=4) ? 255 : 0] set g [expr ($j>4) ? 255 : 0] $::stripeImage set [expr 4*$j+0] $r $::stripeImage set [expr 4*$j+1] $g $::stripeImage set [expr 4*$j+2] 0 $::stripeImage set [expr 4*$j+3] 255 } } # planes for texture coordinate generation set xequalzero {1.0 0.0 0.0 0.0} set slanted {1.0 1.0 1.0 0.0} proc CreateCallback { toglwin } { glClearColor 0.0 0.0 0.0 0.0 glEnable GL_DEPTH_TEST glShadeModel GL_SMOOTH makeStripeImage glPixelStorei GL_UNPACK_ALIGNMENT 1 set ::texName [tcl3dVector GLuint 1] glGenTextures 1 $::texName glBindTexture GL_TEXTURE_1D [$::texName get 0] glTexParameteri GL_TEXTURE_1D GL_TEXTURE_WRAP_S $::GL_REPEAT glTexParameteri GL_TEXTURE_1D GL_TEXTURE_MAG_FILTER $::GL_LINEAR glTexParameteri GL_TEXTURE_1D GL_TEXTURE_MIN_FILTER $::GL_LINEAR glTexImage1D GL_TEXTURE_1D 0 $::GL_RGBA $::stripeImageWidth 0 \ GL_RGBA GL_UNSIGNED_BYTE $::stripeImage glTexEnvf GL_TEXTURE_ENV GL_TEXTURE_ENV_MODE $::GL_MODULATE set ::currentCoeff $::xequalzero set ::currentGenMode $::GL_OBJECT_LINEAR set ::currentPlane $::GL_OBJECT_PLANE glTexGeni GL_S GL_TEXTURE_GEN_MODE $::currentGenMode glTexGenfv GL_S $::currentPlane $::currentCoeff glEnable GL_TEXTURE_GEN_S glEnable GL_TEXTURE_1D glEnable GL_CULL_FACE glEnable GL_LIGHTING glEnable GL_LIGHT0 glEnable GL_AUTO_NORMAL glEnable GL_NORMALIZE glFrontFace GL_CW glCullFace GL_BACK glMaterialf GL_FRONT GL_SHININESS 64.0 } 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] [$toglwin height] glPushMatrix glRotatef 45.0 0.0 0.0 1.0 glBindTexture GL_TEXTURE_1D [$::texName get 0] glutSolidTeapot 2.0 glPopMatrix glFlush } 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 <= $h } { glOrtho -3.5 3.5 [expr -3.5*double($h)/double($w)] \ [expr 3.5*double($h)/double($w)] -3.5 3.5 } else { glOrtho [expr -3.5*double($w)/double($h)] \ [expr 3.5*double($w)/double($h)] -3.5 3.5 -3.5 3.5 } glMatrixMode GL_MODELVIEW glLoadIdentity } proc SetEyeLinear {} { set ::currentGenMode $::GL_EYE_LINEAR set ::currentPlane $::GL_EYE_PLANE glTexGeni GL_S GL_TEXTURE_GEN_MODE $::currentGenMode glTexGenfv GL_S $::currentPlane $::currentCoeff .fr.toglwin postredisplay } proc SetObjLinear {} { set ::currentGenMode $::GL_OBJECT_LINEAR set ::currentPlane $::GL_OBJECT_PLANE glTexGeni GL_S GL_TEXTURE_GEN_MODE $::currentGenMode glTexGenfv GL_S $::currentPlane $::currentCoeff .fr.toglwin postredisplay } proc SetSlanted {} { set ::currentCoeff $::slanted glTexGenfv GL_S $::currentPlane $::currentCoeff .fr.toglwin postredisplay } proc SetZero {} { set ::currentCoeff $::xequalzero glTexGenfv GL_S $::currentPlane $::currentCoeff .fr.toglwin postredisplay } frame .fr pack .fr -expand 1 -fill both togl .fr.toglwin -width 400 -height 400 -double false -depth true \ -createproc CreateCallback \ -reshapeproc ReshapeCallback \ -displayproc DisplayCallback listbox .fr.usage -font $::listFont -height 5 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 texgen" bind .