Demo 33 of 35 in category NeHe
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# Lesson45.tcl
#
# Paul Frazee's Vertex Buffer Object Tutorial
#
# Code Commmenting And Clean Up By Jeff Molofee ( NeHe )
# If You've Found This Code Useful, Please Let Me Know.
# Visit My Site At nehe.gamedev.net
#
# Modified for Tcl3D by Paul Obermeier 2006/08/17
# See www.tcl3d.org for the Tcl3D extension.
package require Img
package require tcl3d
# Font to be used in the Tk listbox.
set listFont {-family {Courier} -size 10}
# Determine the directory of this script.
set gDemo(scriptDir) [file dirname [info script]]
# Display mode.
set fullScreen false
# Window size.
set gDemo(winWidth) 640
set gDemo(winHeight) 480
# Mesh Generation Paramaters
set MESH_RESOLUTION 4.0 ; # Pixels Per Vertex
set MESH_HEIGHTSCALE 1.0 ; # Mesh Height Scale
set g_bUseVBOs 1 ; # If 1, VBOs Will Be Forced On
set g_nTextureId [tcl3dVector GLuint 1] ; # Texture ID
# Vertex Buffer Object Names
set g_nVBOVertices [tcl3dVector GLuint 1] ; # Vertex VBO Name
set g_nVBOTexCoords [tcl3dVector GLuint 1] ; # Texture Coordinate VBO Name
set g_fVBOSupported false ; # ARB_vertex_buffer_object supported?
set g_flYRot 0.0 ; # Rotation
set stopwatch [tcl3dNewSwatch]
set FPS_UPDATE_FREQUENCY 50
set frameCount 0
set totalFrames 0
# Show errors occuring in the Togl callbacks.
proc bgerror { msg } {
tk_messageBox -icon error -type ok -message "Error: $msg\n\n$::errorInfo"
ExitProg
}
# Print info message into widget a the bottom of the window.
proc PrintInfo { msg } {
if { [winfo exists .fr.info] } {
.fr.info configure -text $msg
}
}
# Print info message into widget at the bottom of the window.
proc PrintTimeInfo { msg } {
if { [winfo exists .fr.timeinfo] } {
.fr.timeinfo configure -text $msg
}
}
proc SetFullScreenMode { win } {
set sh [winfo screenheight $win]
set sw [winfo screenwidth $win]
wm minsize $win $sw $sh
wm maxsize $win $sw $sh
set fmtStr [format "%dx%d+0+0" $sw $sh]
wm geometry $win $fmtStr
wm overrideredirect $win 1
focus -force $win
}
proc SetWindowMode { win w h } {
set sh [winfo screenheight $win]
set sw [winfo screenwidth $win]
wm minsize $win 10 10
wm maxsize $win $sw $sh
set fmtStr [format "%dx%d+0+25" $w $h]
wm geometry $win $fmtStr
wm overrideredirect $win 0
focus -force $win
}
# Toggle between windowing and fullscreen mode.
proc ToggleWindowMode {} {
if { $::fullScreen } {
SetFullScreenMode .
set ::fullScreen false
} else {
SetWindowMode . $::gDemo(winWidth) $::gDemo(winHeight)
set ::fullScreen true
}
}
proc GetElapsedSeconds {} {
set currentTime [tcl3dLookupSwatch $::stopwatch]
set sec [expr $currentTime - $::elapsedLastTime]
set ::elapsedLastTime $currentTime
return $sec
}
proc GetFPS { { elapsedFrames 1 } } {
set ::totalFrames [expr $::totalFrames + $elapsedFrames]
set currentTime [tcl3dLookupSwatch $::stopwatch]
set fps [expr $elapsedFrames / ($currentTime - $::s_lastTime)]
set ::s_lastTime $currentTime
return $fps
}
proc DisplayFPS {} {
global frameCount
if { ! [info exists ::animateId] } {
# Animation has been stopped. Do not update fps measurement.
return
}
incr frameCount
if { $frameCount == $::FPS_UPDATE_FREQUENCY } {
set msg [format "%d triangles, %.0f fps" \
[expr $::g_nVertexCount / 3] [GetFPS $frameCount]]
if { $::g_fVBOSupported } {
append msg ", using VBOs"
} else {
append msg ", not using VBOs"
}
PrintTimeInfo $msg
set frameCount 0
}
}
proc LoadImage { imgName numChans } {
if { $numChans != 3 && $numChans != 4 } {
error "Error: Only 3 or 4 channels allowed ($numChans supplied)"
}
set texName [file join $::gDemo(scriptDir) $imgName]
set retVal [catch {set phImg [image create photo -file $texName]} err1]
if { $retVal != 0 } {
error "Error reading image $texName ($err1)"
} else {
set w [image width $phImg]
set h [image height $phImg]
set texImg [tcl3dVectorFromPhoto $phImg $numChans]
}
return [list $phImg $texImg $w $h]
}
proc LoadHeightmap { fileName flHeightScale flResolution } {
# Load Texture Data
set imgInfo [LoadImage $fileName 3]
set phImg [lindex $imgInfo 0]
set imgData [lindex $imgInfo 1]
set imgWidth [lindex $imgInfo 2]
set imgHeight [lindex $imgInfo 3]
# Generate Vertex Field
set vectorList [tcl3dDemoUtilHeightmapFromPhoto $phImg \
$flHeightScale $flResolution]
set ::g_pVertices [lindex $vectorList 0]
set ::g_pTexCoords [lindex $vectorList 1]
set ::g_nVertexCount [lindex $vectorList 2]
# Load The Texture Into OpenGL
glGenTextures 1 $::g_nTextureId ; # Get An Open ID
glBindTexture GL_TEXTURE_2D [$::g_nTextureId get 0] ; # Bind The Texture
glTexImage2D GL_TEXTURE_2D 0 3 $imgWidth $imgHeight 0 GL_RGB GL_UNSIGNED_BYTE $imgData
glTexParameteri GL_TEXTURE_2D GL_TEXTURE_MIN_FILTER $::GL_LINEAR
glTexParameteri GL_TEXTURE_2D GL_TEXTURE_MAG_FILTER $::GL_LINEAR
$imgData delete
image delete $phImg
}
proc BuildVBOs {} {
# Generate And Bind The Vertex Buffer
glGenBuffersARB 1 $::g_nVBOVertices ; # Get A Valid Name
glBindBufferARB GL_ARRAY_BUFFER_ARB [$::g_nVBOVertices get 0] ; # Bind The Buffer
# Load The Data
glBufferDataARB GL_ARRAY_BUFFER_ARB [expr $::g_nVertexCount*3*4] \
$::g_pVertices GL_STATIC_DRAW_ARB
set retVal [tcl3dOglGetError]
if { $retVal ne "" } {
error "Error creating VBO for vertices: $retVal"
}
# Generate And Bind The Texture Coordinate Buffer
glGenBuffersARB 1 $::g_nVBOTexCoords ; # Get A Valid Name
glBindBufferARB GL_ARRAY_BUFFER_ARB [$::g_nVBOTexCoords get 0] ; # Bind The Buffer
# Load The Data
glBufferDataARB GL_ARRAY_BUFFER_ARB [expr $::g_nVertexCount*2*4] \
$::g_pTexCoords GL_STATIC_DRAW_ARB
set retVal [tcl3dOglGetError]
if { $retVal ne "" } {
error "Error creating VBO for tex coords: $retVal"
}
# Our Copy Of The Data Is No Longer Necessary, It Is Safe In The Graphics Card
$::g_pVertices delete
$::g_pTexCoords delete
}
# Resize And Initialize The GL Window
proc ReshapeCallback { toglwin { w -1 } { h -1 } } {
set w [$toglwin width]
set h [$toglwin height]
glViewport 0 0 $w $h ; # Reset The Current Viewport
glMatrixMode GL_PROJECTION ; # Select The Projection Matrix
glLoadIdentity ; # Reset The Projection Matrix
# Calculate The Aspect Ratio Of The Window
gluPerspective 45.0 [expr double($w)/double($h)] 1 1000.0
glMatrixMode GL_MODELVIEW ; # Select The Modelview Matrix
glLoadIdentity ; # Reset The Modelview Matrix
set ::gDemo(winWidth) $w
set ::gDemo(winHeight) $h
}
proc InitHeightData { toglwin } {
LoadHeightmap "Terrain.bmp" $::MESH_HEIGHTSCALE $::MESH_RESOLUTION
# Check For VBOs Supported
if { $::g_bUseVBOs } {
set ::g_fVBOSupported [tcl3dOglHaveExtension $toglwin "GL_ARB_vertex_buffer_object"]
if { $::g_fVBOSupported } {
# Load Vertex Data Into The Graphics Card Memory
BuildVBOs ; # Build The VBOs
}
} else {
set ::g_fVBOSupported false
}
}
# All Setup For OpenGL Goes Here
proc CreateCallback { toglwin } {
tcl3dStartSwatch $::stopwatch
InitHeightData $toglwin
# Setup GL States
glClearColor 0.0 0.0 0.0 0.5 ; # Black Background
glClearDepth 1.0 ; # Depth Buffer Setup
glDepthFunc GL_LEQUAL ; # The Type Of Depth Testing (Less Or Equal)
glEnable GL_DEPTH_TEST ; # Enable Depth Testing
glShadeModel GL_SMOOTH ; # Select Smooth Shading
glEnable GL_TEXTURE_2D ; # Enable Textures
glColor4f 1.0 1.0 1.0 1.0 ; # Set The Color To White
# Set Perspective Calculations To Most Accurate
glHint GL_PERSPECTIVE_CORRECTION_HINT GL_NICEST
tcl3dResetSwatch $::stopwatch
set ::startTime [tcl3dLookupSwatch $::stopwatch]
set ::s_lastTime $::startTime
set ::elapsedLastTime $::startTime
}
# Here's Where We Do All The Drawing
proc DisplayCallback { toglwin } {
set ::g_flYRot [expr $::g_flYRot + [GetElapsedSeconds] * 25.0] ; # Consistantly Rotate The Scenery
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]
glLoadIdentity ; # Reset The Modelview Matrix
DisplayFPS
# Move The Camera
glTranslatef 0.0 -220.0 0.0 ; # Move Above The Terrain
glRotatef 10.0 1.0 0.0 0.0 ; # Look Down Slightly
glRotatef $::g_flYRot 0.0 1.0 0.0 ; # Rotate The Camera
# Enable Pointers
glEnableClientState GL_VERTEX_ARRAY ; # Enable Vertex Arrays
glEnableClientState GL_TEXTURE_COORD_ARRAY ; # Enable Texture Coord Arrays
# Set Pointers To Our Data
if { $::g_fVBOSupported } {
glBindBufferARB GL_ARRAY_BUFFER_ARB [$::g_nVBOVertices get 0]
# Set The Vertex Pointer To The Vertex Buffer
glVertexPointer 3 GL_FLOAT 0 NULL
glBindBufferARB GL_ARRAY_BUFFER_ARB [$::g_nVBOTexCoords get 0]
# Set The TexCoord Pointer To The TexCoord Buffer
glTexCoordPointer 2 GL_FLOAT 0 NULL
} else {
# Set The Vertex Pointer To Our Vertex Data
glVertexPointer 3 GL_FLOAT 0 $::g_pVertices
# Set The Vertex Pointer To Our TexCoord Data
glTexCoordPointer 2 GL_FLOAT 0 $::g_pTexCoords
}
# Draw All Of The Triangles At Once
glDrawArrays GL_TRIANGLES 0 $::g_nVertexCount
# Disable Pointers
glDisableClientState GL_VERTEX_ARRAY ; # Disable Vertex Arrays
glDisableClientState GL_TEXTURE_COORD_ARRAY ; # Disable Texture Coord Arrays
$toglwin swapbuffers
}
proc Animate {} {
.fr.toglwin postredisplay
set ::animateId [tcl3dAfterIdle Animate]
}
proc StartAnimation {} {
tcl3dStartSwatch $::stopwatch
if { ! [info exists ::animateId] } {
Animate
}
}
proc StopAnimation {} {
tcl3dStopSwatch $::stopwatch
if { [info exists ::animateId] } {
after cancel $::animateId
unset ::animateId
}
}
proc Cleanup {} {
# Delete VBOs
if { $::g_fVBOSupported } {
glDeleteBuffersARB 1 [$::g_nVBOVertices get 0]
glDeleteBuffersARB 1 [$::g_nVBOTexCoords get 0]
}
}
# Put all exit related code here.
proc ExitProg {} {
exit
}
# Create the OpenGL window and some Tk helper widgets.
proc CreateWindow {} {
frame .fr
pack .fr -expand 1 -fill both
# Create Our OpenGL Window
togl .fr.toglwin -width $::gDemo(winWidth) -height $::gDemo(winHeight) \
-double true -depth true \
-createcommand CreateCallback \
-reshapecommand ReshapeCallback \
-displaycommand DisplayCallback
listbox .fr.usage -font $::listFont -height 3
label .fr.timeinfo -bg white
label .fr.info
grid .fr.toglwin -row 0 -column 0 -sticky news
grid .fr.usage -row 1 -column 0 -sticky news
grid .fr.timeinfo -row 2 -column 0 -sticky news
grid .fr.info -row 3 -column 0 -sticky news
grid rowconfigure .fr 0 -weight 1
grid columnconfigure .fr 0 -weight 1
wm title . "Tcl3D demo: Paul Frazee's Vertex Buffer Object Tutorial (Lesson 45)"
# Watch For ESC Key And Quit Messages
wm protocol . WM_DELETE_WINDOW "ExitProg"
bind . <Key-Escape> "ExitProg"
bind . <Key-F1> "ToggleWindowMode"
bind .fr.toglwin <1> "StartAnimation"
bind .fr.toglwin <2> "StopAnimation"
bind .fr.toglwin <3> "StopAnimation"
bind .fr.toglwin <Control-Button-1> "StopAnimation"
.fr.usage insert end "Key-Escape Exit"
.fr.usage insert end "Key-F1 Toggle window mode"
.fr.usage insert end "Mouse-L|MR Start|Stop animation"
.fr.usage configure -state disabled
}
if { $argc >= 1 } {
if { [string compare -nocase [lindex $argv 0] "vbo"] == 0 } {
set ::g_bUseVBOs 1
} elseif { [string compare -nocase [lindex $argv 0] "novbo"] == 0 } {
set ::g_bUseVBOs 0
}
}
CreateWindow
PrintInfo [tcl3dOglGetInfoString]
if { [file tail [info script]] eq [file tail $::argv0] } {
# If started directly from tclsh or wish, then start animation.
update
StartAnimation
}
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