openglarea.bash

gtk_server的源代码

#!/bin/bash
#
# Demo with gtkglarea - April 2008, (c) PvE.
#
# The API of GtkGlArea is a bit more convenient than GtkGlExt, IMHO.
#
#---------------------------------------------------------------------

#---------------------------------------------------------------------
# Some constants
#---------------------------------------------------------------------

# Name of PIPE file
declare PI=/tmp/bash.gtk.$$

NULL="NULL"
ESCAPE=65307

# These hex values are retrieved from the GL header files
let GL_DEPTH_BUFFER_BIT=16#100
let GL_COLOR_BUFFER_BIT=16#4000

let GL_LIGHT0=16#4000
let GL_MODELVIEW=16#1700
let GL_POSITION=16#1203
let GL_AMBIENT=16#1200
let GL_DIFFUSE=16#1201
let GL_SPECULAR=16#1202
let GL_SMOOTH=16#1D01
let GL_DEPTH_TEST=16#0B71
let GL_LIGHTING=16#0B50
let GL_FRONT=16#0404
let GL_AMBIENT_AND_DIFFUSE=16#1602

# First message in ASCII characters: "OpenGL demo with BASH"
MSG1=(79 112 101 110 71 76 32 100 101 109 111 32 119 105 116 104 32 66 65 83 72)

# Second message in ASCII characters: "Using GTK-server with GtkGlArea!"
MSG2=(85 115 105 110 103 32 71 84 75 45 115 101 114 118 101 114 32 119 105 116 104 32 71 116 107 71 108 65 114 101 97 33)

#---------------------------------------------------------------------
# Communication function; assignment function
#---------------------------------------------------------------------

function gtk() { echo $1 > $PI; read GTK < $PI; }
function define() { $2 "$3"; eval $1="$GTK"; }

#---------------------------------------------------------------------
# Draw bitmapped text on the screen, character by character
#---------------------------------------------------------------------

function bitmap_text
{
let NR=0

while [[ $NR -lt ${#MSG1[@]} ]]
do
    gtk "glutBitmapCharacter $GLUT_BITMAP_HELVETICA_18 ${MSG1[$NR]}"
    ((NR+=1))
done
}

#---------------------------------------------------------------------
# Draw stroked text on the screen, character by character
#---------------------------------------------------------------------

function stroke_text
{
let NR=0

while [[ $NR -lt ${#MSG2[@]} ]]
do
    gtk "glutStrokeCharacter $GLUT_STROKE_ROMAN ${MSG2[$NR]}"
    ((NR+=1))
done
}

#---------------------------------------------------------------------
# Draw and expose the picture
#
# Note: colors in OpenGL are mostly defined as an array of floats.
# Such an array cannot be passed to the GTK-server, therefore we pass 
# a binary structure which is Base64 encoded. To create a Base64
# encoded float array structure, I used the following:
#
# newlisp -e '(base64-enc (pack "fff" 1 1 0))'
#
# In this example the float array {1.0 1.0 0.0} is shown in Base64 
# and can be passed to the GTK-server. Of course the datatype for the 
# argument in the GL-function in the configfile should be set to
# BASE64 also.
#
# NewLisp can be obtained for free from http://www.newlisp.org
#---------------------------------------------------------------------

function expose
{
# Define the drawing area
gtk "gtk_gl_area_make_current $GLAREA"

# Define clearing color
gtk "glClearColor 0.5 1 1 0"
# Clear screen
((FLAG=$GL_COLOR_BUFFER_BIT|$GL_DEPTH_BUFFER_BIT))
gtk "glClear $FLAG"
# Enable shading, depth and lighting
gtk "glShadeModel $GL_SMOOTH"
gtk "glEnable $GL_DEPTH_TEST"
gtk "glEnable $GL_LIGHTING"
gtk "glEnable $GL_LIGHT0"
# Setup lighting
gtk "glLightfv $GL_LIGHT0 $GL_POSITION AAAAQAAAAEAAAADBAAAAAA=="
gtk "glLightfv $GL_LIGHT0 $GL_DIFFUSE AACAPwAAgD8AAIA/AACAPw=="
gtk "glLightfv $GL_LIGHT0 $GL_AMBIENT mpkZPpqZGT6amRk+"
gtk "glLightfv $GL_LIGHT0 $GL_SPECULAR AACAPwAAgD8AAIA/AACAPw=="
# Setup reflected color of object
gtk "glMaterialfv $GL_FRONT $GL_AMBIENT_AND_DIFFUSE zczMPTMzMz/NzMw9AAAAPw=="
# Make sure we see the model
gtk "glMatrixMode $GL_MODELVIEW"
# Save current matrix
gtk "glPushMatrix"
# Rotate
gtk "glRotatef $ROTX 0 1 0"
gtk "glRotatef $ROTY 1 0 0"
# Dump rotated image
gtk "glutSolidTeapot $SIZE"
# Undo the last rotation
gtk "glLoadIdentity"
# Setup reflected color of font
gtk "glMaterialfv $GL_FRONT $GL_AMBIENT_AND_DIFFUSE AACAP83MzD4AAIA/AAAAAA=="
# Determine position of bitmapped text
gtk "glRasterPos2f 0 -0.8"
# Draw some bitmapped text
bitmap_text
# Setup reflected color of font
gtk "glMaterialfv $GL_FRONT $GL_AMBIENT_AND_DIFFUSE AAAAAAAAAAAAAIA/AAAAAA=="
# Determine position of STROKED text -> drawed so translate
gtk "glTranslatef -0.9 0.8 0.0"
# Setup scaling -> stroked characters are large, make smaller
gtk "glScalef 0.0005 0.0006 0"
# Draw some stroked text
stroke_text
# Now put back the matrix
gtk "glPopMatrix"

# Now swap buffers and draw
gtk "gtk_gl_area_swap_buffers $GLAREA"
}

#---------------------------------------------------------------------
# Main program
#---------------------------------------------------------------------

# Start gtk-server in FIFO mode
gtk-server -fifo=$PI &
while [ ! -p $PI ]; do continue; done

# Check availability of GtkGlArea
define AVAIL gtk "gtk_server_require libgtkgl-2.0.so"
if [[ $AVAIL != "ok" ]]
then
    echo "Install the GtkGlArea libraries 'gtkglarea-1.99.0.tar.bz2' first, and run this demo again."
    gtk "gtk_server_exit"
    exit
fi
define AVAIL gtk "gtk_server_require libglut.so.3"
if [[ $AVAIL != "ok" ]]
then
    echo "Install the GLUT libraries from freeglut.sourceforge.net first, and run this demo again."
    gtk "gtk_server_exit"
    exit
fi

# Define GUI
gtk "gtk_init $NULL $NULL"
# Window
define WINDOW gtk "gtk_window_new 0"
gtk "gtk_window_set_default_size $WINDOW 640 480"
gtk "gtk_window_set_title $WINDOW 'This is a teapot demo with BASH'"
gtk "gtk_window_set_position $WINDOW 1"
# Signal every 100 msecs
gtk "gtk_server_connect $WINDOW show idle"
gtk "gtk_server_timeout 75 $WINDOW show"
gtk "gtk_server_connect $WINDOW key-press-event key-press-event"

#-----------------------------------------------------------------------------
# The call 'gtk_gl_area_new' uses a C array of 32-bit integers to define the
# GLX attribute list.
#
# For the array of integers, we have the same problem as for the colors: we
# need to pass a binary structure. The ony way is base64 encoded.
# To create the GLX attribute list, I used the following:
#
# newlisp -e '(base64-enc (pack "ldldldldldldldldld" 4 8 1 9 1 10 1 5 0))'
#
# The array consists of GDK_GL_RGBA (4), GDK_GL_RED_SIZE (8), the value '1',
# GDK_GL_GREEN_SIZE (9), the value '1', GDK_GL_BLUE_SIZE (10), the value '1',
# GDK_GL_DOUBLEBUFFER (5) and finally GDK_GL_NONE (0).
#
# These values were taken from the GtkGlArea header file.
#
# In the configfile, define 'gtk_gl_area_new' with a BASE64 argument.
#
# NewLisp can be obtained for free from http://www.newlisp.org
#-----------------------------------------------------------------------------

# OpenGL widget
define GLAREA gtk "gtk_gl_area_new BAAAAAgAAAABAAAACQAAAAEAAAAKAAAAAQAAAAUAAAAAAAAA"

gtk "gtk_server_connect $GLAREA expose-event expose"
gtk "gtk_container_add $WINDOW $GLAREA"
gtk "gtk_widget_show_all $WINDOW"

# Initialize GLUT
gtk "glutInit 1 ' '"

# Initialize variables
EVENT=0
ROTX=0
ROTY=330
# size of teapot
SIZE=0.5

define GLUT_BITMAP_HELVETICA_18 gtk "glutBitmapHelvetica18"
define GLUT_STROKE_ROMAN gtk "glutStrokeRoman"

# Mainloop
until [[ $EVENT = $WINDOW || $KEY = $ESCAPE ]]
do
    define EVENT gtk "gtk_server_callback wait"

    # Rotate
    ((ROTX+=3))
    ((ROTY+=2))
    if [[ $ROTX -gt 359 ]]
    then
	ROTX=0
    fi
    if [[ $ROTX -lt 0 ]]
    then
	ROTX=360
    fi
    if [[ $ROTY -gt 359 ]]
    then
	ROTY=0
    fi
    if [[ $ROTY -lt 0 ]]
    then
	ROTY=360
    fi

    # Check events
    case $EVENT in

	"idle")
	    expose
	    ;;
	"expose")
	    expose
	    ;;
	"key-press-event")
	    define KEY gtk "gtk_server_key"
	    ;;
    esac
done

# Exit GTK
gtk "gtk_server_exit"