#!/usr/bin/ksh93

compound c=(
	compound tty=(
		integer max_x
		integer max_y
	)

	compound sample_data=(
		float -a vals
		float min=0
		float max=0
	)
	
	float min_data_shift
	float max_data_shift
	float data_scale_to_tty_max_y
)

integer i


#
# get terminal info
#
(( c.tty.max_x=$(tput cols)-2 ))
(( c.tty.max_y=$(tput lines)-2 ))

#
# collect samples data
#
integer max_i=${c.tty.max_x}
for ((i=0 ; i < max_i ; i++ )) ; do
	(( c.sample_data.vals[i]=sin(i/5.) ))
done

#
# get minimum/maximum value of all data samples
#
# we use $ for i in "${!@}" instead of $ for ((i=0 ; i < ... ; i++ )) # syntax
# here so we can handle sparse data/sparse arrays
#
for i in "${!c.sample_data.vals[@]}" ; do
	(( c.sample_data.min=fmin(c.sample_data.vals[i], c.sample_data.min) ))
	(( c.sample_data.max=fmax(c.sample_data.vals[i], c.sample_data.max) ))
done

#
# calculations for output scaling etc
#
(( c.min_data_shift = c.sample_data.min * -1.0 ))
(( c.max_data_shift = c.min_data_shift + c.sample_data.max ))
(( c.data_scale_to_tty_max_y = c.tty.max_y / c.max_data_shift ))

#
# output
#
tput clear
for i in "${!c.sample_data.vals[@]}" ; do
	tput cup $(( int( c.data_scale_to_tty_max_y * (c.min_data_shift+c.sample_data.vals[i]) ) )) $i
	printf '.'
done

# move cursor to bottom, and then print a newline
tput cup ${c.tty.max_y} ${c.tty.max_x} ; print

#print -v c

# EOF.