iv

#!/bin/bash
# iv - a bash image viewer that uses w3mimgdisplay

# Usage: iv [filename]
# Licence: GPL - quirinpa@gmail.com

# Inspired by -
# blog.z3bra.org/2014/01/images-in-terminal.html
# wiki.vifm.info/index.php?title=How_to_preview_images
# Saitoha sensei... Gomen nasai. Ore wa boke desu.

# Works best with xterm

printf '' "$(
	fsize=(14 7)

	# get number of cols / lines
	read -a tsize <<< $(stty size)

	# get terminal size in pixels
	ssize=($((${fsize[0]} * (${tsize[0]} - 1))) $((${fsize[1]} * ${tsize[1]})))

	# get image dimensions
	read -a isize <<< $(identify -format '%h %w' $1)

	# find ratios
	sratio=$((${ssize[0]} * 100 / ${ssize[1]}))
	iratio=$((${isize[0]} * 100 / ${isize[1]}))

	# decide how the image will spread
	if [[ "$sratio" -gt "$iratio" ]]; then
		# fit horizontally, spread vertically
		[[ "${ssize[1]}" -gt "${isize[1]}" ]] && tw=${isize[1]} || tw=${ssize[1]}
		dsize=($(($tw * $iratio / 100)) $tw)
	else
		# fit vertically, spread horizontally
		echo fit vertically > /dev/tty
		[[ "${ssize[0]}" -gt "${isize[0]}" ]] && th=${isize[0]} || th=${ssize[0]}
		dsize=($th $(($th * 100 / $iratio)))
	fi

	# from Dennis Williamson's answer on
	# stackoverflow.com/questions/2575037/how-to-get-the-cursor-position-in-bash
	get_current_line() {
		exec < /dev/tty
		oldstty=$(stty -g)
		stty raw -echo min 0
		echo -en "\033[6n" > /dev/tty
		IFS=';' read -r -d R -a pos
		stty $oldstty
		echo ${pos[0]:2}
	}

	# get number of lines that the image will occupy
	b=$((${dsize[0]} / ${fsize[0]}))

	# get starting line
	sl=$((`get_current_line` - 1))

	# get number of available lines
	al="$((${tsize[0]} - 1 - $sl))"

	[[ "$al" -ge "$b" ]] && al=$b

	# move down visible lines
	printf "\033["$(($b + 1))"B" > /dev/tty

	# find lines which need to be added
	il=$(($b - $al))

	# print them
	for i in `seq $il`; do printf "\n" > /dev/tty; done

	printf "0;1;0;$((($sl - $il) * ${fsize[0]}));${dsize[1]};${dsize[0]};;;${isize[1]};${isize[0]};$1\\n4;\n3;" | /usr/lib/w3m/w3mimgdisplay
	)"