Stitch, trim, and make a grid of images to make a sprite sheet

spritstictch.sh

#!/bin/bash
echo "Stitching Sprites"

function getImageFiles ()
{
	# Get images name
	dirname="$(pwd | tr '/' ' ' | awk '{print $(NF)}')"
	filename="$dirname"

	files=($(ls))
	fileCount="${#files[@]}"

	# limit to pngs
	for (( i = 0; i < $fileCount; i++ )); do

		testName="${files[$i]}"
		extension="${testName##*.}"

		if [ "$extension" == "png" ]
			then
			pngs=" $pngs $testName "
		fi
	done

	files=($(echo "$pngs"))
	fileCount="${#files[@]}"
}

function calcSheetSize ()
{
	# Get tiles needed
	for (( i = 0; i < $fileCount; i++ )); do

		testSize="$( expr $i \* $i )"

		if [ $testSize -ge $fileCount ]
			then
			width="$i"
			break
		fi
	done

	echo "Sheet size: $width x $width"
}

function getBaseImageInfo ()
{
	# Layer all rendered imaged together
	convert "${files[0]}" "${files[1]}" -composite maxres.png # start with first two
	for (( i = 2; i < $fileCount; i++ )); do
		convert maxres.png "${files[$i]}" -composite maxres.png
	done

	# Get the offset for the crop of the layered images
	offsetxsize="$(convert maxres.png -trim info: | awk '{print $4}' | tr '+' ' ' | awk '{print $2}')"
	offsetysize="$(convert maxres.png -trim info: | awk '{print $4}' | tr '+' ' ' | awk '{print $3}')"

	# Get the dimensions of the layer images.
	trimxsize="$(convert maxres.png -trim info: | awk '{print $3}' | tr 'x' ' ' | awk '{print $1}')"
	trimysize="$(convert maxres.png -trim info: | awk '{print $3}' | tr 'x' ' ' | awk '{print $2}')"

	# Delete uneedded maxres
	rm maxres.png
}

function baseTrim ()
{
	# Crop all images to the dimiseniton and offset fo the trimed layered image
	for (( i = 0; i < $fileCount; i++ )); do
		convert "${files[$i]}"  -crop $(echo $trimxsize)x$trimysize+$offsetxsize+$offsetysize "${files[$i]%.*}_temp.png"
	done
}

function buildSheet ()
{
	# Put images in rows
	for (( row = 0; row < $width; row++ )); do
		convert -size 0x0 xc:blue  "line-$row.png"
		for (( col = 0; col < $width; col++ )); do
			if [ $(expr $(expr $row \* $width) + $col) -ge $fileCount ]
				then
				break
			fi
			convert "line-$row.png" -background none "${files[$(expr $(expr $row \* $width) + $col)]%.*}_temp.png" +append "line-$row.png"
			rm "${files[$(expr $(expr $row \* $width) + $col)]%.*}_temp.png"
		done
	done

	# Put rows on top of eachother into output file and delete row images
	if [ -f ../$filename.png ]
		then
		rm ../$filename.png
		convert -size 0x0 xc:blue ../$filename.png
	fi
	convert ../$filename.png -background none "line-0.png" -append ../$filename.png
	rm "line-0.png"
	for (( row = 1; row < $width; row++ )); do
		convert ../$filename.png -background none "line-$row.png" -append ../$filename.png
		rm "line-$row.png"
	done
}

function specialCaseTest ()
{
	if [ $fileCount -eq 1 ]
		then
		echo "Single image found"
		convert "${files[0]}" -trim ../$filename.png
		exit 0
	fi

	if [ $fileCount -eq 2 ]
		then
		echo "Two images found"
		getBaseImageInfo
		convert "${files[0]}"  -crop $(echo $trimxsize)x$trimysize+$offsetxsize+$offsetysize "${files[0]%.*}_temp.png"
		convert "${files[1]}"  -crop $(echo $trimxsize)x$trimysize+$offsetxsize+$offsetysize "${files[1]%.*}_temp.png"
		convert "${files[0]%.*}_temp.png" -background none "${files[1]%.*}_temp.png" +append ../$filename.png
		rm "${files[0]%.*}_temp.png" "${files[1]%.*}_temp.png"
		exit 0
	fi

}


# Logic
getImageFiles
specialCaseTest
calcSheetSize
getBaseImageInfo
baseTrim
buildSheet