rasterize-resources.sh

#!/bin/bash

if [ -z "$BASH_VERSION" ]; then
	echo "Invalid shell, re-running using bash..."
	exec bash "$0" "$@"
	exit $?
fi
SRCLOC="$( cd "$( dirname "${BASH_SOURCE[0]}" )" && pwd )"

# Find rsvg-convert
if [ -z "$RSVG_CONVERT" ]; then 
	RSVG_CONVERT=`which rsvg-convert`
fi
if [ -z "$RSVG_CONVERT" ]; then 
	echo "rsvg-convert tool not found"
	exit 1
fi
echo "Using $RSVG_CONVERT..."
export RSVG_CONVERT

# Remove previous
rm -rf "$SRCLOC/Resources/Rasterized"

# Rasterize resources
rasterize_resource() {
	if [ -z "$BASH_VERSION" ]; then
		echo "Invalid shell, re-running using bash..."
		exec bash -c 'rasterize_resource "$0"'
		exit $?
	fi

	ORIGIN="$(pwd)/.."
	INPUT_FILENAME="${0##*/}"
	INPUT_FORMAT="${INPUT_FILENAME##*.}"
	FILENAME="${INPUT_FILENAME%.*}"
	OUTPUT_FILENAME="${FILENAME}.png"
	SUBPATH="${0%/*}"
	INPUT="Resources.svg/$SUBPATH/$INPUT_FILENAME"
	OUTPUT="Resources/Rasterized/$SUBPATH/$OUTPUT_FILENAME"
	OUTPUT_PATH="$ORIGIN/Resources/Rasterized/$SUBPATH"
	
	echo "Rasterizing '$FILENAME' (\"$SUBPATH\")"
	
	# Ensure output path exists
	mkdir -p "$OUTPUT_PATH"

	# Rasterize this version as 1:1 version
	(cd "$ORIGIN" && $RSVG_CONVERT -f png -o "$OUTPUT" "$INPUT")

	# If original is 1x scale, ...
	if ! [[ "$FILENAME" =~ @2x$ ]]; then
		# ... and there's no source version that provides 2x, rasterize larger version
		if [ ! -f "$ORIGIN/Resources.svg/$SUBPATH/${FILENAME}@2x.${INPUT_FORMAT}" ]; then
			printf "\t+ 2.0x\n"
			(cd "$ORIGIN" && $RSVG_CONVERT -z 2 -f png -o "$OUTPUT_PATH/${FILENAME}@2x.png" "$INPUT")
            printf "\t+ 3.0x\n"
            (cd "$ORIGIN" && $RSVG_CONVERT -z 3 -f png -o "$OUTPUT_PATH/${FILENAME}@3x.png" "$INPUT")
		fi
	fi

	# If original is 2x scale, ...
	if [[ "$FILENAME" =~ @2x$ ]]; then
		# ... and there's no source version that provides 1x, rasterize smaller version
		if [ ! -f "$ORIGIN/Resources.svg/$SUBPATH/${FILENAME%@2x}.${INPUT_FORMAT}" ]; then
			printf "\t+ 2x * 0.5x = 1.0x\n"
			(cd "$ORIGIN" && $RSVG_CONVERT -z 0.5 -f png -o "$OUTPUT_PATH/${FILENAME%@2x}.png" "$INPUT")
		fi
        printf "\t+ 2x * 1.5x = 3.0x\n"
        (cd "$ORIGIN" && $RSVG_CONVERT -z 1.5 -f png -o "$OUTPUT_PATH/${FILENAME%@2x}@3x.png" "$INPUT")
	fi

	return $?
}
export -f rasterize_resource
(cd "$SRCLOC/Resources.svg" && \
	find . -type f -name "*.svg" -exec sh -c 'rasterize_resource "$0"' {} \;)