moved logo svg to its own folder, modified script to enable use of other logos and added error and usage messages

mepapemaker.sh

@@ -1,46 +1,73 @@
 #!/usr/bin/bash
 
-pape=$1
+logo=$1
+pape=$2
 
-# get the width of the wallpaper
-height=$(magick identify -format "%h" "$pape")
-width=$(magick identify -format "%w" "$pape")
+if [[ -z "$logo" ]] || [[ -z "$pape" ]]; then
+    echo $'Usage: ./mepapemaker.sh <logo> <wallpaper>\n\n<logo> is the logo name without the svg file extension.\nFor <wallpaper>, all image formats supported by\nImageMagick are valid targets.'
+    exit
+fi
+
+if [ ! -f "./logo/$logo.svg" ]; then
+    echo $'No such logo found.\nCheck the logo directory for available options or add\nyour own <logo>.svg to the directory.'
+    exit
+fi
+
+if [ ! -f "$pape" ]; then
+    echo $'Wallpaper not found. Maybe you mistyped?'
+    exit
+fi
+
+# get the width and height of the logo
+lheight=$(magick identify -format "%h" "./logo/$logo.svg")
+lwidth=$(magick identify -format "%w" "./logo/$logo.svg")
 
 # determine smaller dimension to use for scale
-if [[ "$height" -lt "$width" ]]; then
-  scale_val=$height
+if [[ "$lheight" -lt "$lwidth" ]]; then
+  lscale_val=$lheight
 else
-  scale_val=$width
+  lscale_val=$lwidth
+fi
+
+# get the width and height of the wallpaper
+pheight=$(magick identify -format "%h" "$pape")
+pwidth=$(magick identify -format "%w" "$pape")
+
+# determine smaller dimension to use for scale
+if [[ "$pheight" -lt "$pwidth" ]]; then
+  pscale_val=$pheight
+else
+  pscale_val=$pwidth
 fi
 
 # calculate appropriate density to scale the svg
 # 25 is the dimension of either side of the svg
 # 50 is the rough scale of the logo that will be on the final image (in %)
-density=$(awk "BEGIN {print ($scale_val/25.0)*50}")
+density=$(awk "BEGIN {print ($pscale_val/($lscale_val+2).0)*50}")
 
 # generate a PNG mask from the source svg
 magick \
   -density $density \
   -gravity center \
-  arch.svg \
+  ./logo/$logo.svg \
   -background white \
-  -extent "${width}x${height}" \
+  -extent "${pwidth}x${pheight}" \
   -resize 100% \
-  tmp_arch_mask.png
+  tmp_mask.png
 
 # generate wallpaper name
-outfile_name=$(basename "$pape")
+outfile_name=${logo}_btw_$(basename "$pape")
 
 # add arch mask to original image
 magick \
   "$pape" \
-  -write-mask "tmp_arch_mask.png" \
+  -write-mask "tmp_mask.png" \
   -gravity center \
   -blur 0x30 \
   -attenuate 0.3 \
   +noise Laplacian \
   -evaluate Multiply 1.3 \
-  "arch_btw_$outfile_name"
+  "$outfile_name"
 
 # delete temporary file
-rm "tmp_arch_mask.png"
+rm "tmp_mask.png"