1 files changed, 238 insertions, 0 deletions

diff --git a/shopenscad.sh b/shopenscad.sh
new file mode 100755
index 0000000..3c71b1f
--- /dev/null
+++ b/shopenscad.sh
@@ -0,0 +1,238 @@
+#!/bin/bash
+
+#set -x
+
+OPENSCAD=${OPENSCAD:-"openscad"}
+RUN=y
+INTERACTIVE=
+PRINT_VARS=
+USER_OUTPUT_FILENAME=
+SCAD_FILE=
+SHELL_SKEL=
+
+help()
+{
+    cat <<EOF
+$0: parse and execute OpenSCAD files, allowing default variables from input scad
+    to be overridden with values supplied from the shell. (The parsing of scad
+    files is done from the shell mostly with sed, and is very primitive)
+
+Usage: $0 [-h] [-n] [-p] [-i] [-o OUTPUT-FILENAME] INPUT.scad
+
+ -h, --help            display this help
+ -p, --print-vars      print variables parsed from INPUT.scad
+ -i, --interactive     show output command and query for execution
+ -n, --no-act          show output command, do not execute
+ -s, --shell-skel      output a skeleton shell script for generating models
+ -o, --output-filename Specify an output filename. The following variables are
+                       available to you:
+
+                       \$VALUES - all values from INPUT.scad. This is the
+                                  default (-o '\${VALUES}.stl'):
+                         cube-15-10-5.stl
+
+                       \$ALL - all variable names and values from INPUT.scad
+                               (-o '\${ALL}.stl'):
+                         shape=cube,width=15,height=10,depth=5.stl
+
+                       Additionally, all variables parsed from INPUT.scad
+                       are available in the associatve array $SCAD, e.g.:
+                         -o '\${SCAD[part]}.stl'
+
+Usage examples:
+
+      1) Run $OPENSCAD with default values from input scad file:
+
+          $ $0 input.scad
+
+      2) You can override variables in the input file with variables passed in
+         through the shell; this will override "part" and "cubby_width"
+         paramaters from input scad file. (Note that if the part is a string,
+         you need to include quotes.):
+
+          $ cubby_width=200 part='"bottom"' $0 input.scad
+
+
+      3) Generate multiple models:
+
+         $ for w in 250 300 350 400; do
+               cubby_width="$w" part="bottom" $0  cubbies.scad
+           done
+EOF
+}
+
+parse_options()
+{
+    OPTS=$(getopt \
+               --options 'hpinso:' \
+               --longoptions 'help,print-vars,interactive,no-act,shell-skel,output-filename:' \
+               -- "$@")
+    eval set -- "$OPTS"
+    unset OPTS
+
+    if [ $# = 0 ];  then
+        help
+        exit
+    fi
+
+    while true; do
+        case "$1" in
+            -h | --help            ) help; exit;;
+            -p | --print-vars      ) PRINT_VARS=y;;
+            -i | --interactive     ) INTERACTIVE=y;;
+            -n | --no-act          ) RUN=;;
+            -s | --shell-skel      ) SHELL_SKEL=y;;
+            -o | --output-filename ) shift; USER_OUTPUT_FILENAME=$1;;
+            --                     ) shift; break;;
+        esac
+        shift
+    done
+
+    SCAD_FILE="$*";
+    [ -f "$SCAD_FILE" ] || die "$0: Needs an input scad file"
+}
+
+die() { printf 'Error: %s\n' "$*" >&2; exit 1; }
+warn() { printf 'Warning: %s\n' "$*" >&2; }
+
+strip_multiline_comments () {
+    # https://stackoverflow.com/questions/13061785/remove-multi-line-comments
+    # https://stackoverflow.com/users/751863/steve
+    sed -r ':a; s%(.*)/\*.*\*/%\1%; ta; /\/\*/ !b; N; ba'
+}
+
+strip_trailing_semicolon () {
+    sed -r 's/;$//'
+}
+
+strip_leading_spaces () {
+    sed -r 's/^ +//'
+}
+
+strip_trailing_spaces () {
+    sed -r 's/ +$//'
+}
+
+strip_nonassignments () {
+    grep -e '^[A-Za-z0-9_]\+\s*='
+}
+
+chomp () {
+    strip_leading_spaces |strip_trailing_spaces
+}
+
+parse_variable () {
+    #sed -r 's/^([a-zA-Z0-9_]+).*/\1/'
+    sed -r 's/^([^=]+)=.*/\1/'
+}
+
+parse_value () {
+    #sed -r 's/^.*?=\s*([^;]+);.*$/\1/'
+    #sed -r 's/^[^=]+\s*=\s*([^;]+);.*$/\1/'
+    sed -r 's/.*=\s*([^;]+?).*/\1/'
+}
+
+val_to_filename () {
+    echo "$1" |sed -r 's/"//g' |sed -r 's/ /_/g'
+}
+
+strip_after_hidden () {
+    sed -n '/\/\* \[Hidden\] \*\//q;p' "$1"
+}
+
+strip_trailing () {
+    trailing="$1"
+    input="$2"
+    echo ${input%${trailing}}
+}
+
+main()
+{
+    parse_options "$@"
+
+    output_params=""
+    default_output_filename=""
+    ALL=""
+    VALUES=""
+    val_sep="-"
+    var_sep=","
+    declare -A SCAD
+    declare -a scad_var_order
+
+    while IFS= read -r line; do
+        [ "$line" ] || continue;
+        clean="$(echo -n "$line" |chomp)"
+        var=$(echo -n "$clean" |parse_variable |chomp)
+
+        # use value provided on command line preferentially to any values in the .scad file
+        val=""
+        if [[ -n "${!var}" ]]; then
+            val=${!var}
+        else
+            val=$(echo -n "$clean" |parse_value |chomp)
+        fi
+
+        if [ "$var" ] && [ "$val" ]; then
+            scad_var_order+=($var);
+            SCAD[$var]="$val"
+            output_params+="-D '$var=$val' "
+            VALUES+="$(val_to_filename "$val")${val_sep}"
+            ALL+="${var}=$(val_to_filename "$val")${var_sep}"
+        fi;
+    done < <(strip_after_hidden $SCAD_FILE | \
+                 strip_multiline_comments |strip_nonassignments |strip_trailing_semicolon)
+
+    if [ "$PRINT_VARS" ]; then
+        for k in "${scad_var_order[@]}"; do
+            # Make sure quotes surround openscad strings
+            case "${SCAD[$k]:0:1}" in
+                \" ) line="${k}='${SCAD[$k]}'";;
+                \' ) line=${k}="\"${SCAD[$k]}\"";;
+                *  ) line="${k}=${SCAD[$k]}";;
+            esac
+            echo $line
+        done
+        exit
+    fi
+
+    if [ "$SHELL_SKEL" ]; then
+        all_vars=$($0 $SCAD_FILE -p |sed -e 's/^/# /')
+        cat <<EOF
+#!/bin/bash
+shopenscad_cmd="$0 $SCAD_FILE "
+export \$(echo \$(\$shopenscad_cmd -p))
+${all_vars}
+\$shopenscad_cmd
+EOF
+        exit;
+    fi;
+
+    ALL=$(strip_trailing "$var_sep" "$ALL")
+    VALUES=$(strip_trailing "$val_sep" "$VALUES")
+
+    default_output_filename="${VALUES}.stl"
+    output_filename="$default_output_filename"
+    if [ "$USER_OUTPUT_FILENAME" ]; then
+        output_filename=$(echo $(eval "echo $USER_OUTPUT_FILENAME"))
+    fi
+
+    openscad_str="$OPENSCAD '$SCAD_FILE' "$output_params" -o '$output_filename'"
+    echo "${openscad_str}"
+
+    [ ! "$RUN" ]  && [ ! "$INTERACTIVE" ] && exit
+
+    if [ "$INTERACTIVE" ]; then
+        eval_prompt="Evaulate openscad command? (type y for yes, anything else to exit): "
+        read -p "$eval_prompt" -n1 yes_eval_read
+        echo
+        case "$yes_eval_read" in
+            [Yy]) RUN=y ;;       # still true
+            *) RUN=;;
+        esac
+    fi
+
+    [ "$RUN" ] &&  eval "$(echo "$openscad_str")"
+}
+
+main "$@"
+#parse_options "$@"