add sparkmaker wow conversion script

tools/README.md

 
 Simple G-Code sender using pySerial to access serial port.
 For use with Marlin and possibly other RepRap compatible firmwares.
+
+## convert_sparkmaker.py
+
+Convert PrusaSlicer `.sl1` files to Sparkmaker `.wow` files.

tools/convert_sparkmaker.py

+#!/usr/bin/env python
+
+import sys
+import os
+from zipfile import ZipFile
+import re
+import pprint
+import png
+
+###############################################################################
+
+screen_size = (854, 480)
+max_height = 120
+initial_params = {
+    'layer_height': 0.1,
+    'first_layer_height': 0.1,
+    'exposure_time': 15.0,
+    'first_exposure_time': 120.0,
+    'lift_height': 5.0,
+    'lift_speed': 30.0,
+    'sink_speed': 100.0
+}
+
+###############################################################################
+
+def read_prusaslicer_ini(f, params):
+    lines = f.decode("utf-8").split("\n")
+
+    for l in lines:
+        if l.startswith("exposure_time"):
+            params["exposure_time"] = float(l.split(" = ")[1])
+        elif l.startswith("initial_exposure_time"):
+            params["first_exposure_time"] = float(l.split(" = ")[1])
+        elif l.startswith("layer_height"):
+            params["layer_height"] = float(l.split(" = ")[1])
+        elif l.startswith("initial_layer_height"):
+            params["first_layer_height"] = float(l.split(" = ")[1])
+
+def read_config_ini(f, params):
+    lines = f.decode("utf-8").split("\n")
+
+    for l in lines:
+        if l.startswith("expTimeFirst"):
+            params["first_exposure_time"] = float(l.split(" = ")[1])
+        elif l.startswith("expTime"):
+            params["exposure_time"] = float(l.split(" = ")[1])
+        elif l.startswith("layerHeight"):
+            params["layer_height"] = float(l.split(" = ")[1])
+
+def read_sl1(f):
+    params = initial_params
+
+    files = f.namelist()
+    if "prusaslicer.ini" in files:
+        read_prusaslicer_ini(f.read("prusaslicer.ini"), params)
+    else:
+        print("No prusaslicer.ini found in file")
+        if "config.ini" in files:
+            read_config_ini(f.read("config.ini"), params)
+        else:
+            print("No config.ini found in file")
+            sys.exit(1)
+
+    imgs = [x for x in files if x.endswith(".png")]
+    imgs = [x for x in imgs if not x.startswith("thumbnail/")]
+
+    if len(imgs) <= 0:
+        print("No slices found in file. Aborting.")
+        sys.exit(1)
+
+    res = re.findall('(\D*)\d*.*', imgs[0])[0]
+    print("Internal name: \"" + res + "\"")
+    print("Found " + str(len(imgs)) + " slices")
+
+    images = []
+    for img in imgs:
+        images.append(f.read(img))
+
+    return params, images
+
+###############################################################################
+
+def write_image(f, img):
+    p = png.Reader(bytes = img)
+    width, height, rows, info = p.read()
+
+    if width != screen_size[0]:
+        print("Error: layer has wrong width " + str(width) + " != " + str(screen_size[0]))
+        sys.exit(1)
+
+    if height != screen_size[1]:
+        print("Error: layer has wrong height " + str(height) + " != " + str(screen_size[1]))
+        sys.exit(1)
+
+    if (not info['greyscale']) or info['alpha']:
+        print("Error: invalid image encoding")
+        sys.exit(1)
+
+    data = [0] * int(width * height / 8)
+
+    y = 0 # width is 854
+    x = 0 # height is 480
+    for row in rows:
+        for v in row:
+            if v > 0x7F:
+                data[int(height / 8) * y + int(x / 8)] |= (1 << x % 8)
+            y += 1
+        x += 1
+        y = 0
+
+    for d in data:
+        f.write(d.to_bytes(1, 'big'))
+
+def write_wow(f, params, imgs):
+    def write(s):
+        #print(s)
+        f.write((s + "\n").encode())
+
+    write("G21;")
+    write("G91;")
+    write("M17;")
+    write("M106 S0;")
+    write("G28 Z0;")
+
+    first_layer = True
+
+    for i in range(0, len(imgs)):
+        write(";L:" + str(int(i)) + ";")
+        write("M106 S0;")
+
+        lift_up = params['lift_height']
+        lift_down = -(lift_up - params['layer_height'])
+        exposure_time = params['exposure_time']
+        if first_layer:
+            lift_down = -(lift_up - params['first_layer_height'])
+            exposure_time = params['first_exposure_time']
+            first_layer = False
+
+        write("G1 Z" + str(lift_up) + " F" + str(params['lift_speed']) + ";")
+        write("G1 Z" + str(lift_down) + " F" + str(params['sink_speed']) + ";")
+        write("{{")
+        write_image(f, imgs[i])
+        write("}}")
+        write("M106 S255;")
+        write("G4 S" + str(exposure_time) + ";")
+        write("G4 S1;")
+
+    object_height = params['layer_height'] * (len(imgs) - 1) + params['first_layer_height']
+    final_move = max_height - object_height
+
+    write("M106 S0;")
+    write("G1 Z" + str(final_move) + " F25;")
+    write("M18;")
+
+###############################################################################
+
+def main():
+    if len(sys.argv) < 2:
+        print("Usage:")
+        print("    " + sys.argv[0] + " input.sl1 [output.wow]")
+        sys.exit(1)
+
+    in_file_name = sys.argv[1]
+
+    out_file_name = "print.wow"
+    if len(sys.argv) >= 3:
+        out_file_name = sys.argv[2]
+
+    if os.path.exists(out_file_name):
+        print("File already exists: \"" + out_file_name + "\". Aborting.")
+        sys.exit(1)
+
+    with ZipFile(in_file_name, 'r') as sl1:
+        params, imgs = read_sl1(sl1)
+
+    print("Using following parameters:")
+    pprint.pprint(params)
+    print("Writing output to \"" + out_file_name + "\"")
+
+    with open(out_file_name, 'wb') as wow:
+        write_wow(wow, params, imgs)
+
+if __name__ == '__main__':
+    main()