Added checks to stop resizing down if we are creating too much widespace or if the font has decreased too much

lib/dataStructures.py

@@ -211,6 +211,7 @@ class Song:
     self.rightMargin = int(configObj['rightMargin'])
     self.fontMetadata = ImageFont.truetype(configObj['metafontfamily'], int(configObj['metaFontWeight']))
     self.fontSize = int(configObj['songFontWeight'])
+    self.originalFontSize = int(configObj['songFontWeight'])
     self.fontLyrics = ImageFont.truetype(configObj['lyricfontfamily'], self.fontSize)
     self.fontTablature = ImageFont.truetype(configObj['tablaturefontfamliy'], self.fontSize)
     self.configObj = configObj
@@ -285,6 +286,30 @@ class Song:
     currentPageIt = 0
     if not amountOfPages:
       return False
+    # Stop resizing if the font size is becoming too small
+    fontDifference = self.originalFontSize - self.fontSize
+    if fontDifference > self.originalFontSize / 2:
+      print("The original fontSize has already decreased from {} to {}, so we will stop resizing the image down".format(self.originalFontSize, self.fontSize))
+      return False
+    # Stop resizing if we are creating too much widespace on the width
+    smallestWhitespace = self.imageHeight
+    biggestWhitespace = -1
+    for page in self.pages:
+      for section in page.sections:
+          whitespaceOnWidth = self.imageWidth - self.leftMargin - self.rightMargin - section.expectedWidth
+          if whitespaceOnWidth < smallestWhitespace:
+            smallestWhitespace = whitespaceOnWidth
+          if whitespaceOnWidth > biggestWhitespace:
+            biggestWhitespace = whitespaceOnWidth
+    # Sections vary in width, some are very small to begin with
+    # Since (almost empty) lines will result in large whitespace sizes, we are less strict on checking that
+    if biggestWhitespace / self.imageWidth > 0.9:
+      print("Stopping resizing down, since the smallest section has {}% whitespace on the width of the image".format((smallestWhitespace / self.imageWidth )* 100))
+      return False
+    # But the largest section on the page should be able to fit at least half of the available page
+    if smallestWhitespace / self.imageWidth > 0.5:
+      print("Stopping resizing down, since we largest section has {}% whitespace on the width of the image".format((biggestWhitespace / self.imageWidth )* 100))
+      return False
     # get first section on next page, if we have a next page to begin with
     while currentPageIt < amountOfPages - 1:
       curPage = self.pages[currentPageIt]

main.py

@@ -37,6 +37,9 @@ def main():
     print("Start parsing of file '{}'...".format(song.inputFile)) 
     # Initialise internal data structures
     song.initSections()
+    if not song.isParsed:
+      print("Song was not initialized correctly. Skipping...")
+      continue
     # Fit all sections on each page, resizes down if it does not fit on width
     song.fitSectionsByWidth()
     # Prerender: calculate Pages, and move sections into Pages
@@ -47,12 +50,11 @@ def main():
       song.resizeAllSections(-1)
       song.sectionsToPages()
     # Parse as PNG a4
-    if song.isParsed:
-      # Create subdirectory where we will output our images
-      targetDirectory = song.outputLocation + "-a4-png"
-      print("Successfully parsed file. Writing output to '{}'\n".format(targetDirectory)) 
-      # Write out metadata and sections, as many as can fit on one page
-      output2img.outputToImage(targetDirectory, song)
+    # Create subdirectory where we will output our images
+    targetDirectory = song.outputLocation + "-a4-png"
+    print("Successfully parsed file. Writing output to '{}'\n".format(targetDirectory)) 
+    # Write out metadata and sections, as many as can fit on one page
+    output2img.outputToImage(targetDirectory, song)
 
 if __name__ == "__main__":
   main()