From 5d8d8a34060dead1feed352af245e161f8ffd9de Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Juhani=20Krekel=C3=A4?= <juhani@krekelä.fi>
Date: Wed, 22 Mar 2023 19:16:28 +0200
Subject: [PATCH] Improve ANSI escape code support in process_wallpaper.py

---
 process_wallpaper.py | 86 +++++++++++++++++++++++++++++++-------------
 1 file changed, 62 insertions(+), 24 deletions(-)

diff --git a/process_wallpaper.py b/process_wallpaper.py
index a104fc2..f92ab47 100644
--- a/process_wallpaper.py
+++ b/process_wallpaper.py
@@ -1,5 +1,9 @@
 import sys
 
+from collections import namedtuple
+
+Attribute = namedtuple('Attribute', ['fg', 'bg', 'bold'])
+
 WIDTH = 80
 HEIGHT = 25
 # ANSI orders the colours black, red, green, yellow, blue, magenta, cyan, white
@@ -24,7 +28,7 @@ origin_y = int(sys.argv[6])
 assert 0 <= origin_y < HEIGHT
 
 chars = [bytearray([0]*HEIGHT) for _ in range(WIDTH)]
-attributes = [[(default_fgcolor, default_bgcolor)]*HEIGHT for _ in range(WIDTH)]
+attributes = [[(Attribute(default_fgcolor, default_bgcolor, False))]*HEIGHT for _ in range(WIDTH)]
 
 with open(infile, 'rb') as f:
 	ansitext = f.read()
@@ -33,6 +37,9 @@ x = origin_x
 y = origin_y
 fgcolor = default_fgcolor
 bgcolor = default_bgcolor
+bold = False
+
+error = False
 
 line = 1
 line_start = 0
@@ -40,31 +47,59 @@ index = 0
 while index < len(ansitext):
 	if ansitext[index:].startswith(b'\x1b['):
 		index += len(b'\x1b[')
-		escape_length = ansitext[index:].index(b'm')
-		escape = ansitext[index:index+escape_length]
-		for color_parameter in escape.split(b';'):
-			color_parameter = int(color_parameter)
-			if color_parameter == 39:
-				fgcolor = default_fgcolor
-			elif color_parameter == 49:
-				bgcolor = default_bgcolor
-			elif 30 <= color_parameter <= 37:
-				fgcolor = color_map[color_parameter - 30]
-			elif 40 <= color_parameter <= 47:
-				bgcolor = color_map[color_parameter - 40]
-			elif 90 <= color_parameter <= 97:
-				fgcolor = color_map[color_parameter - 90] + 8
-			elif 100 <= color_parameter <= 107:
-				bgcolor = color_map[color_parameter - 100] + 8
-			else:
-				print(f'{line},{index-line_start+1}: Unknown colour escape {color_parameter}')
-		index += escape_length + len(b'm')
+		escape_start = index
+		while index < len(ansitext) and ansitext[index] not in b'CDHJhm':
+			index += 1
+		escape_params = ansitext[escape_start:index]
+		escape_type = ansitext[index:index+1]
+		index += 1
+		if escape_type == b'C':
+			x += int(escape_params)
+		elif escape_type == b'D':
+			x -= int(escape_params)
+		elif escape_type == b'H':
+			row, column = escape_params.split(b';')
+			y = int(row) - 1
+			x = int(column) - 1
+		elif escape_type == b'J':
+			# Erase display
+			# We just ignore this, because why would you have
+			# erase command anywhere but at the start
+			pass
+		elif escape_type == b'h':
+			# Something nonstandard, ignore
+			pass
+		elif escape_type == b'm':
+			for color_parameter in escape_params.split(b';'):
+				color_parameter = int(color_parameter)
+				if color_parameter == 0:
+					bold = False
+				elif color_parameter == 1:
+					bold = True
+				elif color_parameter == 39:
+					fgcolor = default_fgcolor
+				elif color_parameter == 49:
+					bgcolor = default_bgcolor
+				elif 30 <= color_parameter <= 37:
+					fgcolor = color_map[color_parameter - 30]
+				elif 40 <= color_parameter <= 47:
+					bgcolor = color_map[color_parameter - 40]
+				elif 90 <= color_parameter <= 97:
+					fgcolor = color_map[color_parameter - 90] + 8
+				elif 100 <= color_parameter <= 107:
+					bgcolor = color_map[color_parameter - 100] + 8
+				else:
+					print(f'{line},{escape_start-line_start+1}: Unknown colour escape {color_parameter}')
+					error = True
+		else:
+			print(f'{line},{escape_start-line_start+1}: Unknown escape ^[[{escape_params.decode()}{escape_type.decode()}')
+			error = True
 	elif ansitext[index] == 13:
 		x = origin_x
 		index += 1
 	elif ansitext[index] == 10:
 		for i in range(x, WIDTH):
-			attributes[i][y] = (fgcolor, bgcolor)
+			attributes[i][y] = Attribute(fgcolor, bgcolor, bold)
 		x = origin_x
 		y += 1
 		index += 1
@@ -72,13 +107,16 @@ while index < len(ansitext):
 		line_start = index
 	else:
 		chars[x][y] = ansitext[index]
-		attributes[x][y] = (fgcolor, bgcolor)
+		attributes[x][y] = Attribute(fgcolor, bgcolor, bold)
 		index += 1
 		x += 1
 
+if error:
+	sys.exit(1)
+
 with open(outfile, 'wb') as f:
 	for y in range(HEIGHT):
 		for x in range(WIDTH):
-			fgcolor, bgcolor = attributes[x][y]
+			fgcolor, bgcolor, bold = attributes[x][y]
 			char = chars[x][y]
-			f.write(bytes([char, (bgcolor<<4) | fgcolor]))
+			f.write(bytes([char, (bgcolor<<4) | fgcolor | (8 if bold else 0)]))