Script to inline shader into C header file

remoting/tools/build/shader_to_header.py

+#!/usr/bin/python
+# Copyright 2016 The Chromium Authors. All rights reserved.
+# Use of this source code is governed by a BSD-style license that can be
+# found in the LICENSE file.
+
+"""Helper script to inline files as const char[] into a C header file.
+
+Example:
+
+Input File in_a.vert:

[Jamie, 2016/06/06 20:03:48]

s/File/file/

[Yuwei, 2016/06/06 20:35:39]

Done.

+1"
+2
+3\
+
+Output File in_b.frag:

[Jamie, 2016/06/06 20:03:47]

s/File/file/

[Yuwei, 2016/06/06 20:35:39]

Done.

+4
+5
+6
+
+shader_to_header.py "output.h" "in_a.vert" "in_b.frag" will generate
+this:
+
+#ifndef OUTPUT_H_CHxvtO77kdA8xy26
+#define OUTPUT_H_CHxvtO77kdA8xy26
+
+const char kInAVert[] = "1\"\n"
+"2\n"
+"3\\";
+
+const char kInBFrag[] = "4\n"
+"5\n"
+"6";
+
+#endif  // OUTPUT_H_CHxvtO77kdA8xy26
+
+"""
+
+import os.path
+import random
+import string
+import sys
+
+RANDOM_STRING_LENGTH = 16
+STRING_CHARACTERS = string.ascii_uppercase + \

[Jamie, 2016/06/06 20:03:47]

Use parentheses instead of backslashes for line continuation:

https://google.github.io/styleguide/pyguide.html?showone=Line_length#Line_length

[Yuwei, 2016/06/06 20:35:39]

Done.

+                    string.ascii_lowercase + \
+                    string.digits
+
+def random_str():
+  return ''.join(random.choice(STRING_CHARACTERS)
+          for _ in range(RANDOM_STRING_LENGTH))
+
+
+def escape_line(line):
+  # encode('string-escape') doesn't escape double quote so you need to manually
+  # escape it.
+  return line.encode('string-escape').replace('"', '\\"')
+
+
+def main():
+  if len(sys.argv) < 3:
+    print 'Usage: shader_to_header.py <output-file> <input-files...>'
+    return 1
+
+  output_path = sys.argv[1]
+  include_guard = os.path.basename(output_path).upper().replace('.', '_') + \
+                  '_' + random_str()
+
+  with open(output_path, 'w') as output_file:
+    output_file.write('#ifndef ' + include_guard + '\n' +
+                      '#define ' + include_guard + '\n\n')
+
+    existing_names = set()
+    argc = len(sys.argv)
+    for i in xrange(2, argc):
+      input_path = sys.argv[i]
+
+      with open(input_path, 'r') as input_file:
+        # hello_world.vert -> kHelloWorldVert
+        const_name = 'k' + os.path.basename(input_path).title() \
+                     .replace('_', '').replace('.', '')
+        if const_name in existing_names:
+          print >> sys.stderr, 'Error: Constant name ' + const_name + \
+                ' is already used by a previous file. Files with the same' + \
+                ' name can\'t be inlined into the same header.'
+          return 1
+
+        existing_names.add(const_name)
+        text = input_file.read()
+        lines = text.splitlines()
+
+        # 1. Append double quote to the front of each line.
+        # 2. Use '\\n"\n' to connect each line.
+        # 3. Add the double quote to the end to finish the quotation of last
+        #    line.

[Jamie, 2016/06/06 20:03:47]

As discussed, there's no need for this file to be human-readable, so this can be
simplified.

[Yuwei, 2016/06/06 20:35:39]

Done.

+        inlined = '\\n"\n'.join(map(lambda x: '"' + escape_line(x), lines)) + \
+                  '"'
+        output_file.write('const char ' + const_name + '[]' + ' = ' + inlined +
+                          ';\n\n')
+
+    output_file.write('#endif  // ' + include_guard + '\n')
+
+  return 0
+
+
+if __name__ == '__main__':
+  sys.exit(main())