Rewrite the update tool in Python

Less than 200 lines, properly cross platform, actually outputs error
messages if things break, better flag handling. Everyone has
Python anyway.

update/update_hmm.py

@@ -0,0 +1,166 @@
+#!/usr/bin/env python3
+
+import argparse
+import os
+import re
+
+typeReplacements = [
+    ('hmm_', 'HMM_'),
+
+    ('vec', 'Vec'),
+    ('mat', 'Mat'),
+    ('quaternion', 'Quaternion'),
+    ('bool', 'Bool'),
+    ('.InternalElementsSSE', '.SSE'),
+]
+
+funcReplacements = [
+    ('HMM_', 'HMM_'),
+    
+    ('Vec', 'V'),
+    ('Mat', 'M'),
+    ('Quaternion', 'Q'),
+    ('Equals', 'Eq'),
+    ('Subtract', 'Sub'),
+    ('Multiply', 'Mul'),
+    ('Divide', 'Div'),
+    ('Inverse', 'Inv'),
+    ('RSquareRoot', 'InvSqrt'),
+    ('SquareRoot', 'Sqrt'),
+    ('Squared', 'Sqr'),
+    ('Length', 'Len'),
+
+    ('Slerp', 'SLerp'),
+    ('By', ''),
+    ('LinearCombineSSE', 'LinearCombineV4M4'),
+    ('Transpose', 'TransposeM4'),
+    ('Fast', ''), # TODO(port): emit warning, lower precision
+    ('Normalize', 'Norm'),
+    ('ToRadians', 'ToRad')
+]
+
+handedFuncs = [
+    'Perspective',
+    'Rotate',
+    'Orthographic',
+    'LookAt',
+    'FromAxisAngle',
+    'ToQuaternion',
+]
+
+projectionFuncs = [
+    'Perspective',
+    'Orthographic',
+]
+
+numFiles = 0
+numWarnings = 0
+
+def printWarning(msg):
+    global numWarnings
+    numWarnings += 1
+    print('WARNING: {}'.format(msg))
+
+def updateFile(filename):
+    global numFiles
+    print('Updating: {}'.format(filename))
+    numFiles += 1
+    result = ''
+    with open(filename, 'r', newline='') as f:
+        for lineNo, line in enumerate(f):
+            updatedLine = line
+
+            def printLineWarning(msg):
+                printWarning('  Line {}: {}'.format(lineNo + 1, msg))
+
+            def replaceName(m):
+                name = m.group()
+                if name.startswith('hmm_'):
+                    # do type replacements
+                    for before, after in typeReplacements:
+                        if before not in name:
+                            continue
+                        name = name.replace(before, after)
+                else:
+                    # do func replacements
+                    for before, after in funcReplacements:
+                        if before not in name:
+                            continue
+                        name = name.replace(before, after)
+
+                        if after == 'LinearCombineV4M4':
+                            printLineWarning('HMM_LinearCombineSSE is now HMM_LinearCombineV4M4, and will now use a fallback method when SSE is not available. You no longer need to check for the availability of SSE.')
+                        if after == 'V' or after == 'M':
+                            # uppercase the modifier, if any
+                            name = re.sub(
+                                r'[VM]\d[ivfd]?',
+                                lambda m: m.group().upper(),
+                                name
+                            )
+                            # and also nuke the integer constructors
+                            vecIntMatch = re.search(r'(V\d)I', name)
+                            if vecIntMatch:
+                                name = name.replace(vecIntMatch.group(), vecIntMatch.group(1))
+
+                    # add handedness / NDC modifiers
+                    if not any(x in name for x in ['RH', 'LH', 'NO', 'ZO']):
+                        for handedFunc in handedFuncs:
+                            suffixed = handedFunc + '_RH'
+                            if handedFunc in projectionFuncs:
+                                suffixed += '_NO'
+                            name = name.replace(handedFunc, suffixed)
+                return name
+
+            def wrapDegrees(m):
+                name = m.group('name')
+                arg = m.group('arg')
+                if '(' in arg:
+                    # all bets are off, don't wrap the argument
+                    printLineWarning('{} now takes radians, but we were unable to automatically wrap the first argument with HMM_AngleDeg().'.format(name))
+                    return m.group()
+                return '{}(HMM_AngleDeg({}),'.format(name, arg)
+                
+            updatedLine = re.sub(r'(hmm_|HMM_)\w+', replaceName, updatedLine)
+            updatedLine = re.sub(r'(?P<name>HMM_Perspective_RH_NO|HMM_Rotate_RH)\((?P<arg>.*?),', wrapDegrees, updatedLine)
+
+            result += updatedLine
+
+    with open(filename, 'w', newline='') as f:
+        f.write(result)
+
+
+parser = argparse.ArgumentParser(
+    prog = 'update_hmm',
+    description = 'Updates C and C++ source code to use Handmade Math 2.0.',
+)
+parser.add_argument(
+    'filename', nargs='+',
+    help='A file or directory to update to HMM 2.0. If a directory, all files with extensions from --exts will be processed.',
+)
+parser.add_argument(
+    '--exts', nargs='+', default=['.c', '.cpp', '.h', '.hpp'],
+    help='File extensions to run the script on, when targeting a directory. Default: .c, .cpp, .h, .hpp.',
+    metavar='.foo',
+)
+
+args = parser.parse_args()
+
+for path in args.filename:
+    filenames = []
+    if os.path.isfile(path):
+        filenames = [path]
+    else:
+        for root, dirs, files in os.walk(path):
+            for file in files:
+                if file == 'HandmadeMath.h':
+                    printWarning('HandmadeMath.h will not be replaced by this script.')
+                elif file.endswith(tuple(args.exts)):
+                    filenames.append(os.path.join(root, file))
+    
+    for filename in filenames:
+        try:
+            updateFile(filename)
+        except UnicodeDecodeError:
+            pass
+
+    print('Updated {} files with {} warnings.'.format(numFiles, numWarnings))