Allow backslashes, extra slashes in shader/image names

Remove initial slashes or multiple consecutive slashes and convert \ to
/ when looking up shaders or images. Useful for Smokin' Guns assets.

Author: slipher

src/common/FileSystem.cpp

@@ -477,6 +477,27 @@ std::string Build(Str::StringRef base, Str::StringRef path)
 	return out;
 }
 
+std::string NormalizeSlashes(Str::StringRef path)
+{
+	std::string out;
+	out.reserve(path.size());
+	bool lastSlash = true;
+
+	for (char c : path) {
+		if (c == '/' || c == '\\') {
+			if (!lastSlash) {
+				lastSlash = true;
+				out.push_back('/');
+			}
+		} else {
+			out.push_back( c );
+			lastSlash = false;
+		}
+	}
+
+	return out;
+}
+
 std::string DirName(Str::StringRef path)
 {
 	if (path.empty())

src/common/FileSystem.h

@@ -177,6 +177,11 @@ namespace Path {
 	// Build a path from components
 	std::string Build(Str::StringRef base, Str::StringRef path);
 
+	// Replace \ with /
+	// Remove multiple consecutive slashes
+	// Remove initial slashes
+	std::string NormalizeSlashes(Str::StringRef path);
+
 	// Get the directory portion of a path:
 	// a/b/c => a/b
 	// a/b/ => a

src/engine/renderer/tr_image.cpp

@@ -1818,19 +1818,21 @@ Finds or loads the given image.
 Returns nullptr if it fails, not a default image.
 ==============
 */
-image_t *R_FindImageFile( const char *imageName, imageParams_t &imageParams )
+image_t *R_FindImageFile( const char *imageName0, imageParams_t &imageParams )
 {
-	if ( !imageName )
+	if ( !imageName0 )
 	{
 		return nullptr;
 	}
 
-	unsigned hash = GenerateImageHashValue( imageName );
+	std::string imageName = FS::Path::NormalizeSlashes( imageName0 );
+
+	unsigned hash = GenerateImageHashValue( imageName.c_str() );
 
 	// See if the image is already loaded.
 	for ( image_t *image = r_imageHashTable[ hash ]; image; image = image->next )
 	{
-		if ( !Q_strnicmp( imageName, image->name, sizeof( image->name ) ) )
+		if ( Str::IsIEqual( imageName, image->name ) )
 		{
 			if ( imageParams == image->initialParams || r_allowImageParamMismatch.Get() )
 			{
@@ -1889,7 +1891,7 @@ image_t *R_FindImageFile( const char *imageName, imageParams_t &imageParams )
 	byte *pic[ MAX_TEXTURE_MIPS * MAX_TEXTURE_LAYERS ];
 	pic[ 0 ] = nullptr;
 
-	R_LoadImage( imageName, pic, &width, &height, &numLayers, &numMips, &imageParams.bits );
+	R_LoadImage( imageName.c_str(), pic, &width, &height, &numLayers, &numMips, &imageParams.bits);
 
 	if ( *pic )
 	{
@@ -1909,7 +1911,7 @@ image_t *R_FindImageFile( const char *imageName, imageParams_t &imageParams )
 		R_ProcessLightmap( *pic, width, height, imageParams.bits );
 	}
 
-	image_t *image = R_CreateImage( imageName, (const byte **)pic, width, height, numMips, imageParams );
+	image_t *image = R_CreateImage( imageName.c_str(), (const byte**)pic, width, height, numMips, imageParams);
 	image->initialParams = initialParams;
 
 	Z_Free( *pic );

src/engine/renderer/tr_shader.cpp

@@ -6237,7 +6237,8 @@ shader_t       *R_FindShader( const char *name, int flags )
 		return tr.defaultShader;
 	}
 
-	COM_StripExtension3( name, strippedName, sizeof( strippedName ) );
+	COM_StripExtension3( FS::Path::NormalizeSlashes( name ).c_str(),
+	                     strippedName, sizeof( strippedName ) );
 
 	hash = generateHashValue( strippedName, FILE_HASH_SIZE );