/// <summary>Appends the default line terminator to the end of this instance.</summary> public void AppendLine() => _vsb.AppendLine();
private static void PreprocessShaderSource(AssetManager assetManager,
ref Utf16ValueStringBuilder stringBuilder,
string shaderPath,
List <string> shaderIncludePaths,
Stack <string> includeStack)
{
string shaderSource = GetShaderSource(assetManager, shaderPath);
// Skip pre-processing if the string doesn't have any include directives.
if (!shaderSource.Contains("#include "))
{
stringBuilder.Append(shaderSource);
return;
}
// Add current include path to the stack so we can book-keep to prevent circular dependencies.
includeStack.Push(shaderPath);
int lineNumber = 1;
using var lineReader = new LineReader(shaderSource);
for (ReadOnlyMemory <char> line = lineReader.ReadLine(); !lineReader.Finished; line = lineReader.ReadLine())
{
// Check if the line starts with "#include "
if (line.Span.StartsWith(_includeCompare.Span))
{
if (TryParseIncludeLine(line, out var includeFile))
{
string includePath = Path.Combine(Path.GetDirectoryName(shaderPath) ?? throw new Exception(), includeFile.ToString());
if (includeStack.Contains(includePath))
{
throw new ShaderPreprocessException($"Include statement would introduce cyclic dependency: {includeFile}\n" +
$"Parent: \"{shaderPath}\"");
}
shaderIncludePaths.Add(includePath);
stringBuilder.Append("#line 1 ");
stringBuilder.AppendLine((shaderIncludePaths.IndexOf(includePath) + 1).ToString());
PreprocessShaderSource(assetManager,
ref stringBuilder,
includePath,
shaderIncludePaths,
includeStack);
stringBuilder.Append("\n#line ");
stringBuilder.Append(lineNumber);
stringBuilder.AppendLine((shaderIncludePaths.IndexOf(includePath) + 1).ToString());
}
else
{
throw new ShaderPreprocessException($"Error when parsing include statement: {shaderPath}:{lineNumber}");
}
}
else
{
stringBuilder.Append(line);
lineNumber++;
}
stringBuilder.Append('\n');
}
includeStack.Pop();
}