private string GetFunctionSource(List <ZScriptToken> shaderSource)
{
List <string> functionNames = new List <string>();
GetReferencedFunctions(shaderSource, functionNames);
string preOutput = "";
string output = "";
foreach (string functionName in functionNames)
{
ShaderFunction func = GetFunction(functionName);
if (func == null)
{
func = Group.GetFunction(functionName);
}
if (func == null)
{
continue;
}
string funcOutput = string.Format("#line {0}\n", func.Line) + func.ReturnValue + " " + func.Name + " (" + GetTokenListSource(func.Arguments) + ")";
preOutput += funcOutput + ";\n";
funcOutput += " {\n" + string.Format("#line {0}\n", func.CodeLine) + GetTokenListSource(func.Code) + "}\n";
output += funcOutput;
}
return(preOutput + "\n" + output);
}
private void GetReferencedFunctions(List <ZScriptToken> source, List <string> functions)
{
for (int i = 0; i < source.Count; i++)
{
ZScriptToken token = source[i];
if (token.Type != ZScriptTokenType.Identifier)
{
continue;
}
if (functions.Contains(token.Value))
{
continue;
}
// check token to the left - needs to not be identifier.
// check token to the right - needs to be open parenthesis
// ---
// the idea is that we can differentiate pixel = desaturate(...) from vec4 desaturate(1,1,1,1)
//
ZScriptTokenType leftToken = ZScriptTokenType.Invalid;
ZScriptTokenType rightToken = ZScriptTokenType.Invalid;
for (int j = i - 1; j >= 0; j--)
{
ZScriptTokenType tt = source[j].Type;
if (!IsWhitespace(tt))
{
leftToken = tt;
break;
}
}
for (int j = i + 1; j < source.Count; j++)
{
ZScriptTokenType tt = source[j].Type;
if (!IsWhitespace(tt))
{
rightToken = tt;
break;
}
}
if (leftToken != ZScriptTokenType.Identifier && rightToken == ZScriptTokenType.OpenParen)
{
// find function
functions.Add(token.Value);
// if function was found, recurse and find functions it may depend on.
ShaderFunction func = GetFunction(token.Value);
if (func == null)
{
func = Group.GetFunction(token.Value);
}
if (func != null)
{
GetReferencedFunctions(func.Code, functions);
}
}
}
}
private static void CompileShaderFunction(ShaderFunction func, ZScriptTokenizer t)
{
ZScriptToken token;
t.SkipWhitespace();
token = t.ExpectToken(ZScriptTokenType.Identifier);
if (!(token?.IsValid ?? true))
{
throw new ShaderCompileException("Expected function name, got {0}", token?.ToString() ?? "<EOF>");
}
func.Name = token.Value;
t.SkipWhitespace();
token = t.ExpectToken(ZScriptTokenType.OpenParen);
if (!(token?.IsValid ?? true))
{
throw new ShaderCompileException("Expected function argument list, got {0}", token?.ToString() ?? "<EOF>");
}
func.Arguments = ReadEverythingUntil(t, ZScriptTokenType.CloseParen, false, false);
token = t.ExpectToken(ZScriptTokenType.CloseParen);
if (!(token?.IsValid ?? true))
{
throw new ShaderCompileException("Expected end of function arguments, got {0}", token?.ToString() ?? "<EOF>");
}
t.SkipWhitespace();
token = t.ExpectToken(ZScriptTokenType.OpenCurly);
if (!(token?.IsValid ?? true))
{
throw new ShaderCompileException("Expected function code block, got {0}", token?.ToString() ?? "<EOF>");
}
func.CodeLine = t.PositionToLine(token.Position);
func.Code = ReadEverythingUntil(t, ZScriptTokenType.CloseCurly, false, false);
token = t.ExpectToken(ZScriptTokenType.CloseCurly);
if (!(token?.IsValid ?? true))
{
throw new ShaderCompileException("Expected end of function code block, got {0}", token?.ToString() ?? "<EOF>");
}
}
private static void CompileShaderFunctions(Shader output, ZScriptTokenizer t)
{
t.SkipWhitespace();
ZScriptToken token;
token = t.ExpectToken(ZScriptTokenType.OpenCurly);
if (!(token?.IsValid ?? true))
{
throw new ShaderCompileException("Expected functions block, got {0}", token?.ToString() ?? "<EOF>");
}
while (true)
{
t.SkipWhitespace();
token = t.ExpectToken(ZScriptTokenType.Identifier, ZScriptTokenType.CloseCurly);
if (!(token?.IsValid ?? true))
{
throw new ShaderCompileException("Expected function or end of block, got {0}", token?.ToString() ?? "<EOF>");
}
if (token.Type == ZScriptTokenType.CloseCurly)
{
break; // done reading functions
}
bool isoverride = false;
if (token.Value == "override")
{
isoverride = true;
t.SkipWhitespace();
token = t.ExpectToken(ZScriptTokenType.Identifier);
if (!(token?.IsValid ?? true))
{
throw new ShaderCompileException("Expected function return type, got {0}", token?.ToString() ?? "<EOF>");
}
}
// <return value> <name> (<arguments>) { <code> }
ShaderFunction func = new ShaderFunction();
func.Line = t.PositionToLine(token.Position);
func.ReturnValue = token.Value;
func.Override = isoverride;
CompileShaderFunction(func, t);
// check if function with such name already exists in the shader
// delete it.
// overloading is not supported for now
if (!isoverride)
{
ShaderFunction existingFunc = output.Group.GetFunction(func.Name);
if (existingFunc != null)
{
throw new ShaderCompileException("Function {0} is double-defined without 'override' keyword! (previous declaration at line {1})", func.Name, existingFunc.Line);
}
}
for (int i = 0; i < output.Functions.Count; i++)
{
if (output.Functions[i].Name == func.Name)
{
if (!isoverride)
{
throw new ShaderCompileException("Function {0} is double-defined without 'override' keyword! (previous declaration at line {1})", func.Name, output.Functions[i].Line);
}
output.Functions.RemoveAt(i);
i--;
continue;
}
}
output.Functions.Add(func);
}
}