private static void CompileShader(ShaderGroup output, ZScriptTokenizer t)
{
t.SkipWhitespace();
ZScriptToken token = t.ExpectToken(ZScriptTokenType.Identifier);
if (!(token?.IsValid ?? true))
{
throw new ShaderCompileException("Expected shader identifier, got {0}", token?.ToString() ?? "<EOF>");
}
t.SkipWhitespace();
Shader s = new Shader(output);
s.Name = token.Value;
output.Shaders.Add(s);
token = t.ExpectToken(ZScriptTokenType.Identifier, ZScriptTokenType.OpenCurly);
if (!(token?.IsValid ?? true))
{
throw new ShaderCompileException("Expected parent identifier or shader block, got {0}", token?.ToString() ?? "<EOF>");
}
// has parent shader id
if (token.Type == ZScriptTokenType.Identifier)
{
if (token.Value != "extends")
{
throw new ShaderCompileException("Expected 'extends', got {0}", token.ToString());
}
t.SkipWhitespace();
token = t.ExpectToken(ZScriptTokenType.Identifier);
if (!(token?.IsValid ?? true))
{
throw new ShaderCompileException("Expected parent identifier, got {0}", token?.ToString() ?? "<EOF>");
}
s.ParentName = token.Value;
t.SkipWhitespace();
token = t.ExpectToken(ZScriptTokenType.OpenCurly);
if (!(token?.IsValid ?? true))
{
throw new ShaderCompileException("Expected shader block, got {0}", token?.ToString() ?? "<EOF>");
}
}
s.CodeLine = t.PositionToLine(token.Position);
while (true)
{
t.SkipWhitespace();
token = t.ExpectToken(ZScriptTokenType.Identifier, ZScriptTokenType.CloseCurly);
if (!(token?.IsValid ?? true))
{
throw new ShaderCompileException("Expected shader sub-block or end of block, got {0}", token?.ToString() ?? "<EOF>");
}
if (token.Type == ZScriptTokenType.CloseCurly)
{
break;
}
switch (token.Value)
{
case "in":
s.In = CompileShaderDataBlock(t);
break;
case "out":
s.Out = CompileShaderDataBlock(t);
break;
case "v2f":
s.V2F = CompileShaderDataBlock(t);
break;
case "functions":
CompileShaderFunctions(s, t);
break;
case "vertex":
s.SourceVertex = CompileShaderSource(t);
if (s.SourceVertex != null && s.SourceVertex.Count > 0)
{
s.SourceVertexLine = t.PositionToLine(s.SourceVertex[0].Position);
}
break;
case "fragment":
s.SourceFragment = CompileShaderSource(t);
if (s.SourceFragment != null && s.SourceFragment.Count > 0)
{
s.SourceFragmentLine = t.PositionToLine(s.SourceFragment[0].Position);
}
break;
default:
throw new ShaderCompileException("Expected shader sub-block, got {0}", token.ToString());
}
}
}
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);
}
}
// this is to implement partial parsing. it counts {}, (), and []. it stops parsing at the specified type, if outside of nesting.
// also if last block token equals to the type, it will stop at the outer level. (i.e. last })
private static List <ZScriptToken> ReadEverythingUntil(ZScriptTokenizer t, ZScriptTokenType type, bool eofIsOk, bool skipWhitespace)
{
List <ZScriptToken> tokens = new List <ZScriptToken>();
int levelCurly = 0;
int levelSquare = 0;
int levelParen = 0;
while (true)
{
if (skipWhitespace)
{
t.SkipWhitespace();
}
long cpos = t.Reader.BaseStream.Position;
ZScriptToken token = t.ReadToken();
if (token == null)
{
if (!eofIsOk)
{
throw new ShaderCompileException("Expected {0} or token, got <EOF>", type);
}
break;
}
// if this is the end token, don't check anything -- just return
if (levelCurly == 0 && levelSquare == 0 && levelParen == 0 && token.Type == type)
{
// rewind and return token list
t.Reader.BaseStream.Position = cpos;
break;
}
switch (token.Type)
{
case ZScriptTokenType.OpenCurly:
levelCurly++;
break;
case ZScriptTokenType.CloseCurly:
levelCurly--;
break;
case ZScriptTokenType.OpenParen:
levelParen++;
break;
case ZScriptTokenType.CloseParen:
levelParen--;
break;
case ZScriptTokenType.OpenSquare:
levelSquare++;
break;
case ZScriptTokenType.CloseSquare:
levelSquare--;
break;
}
tokens.Add(token);
}
return(tokens);
}
private static void CompileShaderField(ShaderField field, ZScriptTokenizer t)
{
ZScriptToken token;
// read name and array dimensions
while (true)
{
t.SkipWhitespace();
token = t.ExpectToken(ZScriptTokenType.OpenSquare, ZScriptTokenType.Identifier);
if (!(token?.IsValid ?? true))
{
throw new ShaderCompileException("Expected array dimensions or field name, got {0}", token?.ToString() ?? "<EOF>");
}
// array finished
if (token.Type == ZScriptTokenType.Identifier)
{
field.Name = token.Value;
break;
}
// read array
List <ZScriptToken> arrayDimTokens = ReadEverythingUntil(t, ZScriptTokenType.CloseSquare, false, false);
if (field.ArrayDimensions == null)
{
field.ArrayDimensions = new List <List <ZScriptToken> >();
}
field.ArrayDimensions.Add(arrayDimTokens);
token = t.ExpectToken(ZScriptTokenType.CloseSquare);
if (!(token?.IsValid ?? true))
{
throw new ShaderCompileException("Expected closing square brace, got {0}", token?.ToString() ?? "<EOF>");
}
}
// read additional array dimensions if present, and initializer. or end parsing
while (true)
{
t.SkipWhitespace();
token = t.ExpectToken(ZScriptTokenType.OpenSquare, ZScriptTokenType.OpAssign, ZScriptTokenType.Semicolon);
if (!(token?.IsValid ?? true))
{
throw new ShaderCompileException("Expected array dimensions, initializer or semicolon, got {0}", token?.ToString() ?? "<EOF>");
}
// field is done
if (token.Type == ZScriptTokenType.Semicolon)
{
break;
}
// has initializer
if (token.Type == ZScriptTokenType.OpAssign)
{
field.Initializer = ReadEverythingUntil(t, ZScriptTokenType.Semicolon, false, false);
token = t.ExpectToken(ZScriptTokenType.Semicolon);
if (!(token?.IsValid ?? true))
{
throw new ShaderCompileException("Expected semicolon, got {0}", token?.ToString() ?? "<EOF>");
}
break;
}
// read array
List <ZScriptToken> arrayDimTokens = ReadEverythingUntil(t, ZScriptTokenType.CloseSquare, false, false);
if (field.ArrayDimensions == null)
{
field.ArrayDimensions = new List <List <ZScriptToken> >();
}
field.ArrayDimensions.Add(arrayDimTokens);
token = t.ExpectToken(ZScriptTokenType.CloseSquare);
if (!(token?.IsValid ?? true))
{
throw new ShaderCompileException("Expected closing square brace, got {0}", token?.ToString() ?? "<EOF>");
}
}
}
public static ShaderGroup Compile(string src)
{
ShaderGroup output = new ShaderGroup();
using (MemoryStream ms = new MemoryStream(Encoding.UTF8.GetBytes(src)))
using (BinaryReader br = new BinaryReader(ms))
{
ZScriptTokenizer t = new ZScriptTokenizer(br);
// main cycle
// in the root scope, we allow three blocks:
// - uniforms{}
// - functions{}
// - shader <name> {}
// everything else is a syntax error.
while (true)
{
t.SkipWhitespace();
ZScriptToken token = t.ExpectToken(ZScriptTokenType.Identifier);
if (token == null)
{
break;
}
if (!token.IsValid)
{
throw new ShaderCompileException("Expected 'uniforms', 'functions', or 'shader'; got {0}", token.ToString());
}
switch (token.Value)
{
case "uniforms":
CompileUniforms(output, t);
break;
case "functions":
CompileFunctions(output, t);
break;
case "shader":
CompileShader(output, t);
break;
default:
throw new ShaderCompileException("Expected 'uniforms', 'functions', or 'shader'; got {0}", token.ToString());
}
}
// done parsing, postprocess - apply parents
foreach (Shader s in output.Shaders)
{
List <string> parents = new List <string>();
parents.Add(s.Name);
Shader p = s;
while (p.ParentName != null && p.ParentName != "")
{
string parentName = p.ParentName;
if (parents.Contains(parentName))
{
throw new ShaderCompileException("Recursive parent shader {0} found", parentName);
}
parents.Add(parentName);
p = output.GetShader(parentName);
if (p == null)
{
throw new ShaderCompileException("Parent shader {0} not found", parentName);
}
if (s.In == null)
{
s.In = p.In;
}
if (s.Out == null)
{
s.Out = p.Out;
}
if (s.V2F == null)
{
s.V2F = p.V2F;
}
if (s.SourceFragment == null)
{
s.SourceFragment = p.SourceFragment;
s.SourceFragmentLine = p.SourceFragmentLine;
}
if (s.SourceVertex == null)
{
s.SourceVertex = p.SourceVertex;
s.SourceVertexLine = p.SourceVertexLine;
}
// add functions from parent
foreach (ShaderFunction func in p.Functions)
{
if (s.GetFunction(func.Name) == null)
{
s.Functions.Add(func);
}
}
}
}
return(output);
}
}
