/// <summary>
/// Processes an ifdef/else/endif block where Interpret denotes the success of the if statement. Returns true if exited on an endif or false
/// if exited on an else.
/// </summary>
private static bool _ProcessBlock(IEnumerator<string> LineEnumerator, Path File, PrecompilerInput Input, StringBuilder Output, bool Interpret)
{
while (LineEnumerator.MoveNext())
{
string line = LineEnumerator.Current;
// Does this line contain a directive?
if (line.Length > 0)
{
if (line[0] == '#')
{
string[] lineparts = line.Split(' ');
if (lineparts[0] == "#ifdef")
{
if (Interpret)
{
bool contains = Input.Constants.ContainsKey(lineparts[1]);
if (!_ProcessBlock(LineEnumerator, File, Input, Output, contains))
{
_ProcessBlock(LineEnumerator, File, Input, Output, !contains);
}
}
else
{
if (!_ProcessBlock(LineEnumerator, File, Input, Output, false))
{
_ProcessBlock(LineEnumerator, File, Input, Output, false);
}
}
continue;
}
if (lineparts[0] == "#include")
{
if (Interpret)
{
string filepath = lineparts[1].Substring(1, lineparts[1].Length - 2);
BuildSource(File.Parent.Lookup(filepath), Input, Output);
}
continue;
}
if (lineparts[0] == "#else")
{
return false;
}
if (lineparts[0] == "#endif")
{
return true;
}
if (Interpret)
{
if (lineparts[0] == "#define")
{
if (lineparts.Length > 2)
{
Input.Define(lineparts[1], lineparts[2]);
}
else
{
Input.Define(lineparts[1]);
}
continue;
}
if (lineparts[0] == "#undef")
{
Input.Undefine(lineparts[1]);
continue;
}
Output.AppendLine(line);
}
}
else
{
if (Interpret)
{
// Replace constants
Dictionary<int, KeyValuePair<int, string>> matches = new Dictionary<int, KeyValuePair<int, string>>();
foreach (KeyValuePair<string, string> constant in Input.Constants)
{
int ind = line.IndexOf(constant.Key);
while (ind >= 0)
{
int size = constant.Key.Length;
KeyValuePair<int, string> lastmatch;
if (matches.TryGetValue(ind, out lastmatch))
{
if (lastmatch.Key < size)
{
matches[ind] = new KeyValuePair<int, string>(size, constant.Value);
}
}
else
{
matches[ind] = new KeyValuePair<int, string>(size, constant.Value);
}
ind = line.IndexOf(constant.Key, ind + 1);
}
}
if (matches.Count > 0)
{
int c = 0;
var orderedmatches = new List<KeyValuePair<int, KeyValuePair<int, string>>>(matches);
orderedmatches.Sort(delegate(KeyValuePair<int, KeyValuePair<int, string>> a, KeyValuePair<int, KeyValuePair<int, string>> b)
{
if (a.Key > b.Key)
return 1;
if (a.Key < b.Key)
return -1;
return 0;
});
foreach (KeyValuePair<int, KeyValuePair<int, string>> match in orderedmatches)
{
Output.Append(line.Substring(c, match.Key - c));
Output.Append(match.Value.Value);
c = match.Key + match.Value.Key;
}
Output.AppendLine(line.Substring(c));
}
else
{
Output.AppendLine(line);
}
}
}
}
}
return true;
}
/// <summary>
/// Precompiles the source code defined by the lines with the specified constants defined. Outputs the precompiled source
/// to the given stringbuilder.
/// </summary>
public static void BuildSource(Path File, PrecompilerInput Input, StringBuilder Output)
{
string[] lines = Input.GetFile(File);
_ProcessBlock(((IEnumerable<string>)lines).GetEnumerator(), File, Input, Output, true);
}
/// <summary>
/// Loads a shader from the specified file using the specified input.
/// </summary>
public static Shader Load(Path File, PrecompilerInput Input)
{
int vshade = GL.CreateShader(ShaderType.VertexShader);
int fshade = GL.CreateShader(ShaderType.FragmentShader);
StringBuilder vshadesource = new StringBuilder();
StringBuilder fshadesource = new StringBuilder();
PrecompilerInput vpce = Input.Copy();
PrecompilerInput fpce = Input.Copy();
vpce.Define("_VERTEX_", "1");
fpce.Define("_FRAGMENT_", "1");
BuildSource(File, vpce, vshadesource);
GL.ShaderSource(vshade, vshadesource.ToString());
GL.CompileShader(vshade);
string vinfo = GL.GetShaderInfoLog(vshade);
BuildSource(File, fpce, fshadesource);
GL.ShaderSource(fshade, fshadesource.ToString());
GL.CompileShader(fshade);
string finfo = GL.GetShaderInfoLog(fshade);
if (false)
{
if (finfo.Length > 0 || vinfo.Length > 0)
{
throw new Exception("Shader error");
}
}
Shader shade = new Shader();
shade.Program = GL.CreateProgram();
GL.AttachShader(shade.Program, vshade);
GL.AttachShader(shade.Program, fshade);
GL.LinkProgram(shade.Program);
return shade;
}
