Add some documentation to the GLSL compiler

[libs/gl.git] / source / glsl / compiler.cpp

diff --git a/source/glsl/compiler.cpp b/source/glsl/compiler.cpp
index ca6c58057022b8b3a9f69373433c0f6c54a2e35d..5bec9c8b1b8f475163b50a35b57b0a92e5bec84b 100644 (file)
--- a/source/glsl/compiler.cpp
+++ b/source/glsl/compiler.cpp
@@ -21,12 +21,14 @@ namespace SL {
 
 Compiler::Compiler():
        features(Features::from_context()),
-       module(0)
+       module(0),
+       specialized(false)
 { }
 
 Compiler::Compiler(const Features &f):
        features(f),
-       module(0)
+       module(0),
+       specialized(false)
 { }
 
 Compiler::~Compiler()
@@ -63,6 +65,12 @@ void Compiler::load_source(IO::Base &io, const string &src_name)
        load_source(io, 0, src_name);
 }
 
+void Compiler::specialize(const map<string, int> &sv)
+{
+       specialized = true;
+       spec_values = sv;
+}
+
 void Compiler::compile(Mode mode)
 {
        for(list<Stage>::iterator i=module->stages.begin(); i!=module->stages.end(); ++i)
@@ -206,13 +214,20 @@ void Compiler::generate(Stage &stage, Mode mode)
        inject_block(stage.content, module->shared.content);
 
        DeclarationReorderer().apply(stage);
-       BlockResolver().apply(stage);
+
+       // Initial resolving pass
+       BlockHierarchyResolver().apply(stage);
        FunctionResolver().apply(stage);
        VariableResolver().apply(stage);
+
+       /* All variables local to a stage have been resolved.  Resolve non-local
+       variables through interfaces. */
        InterfaceGenerator().apply(stage);
        VariableResolver().apply(stage);
+
        DeclarationReorderer().apply(stage);
        FunctionResolver().apply(stage);
+       ConstantSpecializer().apply(stage, (mode==PROGRAM && specialized ? &spec_values : 0));
        if(mode==PROGRAM)
                LegacyConverter().apply(stage, features);
 }
@@ -222,9 +237,11 @@ bool Compiler::optimize(Stage &stage)
        ConstantConditionEliminator().apply(stage);
 
        FunctionInliner().apply(stage);
-       BlockResolver().apply(stage);
+       BlockHierarchyResolver().apply(stage);
        VariableResolver().apply(stage);
 
+       /* Removing variables or functions may cause things from the previous stage
+       to become unused. */
        bool result = UnusedVariableRemover().apply(stage);
        result |= UnusedFunctionRemover().apply(stage);