Add some documentation to the GLSL compiler

[libs/gl.git] / source / glsl / generate.h

diff --git a/source/glsl/generate.h b/source/glsl/generate.h
index d0cbc08f279c4b8c12837abf2e0f040b784f6f2b..b82bdca365bc02e7fd856c86f5011eb124517f92 100644 (file)
--- a/source/glsl/generate.h
+++ b/source/glsl/generate.h
@@ -11,6 +11,7 @@ namespace Msp {
 namespace GL {
 namespace SL {
 
+/** Combines multiple declarations of the same identifier into one. */
 class DeclarationCombiner: private TraversingVisitor
 {
 private:
@@ -27,7 +28,25 @@ private:
        virtual void visit(VariableDeclaration &);
 };
 
-class BlockResolver: private TraversingVisitor
+/** Manipulates specialization constants.  If values are specified, turns
+specialization constants into normal constants.  Without values assigns
+automatic constant_ids to specialization constants. */
+class ConstantSpecializer: private TraversingVisitor
+{
+private:
+       const std::map<std::string, int> *values;
+
+public:
+       ConstantSpecializer();
+
+       void apply(Stage &, const std::map<std::string, int> *);
+
+private:
+       virtual void visit(VariableDeclaration &);
+};
+
+/** Forms links between nested blocks in the syntax tree. */
+class BlockHierarchyResolver: private TraversingVisitor
 {
 public:
        void apply(Stage &s) { s.content.visit(*this); }
@@ -36,9 +55,12 @@ private:
        virtual void enter(Block &);
 };
 
+/** Resolves variable references.  Variable references which match the name
+of an interface block are turned into interface block references. */
 class VariableResolver: private TraversingVisitor
 {
 private:
+       Stage *stage;
        Block *builtins;
        std::map<std::string, VariableDeclaration *> *members;
        RefPtr<InterfaceBlockReference> iface_ref;
@@ -66,19 +88,29 @@ private:
        virtual void visit(InterfaceBlock &);
 };
 
+/** Resolves function declarations and calls. */
 class FunctionResolver: private TraversingVisitor
 {
 private:
+       Stage *stage;
        std::map<std::string, std::vector<FunctionDeclaration *> > functions;
 
 public:
-       void apply(Stage &s) { s.content.visit(*this); }
+       void apply(Stage &);
 
 private:
        virtual void visit(FunctionCall &);
        virtual void visit(FunctionDeclaration &);
 };
 
+/** Materializes implicitly declared interfaces.
+
+Out variable declarations inside functions are moved to the global scope.
+
+Passthrough statements are processed, generating out variables to match in
+variables and copying values.
+
+Unresolved variables are looked up in the previous stage's out variables. */
 class InterfaceGenerator: private TraversingVisitor
 {
 private:
@@ -112,6 +144,8 @@ private:
        virtual void visit(Passthrough &);
 };
 
+/** Reorders declarations to ensure that declarations always appear before
+references. */
 class DeclarationReorderer: private TraversingVisitor
 {
 private: