More efficient stack management

[libs/gl.git] / source / renderer.h

diff --git a/source/renderer.h b/source/renderer.h
index 5536702b751a6d83288f14307eb6b6609b185dab..6115a7feeae33deadf6bb327f2d83703cd6f2d87 100644 (file)
--- a/source/renderer.h
+++ b/source/renderer.h
@@ -26,6 +26,11 @@ will often be more efficient.  This is especially true for ObjectInstances.
 The Renderer works by deferring GL state changes until something is actually
 being drawn.  This avoids many unnecessary GL calls if consecutive renderables
 use the same resources.
+
+A state stack is provided to help with state scoping.  Typically a Renderable
+will push the current state on entry, set whatever state it requires, render
+itself, and pop the state when it's done.  An RAII helper class is provided for
+the push/pop operation.
 */
 class Renderer
 {
@@ -47,7 +52,7 @@ private:
                const Texturing *texturing;
                const Material *material;
                const Program *shprog;
-               std::vector<const ProgramData *> shdata;
+               unsigned shdata_count;
                const WindingTest *winding_test;
 
                State();
@@ -67,12 +72,13 @@ private:
        MtxStack mtx_stack;
        bool mtx_changed;
        const Camera *camera;
-       std::list<State> state_stack;
+       std::vector<State> state_stack;
        State *state;
+       std::vector<const ProgramData *> shdata_stack;
+       bool shdata_changed;
        const VertexArray *vertex_array;
        bool vertex_array_changed;
        const Buffer *element_buffer;
-       bool shdata_changed;
 
 public:
        Renderer(const Camera *);
@@ -99,7 +105,11 @@ public:
        void set_element_buffer(const Buffer *);
        void set_winding_test(const WindingTest *);
 
+       /** Saves the current state so it can be restored later. */
        void push_state();
+
+       /** Restores a previously saved state.  Must be matched with an earlier
+       push_state call. */
        void pop_state();
 
        /** Prepares for temporarily bypassing the Renderer by synchronizing the