More efficient stack management

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

diff --git a/source/renderer.h b/source/renderer.h
index dd54ca1691dfaf49233608ff85f2ff5de9e69440..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 *);
@@ -85,13 +91,25 @@ public:
        void set_texture(const Texture *);
        void set_texturing(const Texturing *);
        void set_material(const Material *);
-       void set_shader(const Program *, const ProgramData *);
-       void add_shader_data(const ProgramData *);
+
+       /** Sets the shader program to use.  An initial set of data can be set as
+       well, with the same semantics as add_shader_data. */
+       void set_shader_program(const Program *prog, const ProgramData *data = 0);
+
+       /** Adds another set of data to be use with shader programs.  The data is
+       independent of any shader program changes and remains in effect until the
+       Renderer state is popped. */
+       void add_shader_data(const ProgramData &data);
+
        void set_vertex_array(const VertexArray *);
        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