More efficient stack management

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

diff --git a/source/renderer.cpp b/source/renderer.cpp
index 46df5bf52777564ea62b9d995693c57f7e0d5fa9..94875084f65e2d7519be80e0bc76f5b06500f1b7 100644 (file)
--- a/source/renderer.cpp
+++ b/source/renderer.cpp
@@ -1,14 +1,7 @@
-/* $Id$
-
-This file is part of libmspgl
-Copyright © 2011  Mikko Rasa, Mikkosoft Productions
-Distributed under the LGPL
-*/
-
-#include <msp/core/except.h>
 #include "batch.h"
 #include "buffer.h"
 #include "camera.h"
+#include "error.h"
 #include "material.h"
 #include "program.h"
 #include "programdata.h"
@@ -28,11 +21,14 @@ Renderer::Renderer(const Camera *c):
        mtx_changed(false),
        camera(c),
        state_stack(1),
-       state(&state_stack.back()),
        vertex_array(0),
        vertex_array_changed(false),
        element_buffer(0)
 {
+       state_stack.reserve(16);
+       shdata_stack.reserve(32);
+       state = &state_stack.back();
+
        MatrixStack::modelview().push();
        if(camera)
        {
@@ -75,21 +71,22 @@ void Renderer::set_material(const Material *m)
        state->material = m;
 }
 
-void Renderer::set_shader(const Program *p, const ProgramData *d)
+void Renderer::set_shader_program(const Program *p, const ProgramData *d)
 {
        state->shprog = p;
-       if(d)
-               state->shdata.assign(1, d);
-       else
-               state->shdata.clear();
+       if(p && d)
+               add_shader_data(*d);
+
+       /* Even if we have no new shdata, the existing ones need to be re-applied
+       to the new program */
+       shdata_changed = true;
 }
 
-void Renderer::add_shader_data(const ProgramData *d)
+void Renderer::add_shader_data(const ProgramData &d)
 {
-       if(!state->shprog)
-               throw InvalidState("No shader program");
-
-       state->shdata.push_back(d);
+       shdata_stack.push_back(&d);
+       state->shdata_count = shdata_stack.size();
+       shdata_changed = true;
 }
 
 void Renderer::set_vertex_array(const VertexArray *a)
@@ -118,12 +115,15 @@ void Renderer::push_state()
 void Renderer::pop_state()
 {
        if(state_stack.size()==1)
-               throw InvalidState("Can't pop the last state");
+               throw stack_underflow("Renderer::pop_state");
 
        state_stack.pop_back();
        state = &state_stack.back();
+       if(shdata_stack.size()>state->shdata_count)
+               shdata_stack.erase(shdata_stack.begin()+state->shdata_count, shdata_stack.end());
        mtx_stack.pop();
        mtx_changed = true;
+       shdata_changed = true;
 }
 
 void Renderer::escape()
@@ -135,7 +135,7 @@ void Renderer::escape()
 void Renderer::draw(const Batch &batch)
 {
        if(!vertex_array)
-               throw InvalidState("Can't draw without a vertex array");
+               throw invalid_operation("Renderer::draw");
 
        apply_state();
 
@@ -177,8 +177,12 @@ void Renderer::apply_state()
        if(state->shprog)
        {
                state->shprog->bind();
-               for(vector<const ProgramData *>::const_iterator i=state->shdata.begin(); i!=state->shdata.end(); ++i)
-                       (*i)->apply();
+               if(shdata_changed)
+               {
+                       for(vector<const ProgramData *>::const_iterator i=shdata_stack.begin(); i!=shdata_stack.end(); ++i)
+                               (*i)->apply();
+                       shdata_changed = false;
+               }
        }
        else
                Program::unbind();