Add functions to control environment map updates

If the environment changes only very slowly or not at all, it may be
desirable to not update the map every frame.

diff --git a/source/environmentmap.cpp b/source/environmentmap.cpp
index 95e2c4394c809a8c05be4515159b2da4fdc02d84..9c4df092481789d270669450b18f21b6ff71f1e4 100644 (file)
--- a/source/environmentmap.cpp
+++ b/source/environmentmap.cpp
@@ -1,8 +1,11 @@
+#include <algorithm>
 #include <cmath>
 #include "environmentmap.h"
 #include "renderer.h"
 #include "texunit.h"
 
+using namespace std;
+
 namespace Msp {
 namespace GL {
 
@@ -10,7 +13,9 @@ EnvironmentMap::EnvironmentMap(unsigned s, Renderable &r, Renderable &e):
        Effect(r),
        size(s),
        environment(e),
-       rendered(false)
+       rendered(false),
+       update_interval(1),
+       update_delay(0)
 {
        env_tex.storage(RGB, size);
        env_tex.set_wrap(CLAMP_TO_EDGE);
@@ -34,6 +39,17 @@ void EnvironmentMap::set_depth_clip(float n, float f)
        camera.set_depth_clip(n, f);
 }
 
+void EnvironmentMap::set_update_interval(unsigned i)
+{
+       update_interval = i;
+       update_delay = min(update_delay, update_interval-1);
+}
+
+void EnvironmentMap::queue_update()
+{
+       update_delay = 0;
+}
+
 void EnvironmentMap::setup_frame(Renderer &renderer)
 {
        if(rendered)
@@ -41,6 +57,14 @@ void EnvironmentMap::setup_frame(Renderer &renderer)
 
        rendered = true;
        renderable.setup_frame(renderer);
+
+       if(update_delay)
+       {
+               if(update_interval)
+                       --update_delay;
+               return;
+       }
+       update_delay = update_interval-1;
        environment.setup_frame(renderer);
 
        const Matrix *matrix = renderable.get_matrix();

diff --git a/source/environmentmap.h b/source/environmentmap.h
index 5f3b6a14b81b0493ac0e9fe2acbdb78bff7d5726..6fdd3749a9e316e6cad18cf6caeccc37613ad86c 100644 (file)
--- a/source/environmentmap.h
+++ b/source/environmentmap.h
@@ -35,11 +35,15 @@ private:
        Camera camera;
        mutable ProgramData shdata;
        bool rendered;
+       unsigned update_interval;
+       unsigned update_delay;
 
 public:
        EnvironmentMap(unsigned size, Renderable &rend, Renderable &env);
 
        void set_depth_clip(float, float);
+       void set_update_interval(unsigned);
+       void queue_update();
 
        virtual void setup_frame(Renderer &);
        virtual void finish_frame();