From: Mikko Rasa <tdb@tdb.fi>
Date: Sun, 1 Jul 2018 10:05:39 +0000 (+0300)
Subject: Add functions to control environment map updates
X-Git-Url: http://git.tdb.fi/?p=libs%2Fgl.git;a=commitdiff_plain;h=4598d28936d3a4772927d1e3a1534f872731b358

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 95e2c439..9c4df092 100644
--- 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 5f3b6a14..6fdd3749 100644
--- 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();