From ce1a6ce9a4816ba2590a47a9692c715018bb1f32 Mon Sep 17 00:00:00 2001
From: Martin Felis <martin@fysx.org>
Date: Sun, 8 Jul 2018 14:00:30 +0200
Subject: [PATCH] Tweaked shadow map cascades and adaptively send the program
 to sleep to reach a specfied refresh rate

---
 src/RuntimeModuleManager.h  | 1 +
 src/main.cc                 | 6 +++++-
 src/modules/RenderModule.cc | 9 ++++++---
 3 files changed, 12 insertions(+), 4 deletions(-)

diff --git a/src/RuntimeModuleManager.h b/src/RuntimeModuleManager.h
index ce9051b..c0b69af 100644
--- a/src/RuntimeModuleManager.h
+++ b/src/RuntimeModuleManager.h
@@ -23,6 +23,7 @@ struct RuntimeModule {
 struct RuntimeModuleManager {
 	std::vector<RuntimeModule*> mModules;
 	int mNumUpdatesSinceLastModuleChange = 0;
+	int mTargetFPS = 30;
 
 	void RegisterModule(const char* name);
 	void UnregisterModules();
diff --git a/src/main.cc b/src/main.cc
index c240e58..f8bc9f0 100644
--- a/src/main.cc
+++ b/src/main.cc
@@ -231,7 +231,11 @@ int main(void)
 
 		ImGui::Render();
 
-		usleep(16000);
+		// Send the application to sleep if we have some time left for this frame 
+		double frame_target_time = 1.0 / module_manager.mTargetFPS;
+		if (frame_delta_time < frame_target_time) {
+			usleep ((frame_target_time - frame_delta_time) * 1000000 * 0.98);
+		}
 
 		if (glfwGetKey(gWindow, GLFW_KEY_F5) == GLFW_PRESS) {
 			gFileModificationObserver->Update();
diff --git a/src/modules/RenderModule.cc b/src/modules/RenderModule.cc
index c4217f9..21a8b9c 100644
--- a/src/modules/RenderModule.cc
+++ b/src/modules/RenderModule.cc
@@ -280,7 +280,10 @@ void Light::UpdateSplits(const Camera& camera) {
 	assert(camera.mIsOrthographic == false);
 
 	float near = camera.mNear;
-	float far = camera.mFar;
+	// Clamp the far plane of the camera so that we only 
+	// create shadow maps for things that are relatively near
+	// the camera.
+	float far = fmin(camera.mFar, 10.0f);
 	float length = far - near;
 	float split_near = near;
 	float aspect = camera.mWidth / camera.mHeight;
@@ -296,8 +299,8 @@ void Light::UpdateSplits(const Camera& camera) {
 	Matrix44f light_matrix_inv = light_matrix.inverse();
 
 	mShadowSplits[0] = near;
-	mShadowSplits[1] = near + length * 0.02;
-	mShadowSplits[2] = near + length * 0.2;
+	mShadowSplits[1] = near + length * 0.1;
+	mShadowSplits[2] = near + length * 0.25;
 	mShadowSplits[3] = far;
 
 	for (int i = 0; i < cNumSplits; ++i) {