Update stencils and billboards less often

No need to update these every frame when little of nothing has changed.
Instead, track the angle previously rendered and updated only when the
new angle has diverged sufficiently from this. Larger updates update
more frequently.

2 files changed, 12 insertions, 5 deletions

diff --git a/game/scenary/foliage.cpp b/game/scenary/foliage.cpp
index 680d902..0981ffc 100644
--- a/game/scenary/foliage.cpp
+++ b/game/scenary/foliage.cpp
@@ -9,8 +9,9 @@
 
 static_assert(std::is_constructible_v<Foliage>);
 constexpr float OBJECT_BILLBOARD_DIVISOR = 64;
+constexpr float BILLBOARD_ANGLE_TOLERANCE = 250.F; // Radians per mm size
 constexpr float ASSUMED_VIEWPORT = 1440;
-constexpr float OVER_SAMPLE_MULTIPLIER = 4; // Use mesh until billboard 1/4 of rendered size
+constexpr float OVER_SAMPLE_MULTIPLIER = 2; // Use mesh until billboard 1/2 of rendered size
 
 namespace {
 	GLsizei
@@ -51,18 +52,22 @@ Foliage::postLoad()
 }
 
 void
-Foliage::updateStencil(const ShadowStenciller & ss) const
+Foliage::updateStencil(const ShadowStenciller & shadowStenciller) const
 {
-	if (instancePartitions.second.second != instancePartitions.second.first) {
-		ss.renderStencil(shadowStencil, *bodyMesh, texture);
+	if (instancePartitions.second.second != instancePartitions.second.first
+			&& glm::distance(shadowStenciller.getLightDirection(), shadowStencilDir)
+					> BILLBOARD_ANGLE_TOLERANCE / bodyMesh->getDimensions().size) {
+		shadowStenciller.renderStencil(shadowStencil, *bodyMesh, texture);
 	}
 }
 
 void
 Foliage::updateBillboard(const BillboardPainter & bbp) const
 {
-	if (instancePartitions.first != instancePartitions.second.first) {
+	if (instancePartitions.first != instancePartitions.second.first
+			&& std::abs(bbp.getAngle() - billboardAngle) > BILLBOARD_ANGLE_TOLERANCE / bodyMesh->getDimensions().size) {
 		bbp.renderBillBoard(billboard, *bodyMesh, texture);
+		billboardAngle = bbp.getAngle();
 	}
 }
 
diff --git a/game/scenary/foliage.h b/game/scenary/foliage.h
index c457404..3d73573 100644
--- a/game/scenary/foliage.h
+++ b/game/scenary/foliage.h
@@ -37,7 +37,9 @@ protected:
 	void postLoad() override;
 	GLsizei billboardSize {};
 	RelativeDistance useMeshClipDist {};
+	mutable Direction2D shadowStencilDir {std::numeric_limits<Direction2D::value_type>::infinity()};
 	glTexture shadowStencil;
+	mutable Angle billboardAngle = std::numeric_limits<Angle>::infinity();
 	glTextures<3> billboard;
 
 private: