From 5273a03417b0bb1b1f9f0baabee22466c8ea440c Mon Sep 17 00:00:00 2001
From: Dan Goodliffe <dan@randomdan.homeip.net>
Date: Wed, 4 Mar 2026 03:12:26 +0000
Subject: 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.
---
 gfx/gl/shadowStenciller.cpp | 9 ++++++++-
 1 file changed, 8 insertions(+), 1 deletion(-)

(limited to 'gfx/gl/shadowStenciller.cpp')

diff --git a/gfx/gl/shadowStenciller.cpp b/gfx/gl/shadowStenciller.cpp
index 7a0fc9b..19c8bef 100644
--- a/gfx/gl/shadowStenciller.cpp
+++ b/gfx/gl/shadowStenciller.cpp
@@ -10,7 +10,7 @@
 #include <stdexcept>
 
 ShadowStenciller::ShadowStenciller() :
-	shadowCaster {shadowStencil_vert, shadowStencil_geom, shadowStencil_frag}, viewProjections {}
+	shadowCaster {shadowStencil_vert, shadowStencil_geom, shadowStencil_frag}, lightDir {}, viewProjections {}
 {
 	glDebugScope _ {fbo};
 	glBindFramebuffer(GL_FRAMEBUFFER, fbo);
@@ -22,6 +22,7 @@ ShadowStenciller::ShadowStenciller() :
 void
 ShadowStenciller::setLightDirection(const LightDirection & lightDir)
 {
+	this->lightDir = lightDir.position();
 	viewProjections = [&lightDir]<GLint... Ep>(std::integer_sequence<GLint, Ep...>) {
 		constexpr float STEP = two_pi / STENCIL_ANGLES<decltype(two_pi)>;
 		return std::array {rotate_pitch<4>(half_pi - lightDir.position().y)
@@ -29,6 +30,12 @@ ShadowStenciller::setLightDirection(const LightDirection & lightDir)
 	}(std::make_integer_sequence<GLint, STENCIL_ANGLES<GLint>>());
 }
 
+Direction2D
+ShadowStenciller::getLightDirection() const
+{
+	return lightDir;
+}
+
 glTexture
 ShadowStenciller::createStencilTexture(GLsizei width, GLsizei height)
 {
-- 
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