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.

1 files changed, 8 insertions, 1 deletions

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)
 {