Add whatever I was working on for the last month

1 files changed, 60 insertions, 0 deletions

diff --git a/game/client/interpolation.cc b/game/client/interpolation.cc
new file mode 100644
index 0000000..841d429
--- /dev/null
+++ b/game/client/interpolation.cc
@@ -0,0 +1,60 @@
+#include "client/pch.hh"
+#include "client/interpolation.hh"
+
+#include "core/constexpr.hh"
+
+#include "shared/coord.hh"
+#include "shared/dimension.hh"
+#include "shared/head.hh"
+#include "shared/transform.hh"
+
+#include "client/globals.hh"
+
+static void transform_interpolate(float alpha)
+{
+    auto group = globals::dimension->entities.group<TransformComponentIntr>(entt::get<TransformComponent, TransformComponentPrev>);
+
+    for(auto [entity, interp, current, previous] : group.each()) {
+        interp.angles[0] = cxpr::lerp(previous.angles[0], current.angles[0], alpha);
+        interp.angles[1] = cxpr::lerp(previous.angles[1], current.angles[1], alpha);
+        interp.angles[2] = cxpr::lerp(previous.angles[2], current.angles[2], alpha);
+
+        // Figure out previous chunk-local floating-point coordinates transformed
+        // to the current WorldCoord's chunk domain coordinates; we're interpolating
+        // against these instead of using previous.position.local to prevent jittering
+        auto previous_shift = coord::to_relative(current.chunk, current.local, previous.chunk, previous.local);
+        auto previous_local = current.local + previous_shift;
+
+        interp.chunk.x = current.chunk.x;
+        interp.chunk.y = current.chunk.y;
+        interp.chunk.z = current.chunk.z;
+
+        interp.local.x = cxpr::lerp(previous_local.x, current.local.x, alpha);
+        interp.local.y = cxpr::lerp(previous_local.y, current.local.y, alpha);
+        interp.local.z = cxpr::lerp(previous_local.z, current.local.z, alpha);
+    }
+}
+
+static void head_interpolate(float alpha)
+{
+    auto group = globals::dimension->entities.group<HeadComponentIntr>(entt::get<HeadComponent, HeadComponentPrev>);
+
+    for(auto [entity, interp, current, previous] : group.each()) {
+        interp.angles[0] = cxpr::lerp(previous.angles[0], current.angles[0], alpha);
+        interp.angles[1] = cxpr::lerp(previous.angles[1], current.angles[1], alpha);
+        interp.angles[2] = cxpr::lerp(previous.angles[2], current.angles[2], alpha);
+
+        interp.offset.x = cxpr::lerp(previous.offset.x, current.offset.x, alpha);
+        interp.offset.y = cxpr::lerp(previous.offset.y, current.offset.y, alpha);
+        interp.offset.z = cxpr::lerp(previous.offset.z, current.offset.z, alpha);
+    }
+}
+
+void interpolation::update(void)
+{
+    if(globals::dimension) {
+        auto alpha = static_cast<float>(globals::fixed_accumulator) / static_cast<float>(globals::fixed_frametime_us);
+        transform_interpolate(alpha);
+        head_interpolate(alpha);
+    }
+}
\ No newline at end of file