draw optimizations

client/world/renderer_helper.go

@@ -0,0 +1,36 @@
+package world
+
+func (w *World) candSeenResetIfOverflow() {
+	w.candEpoch++
+	if w.candEpoch != 0 {
+		return
+	}
+	// overflow: reset stamp array
+	for i := range w.candStamp {
+		w.candStamp[i] = 0
+	}
+	w.candEpoch = 1
+}
+
+func (w *World) candSeenMark(id PrimitiveID) bool {
+	// ensure stamp capacity
+	uid := uint32(id)
+	if int(uid) >= len(w.candStamp) {
+		// grow to next power-ish
+		n := len(w.candStamp)
+		if n == 0 {
+			n = 1024
+		}
+		for n <= int(uid) {
+			n *= 2
+		}
+		ns := make([]uint32, n)
+		copy(ns, w.candStamp)
+		w.candStamp = ns
+	}
+	if w.candStamp[uid] == w.candEpoch {
+		return true
+	}
+	w.candStamp[uid] = w.candEpoch
+	return false
+}