From 3777d9a6b4f886dcc37fce9aa16038d5fcbc5dc5 Mon Sep 17 00:00:00 2001
From: Alug <alugfolie@proton.me>
Date: Sun, 22 Mar 2026 14:16:37 -0400
Subject: [PATCH] Improve speed of find_close_polyvertex in debug builds

for #226
---
 src/hardware/hw_map.c | 67 +++++++++++++++++++++++++++++++++++--------
 1 file changed, 55 insertions(+), 12 deletions(-)

diff --git a/src/hardware/hw_map.c b/src/hardware/hw_map.c
index f70457ebf..7a78f60f9 100644
--- a/src/hardware/hw_map.c
+++ b/src/hardware/hw_map.c
@@ -130,16 +130,46 @@ static polyvertex_t *find_close_polyvertex(float x, float y, float ep)
 {
 	polyvertex_store_t *psv;
 	polyvertex_t *pv;
+	float dx, dy;
 	INT32 i;
 
+	// eep!
+	const float eep = ep*ep;
+
+	// we do some lööp unrollin
+	// those checks stink in debug builds and take literal ages
+	// unrolling the loops to check 8 at a time with extra early rejects
+	// cuts the total time by around 54% on my maschine
+
+#define CHECKVERTEX(p) \
+	dx = (p)->x - x; \
+	/* reject vertices that are waaay off by checking in a square */ \
+	if (!(dx < -ep || dx > ep)) { \
+		dy = (p)->y - y; \
+		if (!(dy < -ep || dy > ep)) \
+			if (dx*dx + dy*dy < eep) /* close enough to be the same vertex */ \
+				return (p); \
+	}
+
 	// Search level map vertexes.
 	pv = poly_vert;
-	for (i = numvertexes; i > 0; i--)
+	for (i = numvertexes; i >= 8; i -= 8)
 	{
-		const float dx = pv->x - x;
-		const float dy = pv->y - y;
-		if (dx*dx + dy*dy < ep*ep)
-			return pv;  // close enough to be the same vertex
+		CHECKVERTEX(pv);
+		CHECKVERTEX(pv + 1);
+		CHECKVERTEX(pv + 2);
+		CHECKVERTEX(pv + 3);
+		CHECKVERTEX(pv + 4);
+		CHECKVERTEX(pv + 5);
+		CHECKVERTEX(pv + 6);
+		CHECKVERTEX(pv + 7);
+
+		pv += 8;
+	}
+
+	for (; i > 0; i--)
+	{
+		CHECKVERTEX(pv);
 		pv++;
 	}
 
@@ -147,20 +177,33 @@ static polyvertex_t *find_close_polyvertex(float x, float y, float ep)
 	psv = polyvert_store;
 	while (psv)
 	{
-		// Search all vertex in a polyvertex_store_t
 		pv = psv->pv;
-		for (i = psv->num_vert_used; i > 0; i--)
+		for (i = psv->num_vert_used; i >= 8; i -= 8)
 		{
-			const float dx = pv->x - x;
-			const float dy = pv->y - y;
-			if (dx*dx + dy*dy < ep*ep)
-				return pv;  // close enough to be the same vertex
+			CHECKVERTEX(pv);
+			CHECKVERTEX(pv + 1);
+			CHECKVERTEX(pv + 2);
+			CHECKVERTEX(pv + 3);
+			CHECKVERTEX(pv + 4);
+			CHECKVERTEX(pv + 5);
+			CHECKVERTEX(pv + 6);
+			CHECKVERTEX(pv + 7);
+
+			pv += 8;
+		}
+
+		for (; i > 0; i--)
+		{
+			CHECKVERTEX(pv);
 			pv++;
 		}
+
 		psv = psv->next;
 	}
+#undef CHECKVERTEX
 
-	return NULL;  // none found
+	// none found
+	return NULL;
 }
 
 // Store a new polyvertex.