From e0eacf401451860d86a32c3c54190f65d5adb1e1 Mon Sep 17 00:00:00 2001
From: Bill Currie <bill@taniwha.org>
Date: Sat, 20 Mar 2021 16:06:15 +0900
Subject: [PATCH] [model] Make set and mix versions of Mod_LeafPVS

The re-entrant version was a good start, but being able to mix while
decompressing saves having to have a temporary buffer somewhere.
---
 include/QF/model.h              |  6 ++--
 libs/models/brush/model_brush.c | 57 +++++++++++++++++++++++++++++----
 2 files changed, 55 insertions(+), 8 deletions(-)

diff --git a/include/QF/model.h b/include/QF/model.h
index 0a7069d3f..1c5969820 100644
--- a/include/QF/model.h
+++ b/include/QF/model.h
@@ -435,8 +435,10 @@ mleaf_t *Mod_PointInLeaf (const vec3_t p, model_t *model) __attribute__((pure));
 byte *Mod_LeafPVS (const mleaf_t *leaf, const model_t *model);
 
 // NOTE: the buffer pointed to by out must be at least MAP_PVS_BYTES in size
-void Mod_LeafPVS_r (const mleaf_t *leaf, const model_t *model, byte defvis,
-					byte *out);
+void Mod_LeafPVS_set (const mleaf_t *leaf, const model_t *model, byte defvis,
+					  byte *out);
+void Mod_LeafPVS_mix (const mleaf_t *leaf, const model_t *model, byte defvis,
+					  byte *out);
 
 void Mod_Print (void);
 
diff --git a/libs/models/brush/model_brush.c b/libs/models/brush/model_brush.c
index 6270de72b..1e2fa81a4 100644
--- a/libs/models/brush/model_brush.c
+++ b/libs/models/brush/model_brush.c
@@ -86,8 +86,8 @@ Mod_PointInLeaf (const vec3_t p, model_t *model)
 }
 
 static inline void
-Mod_DecompressVis (const byte *in, const mod_brush_t *brush, byte defvis,
-				   byte *out)
+Mod_DecompressVis_set (const byte *in, const mod_brush_t *brush, byte defvis,
+					   byte *out)
 {
 	byte       *start = out;
 	int			row, c;
@@ -117,6 +117,35 @@ Mod_DecompressVis (const byte *in, const mod_brush_t *brush, byte defvis,
 	} while (out - start < row);
 }
 
+static inline void
+Mod_DecompressVis_mix (const byte *in, const mod_brush_t *brush, byte defvis,
+					   byte *out)
+{
+	byte       *start = out;
+	int			row, c;
+
+	row = (brush->numleafs + 7) >> 3;
+
+	if (!in) {							// no vis info, so make all visible
+		while (row) {
+			*out++ |= defvis;
+			row--;
+		}
+		return;
+	}
+
+	do {
+		if (*in) {
+			*out++ |= *in++;
+			continue;
+		}
+
+		c = in[1];
+		in += 2;
+		out += c;
+	} while (out - start < row);
+}
+
 VISIBLE byte *
 Mod_LeafPVS (const mleaf_t *leaf, const model_t *model)
 {
@@ -127,19 +156,35 @@ Mod_LeafPVS (const mleaf_t *leaf, const model_t *model)
 		}
 		return mod_novis;
 	}
-	Mod_DecompressVis (leaf->compressed_vis, &model->brush, 0xff, decompressed);
+	Mod_DecompressVis_set (leaf->compressed_vis, &model->brush, 0xff,
+						   decompressed);
 	return decompressed;
 }
 
 VISIBLE void
-Mod_LeafPVS_r (const mleaf_t *leaf, const model_t *model, byte defvis,
-			   byte *out)
+Mod_LeafPVS_set (const mleaf_t *leaf, const model_t *model, byte defvis,
+				 byte *out)
 {
 	if (leaf == model->brush.leafs) {
 		memset (out, defvis, sizeof (mod_novis));
 		return;
 	}
-	return Mod_DecompressVis (leaf->compressed_vis, &model->brush, defvis, out);
+	return Mod_DecompressVis_set (leaf->compressed_vis, &model->brush, defvis,
+								  out);
+}
+
+VISIBLE void
+Mod_LeafPVS_mix (const mleaf_t *leaf, const model_t *model, byte defvis,
+				 byte *out)
+{
+	if (leaf == model->brush.leafs) {
+		for (int i = MAP_PVS_BYTES; i-- > 0; ) {
+			*out++ |= defvis;
+		}
+		return;
+	}
+	return Mod_DecompressVis_mix (leaf->compressed_vis, &model->brush, defvis,
+								  out);
 }
 
 // BRUSHMODEL LOADING =========================================================