From 93551117b1b74e738de899b8cb9111a645b0e9d2 Mon Sep 17 00:00:00 2001
From: Nico de Poel <ndepoel@gmail.com>
Date: Sat, 28 Jan 2023 00:14:16 +0100
Subject: [PATCH] Added surface flags, allowing for rendering of water surfaces

---
 bsp.h    |  7 +++++++
 main.cpp | 17 +++++++++++++++--
 ps1bsp.h | 18 ++++++++++++++++--
 3 files changed, 38 insertions(+), 4 deletions(-)

diff --git a/bsp.h b/bsp.h
index fe8089d..138191b 100644
--- a/bsp.h
+++ b/bsp.h
@@ -1,5 +1,12 @@
 #pragma once
 
+#define CONTENTS_EMPTY      -1
+#define CONTENTS_SOLID      -2
+#define CONTENTS_WATER      -3
+#define CONTENTS_SLIME      -4
+#define CONTENTS_LAVA       -5
+#define CONTENTS_SKY        -6
+
 typedef struct                 // A Directory entry
 {
 	long  offset;                // Offset to entry, in bytes, from start of file
diff --git a/main.cpp b/main.cpp
index 1fd45dc..3e57c3a 100644
--- a/main.cpp
+++ b/main.cpp
@@ -149,10 +149,23 @@ int process_faces(const world_t* world, const std::vector<ps1bsp_texture_t>& tex
 		const miptex_t* miptex = &world->miptexes[texinfo->texture_id];
 		const ps1bsp_texture_t& ps1tex = textures[texinfo->texture_id];
 
-		auto polygons = tesselator.tesselateFace(face);
-
 		outFace->firstPolygon = (unsigned short)outPolygons.size();
 
+		// Skip sky surfaces for now
+		if (!strncmp(miptex->name, "sky", 3))
+		{
+			outFace->flags |= SURF_DRAWSKY;
+			outFace->numPolygons = 0;
+			continue;
+		}
+
+		// Draw water as fullbright transparent surfaces
+		if (miptex->name[0] == '*')
+		{
+			outFace->flags |= SURF_DRAWTURB | SURF_DRAWWATER;
+		}
+
+		auto polygons = tesselator.tesselateFace(face);
 		for (auto polyIter = polygons.begin(); polyIter != polygons.end(); ++polyIter)
 		{
 			ps1bsp_polygon_t outPoly = { 0 };
diff --git a/ps1bsp.h b/ps1bsp.h
index 0d1d57e..8c16883 100644
--- a/ps1bsp.h
+++ b/ps1bsp.h
@@ -57,6 +57,7 @@ typedef struct
 } ps1bsp_vertex_t;
 
 // Texture UV and lighting data for a vertex on a particular polygon.
+// TODO: break up into poly vertex (index + uv) and surface vertex (index + light) shared between polygons.
 typedef struct
 {
 	unsigned short index;
@@ -83,6 +84,20 @@ typedef struct
 	unsigned char b : 5;
 } ps1bsp_facevertex_t;
 
+#define SURF_PLANEBACK		0x2
+#define SURF_DRAWSKY		0x4
+#define SURF_DRAWSPRITE		0x8
+#define SURF_DRAWTURB		0x10
+#define SURF_DRAWTILED		0x20
+#define SURF_DRAWBACKGROUND	0x40
+#define SURF_UNDERWATER		0x80
+#define SURF_NOTEXTURE		0x100
+#define SURF_DRAWFENCE		0x200
+#define SURF_DRAWLAVA		0x400
+#define SURF_DRAWSLIME		0x800
+#define SURF_DRAWTELE		0x1000
+#define SURF_DRAWWATER		0x2000
+
 // High quality: Face -> polygons -> polygon vertex indices (index + UV + light) -> vertices
 // Low quality: Face -> face vertex indices (index + color) -> vertices
 typedef struct
@@ -99,14 +114,13 @@ typedef struct
 	unsigned char numFaceVertices;
 
 	unsigned char textureId;
+	unsigned short flags;
 
 	// Used for backface culling
 	SVECTOR center;
 
 	// Which frame was this face last drawn on? Used to check if this face should be drawn.
 	u_long drawFrame;
-
-	u_short pad;	// For 32-bit alignment
 } ps1bsp_face_t;
 
 typedef struct