Added computation of face area by projecting its vertices onto its plane and then generating a bounding box. Will be used for determining tessellation subdivisions.

bsp.h

@@ -49,7 +49,7 @@ typedef struct BoundBox                 // Bounding Box, Float values
     vec3_t   min;                // minimum values of X,Y,Z
     vec3_t   max;                // maximum values of X,Y,Z
 
-    BoundBox() { }
+    BoundBox(): min(FLT_MAX, FLT_MAX, FLT_MAX), max(FLT_MIN, FLT_MIN, FLT_MIN) { }
 
     void init(vec3_t point)
     {
@@ -75,10 +75,19 @@ typedef struct BoundBox                 // Bounding Box, Float values
     }
 } boundbox_t;
 
-typedef struct                 // Bounding Box, Short values
+typedef struct BBoxShort            // Bounding Box, Short values
 {
     short   min[3];                 // minimum values of X,Y,Z
     short   max[3];                 // maximum values of X,Y,Z
+
+    vec3_t getCenter() const
+    {
+        return vec3_t(
+            ((float)max[0] + (float)min[0]) / 2,
+            ((float)max[1] + (float)min[1]) / 2,
+            ((float)max[2] + (float)min[2]) / 2
+        );
+    }
 } bboxshort_t;
 
 typedef struct                 // Mip texture list header

common.h

@@ -3,6 +3,7 @@
 #include <cstdlib>
 #include <cstdio>
 #include <cmath>
+#include <cfloat>
 #include <vector>
 #include <unordered_map>
 #include <unordered_set>
@@ -23,6 +24,16 @@ typedef struct Vec3                 // Vector or Position
         return Vec3(x + other.x, y + other.y, z + other.z);
     }
 
+    Vec3 operator-(const Vec3& other) const
+    {
+        return Vec3(x - other.x, y - other.y, z - other.z);
+    }
+
+    Vec3 operator*(float mul) const
+    {
+        return Vec3(x * mul, y * mul, z * mul);
+    }
+
     Vec3 operator/(float div) const
     {
         return Vec3(x / div, y / div, z / div);
@@ -32,9 +43,25 @@ typedef struct Vec3                 // Vector or Position
     {
         return Vec3(-x, -y, -z);
     }
-} vec3_t;
 
-inline float dotProduct(vec3_t a, vec3_t b)
+    float magnitude() const
     {
-	return a.x * b.x + a.y * b.y + a.z * b.z;
+        return sqrtf(x * x + y * y + z * z);
     }
+
+    Vec3 normalized() const
+    {
+        float invMag = 1.0f / magnitude();
+        return Vec3(x * invMag, y * invMag, z * invMag);
+    }
+
+    float dotProduct(const Vec3 &other) const
+    {
+        return x * other.x + y * other.y + z * other.z;
+    }
+
+    Vec3 crossProduct(const Vec3 &other) const
+    {
+        return Vec3(y * other.z - z * other.y, z * other.x - x * other.z, x * other.y - y * other.x);
+    }
+} vec3_t;

lighting.cpp

@@ -147,7 +147,7 @@ std::unordered_map<const edge_t*, EdgeData> analyze_edges(const world_t* world)
 			const plane_t* planeB = &world->planes[faceB->plane_id];
 			vec3_t normalA = faceA->side ? -planeA->normal : planeA->normal;
 			vec3_t normalB = faceB->side ? -planeB->normal : planeB->normal;
-			float dot = dotProduct(normalA, normalB);
+			float dot = normalA.dotProduct(normalB);
 			bool isSmooth = dot >= 0.5f;//&& dot <= 1;
 			iter->second.isSharpEdge = !isSmooth;
 			break;
@@ -239,7 +239,7 @@ unsigned char compute_faceVertex_light2(const world_t* world, const face_t* face
 		const plane_t* otherPlane = &world->planes[otherFace->plane_id];
 		vec3_t otherNormal = otherFace->side ? -otherPlane->normal : otherPlane->normal;
 
-		float dot = dotProduct(thisNormal, otherNormal);
+		float dot = thisNormal.dotProduct(otherNormal);
 		if (dot < 0.5f)
 			continue;	// Sharp edge, we don't want light contribution from this face
 
@@ -249,3 +249,8 @@ unsigned char compute_faceVertex_light2(const world_t* world, const face_t* face
 
 	return (unsigned char)(light / numSamples);
 }
+
+// Further improvements:
+// - Reconstruct connected surfaces through vertices and edges, so we can fully sample all adjacent lightmaps.
+//   Right now we don't properly detect when one face has vertices halfway along the edge of an adjacent face.
+// - Sample more lightmap points around each vertex to obtain a more representative average value

main.cpp

@@ -179,7 +179,7 @@ static SVECTOR convertNormal(vec3_t normal)
 	return outNormal;
 }
 
-static SVECTOR convertPoint(vec3_t point)
+static SVECTOR convertWorldPosition(vec3_t point)
 {
 	SVECTOR outPoint;
 	outPoint.vx = (short)(point.x * 4);
@@ -189,6 +189,42 @@ static SVECTOR convertPoint(vec3_t point)
 	return outPoint;
 }
 
+static float computeFaceArea(const world_t* world, const face_t* face)
+{
+	const plane_t* plane = &world->planes[face->plane_id];
+
+	// Construct a tangent and bitangent for the plane using the face's first vertex
+	int edgeIdx = world->edgeList[face->ledge_id];
+	unsigned short vertIndex = edgeIdx > 0 ?
+		world->edges[edgeIdx].vertex0 :
+		world->edges[-edgeIdx].vertex1;
+
+	const vertex_t* vertex = &world->vertices[vertIndex];
+	Vec3 refPoint = plane->normal * plane->dist;
+	Vec3 tangent = (vertex->toVec() - refPoint).normalized();
+	Vec3 bitangent = plane->normal.crossProduct(tangent);
+
+	// Project all face vertices onto the face's plane
+	BoundBox bounds;
+	for (int edgeListIdx = 0; edgeListIdx < face->ledge_num; ++edgeListIdx)
+	{
+		edgeIdx = world->edgeList[face->ledge_id + edgeListIdx];
+		vertIndex = edgeIdx > 0 ?
+			world->edges[edgeIdx].vertex0 :
+			world->edges[-edgeIdx].vertex1;
+
+		vertex_t* vertex = &world->vertices[vertIndex];
+		Vec3 vec = vertex->toVec();
+
+		float x = tangent.dotProduct(vec);
+		float y = bitangent.dotProduct(vec);
+		bounds.includePoint(Vec3(x, y, 0));
+	}
+
+	Vec3 extents = bounds.max - bounds.min;
+	return extents.x * extents.y;
+}
+
 int process_faces(const world_t* world)
 {
 	// Write some data to a file
@@ -241,9 +277,8 @@ int process_faces(const world_t* world)
 		outFace.side = face->side;
 		outFace.firstFaceVertex = (unsigned short)outFaceVertices.size();
 
-		Vec3 vertexSum;
-
 		// Traverse the list of face edges to collect all of the face's vertices
+		Vec3 vertexSum;
 		BoundBox bounds;
 		for (int edgeListIdx = 0; edgeListIdx < face->ledge_num; ++edgeListIdx)
 		{
@@ -283,7 +318,9 @@ int process_faces(const world_t* world)
 		//	export_lightmap(world, face, bounds, faceIdx);
 
 		outFace.numFaceVertices = (unsigned short)(outFaceVertices.size() - outFace.firstFaceVertex);
-		outFace.centerPoint = convertPoint(vertexSum / outFace.numFaceVertices);
+		outFace.centerPoint = convertWorldPosition(vertexSum / outFace.numFaceVertices);
+		float area = computeFaceArea(world, face);
+		outFace.centerPoint.pad = (short)(sqrt(area));
 		outFaces.push_back(outFace);
 	}
 
@@ -363,6 +400,8 @@ int process_faces(const world_t* world)
 		outLeaf.firstLeafFace = leaf->lface_id;
 		outLeaf.numLeafFaces = leaf->lface_num;
 
+		//outLeaf.center = convertWorldPosition(leaf->bound.getCenter());
+
 		outLeaves.push_back(outLeaf);
 	}
 

ps1bsp.h

@@ -105,7 +105,8 @@ typedef struct
 	int type;
 	int vislist;
 
-	// TODO: add bounding box for frustum culing
+	// TODO: add bounding box for frustum culling (or do we? could save half the number of bounds checks if we only check nodes)
+	//SVECTOR center;
 
 	u_short firstLeafFace;
 	u_short numLeafFaces;