Tweaked light sampling a bit more, should be more accurate to Quake's original implementation now (though it hardly makes any difference in practice)

lighting.cpp

@@ -9,14 +9,14 @@ bool sample_lightmap(const world_t* world, const face_t* face, const FaceBound&
 	Vec3 minBounds = (bounds.lightmapBounds.min / 16).floor();
 	Vec3 maxBounds = (bounds.lightmapBounds.max / 16).ceil();
 
-	int width = (int)((maxBounds.x - minBounds.x) * 16.f);	// extents[0]
-	int height = (int)((maxBounds.y - minBounds.y) * 16.f);	// extents[1]
-
-	minBounds = minBounds * 16.f;	// texturemins.xy
+	int width = ((int)maxBounds.x - (int)minBounds.x) * 16;		// extents[0]
+	int height = ((int)maxBounds.y - (int)minBounds.y) * 16;	// extents[1]
+	int minX = (int)minBounds.x * 16;	// texturemins[0]
+	int minY = (int)minBounds.y * 16;	// texturemins[1]
 
 	Vec3 uv = bounds.lightmapTransform.TransformPoint(point);
-	int u = (int)(uv.x - minBounds.x);
-	int v = (int)(uv.y - minBounds.y);
+	int u = (int)uv.x - minX;
+	int v = (int)uv.y - minY;
 
 	if (u < 0 || v < 0 || u > width || v > height)
 		return false;
@@ -312,6 +312,11 @@ SurfaceList group_surfaces(const world_t* world, const VertexFaces& vertexFaces)
 	return surfaces;
 }
 
+unsigned char compute_faceVertex_light3(const world_t* world, const face_t* refFace, const FaceBounds& faceBounds, Vec3 point)
+{
+	return sample_lightmap(world, refFace, faceBounds.find(refFace)->second, point);
+}
+
 unsigned char compute_faceVertex_light4(const world_t* world, const face_t* refFace, const FaceBounds& faceBounds, Vec3 point)
 {
 	if (refFace->lightmap < 0)

lighting.h

@@ -48,5 +48,6 @@ unsigned char compute_faceVertex_light(const world_t* world, const face_t* face,
 unsigned char compute_faceVertex_light2(const world_t* world, const face_t* face, unsigned short vertexIndex, const FaceBounds& faceBounds, const VertexFaces& vertexFaces);
 
 SurfaceList group_surfaces(const world_t* world, const VertexFaces& vertexFaces);
+unsigned char compute_faceVertex_light3(const world_t* world, const face_t* refFace, const FaceBounds& faceBounds, Vec3 point);
 unsigned char compute_faceVertex_light4(const world_t* world, const face_t* refFace, const FaceBounds& faceBounds, Vec3 point);
 unsigned char compute_faceVertex_light5(const world_t* world, const face_t* refFace, const FaceBounds& faceBounds, Vec3 point);