Sped up plane calculations by making use of axis-aligned properties

ps1bsp.h

@@ -85,7 +85,8 @@ typedef struct
 typedef struct
 {
 	SVECTOR normal;
-	int dist;
+	short dist;
+	short type;
 } ps1bsp_plane_t;
 
 typedef struct

world.c

@@ -205,10 +205,22 @@ static INLINE void drawface_quad_strip(const ps1bsp_face_t *face, SVECTOR *vecs)
 
 static INLINE short world_pointPlaneDist(const VECTOR *point, const ps1bsp_plane_t *plane)
 {
-    // TODO: can be optimized for axis-aligned planes, no need for a dot product there
+    // Make use of axis-aligned planes to skip the need for a dot product
+    if (plane->type < 3)
+        return (short)(((int*)point)[plane->type] - plane->dist);
+    
     return m_pointPlaneDist2(*point, plane->normal, plane->dist);
 }
 
+static INLINE short world_planeDot(const SVECTOR *dir, const ps1bsp_plane_t *plane)
+{
+    // Make use of axis-aligned planes to skip the need for a dot product
+    if (plane->type < 3)
+        return ((short*)dir)[plane->type];
+
+    return m_dot12s(*dir, plane->normal);
+}
+
 static void world_drawface(const world_t *world, const ps1bsp_face_t *face)
 {
     // Backface culling using the face's plane and center point
@@ -219,7 +231,7 @@ static void world_drawface(const world_t *world, const ps1bsp_face_t *face)
     cam_vec.vz = center.vz - cam_pos.vz;
     
     const ps1bsp_plane_t *plane = &world->planes[face->planeId];
-    short dot = m_dot12s(cam_vec, plane->normal);
+    short dot = world_planeDot(&cam_vec, plane);
     if ((dot >= 0) ^ face->side)
         return;