Clean up LOS precalculation settings.

The maximal boundary within which losight/find_ray will work is
now clearly defined at the start of los.cc. By default, it's
the circle with radius LOS_MAX_RADIUS == LOS_RADIUS.

5 files changed, 23 insertions, 15 deletions

diff --git a/crawl-ref/source/defines.h b/crawl-ref/source/defines.h
index 2ef5a2fee9..a5ca761886 100644
--- a/crawl-ref/source/defines.h
+++ b/crawl-ref/source/defines.h
@@ -107,7 +107,12 @@ const int LABYRINTH_BORDER = 4;
 #define Y_ABYSS_CENTER          (Y_ABYSS_1 + Y_ABYSS_WIDTH / 2)
 
 #define LOS_RADIUS 8
-#define ENV_SHOW_OFFSET (LOS_RADIUS + 1)
+#define LOS_RADIUS_SQ (LOS_RADIUS * LOS_RADIUS + 1)
+#define LOS_MAX_RADIUS LOS_RADIUS
+#define LOS_MAX_RADIUS_SQ (LOS_MAX_RADIUS * LOS_MAX_RADIUS + 1)
+#define LOS_MAX_RADIUS LOS_RADIUS
+#define LOS_MAX_RANGE LOS_MAX_RADIUS
+#define ENV_SHOW_OFFSET (LOS_MAX_RANGE + 1)
 #define ENV_SHOW_DIAMETER (ENV_SHOW_OFFSET * 2 + 1)
 
 #define VIEW_BASE_WIDTH 33      // FIXME: never used
diff --git a/crawl-ref/source/los.cc b/crawl-ref/source/los.cc
index ad0798f697..7c00a0b3e4 100644
--- a/crawl-ref/source/los.cc
+++ b/crawl-ref/source/los.cc
@@ -58,8 +58,13 @@ REVISION("$Rev$");
 #include "stuff.h"
 #include "terrain.h"
 
-#define LONGSIZE (sizeof(unsigned long)*8)
-#define LOS_MAX_RANGE 9
+// This determines which cells are considered out of range during
+// precalculations (only positive quadrant used).
+// For the LOS code to work correctly, any bounds function that
+// is used needs to satisfy
+//     bds_func(p) == true  ==>  bds_precalc(p) == true
+// This used to be the entire LOS_MAX_RANGE rectangle.
+const bounds_func& bds_precalc = bds_maxlos;
 
 // These determine what rays are cast in the precomputation,
 // and affect start-up time significantly.
@@ -125,9 +130,7 @@ void clear_rays_on_exit()
 }
 
 // Pre-squared LOS radius.
-#define LOS_RADIUS2 (LOS_RADIUS * LOS_RADIUS + 1)
-
-int _los_radius_squared = LOS_RADIUS2;
+int _los_radius_squared = LOS_RADIUS_SQ;
 
 void setLOSRadius(int newLR)
 {
@@ -158,9 +161,9 @@ struct los_ray : public ray_def
     }
 
     // Shoot a ray from the given start point (accx, accy) with the given
-    // slope, bounded by the given pre-squared LOS radius.
+    // slope, bounded by the pre-calc bounds function.
     // Returns the cells it travels through, excluding the origin.
-    std::vector<coord_def> footprint(int radius2)
+    std::vector<coord_def> footprint()
     {
         std::vector<coord_def> cs;
         los_ray copy = *this;
@@ -170,7 +173,7 @@ struct los_ray : public ray_def
         {
             copy.raw_advance_pos();
             c = copy.pos();
-            if (c.abs() > radius2)
+            if (!bds_precalc(c))
                 break;
             cs.push_back(c);
         }
@@ -374,7 +377,7 @@ static std::vector<int> _find_minimal_cellrays()
 static void _register_ray(double accx, double accy, double slope)
 {
     los_ray ray = los_ray(accx, accy, slope);
-    std::vector<coord_def> coords = ray.footprint(LOS_RADIUS2);
+    std::vector<coord_def> coords = ray.footprint();
 
     if (_is_duplicate_ray(coords))
         return;
diff --git a/crawl-ref/source/los.h b/crawl-ref/source/los.h
index 7fcc406878..3b84c3bb76 100644
--- a/crawl-ref/source/los.h
+++ b/crawl-ref/source/los.h
@@ -13,7 +13,6 @@
 
 bool double_is_zero(const double x);
 
-
 void setLOSRadius(int newLR);
 int get_los_radius_squared(); // XXX
 
diff --git a/crawl-ref/source/losparam.cc b/crawl-ref/source/losparam.cc
index 52a2856c80..b281aa7df9 100644
--- a/crawl-ref/source/losparam.cc
+++ b/crawl-ref/source/losparam.cc
@@ -63,7 +63,7 @@ bool bounds_radius_sq::operator()(const coord_def& p) const
 }
 
 // LOS bounded by current global LOS radius.
-bool bounds_los_radius::operator()(const coord_def& p) const
+bool bounds_cur_los_radius::operator()(const coord_def& p) const
 {
     return (p.abs() <= get_los_radius_squared());
 }
diff --git a/crawl-ref/source/losparam.h b/crawl-ref/source/losparam.h
index 82dee24519..8818f3a7d8 100644
--- a/crawl-ref/source/losparam.h
+++ b/crawl-ref/source/losparam.h
@@ -60,14 +60,15 @@ struct bounds_radius_sq : bounds_func
         : radius_sq(r_sq) {}
     bool operator()(const coord_def& p) const;
 };
-static bounds_radius_sq bds_maxlos(LOS_RADIUS);
+static bounds_radius_sq bds_deflos = bounds_radius_sq(LOS_RADIUS_SQ);
+static bounds_radius_sq bds_maxlos = bounds_radius_sq(LOS_MAX_RADIUS_SQ);
 
 // LOS bounded by current global LOS radius.
-struct bounds_los_radius : bounds_func
+struct bounds_cur_los_radius : bounds_func
 {
     bool operator()(const coord_def& p) const;
 };
-static bounds_los_radius bds_default;
+static bounds_cur_los_radius bds_default;
 
 // Subclasses of this are passed to losight() to modify the
 // LOS calculation. Implementations will have to translate between