Create coord-circle.cc containing circle_def.

circle_def unifies the shapes that a radius_iterator can iterate
over. It's meant to replace bounds_func in losparam.h and eventually
provide a base for radius_iterator.

3 files changed, 183 insertions, 0 deletions

diff --git a/crawl-ref/source/coord-circle.cc b/crawl-ref/source/coord-circle.cc
new file mode 100644
index 0000000000..4170662b10
--- /dev/null
+++ b/crawl-ref/source/coord-circle.cc
@@ -0,0 +1,106 @@
+#include "AppHdr.h"
+
+#include "coord-circle.h"
+
+#include "coordit.h"
+
+#include <cmath>
+
+rectangle_iterator rect_def::iter() const
+{
+    return (rectangle_iterator(min, max));
+}
+
+circle_def::circle_def()
+    : los_radius(true), origin(coord_def(0,0))
+{
+    // Set up bounding box and shape.
+    init(LOS_MAX_RADIUS, C_ROUND);
+}
+
+circle_def::circle_def(int param, circle_type ctype)
+    : los_radius(false), origin(coord_def(0,0))
+{
+    init(param, ctype);
+}
+
+circle_def::circle_def(const coord_def &origin_, int param,
+                       circle_type ctype)
+    : los_radius(false), origin(origin_)
+{
+    init(param, ctype);
+}
+
+void circle_def::init(int param, circle_type ctype)
+{
+    switch (ctype)
+    {
+    case C_SQUARE:
+        shape = SH_SQUARE;
+        radius = param;
+        break;
+    case C_CIRCLE:
+        shape = SH_CIRCLE;
+        radius = static_cast<int>(ceil(sqrt(radius_sq)));
+        radius_sq = param;
+        break;
+    case C_ROUND:
+        shape = SH_CIRCLE;
+        radius = param;
+        radius_sq = radius * radius + 1;
+        break;
+    case C_POINTY:
+        shape = SH_CIRCLE;
+        radius = param;
+        radius_sq = radius * radius;
+    }
+    bbox = rect_def(origin - coord_def(radius, radius),
+                    origin + coord_def(radius, radius));
+}
+
+const rect_def& circle_def::get_bbox() const
+{
+    return (bbox);
+}
+
+bool circle_def::contains(const coord_def &p) const
+{
+    switch (shape)
+    {
+    case SH_SQUARE:
+        return ((p - origin).rdist() <= radius);
+    case SH_CIRCLE:
+        return ((p - origin).abs() <= radius_sq);
+    default:
+        return (false);
+    }
+}
+
+circle_iterator::circle_iterator(const circle_def &circle_)
+    : circle(circle_), iter(circle_.get_bbox().iter())
+{
+    while (iter && !circle.contains(*iter))
+        ++iter;
+}
+
+circle_iterator::operator bool() const
+{
+    return ((bool)iter);
+}
+
+coord_def circle_iterator::operator*() const
+{
+    return (*iter);
+}
+
+void circle_iterator::operator++()
+{
+    do
+        ++iter;
+    while (iter && !circle.contains(*iter));
+}
+
+void circle_iterator::operator++(int)
+{
+    ++(*this);
+}
diff --git a/crawl-ref/source/coord-circle.h b/crawl-ref/source/coord-circle.h
new file mode 100644
index 0000000000..172e2600b6
--- /dev/null
+++ b/crawl-ref/source/coord-circle.h
@@ -0,0 +1,76 @@
+#ifndef COORD_CIRCLE_H
+#define COORD_CIRCLE_H
+
+#include "coordit.h"
+
+enum shape_type
+{
+    SH_SQUARE,     // square around an origin
+    SH_CIRCLE      // circle around an origin
+};
+
+enum circle_type
+{
+    C_SQUARE,
+    C_CIRCLE,
+    C_POINTY,
+    C_ROUND
+};
+
+class rect_def
+{
+    coord_def min;
+    coord_def max;
+
+public:
+    rect_def() {}
+    rect_def(const coord_def &min_, const coord_def &max_)
+        : min(min_), max(max_) {}
+
+    rectangle_iterator iter() const;
+};
+
+class circle_iterator;
+class circle_def
+{
+    bool los_radius;
+    shape_type shape;
+
+    coord_def origin;
+    int radius;
+    int radius_sq;
+    rect_def bbox;
+
+public:
+    // Circle around (0,0) with radius that tracks global LOS radius.
+    circle_def();
+    // Circle around (0,0) of specified shape and size.
+    explicit circle_def(int param, circle_type ctype = C_SQUARE);
+    // Circle around given origin of specified shape and size.
+    circle_def(const coord_def &origin_, int param, circle_type ctype = C_SQUARE);
+
+    bool contains(const coord_def &p) const;
+    const rect_def& get_bbox() const;
+
+    circle_iterator iter() const;
+
+private:
+    void init(int param, circle_type ctype);
+};
+
+class circle_iterator
+{
+    const circle_def &circle;
+    rectangle_iterator iter;
+
+public:
+    circle_iterator(const circle_def &circle_);
+
+    operator bool() const;
+    coord_def operator*() const;
+
+    void operator++();
+    void operator++(int);
+};
+
+#endif
diff --git a/crawl-ref/source/makefile.obj b/crawl-ref/source/makefile.obj
index 588ab56676..90bc0375b9 100644
--- a/crawl-ref/source/makefile.obj
+++ b/crawl-ref/source/makefile.obj
@@ -19,6 +19,7 @@ colour.o \
 command.o \
 coord.o \
 coordit.o \
+coord-circle.o \
 ctest.o \
 database.o \
 dbg-asrt.o \