Modularize the libdimension codebase.

1 files changed, 129 insertions, 0 deletions

diff --git a/libdimension/dimension/math/aabb.h b/libdimension/dimension/math/aabb.h
new file mode 100644
index 0000000..14cc575
--- /dev/null
+++ b/libdimension/dimension/math/aabb.h
@@ -0,0 +1,129 @@
+/*************************************************************************
+ * Copyright (C) 2009-2014 Tavian Barnes <tavianator@tavianator.com>     *
+ *                                                                       *
+ * This file is part of The Dimension Library.                           *
+ *                                                                       *
+ * The Dimension Library is free software; you can redistribute it and/  *
+ * or modify it under the terms of the GNU Lesser General Public License *
+ * as published by the Free Software Foundation; either version 3 of the *
+ * License, or (at your option) any later version.                       *
+ *                                                                       *
+ * The Dimension Library is distributed in the hope that it will be      *
+ * useful, but WITHOUT ANY WARRANTY; without even the implied warranty   *
+ * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU  *
+ * Lesser General Public License for more details.                       *
+ *                                                                       *
+ * You should have received a copy of the GNU Lesser General Public      *
+ * License along with this program.  If not, see                         *
+ * <http://www.gnu.org/licenses/>.                                       *
+ *************************************************************************/
+
+/**
+ * @file
+ * Axis-aligned bounding boxes.
+ */
+
+#ifndef DMNSN_MATH_H
+#error "Please include <dimension/math.h> instead of this header directly."
+#endif
+
+/** An axis-aligned bounding box. */
+typedef struct dmnsn_aabb {
+  dmnsn_vector min; /**< The coordinate-wise minimum extent of the box. */
+  dmnsn_vector max; /**< The coordinate-wise maximum extent of the box. */
+} dmnsn_aabb;
+
+/** A standard format string for bounding boxes. */
+#define DMNSN_AABB_FORMAT "(<%g, %g, %g> ==> <%g, %g, %g>)"
+/** The appropriate arguements to printf() a bounding box. */
+#define DMNSN_AABB_PRINTF(box)                                          \
+  DMNSN_VECTOR_PRINTF((box).min), DMNSN_VECTOR_PRINTF((box).max)
+
+/**
+ * Construct a new bounding box.
+ * @param[in] min  The minimal extent of the bounding box.
+ * @param[in] max  The maximal extent of the bounding box.
+ * @return The new bounding box.
+ */
+DMNSN_INLINE dmnsn_aabb
+dmnsn_new_aabb(dmnsn_vector min, dmnsn_vector max)
+{
+  dmnsn_aabb box = { min, max };
+  return box;
+}
+
+/** Return the bounding box which contains nothing. */
+DMNSN_INLINE dmnsn_aabb
+dmnsn_zero_aabb(void)
+{
+  dmnsn_aabb box = {
+    {  DMNSN_INFINITY,  DMNSN_INFINITY,  DMNSN_INFINITY },
+    { -DMNSN_INFINITY, -DMNSN_INFINITY, -DMNSN_INFINITY }
+  };
+  return box;
+}
+
+/** Return the bounding box which contains everything. */
+DMNSN_INLINE dmnsn_aabb
+dmnsn_infinite_aabb(void)
+{
+  dmnsn_aabb box = {
+    { -DMNSN_INFINITY, -DMNSN_INFINITY, -DMNSN_INFINITY },
+    {  DMNSN_INFINITY,  DMNSN_INFINITY,  DMNSN_INFINITY }
+  };
+  return box;
+}
+
+/**
+ * Construct a new symmetric bounding box.
+ * @param[in] r  The extent of the bounding box from the origin.
+ * @return The new bounding box.
+ */
+DMNSN_INLINE dmnsn_aabb
+dmnsn_symmetric_aabb(dmnsn_vector r)
+{
+  dmnsn_vector minus_r = dmnsn_vector_negate(r);
+  dmnsn_aabb box = {
+    dmnsn_vector_min(r, minus_r),
+    dmnsn_vector_max(r, minus_r)
+  };
+  return box;
+}
+
+/** Return whether \p p is within the axis-aligned bounding box. */
+DMNSN_INLINE bool
+dmnsn_aabb_contains(dmnsn_aabb box, dmnsn_vector p)
+{
+  return (p.x >= box.min.x && p.y >= box.min.y && p.z >= box.min.z)
+      && (p.x <= box.max.x && p.y <= box.max.y && p.z <= box.max.z);
+}
+
+/** Return whether a bounding box is infinite. */
+DMNSN_INLINE bool
+dmnsn_aabb_is_infinite(dmnsn_aabb box)
+{
+  return box.min.x == -DMNSN_INFINITY;
+}
+
+/**
+ * Expand a bounding box to contain a point
+ * @param[in] box  The bounding box to expand.
+ * @param[in] point  The point to swallow.
+ * @return The expanded bounding box.
+ */
+DMNSN_INLINE dmnsn_aabb
+dmnsn_aabb_swallow(dmnsn_aabb box, dmnsn_vector point)
+{
+  dmnsn_aabb ret = {
+    dmnsn_vector_min(box.min, point),
+    dmnsn_vector_max(box.max, point)
+  };
+  return ret;
+}
+
+/** Return whether a bounding box has any NaN components. */
+DMNSN_INLINE bool
+dmnsn_aabb_isnan(dmnsn_aabb box)
+{
+  return dmnsn_vector_isnan(box.min) || dmnsn_vector_isnan(box.max);
+}