Split up objects, finishes, pigments, lights, cameras, etc.

1 files changed, 143 insertions, 0 deletions

diff --git a/libdimension/cube.c b/libdimension/cube.c
new file mode 100644
index 0000000..57dd12b
--- /dev/null
+++ b/libdimension/cube.c
@@ -0,0 +1,143 @@
+/*************************************************************************
+ * Copyright (C) 2009 Tavian Barnes <tavianator@gmail.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/>.                                       *
+ *************************************************************************/
+
+#include "dimension.h"
+#include <stdlib.h> /* For malloc */
+#include <math.h>   /* For sqrt   */
+
+/*
+ * Cube
+ */
+
+/* Cube callbacks */
+static dmnsn_intersection *dmnsn_cube_intersection_fn(const dmnsn_object *cube,
+                                                      dmnsn_line line);
+static int dmnsn_cube_inside_fn(const dmnsn_object *cube,
+                                  dmnsn_vector point);
+
+/* Allocate a new cube object */
+dmnsn_object *
+dmnsn_new_cube()
+{
+  dmnsn_object *cube = dmnsn_new_object();
+  if (cube) {
+    cube->intersection_fn = &dmnsn_cube_intersection_fn;
+    cube->inside_fn       = &dmnsn_cube_inside_fn;
+    cube->min             = dmnsn_new_vector(-1.0, -1.0, -1.0);
+    cube->max             = dmnsn_new_vector(1.0, 1.0, 1.0);
+  }
+  return cube;
+}
+
+/* Intersections callback for a cube */
+static dmnsn_intersection *
+dmnsn_cube_intersection_fn(const dmnsn_object *cube, dmnsn_line line)
+{
+  double t = -1.0, t_temp;
+  dmnsn_vector p, normal;
+  dmnsn_intersection *intersection = NULL;
+
+  /* Six ray-plane intersection tests (x, y, z) = +/- 1.0 */
+
+  if (line.n.x != 0.0) {
+    /* x = -1.0 */
+    t_temp = (-1.0 - line.x0.x)/line.n.x;
+    p = dmnsn_line_point(line, t_temp);
+    if (p.y >= -1.0 && p.y <= 1.0 && p.z >= -1.0 && p.z <= 1.0
+        && t_temp >= 0.0 && (t < 0.0 || t_temp < t))
+    {
+      t = t_temp;
+      normal = dmnsn_new_vector(-copysign(1.0, line.n.x), 0.0, 0.0);
+    }
+
+    /* x = 1.0 */
+    t_temp = (1.0 - line.x0.x)/line.n.x;
+    p = dmnsn_line_point(line, t_temp);
+    if (p.y >= -1.0 && p.y <= 1.0 && p.z >= -1.0 && p.z <= 1.0
+        && t_temp >= 0.0 && (t < 0.0 || t_temp < t))
+    {
+      t = t_temp;
+      normal = dmnsn_new_vector(-copysign(1.0, line.n.x), 0.0, 0.0);
+    }
+  }
+
+  if (line.n.y != 0.0) {
+    /* y = -1.0 */
+    t_temp = (-1.0 - line.x0.y)/line.n.y;
+    p = dmnsn_line_point(line, t_temp);
+    if (p.x >= -1.0 && p.x <= 1.0 && p.z >= -1.0 && p.z <= 1.0
+        && t_temp >= 0.0 && (t < 0.0 || t_temp < t))
+    {
+      t = t_temp;
+      normal = dmnsn_new_vector(0.0, -copysign(1.0, line.n.y), 0.0);
+    }
+
+    /* y = 1.0 */
+    t_temp = (1.0 - line.x0.y)/line.n.y;
+    p = dmnsn_line_point(line, t_temp);
+    if (p.x >= -1.0 && p.x <= 1.0 && p.z >= -1.0 && p.z <= 1.0
+        && t_temp >= 0.0 && (t < 0.0 || t_temp < t))
+    {
+      t = t_temp;
+      normal = dmnsn_new_vector(0.0, -copysign(1.0, line.n.y), 0.0);
+    }
+  }
+
+  if (line.n.z != 0.0) {
+    /* z = -1.0 */
+    t_temp = (-1.0 - line.x0.z)/line.n.z;
+    p = dmnsn_line_point(line, t_temp);
+    if (p.x >= -1.0 && p.x <= 1.0 && p.y >= -1.0 && p.y <= 1.0
+        && t_temp >= 0.0 && (t < 0.0 || t_temp < t))
+    {
+      t = t_temp;
+      normal = dmnsn_new_vector(0.0, 0.0, -copysign(1.0, line.n.z));
+    }
+
+    /* z = 1.0 */
+    t_temp = (1.0 - line.x0.z)/line.n.z;
+    p = dmnsn_line_point(line, t_temp);
+    if (p.x >= -1.0 && p.x <= 1.0 && p.y >= -1.0 && p.y <= 1.0
+        && t_temp >= 0.0 && (t < 0.0 || t_temp < t))
+    {
+      t = t_temp;
+      normal = dmnsn_new_vector(0.0, 0.0, -copysign(1.0, line.n.z));
+    }
+  }
+
+  if (t >= 0.0) {
+    intersection = dmnsn_new_intersection();
+    intersection->ray     = line;
+    intersection->t       = t;
+    intersection->normal  = normal;
+    intersection->texture = cube->texture;
+  }
+
+  return intersection;
+}
+
+/* Inside callback for a cube */
+static int
+dmnsn_cube_inside_fn(const dmnsn_object *cube, dmnsn_vector point)
+{
+  return point.x > -1.0 && point.x < 1.0
+      && point.y > -1.0 && point.y < 1.0
+      && point.z > -1.0 && point.z < 1.0;
+}