Begin object type, with sphere example.

6 files changed, 146 insertions, 3 deletions

diff --git a/libdimension/Makefile.am b/libdimension/Makefile.am
index 7114b04..136d652 100644
--- a/libdimension/Makefile.am
+++ b/libdimension/Makefile.am
@@ -17,10 +17,10 @@
 ## along with this program.  If not, see <http://www.gnu.org/licenses/>. ##
 ###########################################################################
 
-nobase_include_HEADERS = dimension.h dimension/array.h dimension/canvas.h dimension/color.h dimension/error.h dimension/geometry.h dimension/png.h
+nobase_include_HEADERS = dimension.h dimension/array.h dimension/canvas.h dimension/color.h dimension/error.h dimension/geometry.h dimension/png.h dimension/object.h dimension/sphere.h
 
 lib_LTLIBRARIES = libdimension.la
 
-libdimension_la_SOURCES = $(nobase_include_HEADERS) array.c canvas.c color.c error.c geometry.c png.c
+libdimension_la_SOURCES = $(nobase_include_HEADERS) array.c canvas.c color.c error.c geometry.c png.c object.c sphere.c
 libdimension_la_LDFLAGS = -version-info 0:0:0
 libdimension_la_LIBADD  = -lm -lpthread -lpng
diff --git a/libdimension/array.c b/libdimension/array.c
index 97ce716..e6e4363 100644
--- a/libdimension/array.c
+++ b/libdimension/array.c
@@ -24,7 +24,7 @@
 dmnsn_array *
 dmnsn_new_array(size_t obj_size)
 {
-  dmnsn_array *array = malloc(sizeof(array));
+  dmnsn_array *array = malloc(sizeof(dmnsn_array));
   if (array) {
     array->obj_size = obj_size;
     array->length   = 0;
diff --git a/libdimension/dimension/object.h b/libdimension/dimension/object.h
index 737a49d..c79d62e 100644
--- a/libdimension/dimension/object.h
+++ b/libdimension/dimension/object.h
@@ -26,9 +26,18 @@
  */
 
 typedef dmnsn_array *dmnsn_object_intersections_fn(dmnsn_line line);
+typedef int dmnsn_object_inside_fn(dmnsn_vector point);
 
 typedef struct {
+  /* Generic pointer for object info */
+  void *ptr;
+
+  /* Callback functions */
   dmnsn_object_intersections_fn *intersections_fn;
+  dmnsn_object_inside_fn        *inside_fn;
 } dmnsn_object;
 
+dmnsn_object *dmnsn_new_object();
+void dmnsn_delete_object(dmnsn_object *object);
+
 #endif /* DIMENSION_OBJECT_H */
diff --git a/libdimension/dimension/sphere.h b/libdimension/dimension/sphere.h
new file mode 100644
index 0000000..2547965
--- /dev/null
+++ b/libdimension/dimension/sphere.h
@@ -0,0 +1,31 @@
+/*************************************************************************
+ * Copyright (C) 2008 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/>.                                       *
+ *************************************************************************/
+
+#ifndef DIMENSION_SPHERE_H
+#define DIMENSION_SPHERE_H
+
+/*
+ * A sphere object, of radius 1, centered at the origin.
+ */
+
+dmnsn_object *dmnsn_new_sphere();
+void dmnsn_delete_sphere(dmnsn_object *sphere);
+
+#endif /* DIMENSION_SPHERE_H */
diff --git a/libdimension/object.c b/libdimension/object.c
new file mode 100644
index 0000000..39064f3
--- /dev/null
+++ b/libdimension/object.c
@@ -0,0 +1,34 @@
+/*************************************************************************
+ * Copyright (C) 2008 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 */
+
+dmnsn_object *
+dmnsn_new_object()
+{
+  return malloc(sizeof(dmnsn_object));
+}
+
+void
+dmnsn_delete_object(dmnsn_object *object)
+{
+  free(object);
+}
diff --git a/libdimension/sphere.c b/libdimension/sphere.c
new file mode 100644
index 0000000..4b99eaf
--- /dev/null
+++ b/libdimension/sphere.c
@@ -0,0 +1,69 @@
+/*************************************************************************
+ * Copyright (C) 2008 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   */
+
+static dmnsn_array *dmnsn_sphere_intersections_fn(dmnsn_line line);
+static int dmnsn_sphere_inside_fn(dmnsn_vector point);
+
+dmnsn_object *
+dmnsn_new_sphere()
+{
+  dmnsn_object *sphere = dmnsn_new_object();
+  sphere->intersections_fn = &dmnsn_sphere_intersections_fn;
+  sphere->inside_fn        = &dmnsn_sphere_inside_fn;
+  return sphere;
+}
+
+void
+dmnsn_delete_sphere(dmnsn_object *sphere)
+{
+  dmnsn_delete_object(sphere);
+}
+
+static dmnsn_array *
+dmnsn_sphere_intersections_fn(dmnsn_line line)
+{
+  double a, b, c, t[2];
+  dmnsn_array *array = dmnsn_new_array(sizeof(double));
+
+  // Solve (x0 + nx*t)^2 + (y0 + ny*t)^2 + (z0 + nz*t)^2 == 1
+
+  a = line.n.x*line.n.x + line.n.y*line.n.y + line.n.z*line.n.z;
+  b = 2.0*(line.n.x*line.x0.x + line.n.y*line.x0.y + line.n.z*line.x0.z);
+  c = line.x0.x*line.x0.x + line.x0.y*line.x0.y + line.x0.z*line.x0.z - 1.0;
+
+  if (b*b - 4.0*a*c >= 0) {
+    t[0] = (-b + sqrt(b*b - 4.0*a*c))/(2*a);
+    t[1] = (-b - sqrt(b*b - 4.0*a*c))/(2*a);
+    dmnsn_array_set(array, 0, &t[0]);
+    dmnsn_array_set(array, 1, &t[1]);
+  }
+
+  return array;
+}
+
+static int
+dmnsn_sphere_inside_fn(dmnsn_vector point)
+{
+  return sqrt(point.x*point.x + point.y*point.y + point.z*point.z) < 1.0;
+}