Implement sky spheres.

1 files changed, 72 insertions, 0 deletions

diff --git a/libdimension/sky_sphere.c b/libdimension/sky_sphere.c
new file mode 100644
index 0000000..bb38c16
--- /dev/null
+++ b/libdimension/sky_sphere.c
@@ -0,0 +1,72 @@
+/*************************************************************************
+ * Copyright (C) 2009-2010 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/>.                                       *
+ *************************************************************************/
+
+/**
+ * @file
+ * Sky spheres.
+ */
+
+#include "dimension.h"
+
+dmnsn_sky_sphere *
+dmnsn_new_sky_sphere()
+{
+  dmnsn_sky_sphere *sky_sphere = dmnsn_malloc(sizeof(dmnsn_sky_sphere));
+  sky_sphere->pigments = dmnsn_new_array(sizeof(dmnsn_pigment *));
+  sky_sphere->trans = dmnsn_identity_matrix();
+  return sky_sphere;
+}
+
+void
+dmnsn_delete_sky_sphere(dmnsn_sky_sphere *sky_sphere)
+{
+  if (sky_sphere) {
+    DMNSN_ARRAY_FOREACH (dmnsn_pigment **, pigment, sky_sphere->pigments) {
+      dmnsn_delete_pigment(*pigment);
+    }
+    dmnsn_free(sky_sphere);
+  }
+}
+
+void
+dmnsn_sky_sphere_init(dmnsn_sky_sphere *sky_sphere)
+{
+  DMNSN_ARRAY_FOREACH (dmnsn_pigment **, pigment, sky_sphere->pigments) {
+    (*pigment)->trans = dmnsn_matrix_mul(sky_sphere->trans, (*pigment)->trans);
+    dmnsn_pigment_init(*pigment);
+  }
+}
+
+dmnsn_color
+dmnsn_sky_sphere_color(const dmnsn_sky_sphere *sky_sphere, dmnsn_vector d)
+{
+  dmnsn_color color = dmnsn_black;
+  color.trans = 1.0;
+
+  DMNSN_ARRAY_FOREACH (const dmnsn_pigment **, pigment, sky_sphere->pigments) {
+    dmnsn_pigment_fn *pigment_fn = (*pigment)->pigment_fn;
+    if (pigment_fn) {
+      dmnsn_color sky = (*pigment_fn)(*pigment, d);
+      color = dmnsn_color_add(dmnsn_color_filter(color, sky), sky);
+    }
+  }
+
+  return color;
+}