Implement sky spheres.

1 files changed, 63 insertions, 0 deletions

diff --git a/libdimension/dimension/sky_sphere.h b/libdimension/dimension/sky_sphere.h
new file mode 100644
index 0000000..5edacb0
--- /dev/null
+++ b/libdimension/dimension/sky_sphere.h
@@ -0,0 +1,63 @@
+/*************************************************************************
+ * Copyright (C) 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.
+ */
+
+#ifndef DIMENSION_SKY_SPHERE_H
+#define DIMENSION_SKY_SPHERE_H
+
+/** A sky sphere. */
+typedef struct dmnsn_sky_sphere {
+  /** An array of pigments in inside-to-outside order. */
+  dmnsn_array *pigments;
+  dmnsn_matrix trans;
+} dmnsn_sky_sphere;
+
+/**
+ * Create a sky sphere.
+ * @return A new blank sky sphere.
+ */
+dmnsn_sky_sphere *dmnsn_new_sky_sphere();
+
+/**
+ * Delete a sky sphere.
+ * @param[in,out] sky_sphere  The sky sphere to delete.
+ */
+void dmnsn_delete_sky_sphere(dmnsn_sky_sphere *sky_sphere);
+
+/**
+ * Initialize a sky sphere.
+ * @param[in,out] sky_sphere  The sky sphere to initialize.
+ */
+void dmnsn_sky_sphere_init(dmnsn_sky_sphere *sky_sphere);
+
+/**
+ * Evaluate the color of the sky sphere.
+ * @param[in] sky_sphere  The sky sphere to evaluate.
+ * @param[in] d           The direction to look.
+ * @return The color of the sky in the direction of \p d.
+ */
+dmnsn_color dmnsn_sky_sphere_color(const dmnsn_sky_sphere *sky_sphere,
+                                   dmnsn_vector d);
+
+#endif /* DIMENSION_SKY_SPHERE_H */