Add gradient pattern.

4 files changed, 88 insertions, 20 deletions

diff --git a/libdimension/Makefile.am b/libdimension/Makefile.am
index 8558a48..7875682 100644
--- a/libdimension/Makefile.am
+++ b/libdimension/Makefile.am
@@ -66,6 +66,7 @@ libdimension_la_SOURCES = $(nobase_include_HEADERS)                            \
                           error.c                                              \
                           finish_combination.c                                 \
                           geometry.c                                           \
+                          gradient.c                                           \
                           inlines.c                                            \
                           interior.c                                           \
                           light.c                                              \
diff --git a/libdimension/dimension/patterns.h b/libdimension/dimension/patterns.h
index c6dc08a..cd4aa35 100644
--- a/libdimension/dimension/patterns.h
+++ b/libdimension/dimension/patterns.h
@@ -26,5 +26,6 @@
 #define DIMENSION_PATTERNS_H
 
 dmnsn_pattern *dmnsn_new_checker_pattern();
+dmnsn_pattern *dmnsn_new_gradient_pattern(dmnsn_vector orientation);
 
 #endif /* DIMENSION_PATTERNS_H */
diff --git a/libdimension/gradient.c b/libdimension/gradient.c
new file mode 100644
index 0000000..6bcb3b8
--- /dev/null
+++ b/libdimension/gradient.c
@@ -0,0 +1,50 @@
+/*************************************************************************
+ * 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/>.                                       *
+ *************************************************************************/
+
+#include "dimension.h"
+
+/*
+ * Gradient pattern
+ */
+
+static double
+dmnsn_gradient_pattern_fn(const dmnsn_pattern *gradient, dmnsn_vector v)
+{
+  dmnsn_vector *orientation = gradient->ptr;
+  double n = fmod(dmnsn_vector_dot(*orientation, v), 1.0);
+  if (n < -dmnsn_epsilon)
+    n += 1.0;
+  return n;
+}
+
+dmnsn_pattern *
+dmnsn_new_gradient_pattern(dmnsn_vector orientation)
+{
+  dmnsn_pattern *gradient = dmnsn_new_pattern();
+
+  dmnsn_vector *payload = dmnsn_malloc(sizeof(dmnsn_vector));
+  *payload = dmnsn_vector_normalize(orientation);
+
+  gradient->pattern_fn = &dmnsn_gradient_pattern_fn;
+  gradient->free_fn    = &dmnsn_free;
+  gradient->ptr        = payload;
+
+  return gradient;
+}
diff --git a/tests/libdimension/render.c b/tests/libdimension/render.c
index d4c5edc..4f8f23e 100644
--- a/tests/libdimension/render.c
+++ b/tests/libdimension/render.c
@@ -104,28 +104,43 @@ dmnsn_new_test_scene(void)
   dmnsn_object *csg = dmnsn_new_csg_difference(cube, sphere);
   dmnsn_array_push(scene->objects, &csg);
 
+  dmnsn_array *arrow_array = dmnsn_new_array(sizeof(dmnsn_object *));
+
   dmnsn_object *cylinder = dmnsn_new_cylinder(0.1, 0.1, false);
-  cylinder->trans =
-    dmnsn_matrix_mul(
-      dmnsn_rotation_matrix(dmnsn_new_vector(dmnsn_radians(-45.0), 0.0, 0.0)),
-      dmnsn_scale_matrix(dmnsn_new_vector(1.0, 1.25, 1.0))
-    );
-  cylinder->texture = dmnsn_new_texture();
-  cylinder->texture->pigment = dmnsn_new_solid_pigment(dmnsn_red);
-  dmnsn_array_push(scene->objects, &cylinder);
+  cylinder->trans = dmnsn_scale_matrix(dmnsn_new_vector(1.0, 1.25, 1.0));
+  dmnsn_array_push(arrow_array, &cylinder);
 
   dmnsn_object *cone = dmnsn_new_cylinder(0.1, 0.0, true);
   cone->trans =
     dmnsn_matrix_mul(
-      dmnsn_rotation_matrix(dmnsn_new_vector(dmnsn_radians(-45.0), 0.0, 0.0)),
-      dmnsn_matrix_mul(
-        dmnsn_translation_matrix(dmnsn_new_vector(0.0, 1.375, 0.0)),
-        dmnsn_scale_matrix(dmnsn_new_vector(1.0, 0.125, 1.0))
-      )
+      dmnsn_translation_matrix(dmnsn_new_vector(0.0, 1.375, 0.0)),
+      dmnsn_scale_matrix(dmnsn_new_vector(1.0, 0.125, 1.0))
+    );
+  dmnsn_array_push(arrow_array, &cone);
+
+  dmnsn_object *arrow = dmnsn_new_csg_union(arrow_array);
+  arrow->trans = dmnsn_rotation_matrix(
+    dmnsn_new_vector(dmnsn_radians(-45.0), 0.0, 0.0)
+  );
+  dmnsn_pattern *gradient = dmnsn_new_gradient_pattern(dmnsn_y);
+  dmnsn_color_map *gradient_color_map = dmnsn_new_color_map();
+  dmnsn_add_color_map_entry(gradient_color_map, 0.0,     dmnsn_red);
+  dmnsn_add_color_map_entry(gradient_color_map, 1.0/6.0, dmnsn_orange);
+  dmnsn_add_color_map_entry(gradient_color_map, 2.0/6.0, dmnsn_yellow);
+  dmnsn_add_color_map_entry(gradient_color_map, 3.0/6.0, dmnsn_green);
+  dmnsn_add_color_map_entry(gradient_color_map, 4.0/6.0, dmnsn_blue);
+  dmnsn_add_color_map_entry(gradient_color_map, 5.0/6.0, dmnsn_magenta);
+  dmnsn_add_color_map_entry(gradient_color_map, 1.0,     dmnsn_red);
+  arrow->texture = dmnsn_new_texture();
+  arrow->texture->pigment
+    = dmnsn_new_color_map_pigment(gradient, gradient_color_map);
+  arrow->texture->trans =
+    dmnsn_matrix_mul(
+      dmnsn_translation_matrix(dmnsn_new_vector(0.0, -1.25, 0.0)),
+      dmnsn_scale_matrix(dmnsn_new_vector(1.0, 2.75, 1.0))
     );
-  cone->texture = dmnsn_new_texture();
-  cone->texture->pigment = dmnsn_new_solid_pigment(dmnsn_red);
-  dmnsn_array_push(scene->objects, &cone);
+  dmnsn_array_push(scene->objects, &arrow);
+  dmnsn_delete_array(arrow_array);
 
   dmnsn_array *torus_array = dmnsn_new_array(sizeof(dmnsn_object *));
 
@@ -154,10 +169,11 @@ dmnsn_new_test_scene(void)
   plane->trans = dmnsn_translation_matrix(dmnsn_new_vector(0.0, -2.0, 0.0));
   plane->texture = dmnsn_new_texture();
   dmnsn_pattern *checker = dmnsn_new_checker_pattern();
-  dmnsn_color_map *color_map = dmnsn_new_color_map();
-  dmnsn_add_color_map_entry(color_map, 0.0, dmnsn_black);
-  dmnsn_add_color_map_entry(color_map, 1.0, dmnsn_white);
-  plane->texture->pigment = dmnsn_new_color_map_pigment(checker, color_map);
+  dmnsn_color_map *checker_color_map = dmnsn_new_color_map();
+  dmnsn_add_color_map_entry(checker_color_map, 0.0, dmnsn_black);
+  dmnsn_add_color_map_entry(checker_color_map, 1.0, dmnsn_white);
+  plane->texture->pigment
+    = dmnsn_new_color_map_pigment(checker, checker_color_map);
   dmnsn_array_push(scene->objects, &plane);
 
   return scene;