Generisise map implementation.

8 files changed, 247 insertions, 120 deletions

diff --git a/dimension/realize.c b/dimension/realize.c
index 2f74ce0..ddccf89 100644
--- a/dimension/realize.c
+++ b/dimension/realize.c
@@ -480,29 +480,29 @@ dmnsn_realize_pattern(dmnsn_astnode astnode)
   return pattern;
 }
 
-static dmnsn_color_map *
+static dmnsn_map *
 dmnsn_realize_color_list(dmnsn_astnode astnode)
 {
   dmnsn_assert(astnode.type == DMNSN_AST_COLOR_LIST, "Expected a color list.");
 
-  dmnsn_color_map *color_map = dmnsn_new_color_map();
+  dmnsn_map *color_map = dmnsn_new_color_map();
 
   double n = 0.0, i = 1.0/(dmnsn_array_size(astnode.children) - 1);
   DMNSN_ARRAY_FOREACH (dmnsn_astnode *, entry, astnode.children) {
     dmnsn_color color = dmnsn_realize_color(*entry);
-    dmnsn_add_color_map_entry(color_map, n, color);
+    dmnsn_add_map_entry(color_map, n, &color);
     n += i;
   }
 
   return color_map;
 }
 
-static dmnsn_color_map *
+static dmnsn_map *
 dmnsn_realize_color_map(dmnsn_astnode astnode)
 {
   dmnsn_assert(astnode.type == DMNSN_AST_COLOR_MAP, "Expected a color_map.");
 
-  dmnsn_color_map *color_map = dmnsn_new_color_map();
+  dmnsn_map *color_map = dmnsn_new_color_map();
 
   DMNSN_ARRAY_FOREACH (dmnsn_astnode *, entry, astnode.children) {
     dmnsn_assert(entry->type == DMNSN_AST_COLOR_MAP_ENTRY,
@@ -515,7 +515,7 @@ dmnsn_realize_color_map(dmnsn_astnode astnode)
     double n = dmnsn_realize_float(n_node);
     dmnsn_color color = dmnsn_realize_color(color_node);
 
-    dmnsn_add_color_map_entry(color_map, n, color);
+    dmnsn_add_map_entry(color_map, n, &color);
   }
 
   return color_map;
@@ -528,7 +528,7 @@ dmnsn_realize_pattern_pigment(dmnsn_astnode type, dmnsn_astnode modifiers)
                "Expected pigment modifiers");
 
   dmnsn_pattern *pattern = dmnsn_realize_pattern(type);
-  dmnsn_color_map *color_map = NULL;
+  dmnsn_map *color_map = NULL;
 
   /* Set up the color_map */
   DMNSN_ARRAY_FOREACH_REVERSE (dmnsn_astnode *, modifier, modifiers.children) {
@@ -558,18 +558,18 @@ dmnsn_realize_pattern_pigment(dmnsn_astnode type, dmnsn_astnode modifiers)
     /* Default checker pattern is blue and green */
     if (!color_map)
       color_map = dmnsn_new_color_map();
-    if (dmnsn_array_size(color_map) < 1)
-      dmnsn_add_color_map_entry(color_map, 0.0, dmnsn_blue);
-    if (dmnsn_array_size(color_map) < 2)
-      dmnsn_add_color_map_entry(color_map, 1.0, dmnsn_green);
+    if (dmnsn_map_size(color_map) < 1)
+      dmnsn_add_map_entry(color_map, 0.0, &dmnsn_blue);
+    if (dmnsn_map_size(color_map) < 2)
+      dmnsn_add_map_entry(color_map, 1.0, &dmnsn_green);
     break;
 
   default:
     /* Default map is grayscale */
     if (!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);
+      dmnsn_add_map_entry(color_map, 0.0, &dmnsn_black);
+      dmnsn_add_map_entry(color_map, 1.0, &dmnsn_white);
     }
     break;
   }
diff --git a/libdimension/Makefile.am b/libdimension/Makefile.am
index 86caa57..e56a22b 100644
--- a/libdimension/Makefile.am
+++ b/libdimension/Makefile.am
@@ -37,6 +37,7 @@ nobase_include_HEADERS = dimension.h                                           \
                          dimension/lights.h                                    \
                          dimension/list.h                                      \
                          dimension/malloc.h                                    \
+                         dimension/map.h                                       \
                          dimension/object.h                                    \
                          dimension/objects.h                                   \
                          dimension/pattern.h                                   \
@@ -75,6 +76,7 @@ libdimension_la_SOURCES = $(nobase_include_HEADERS)                            \
                           light.c                                              \
                           list.c                                               \
                           malloc.c                                             \
+                          map.c                                                \
                           object.c                                             \
                           pattern.c                                            \
                           perspective.c                                        \
diff --git a/libdimension/color_map.c b/libdimension/color_map.c
index c794374..f7d800e 100644
--- a/libdimension/color_map.c
+++ b/libdimension/color_map.c
@@ -25,71 +25,16 @@
 
 #include "dimension.h"
 
-/** An [index, color] pair. */
-typedef struct dmnsn_color_map_entry {
-  double n;
-  dmnsn_color color;
-} dmnsn_color_map_entry;
-
-dmnsn_color_map *
-dmnsn_new_color_map(void)
-{
-  return dmnsn_new_array(sizeof(dmnsn_color_map_entry));
-}
-
-void
-dmnsn_delete_color_map(dmnsn_color_map *map)
-{
-  dmnsn_delete_array(map);
-}
-
-void
-dmnsn_add_color_map_entry(dmnsn_color_map *map, double n, dmnsn_color c)
-{
-  dmnsn_color_map_entry entry = { .n = n, .color = c };
-
-  /* Sorted insertion */
-  size_t i;
-  dmnsn_color_map_entry *other = dmnsn_array_last(map);
-  for (i = dmnsn_array_size(map); i-- > 0;) {
-    if (other->n <= n)
-      break;
-  }
-
-  dmnsn_array_insert(map, i + 1, &entry);
-}
-
-dmnsn_color
-dmnsn_color_map_value(const dmnsn_color_map *map, double n)
+dmnsn_map *
+dmnsn_new_color_map()
 {
-  dmnsn_color_map_entry *entry = dmnsn_array_first(map);
-
-  double n1, n2 = 0.0;
-  dmnsn_color c1, c2 = entry->color;
-
-  if (n < n2) {
-    return c2;
-  }
-
-  for (; entry <= (dmnsn_color_map_entry *)dmnsn_array_last(map); ++entry) {
-    n1 = n2;
-    c1 = c2;
-
-    n2 = entry->n;
-    c2 = entry->color;
-
-    if (n < n2) {
-      return dmnsn_color_gradient(c1, c2, (n - n1)/(n2 - n1));
-    }
-  }
-
-  return c2;
+  return dmnsn_new_map(sizeof(dmnsn_color));
 }
 
 /** Payload for a color_map pigment. */
 typedef struct dmnsn_color_map_payload {
   dmnsn_pattern *pattern;
-  dmnsn_color_map *map;
+  dmnsn_map *map;
 } dmnsn_color_map_payload;
 
 /** Free a color_map payload. */
@@ -97,7 +42,7 @@ static void
 dmnsn_delete_color_map_payload(void *ptr)
 {
   dmnsn_color_map_payload *payload = ptr;
-  dmnsn_delete_color_map(payload->map);
+  dmnsn_delete_map(payload->map);
   dmnsn_delete_pattern(payload->pattern);
   dmnsn_free(payload);
 }
@@ -107,8 +52,11 @@ static dmnsn_color
 dmnsn_color_map_pigment_fn(const dmnsn_pigment *pigment, dmnsn_vector v)
 {
   const dmnsn_color_map_payload *payload = pigment->ptr;
-  return dmnsn_color_map_value(payload->map,
-                               dmnsn_pattern_value(payload->pattern, v));
+  double n;
+  dmnsn_color color1, color2;
+  dmnsn_evaluate_map(payload->map, dmnsn_pattern_value(payload->pattern, v),
+                     &n, &color1, &color2);
+  return dmnsn_color_gradient(color1, color2, n);
 }
 
 /** color_map initialization callback. */
@@ -122,7 +70,7 @@ dmnsn_color_map_initialize_fn(dmnsn_pigment *pigment)
 }
 
 dmnsn_pigment *
-dmnsn_new_color_map_pigment(dmnsn_pattern *pattern, dmnsn_color_map *map)
+dmnsn_new_color_map_pigment(dmnsn_pattern *pattern, dmnsn_map *map)
 {
   dmnsn_pigment *pigment = dmnsn_new_pigment();
 
diff --git a/libdimension/dimension.h b/libdimension/dimension.h
index d4ce61e..fb8efb5 100644
--- a/libdimension/dimension.h
+++ b/libdimension/dimension.h
@@ -68,6 +68,7 @@ typedef void dmnsn_free_fn(void *ptr);
 #include <dimension/png.h>
 #include <dimension/pattern.h>
 #include <dimension/patterns.h>
+#include <dimension/map.h>
 #include <dimension/texture.h>
 #include <dimension/pigments.h>
 #include <dimension/finishes.h>
diff --git a/libdimension/dimension/map.h b/libdimension/dimension/map.h
new file mode 100644
index 0000000..1cd0f55
--- /dev/null
+++ b/libdimension/dimension/map.h
@@ -0,0 +1,76 @@
+/*************************************************************************
+ * 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
+ * Generic maps (backend for color_maps, pigment_maps, etc.).
+ */
+
+#ifndef DIMENSION_MAP_H
+#define DIMENSION_MAP_H
+
+/** A map. */
+typedef struct dmnsn_map {
+  dmnsn_free_fn *free_fn; /**< Destructor callback. */
+  size_t obj_size; /**< @internal The size of the mapped objects. */
+  dmnsn_array *array; /**< @internal The map entries. */
+} dmnsn_map;
+
+/**
+ * Create an empty map.
+ * @param[in] size  The size of the objects to store in the map.
+ * @return A map with no entries.
+ */
+dmnsn_map *dmnsn_new_map(size_t size);
+
+/**
+ * Delete a map.
+ * @param[in,out] map  The map to delete.
+ */
+void dmnsn_delete_map(dmnsn_map *map);
+
+/**
+ * Add an entry (a scalar-object pair) to a color map.
+ * @param[in,out] map     The color map to add to.
+ * @param[in]     n       The index of the entry.
+ * @param[in]     object  The value of the entry.
+ */
+void dmnsn_add_map_entry(dmnsn_map *map, double n, const void *obj);
+
+/**
+ * Return the number of entries in a map.
+ * @param[in] map  The map to measure.
+ * @return The size of \p map.
+ */
+size_t dmnsn_map_size(const dmnsn_map *map);
+
+/**
+ * Evaluate a map.
+ * @param[in]  map   The map to evaluate.
+ * @param[in]  n     The index to evaluate.
+ * @param[out] val   The normalized distance of \p n from \p obj1.
+ * @param[out] obj1  The first object.
+ * @param[out] obj2  The second object.
+ */
+void dmnsn_evaluate_map(const dmnsn_map *map, double n,
+                        double *val, void *obj1, void *obj2);
+
+#endif /* DIMENSION_MAP_H */
diff --git a/libdimension/dimension/pigments.h b/libdimension/dimension/pigments.h
index 68a9c66..687080f 100644
--- a/libdimension/dimension/pigments.h
+++ b/libdimension/dimension/pigments.h
@@ -41,37 +41,11 @@ dmnsn_pigment *dmnsn_new_solid_pigment(dmnsn_color color);
  */
 dmnsn_pigment *dmnsn_new_canvas_pigment(dmnsn_canvas *canvas);
 
-/** Color map. */
-typedef dmnsn_array dmnsn_color_map;
-
-/**
- * Create an empty color map.
- * @return A color map with no entries.
- */
-dmnsn_color_map *dmnsn_new_color_map(void);
-
-/**
- * Delete a color map.
- * @param[in,out] map  The color map to delete.
- */
-void dmnsn_delete_color_map(dmnsn_color_map *map);
-
-/**
- * Add an entry (a scalar-color pair) to a color map.
- * @param[in,out] map  The color map to add to.
- * @param[in]     n    The index of the entry.
- * @param[in]     c    The value of the entry.
- */
-void dmnsn_add_color_map_entry(dmnsn_color_map *map, double n, dmnsn_color c);
-
 /**
- * Evaluate a color map.
- * @param[in] map  The map to evaluate.
- * @param[in] n    The index to evaluate.
- * @return The value of the gradient between the the two indicies closest to
- * \p n.
+ * Construct a color map.
+ * @return An empty color map.
  */
-dmnsn_color dmnsn_color_map_value(const dmnsn_color_map *map, double n);
+dmnsn_map *dmnsn_new_color_map();
 
 /**
  * A color-mapped pigment.
@@ -80,6 +54,6 @@ dmnsn_color dmnsn_color_map_value(const dmnsn_color_map *map, double n);
  * @return A pigment mapping the pattern to color values.
  */
 dmnsn_pigment *dmnsn_new_color_map_pigment(dmnsn_pattern *pattern,
-                                           dmnsn_color_map *map);
+                                           dmnsn_map *map);
 
 #endif /* DIMENSION_PIGMENTS_H */
diff --git a/libdimension/map.c b/libdimension/map.c
new file mode 100644
index 0000000..3ea4b0c
--- /dev/null
+++ b/libdimension/map.c
@@ -0,0 +1,126 @@
+/*************************************************************************
+ * 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
+ * Generic maps.
+ */
+
+#include "dimension.h"
+#include <alloca.h>
+
+/** An [index, object] pair. */
+typedef struct dmnsn_map_entry {
+  double n;
+  char object[];
+} dmnsn_map_entry;
+
+dmnsn_map *
+dmnsn_new_map(size_t size)
+{
+  dmnsn_map *map = dmnsn_malloc(sizeof(dmnsn_map));
+  map->free_fn = NULL;
+  map->obj_size = size;
+  map->array = dmnsn_new_array(sizeof(dmnsn_map_entry) + size);
+  return map;
+}
+
+void
+dmnsn_delete_map(dmnsn_map *map)
+{
+  if (map) {
+    if (map->free_fn) {
+      for (size_t i = 0; i < dmnsn_array_size(map->array); ++i) {
+        dmnsn_map_entry *entry = dmnsn_array_at(map->array, i);
+        (*map->free_fn)(entry->object);
+      }
+    }
+
+    dmnsn_delete_array(map->array);
+    dmnsn_free(map);
+  }
+}
+
+void
+dmnsn_add_map_entry(dmnsn_map *map, double n, const void *obj)
+{
+  dmnsn_map_entry *entry = alloca(sizeof(dmnsn_map_entry) + map->obj_size);
+  entry->n = n;
+  memcpy(entry->object, obj, map->obj_size);
+
+  /* Sorted insertion */
+  size_t i;
+  for (i = dmnsn_array_size(map->array); i-- > 0;) {
+    dmnsn_map_entry *other = dmnsn_array_at(map->array, i);
+    if (other->n <= n)
+      break;
+  }
+
+  dmnsn_array_insert(map->array, i + 1, entry);
+}
+
+size_t
+dmnsn_map_size(const dmnsn_map *map)
+{
+  return dmnsn_array_size(map->array);
+}
+
+void
+dmnsn_evaluate_map(const dmnsn_map *map, double n,
+                   double *val, void *obj1, void *obj2)
+{
+  dmnsn_assert(dmnsn_array_size(map->array) > 0,
+               "Attempt to evaluate empty map.");
+
+  const dmnsn_map_entry *entry = dmnsn_array_first(map->array);
+
+  double n1, n2 = 0.0;
+  const void *o1, *o2 = entry->object;
+
+  if (n < n2) {
+    *val = 0.0;
+    memcpy(obj1, o2, map->obj_size);
+    memcpy(obj2, o2, map->obj_size);
+    return;
+  }
+
+  const dmnsn_map_entry *last = dmnsn_array_last(map->array);
+  ptrdiff_t skip = sizeof(dmnsn_map_entry) + map->obj_size;
+  for (; entry <= last;
+       entry = (const dmnsn_map_entry *)((const char *)entry + skip))
+  {
+    n1 = n2;
+    o1 = o2;
+
+    n2 = entry->n;
+    o2 = entry->object;
+
+    if (n < n2) {
+      *val = (n - n1)/(n2 - n1);
+      memcpy(obj1, o1, map->obj_size);
+      memcpy(obj2, o2, map->obj_size);
+      return;
+    }
+  }
+
+  *val = 1.0;
+  memcpy(obj1, o2, map->obj_size);
+  memcpy(obj2, o2, map->obj_size);
+}
diff --git a/tests/libdimension/render.c b/tests/libdimension/render.c
index 31518bf..5ba075d 100644
--- a/tests/libdimension/render.c
+++ b/tests/libdimension/render.c
@@ -71,11 +71,11 @@ dmnsn_new_test_scene(void)
   /* Sky sphere */
   scene->sky_sphere = dmnsn_new_sky_sphere();
   dmnsn_pattern *sky_gradient = dmnsn_new_gradient_pattern(dmnsn_y);
-  dmnsn_color_map *sky_gradient_color_map = dmnsn_new_color_map();
-  dmnsn_add_color_map_entry(sky_gradient_color_map, 0.0, dmnsn_orange);
+  dmnsn_map *sky_gradient_color_map = dmnsn_new_color_map();
+  dmnsn_add_map_entry(sky_gradient_color_map, 0.0, &dmnsn_orange);
   dmnsn_color background = dmnsn_color_from_sRGB((dmnsn_sRGB){ 0.0, 0.1, 0.2 });
   background.filter = 0.1;
-  dmnsn_add_color_map_entry(sky_gradient_color_map, 0.35, background);
+  dmnsn_add_map_entry(sky_gradient_color_map, 0.35, &background);
   dmnsn_pigment *sky_pigment
     = dmnsn_new_color_map_pigment(sky_gradient, sky_gradient_color_map);
   dmnsn_array_push(scene->sky_sphere->pigments, &sky_pigment);
@@ -134,14 +134,14 @@ dmnsn_new_test_scene(void)
     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);
+  dmnsn_map *gradient_color_map = dmnsn_new_color_map();
+  dmnsn_add_map_entry(gradient_color_map, 0.0,     &dmnsn_red);
+  dmnsn_add_map_entry(gradient_color_map, 1.0/6.0, &dmnsn_orange);
+  dmnsn_add_map_entry(gradient_color_map, 2.0/6.0, &dmnsn_yellow);
+  dmnsn_add_map_entry(gradient_color_map, 3.0/6.0, &dmnsn_green);
+  dmnsn_add_map_entry(gradient_color_map, 4.0/6.0, &dmnsn_blue);
+  dmnsn_add_map_entry(gradient_color_map, 5.0/6.0, &dmnsn_magenta);
+  dmnsn_add_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);
@@ -180,9 +180,9 @@ 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 *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);
+  dmnsn_map *checker_color_map = dmnsn_new_color_map();
+  dmnsn_add_map_entry(checker_color_map, 0.0, &dmnsn_black);
+  dmnsn_add_map_entry(checker_color_map, 1.0, &dmnsn_white);
   plane->texture->pigment
     = dmnsn_new_color_map_pigment(checker, checker_color_map);
   plane->texture->pigment->quick_color