Improve CSG and light handling.

- Lights can be inside CSG objects
- Lights can be modified by transformations
- CSG objects can contain only one object

7 files changed, 296 insertions, 139 deletions

diff --git a/dimension/common.rules b/dimension/common.rules
index e604b9f..c5f9eea 100644
--- a/dimension/common.rules
+++ b/dimension/common.rules
@@ -236,8 +236,8 @@ MERGE: "merge" "{"
      }
 ;
 
-OBJECTS: OBJECT OBJECT {
-         $$ = dmnsn_new_astnode2(DMNSN_AST_ARRAY, @$, $1, $2);
+OBJECTS: OBJECT {
+         $$ = dmnsn_new_astnode1(DMNSN_AST_ARRAY, @$, $1);
        }
        | OBJECTS OBJECT {
          $$ = $1;
@@ -246,9 +246,10 @@ OBJECTS: OBJECT OBJECT {
 
 LIGHT_SOURCE: "light_source" "{"
                 VECTOR "," COLOR
+                OBJECT_MODIFIERS
               "}"
             {
-              $$ = dmnsn_new_astnode2(DMNSN_AST_LIGHT_SOURCE, @$, $3, $5);
+              $$ = dmnsn_new_astnode3(DMNSN_AST_LIGHT_SOURCE, @$, $3, $5, $6);
             }
 ;
 
diff --git a/dimension/parse.c b/dimension/parse.c
index 19ba24c..2f717f9 100644
--- a/dimension/parse.c
+++ b/dimension/parse.c
@@ -536,12 +536,7 @@ dmnsn_vector_promote(dmnsn_astnode astnode, dmnsn_symbol_table *symtable)
 
     while (dmnsn_array_size(promoted.children) < DMNSN_VECTOR_NELEM) {
       component = dmnsn_copy_astnode(component);
-      component.type = DMNSN_AST_INTEGER;
-
-      long *val = dmnsn_malloc(sizeof(long));
-      *val = 0;
-
-      component.ptr = val;
+      dmnsn_make_ast_integer(&component, 0);
       dmnsn_array_push(promoted.children, &component);
     }
   } else {
@@ -1759,6 +1754,8 @@ dmnsn_print_astnode(FILE *file, dmnsn_astnode astnode)
 
   case DMNSN_AST_FLOAT:
     dvalue = *(double *)astnode.ptr;
+    /* Don't print -0 */
+    if (dvalue == 0.0) dvalue = 0.0;
     fprintf(file, "(%s %g)", dmnsn_astnode_string(astnode.type), dvalue);
     break;
 
diff --git a/dimension/realize.c b/dimension/realize.c
index 215d891..b5c6066 100644
--- a/dimension/realize.c
+++ b/dimension/realize.c
@@ -643,7 +643,76 @@ dmnsn_realize_object_modifiers(dmnsn_astnode astnode, dmnsn_object *object)
   }
 }
 
-static dmnsn_object *dmnsn_realize_object(dmnsn_astnode astnode);
+static void
+dmnsn_realize_light_source_modifiers(dmnsn_astnode astnode, dmnsn_light *light)
+{
+  dmnsn_assert(astnode.type == DMNSN_AST_OBJECT_MODIFIERS,
+               "Expected object modifiers.");
+
+  unsigned int i;
+  for (i = 0; i < dmnsn_array_size(astnode.children); ++i) {
+    dmnsn_astnode modifier;
+    dmnsn_array_get(astnode.children, i, &modifier);
+
+    switch (modifier.type) {
+    case DMNSN_AST_ROTATION:
+      light->x0 = dmnsn_matrix_vector_mul(
+        dmnsn_realize_rotation(modifier),
+        light->x0
+      );
+      break;
+    case DMNSN_AST_SCALE:
+      light->x0 = dmnsn_matrix_vector_mul(
+        dmnsn_realize_scale(modifier),
+        light->x0
+      );
+      break;
+    case DMNSN_AST_TRANSLATION:
+      light->x0 = dmnsn_matrix_vector_mul(
+        dmnsn_realize_translation(modifier),
+        light->x0
+      );
+      break;
+
+    case DMNSN_AST_TEXTURE:
+    case DMNSN_AST_PIGMENT:
+    case DMNSN_AST_FINISH:
+    case DMNSN_AST_INTERIOR:
+      dmnsn_diagnostic(modifier.filename, modifier.line, modifier.col,
+                       "WARNING: ignoring %s applied to light source",
+                       dmnsn_astnode_string(modifier.type));
+      break;
+
+    default:
+      dmnsn_assert(false, "Invalid object modifier.");
+    }
+  }
+}
+
+static dmnsn_light *
+dmnsn_realize_light_source(dmnsn_astnode astnode)
+{
+  dmnsn_assert(astnode.type == DMNSN_AST_LIGHT_SOURCE,
+               "Expected a light source.");
+
+  dmnsn_astnode point, color_node;
+  dmnsn_array_get(astnode.children, 0, &point);
+  dmnsn_array_get(astnode.children, 1, &color_node);
+
+  dmnsn_vector x0 = dmnsn_realize_vector(point);
+  dmnsn_color color = dmnsn_realize_color(color_node);
+
+  dmnsn_light *light = dmnsn_new_point_light(x0, color);
+
+  dmnsn_astnode modifiers;
+  dmnsn_array_get(astnode.children, 2, &modifiers);
+  dmnsn_realize_light_source_modifiers(modifiers, light);
+
+  return light;
+}
+
+static dmnsn_object *dmnsn_realize_object(dmnsn_astnode astnode,
+                                          dmnsn_array *lights);
 
 static dmnsn_object *
 dmnsn_realize_box(dmnsn_astnode astnode)
@@ -702,155 +771,103 @@ dmnsn_realize_sphere(dmnsn_astnode astnode)
   return sphere;
 }
 
+typedef dmnsn_object *dmnsn_csg_object_fn(dmnsn_object *a, dmnsn_object *b);
+
+/* Generalized CSG realizer */
 static dmnsn_object *
-dmnsn_realize_union(dmnsn_astnode astnode)
+dmnsn_realize_csg(dmnsn_astnode astnode, dmnsn_array *lights,
+                  dmnsn_csg_object_fn *csg_object_fn)
 {
-  dmnsn_assert(astnode.type == DMNSN_AST_UNION, "Expected a union.");
-
-  dmnsn_astnode objects;
+  dmnsn_astnode objects, modifiers;
   dmnsn_array_get(astnode.children, 0, &objects);
+  dmnsn_array_get(astnode.children, 1, &modifiers);
 
-  dmnsn_astnode o1node, o2node;
-  dmnsn_array_get(objects.children, 0, &o1node);
-  dmnsn_array_get(objects.children, 1, &o2node);
-
-  dmnsn_object *o1 = dmnsn_realize_object(o1node);
-  dmnsn_object *o2 = dmnsn_realize_object(o2node);
+  unsigned int i;
+  dmnsn_object *csg = NULL;
+  for (i = 0; i < dmnsn_array_size(objects.children) && !csg; ++i) {
+    dmnsn_astnode onode;
+    dmnsn_array_get(objects.children, i, &onode);
 
-  dmnsn_object *csg = dmnsn_new_csg_union(o1, o2);
+    if (onode.type == DMNSN_AST_LIGHT_SOURCE) {
+      dmnsn_light *light = dmnsn_realize_light_source(onode);
+      dmnsn_realize_light_source_modifiers(modifiers, light);
+      dmnsn_array_push(lights, &light);
+    } else {
+      csg = dmnsn_realize_object(onode, lights);
+    }
+  }
 
-  unsigned int i;
-  for (i = 2; i < dmnsn_array_size(objects.children); ++i) {
+  for (; i < dmnsn_array_size(objects.children); ++i) {
     dmnsn_astnode onode;
     dmnsn_array_get(objects.children, i, &onode);
 
-    dmnsn_object *object = dmnsn_realize_object(onode);
-    csg = dmnsn_new_csg_union(csg, object);
+    if (onode.type == DMNSN_AST_LIGHT_SOURCE) {
+      dmnsn_light *light = dmnsn_realize_light_source(onode);
+      dmnsn_realize_light_source_modifiers(modifiers, light);
+      dmnsn_array_push(lights, &light);
+    } else {
+      dmnsn_object *object = dmnsn_realize_object(onode, lights);
+      csg = (*csg_object_fn)(csg, object);
+    }
   }
 
-  dmnsn_astnode modifiers;
-  dmnsn_array_get(astnode.children, 1, &modifiers);
   dmnsn_realize_object_modifiers(modifiers, csg);
-
   return csg;
 }
 
 static dmnsn_object *
-dmnsn_realize_intersection(dmnsn_astnode astnode)
+dmnsn_realize_union(dmnsn_astnode astnode, dmnsn_array *lights)
+{
+  dmnsn_assert(astnode.type == DMNSN_AST_UNION, "Expected a union.");
+  return dmnsn_realize_csg(astnode, lights, &dmnsn_new_csg_union);
+}
+
+static dmnsn_object *
+dmnsn_realize_intersection(dmnsn_astnode astnode, dmnsn_array *lights)
 {
   dmnsn_assert(astnode.type == DMNSN_AST_INTERSECTION,
                "Expected an intersection.");
-
-  dmnsn_astnode objects;
-  dmnsn_array_get(astnode.children, 0, &objects);
-
-  dmnsn_astnode o1node, o2node;
-  dmnsn_array_get(objects.children, 0, &o1node);
-  dmnsn_array_get(objects.children, 1, &o2node);
-
-  dmnsn_object *o1 = dmnsn_realize_object(o1node);
-  dmnsn_object *o2 = dmnsn_realize_object(o2node);
-
-  dmnsn_object *csg = dmnsn_new_csg_intersection(o1, o2);
-
-  unsigned int i;
-  for (i = 2; i < dmnsn_array_size(objects.children); ++i) {
-    dmnsn_astnode onode;
-    dmnsn_array_get(objects.children, i, &onode);
-
-    dmnsn_object *object = dmnsn_realize_object(onode);
-    csg = dmnsn_new_csg_intersection(csg, object);
-  }
-
-  dmnsn_astnode modifiers;
-  dmnsn_array_get(astnode.children, 1, &modifiers);
-  dmnsn_realize_object_modifiers(modifiers, csg);
-
-  return csg;
+  return dmnsn_realize_csg(astnode, lights, &dmnsn_new_csg_intersection);
 }
 
 static dmnsn_object *
-dmnsn_realize_difference(dmnsn_astnode astnode)
+dmnsn_realize_difference(dmnsn_astnode astnode, dmnsn_array *lights)
 {
   dmnsn_assert(astnode.type == DMNSN_AST_DIFFERENCE, "Expected a difference.");
-
-  dmnsn_astnode objects;
-  dmnsn_array_get(astnode.children, 0, &objects);
-
-  dmnsn_astnode o1node, o2node;
-  dmnsn_array_get(objects.children, 0, &o1node);
-  dmnsn_array_get(objects.children, 1, &o2node);
-
-  dmnsn_object *o1 = dmnsn_realize_object(o1node);
-  dmnsn_object *o2 = dmnsn_realize_object(o2node);
-
-  dmnsn_object *csg = dmnsn_new_csg_difference(o1, o2);
-
-  unsigned int i;
-  for (i = 2; i < dmnsn_array_size(objects.children); ++i) {
-    dmnsn_astnode onode;
-    dmnsn_array_get(objects.children, i, &onode);
-
-    dmnsn_object *object = dmnsn_realize_object(onode);
-    csg = dmnsn_new_csg_difference(csg, object);
-  }
-
-  dmnsn_astnode modifiers;
-  dmnsn_array_get(astnode.children, 1, &modifiers);
-  dmnsn_realize_object_modifiers(modifiers, csg);
-
-  return csg;
+  return dmnsn_realize_csg(astnode, lights, &dmnsn_new_csg_difference);
 }
 
 static dmnsn_object *
-dmnsn_realize_merge(dmnsn_astnode astnode)
+dmnsn_realize_merge(dmnsn_astnode astnode, dmnsn_array *lights)
 {
   dmnsn_assert(astnode.type == DMNSN_AST_MERGE, "Expected a merge.");
-
-  dmnsn_astnode objects;
-  dmnsn_array_get(astnode.children, 0, &objects);
-
-  dmnsn_astnode o1node, o2node;
-  dmnsn_array_get(objects.children, 0, &o1node);
-  dmnsn_array_get(objects.children, 1, &o2node);
-
-  dmnsn_object *o1 = dmnsn_realize_object(o1node);
-  dmnsn_object *o2 = dmnsn_realize_object(o2node);
-
-  dmnsn_object *csg = dmnsn_new_csg_merge(o1, o2);
-
-  unsigned int i;
-  for (i = 2; i < dmnsn_array_size(objects.children); ++i) {
-    dmnsn_astnode onode;
-    dmnsn_array_get(objects.children, i, &onode);
-
-    dmnsn_object *object = dmnsn_realize_object(onode);
-    csg = dmnsn_new_csg_merge(csg, object);
-  }
-
-  dmnsn_astnode modifiers;
-  dmnsn_array_get(astnode.children, 1, &modifiers);
-  dmnsn_realize_object_modifiers(modifiers, csg);
-
-  return csg;
+  return dmnsn_realize_csg(astnode, lights, &dmnsn_new_csg_merge);
 }
 
+/* Realize an object, or maybe a light */
 static dmnsn_object *
-dmnsn_realize_object(dmnsn_astnode astnode)
+dmnsn_realize_object(dmnsn_astnode astnode, dmnsn_array *lights)
 {
   switch (astnode.type) {
   case DMNSN_AST_BOX:
     return dmnsn_realize_box(astnode);
   case DMNSN_AST_DIFFERENCE:
-    return dmnsn_realize_difference(astnode);
+    return dmnsn_realize_difference(astnode, lights);
   case DMNSN_AST_INTERSECTION:
-    return dmnsn_realize_intersection(astnode);
+    return dmnsn_realize_intersection(astnode, lights);
   case DMNSN_AST_MERGE:
-    return dmnsn_realize_merge(astnode);
+    return dmnsn_realize_merge(astnode, lights);
   case DMNSN_AST_SPHERE:
     return dmnsn_realize_sphere(astnode);
   case DMNSN_AST_UNION:
-    return dmnsn_realize_union(astnode);
+    return dmnsn_realize_union(astnode, lights);
+
+  case DMNSN_AST_LIGHT_SOURCE:
+    {
+      dmnsn_light *light = dmnsn_realize_light_source(astnode);
+      dmnsn_array_push(lights, &light);
+      return NULL;
+    }
 
   default:
     dmnsn_assert(false, "Expected an object.");
@@ -858,24 +875,6 @@ dmnsn_realize_object(dmnsn_astnode astnode)
   }
 }
 
-static dmnsn_light *
-dmnsn_realize_light_source(dmnsn_astnode astnode)
-{
-  dmnsn_assert(astnode.type == DMNSN_AST_LIGHT_SOURCE,
-               "Expected a light source.");
-
-  dmnsn_astnode point, color_node;
-  dmnsn_array_get(astnode.children, 0, &point);
-  dmnsn_array_get(astnode.children, 1, &color_node);
-
-  dmnsn_vector x0 = dmnsn_realize_vector(point);
-  dmnsn_color color = dmnsn_realize_color(color_node);
-
-  dmnsn_light *light = dmnsn_new_point_light(x0, color);
-
-  return light;
-}
-
 static dmnsn_scene *
 dmnsn_realize_astree(const dmnsn_astree *astree)
 {
@@ -928,8 +927,9 @@ dmnsn_realize_astree(const dmnsn_astree *astree)
     case DMNSN_AST_MERGE:
     case DMNSN_AST_SPHERE:
     case DMNSN_AST_UNION:
-      object = dmnsn_realize_object(astnode);
-      dmnsn_array_push(scene->objects, &object);
+      object = dmnsn_realize_object(astnode, scene->lights);
+      if (object)
+        dmnsn_array_push(scene->objects, &object);
       break;
 
     case DMNSN_AST_LIGHT_SOURCE:
diff --git a/tests/dimension/Makefile.am b/tests/dimension/Makefile.am
index bb4aa0f..44afead 100644
--- a/tests/dimension/Makefile.am
+++ b/tests/dimension/Makefile.am
@@ -19,7 +19,14 @@
 
 INCLUDES = -I$(top_srcdir)/libdimension
 
-TESTS = punctuation.sh numeric.sh strings.sh labels.sh directives.sh arithexp.sh demo.sh
+TESTS = punctuation.sh                                                         \
+        numeric.sh                                                             \
+        strings.sh                                                             \
+        labels.sh                                                              \
+        directives.sh                                                          \
+        arithexp.sh                                                            \
+        csg.sh                                                                 \
+        demo.sh
 TESTS_ENVIRONMENT = top_builddir=$(top_builddir)
 
 .sh:
@@ -33,6 +40,7 @@ EXTRA_DIST = $(TESTS)                                                          \
              directives.inc                                                    \
              directives.pov                                                    \
              arithexp.pov                                                      \
+             csg.pov                                                           \
              demo.pov
 
 clean-local:
diff --git a/tests/dimension/csg.pov b/tests/dimension/csg.pov
new file mode 100644
index 0000000..046510f
--- /dev/null
+++ b/tests/dimension/csg.pov
@@ -0,0 +1,65 @@
+/*************************************************************************
+ * Copyright (C) 2010 Tavian Barnes <tavianator@gmail.com>               *
+ *                                                                       *
+ * This file is part of The Dimension Test Suite.                        *
+ *                                                                       *
+ * The Dimension Test Suite is free software; you can redistribute it    *
+ * and/or modify it under the terms of the GNU 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 Test Suite 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  *
+ * General Public License for more details.                              *
+ *                                                                       *
+ * You should have received a copy of the GNU General Public License     *
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>. *
+ *************************************************************************/
+
+// Test constructive solid geometry
+
+camera {
+  perspective
+  location -4*z
+  right    1.6*x
+  look_at  0
+}
+
+background {
+  color rgbf <0, 0.1, 0.2, 0.1>
+}
+
+/* One-object unions */
+
+union {
+  sphere {
+    -1.5*x, 1
+    pigment { color red 1 }
+  }
+}
+
+union {
+  light_source {
+    20*y, color rgb 0.5
+  }
+}
+
+/* CSG with lights */
+difference {
+  light_source {
+    -15*x, color rgb 0.5
+  }
+  sphere {
+    1.5*x - 20*y, 1
+    pigment { color green 1 }
+  }
+  light_source {
+    15*x, color rgb 0.5
+  }
+  box {
+    <0.7, -20.8, -0.8>, <2.3, -19.2, 0.8>
+    pigment { color blue 1 }
+  }
+  translate 20*y
+}
diff --git a/tests/dimension/csg.sh b/tests/dimension/csg.sh
new file mode 100755
index 0000000..c27e448
--- /dev/null
+++ b/tests/dimension/csg.sh
@@ -0,0 +1,85 @@
+#!/bin/sh
+
+#########################################################################
+# Copyright (C) 2010 Tavian Barnes <tavianator@gmail.com>               #
+#                                                                       #
+# This file is part of The Dimension Test Suite.                        #
+#                                                                       #
+# The Dimension Test Suite is free software; you can redistribute it    #
+# and/or modify it under the terms of the GNU 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 Test Suite 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  #
+# General Public License for more details.                              #
+#                                                                       #
+# You should have received a copy of the GNU General Public License     #
+# along with this program.  If not, see <http://www.gnu.org/licenses/>. #
+#########################################################################
+
+csg=$(${top_builddir}/dimension/dimension --parse ${srcdir}/csg.pov)
+csg_exp="$(echo -n \
+'((camera
+    perspective
+    (location (vector (integer 0) (integer 0) (integer -4)
+                      (integer 0) (integer 0)))
+    (right (vector (float 1.6) (float 0) (float 0) (float 0) (float 0)))
+    (look_at (vector (integer 0) (integer 0) (integer 0)
+                     (integer 0) (integer 0))))
+  (background
+    (vector (integer 0) (float 0.1) (float 0.2) (float 0.1) (integer 0)))
+  (union
+    (array
+      (sphere
+        (vector (float -1.5) (float 0) (float 0) (float 0) (float 0))
+        (integer 1)
+        (object-modifiers
+          (pigment
+            (vector (integer 1) (integer 0) (integer 0)
+                    (integer 0) (integer 0))))))
+    object-modifiers)
+  (union
+    (array
+      (light_source
+        (vector (integer 0) (integer 20) (integer 0) (integer 0) (integer 0))
+        (vector (float 0.5) (float 0.5) (float 0.5) (integer 0) (integer 0))
+        object-modifiers))
+    object-modifiers)
+  (difference
+    (array
+      (light_source
+        (vector (integer -15) (integer 0) (integer 0) (integer 0) (integer 0))
+        (vector (float 0.5) (float 0.5) (float 0.5) (integer 0) (integer 0))
+        object-modifiers)
+      (sphere
+        (vector (float 1.5) (float -20) (float 0) (float 0) (float 0))
+        (integer 1)
+        (object-modifiers
+          (pigment
+            (vector (integer 0) (integer 1) (integer 0)
+                    (integer 0) (integer 0)))))
+      (light_source
+        (vector (integer 15) (integer 0) (integer 0) (integer 0) (integer 0))
+        (vector (float 0.5) (float 0.5) (float 0.5) (integer 0) (integer 0))
+        object-modifiers)
+      (box
+        (vector (float 0.7) (float -20.8) (float -0.8) (integer 0) (integer 0))
+        (vector (float 2.3) (float -19.2) (float 0.8) (integer 0) (integer 0))
+        (object-modifiers
+          (pigment
+            (vector (integer 0) (integer 0) (integer 1)
+                    (integer 0) (integer 0))))))
+    (object-modifiers
+      (translate (vector (integer 0) (integer 20) (integer 0)
+                         (integer 0) (integer 0))))))' \
+| tr '\n' ' ' | sed -r 's/[[:space:]]+/ /g')"
+
+if [ "$csg" != "$csg_exp" ]; then
+  echo "csg.pov parsed as \"$csg\"" >&2
+  echo "      -- expected \"$csg_exp\"" >&2
+  exit 1
+fi
+
+${top_builddir}/dimension/dimension -w768 -h480 -o csg.png ${srcdir}/csg.pov
diff --git a/tests/dimension/demo.sh b/tests/dimension/demo.sh
index 687d43c..7e9306a 100755
--- a/tests/dimension/demo.sh
+++ b/tests/dimension/demo.sh
@@ -34,7 +34,8 @@ demo_exp=$(echo -n \
     (vector (integer 0) (float 0.1) (float 0.2) (float 0.1) (integer 0)))
   (light_source
     (vector (integer -15) (integer 20) (integer 10) (integer 0) (integer 0))
-    (vector (integer 1) (integer 1) (integer 1) (integer 0) (integer 0)))
+    (vector (integer 1) (integer 1) (integer 1) (integer 0) (integer 0))
+    object-modifiers)
   (difference
     (array
       (box