Implement background colors.

6 files changed, 41 insertions, 33 deletions

diff --git a/dimension/grammar.y b/dimension/grammar.y
index ddc7418..01e2c0f 100644
--- a/dimension/grammar.y
+++ b/dimension/grammar.y
@@ -270,7 +270,7 @@ yyerror(YYLTYPE *locp, dmnsn_array *astree, dmnsn_token_iterator *iterator,
 %token DMNSN_T_AUTOSTOP
 %token DMNSN_T_AVERAGE
 %token DMNSN_T_B_SPLINE
-%token DMNSN_T_BACKGROUND
+%token DMNSN_T_BACKGROUND               "background"
 %token DMNSN_T_BEZIER_SPLINE
 %token DMNSN_T_BICUBIC_PATCH
 %token DMNSN_T_BLACK_HOLE
@@ -703,6 +703,10 @@ yyerror(YYLTYPE *locp, dmnsn_array *astree, dmnsn_token_iterator *iterator,
 /* Transformations */
 %type <astnode> TRANSFORMATION
 
+/* Atmospheric effects */
+%type <astnode> ATMOSPHERIC_EFFECT
+%type <astnode> BACKGROUND
+
 /* Objects */
 %type <astnode> OBJECT
 %type <astnode> FINITE_SOLID_OBJECT
@@ -749,7 +753,8 @@ SCENE: /* empty */ { }
      }
 ;
 
-SCENE_ITEM: OBJECT
+SCENE_ITEM: ATMOSPHERIC_EFFECT
+          | OBJECT
 ;
 
 /* Transformations */
@@ -765,6 +770,16 @@ TRANSFORMATION: "rotate" VECTOR {
               }
 ;
 
+/* Atmospheric effects */
+
+ATMOSPHERIC_EFFECT: BACKGROUND
+;
+
+BACKGROUND: "background" "{" COLOR "}" {
+            $$ = dmnsn_new_astnode1(DMNSN_AST_BACKGROUND, @$, $3);
+          }
+;
+
 /* Objects */
 
 OBJECT: FINITE_SOLID_OBJECT
@@ -1466,6 +1481,8 @@ dmnsn_astnode_string(dmnsn_astnode_type astnode_type)
   dmnsn_astnode_map(DMNSN_AST_SCALE, "scale");
   dmnsn_astnode_map(DMNSN_AST_TRANSLATION, "translate");
 
+  dmnsn_astnode_map(DMNSN_AST_BACKGROUND, "background");
+
   dmnsn_astnode_map(DMNSN_AST_BOX, "box");
   dmnsn_astnode_map(DMNSN_AST_SPHERE, "sphere");
   dmnsn_astnode_map(DMNSN_AST_LIGHT_SOURCE, "light_source");
diff --git a/dimension/lexer.l b/dimension/lexer.l
index 58bdc0e..d91855d 100644
--- a/dimension/lexer.l
+++ b/dimension/lexer.l
@@ -150,6 +150,7 @@ unsigned long wchar;
 }
 
 (?# Keywords)
+"background"    PUSH_TOKEN(DMNSN_T_BACKGROUND);
 "box"           PUSH_TOKEN(DMNSN_T_BOX);
 "blue"          PUSH_TOKEN(DMNSN_T_BLUE);
 "camera"        PUSH_TOKEN(DMNSN_T_CAMERA);
diff --git a/dimension/parse.h b/dimension/parse.h
index 1bf4436..f0bc994 100644
--- a/dimension/parse.h
+++ b/dimension/parse.h
@@ -29,6 +29,8 @@ typedef enum {
   DMNSN_AST_SCALE,
   DMNSN_AST_TRANSLATION,
 
+  DMNSN_AST_BACKGROUND,
+
   DMNSN_AST_BOX,
   DMNSN_AST_LIGHT_SOURCE,
   DMNSN_AST_SPHERE,
diff --git a/dimension/realize.c b/dimension/realize.c
index ac0231b..8d811fc 100644
--- a/dimension/realize.c
+++ b/dimension/realize.c
@@ -356,9 +356,7 @@ dmnsn_realize(const dmnsn_array *astree)
   scene->default_texture->finish->ambient = 0.1;
 
   /* Background color */
-  dmnsn_sRGB background_sRGB = { .R = 0.0, .G = 0.0, .B = 0.1 };
-  scene->background = dmnsn_color_from_sRGB(background_sRGB);
-  scene->background.filter = 0.1;
+  scene->background = dmnsn_black;
 
   /* Allocate a canvas */
   scene->canvas = dmnsn_new_canvas(768, 480);
@@ -403,6 +401,11 @@ dmnsn_realize(const dmnsn_array *astree)
     dmnsn_light  *light;
     dmnsn_object *object;
     switch (astnode.type) {
+    case DMNSN_AST_BACKGROUND:
+      dmnsn_array_get(astnode.children, 0, &astnode);
+      scene->background = dmnsn_realize_color(astnode);
+      break;
+
     case DMNSN_AST_BOX:
       object = dmnsn_realize_box(astnode);
       dmnsn_array_push(scene->objects, &object);
diff --git a/tests/dimension/demo.pov b/tests/dimension/demo.pov
index b6833bc..c6f99fb 100644
--- a/tests/dimension/demo.pov
+++ b/tests/dimension/demo.pov
@@ -19,21 +19,25 @@
 
 // Render demo scene
 
+background {
+  color rgbf <0, 0, 0.1, 0.1>
+}
+
 light_source {
-  <-15, 20, 10>, rgb <1, 1, 1>
+  <-15, 20, 10>, color rgb <1, 1, 1>
 }
 
 box {
   <-1, -1, -1>, <1, 1, 1>
   rotate <45, 0, 0>
   pigment {
-    rgbft <0, 0, 1, 0.25, 0.25>
+    color rgbft <0, 0, 1, 0.25, 0.25>
   }
 }
 
 sphere {
   <0, 0, 0>, 1.25
   pigment {
-    rgb <0, 1, 0>
+    color rgb <0, 1, 0>
   }
 }
diff --git a/tests/dimension/demo.sh b/tests/dimension/demo.sh
index fbd6fc3..0d8da5a 100755
--- a/tests/dimension/demo.sh
+++ b/tests/dimension/demo.sh
@@ -19,30 +19,11 @@
 # along with this program.  If not, see <http://www.gnu.org/licenses/>. #
 #########################################################################
 
-demo=$(${top_builddir}/dimension/dimension --tokenize --parse ${srcdir}/demo.pov)
-demo_exp="$(echo -n \
-'(light_source {
-    < - (integer "15") , (integer "20") , (integer "10") > ,
-    rgb < (integer "1") , (integer "1") , (integer "1") >
-  }
-  box {
-    < - (integer "1") , - (integer "1") , - (integer "1") > ,
-    < (integer "1") , (integer "1") , (integer "1") >
-    rotate < (integer "45") , (integer "0") , (integer "0") >
-    pigment {
-      rgbft < (integer "0") , (integer "0") , (integer "1") ,
-              (float "0.25") , (float "0.25") >
-    }
-  }
-  sphere {
-    < (integer "0") , (integer "0") , (integer "0") > , (float "1.25")
-    pigment {
-      rgb < (integer "0") , (integer "1") , (integer "0") >
-    }
-  })' \
-| tr '\n' ' ' | sed -r 's/[[:space:]]+/ /g')
-$(echo -n \
-'((light_source
+demo=$(${top_builddir}/dimension/dimension --parse ${srcdir}/demo.pov)
+demo_exp=$(echo -n \
+'((background
+    (vector (integer 0) (integer 0) (float 0.1) (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)))
   (box
@@ -61,7 +42,7 @@ $(echo -n \
       (texture
         (pigment (vector (integer 0) (integer 1) (integer 0)
                          (integer 0) (integer 0)))))))' \
-| tr '\n' ' ' | sed -r 's/[[:space:]]+/ /g')"
+| tr '\n' ' ' | sed -r 's/[[:space:]]+/ /g')
 
 if [ "$demo" != "$demo_exp" ]; then
   echo "demo.pov parsed as \"$demo\"" >&2