Implement point lights.

4 files changed, 47 insertions, 35 deletions

diff --git a/dimension/grammar.y b/dimension/grammar.y
index 06260d4..27685b7 100644
--- a/dimension/grammar.y
+++ b/dimension/grammar.y
@@ -429,7 +429,7 @@ yyerror(YYLTYPE *locp, dmnsn_array *astree, dmnsn_token_iterator *iterator,
 %token DMNSN_T_LATHE
 %token DMNSN_T_LEOPARD
 %token DMNSN_T_LIGHT_GROUP
-%token DMNSN_T_LIGHT_SOURCE
+%token DMNSN_T_LIGHT_SOURCE             "light_source"
 %token DMNSN_T_LINEAR_SPLINE
 %token DMNSN_T_LINEAR_SWEEP
 %token DMNSN_T_LN
@@ -687,7 +687,7 @@ yyerror(YYLTYPE *locp, dmnsn_array *astree, dmnsn_token_iterator *iterator,
 %token DMNSN_T_RANGE
 %token DMNSN_T_READ
 %token DMNSN_T_RENDER
-%token DMNSN_T_STATISTICS 
+%token DMNSN_T_STATISTICS
 %token DMNSN_T_SWITCH
 %token DMNSN_T_UNDEF
 %token DMNSN_T_VERSION
@@ -711,6 +711,7 @@ yyerror(YYLTYPE *locp, dmnsn_array *astree, dmnsn_token_iterator *iterator,
 %type <astnode> OBJECT
 %type <astnode> FINITE_SOLID_OBJECT
 %type <astnode> BOX
+%type <astnode> LIGHT_SOURCE
 %type <astnode> SPHERE
 
 /* Object modifiers */
@@ -771,6 +772,7 @@ TRANSFORMATION: "rotate" VECTOR {
 /* Objects */
 
 OBJECT: FINITE_SOLID_OBJECT
+      | LIGHT_SOURCE
 ;
 
 FINITE_SOLID_OBJECT: BOX
@@ -786,6 +788,14 @@ BOX: "box" "{"
    }
 ;
 
+LIGHT_SOURCE: "light_source" "{"
+                VECTOR "," COLOR
+              "}"
+            {
+              $$ = dmnsn_new_astnode2(DMNSN_AST_LIGHT_SOURCE, @$, $3, $5);
+            }
+;
+
 SPHERE: "sphere" "{"
           VECTOR "," FLOAT
           OBJECT_MODIFIERS
@@ -1455,6 +1465,7 @@ dmnsn_astnode_string(dmnsn_astnode_type astnode_type)
 
   dmnsn_astnode_map(DMNSN_AST_BOX, "box");
   dmnsn_astnode_map(DMNSN_AST_SPHERE, "sphere");
+  dmnsn_astnode_map(DMNSN_AST_LIGHT_SOURCE, "light_source");
 
   dmnsn_astnode_map(DMNSN_AST_OBJECT_MODIFIERS, "object-modifiers");
 
diff --git a/dimension/lexer.l b/dimension/lexer.l
index ac90d8e..58bdc0e 100644
--- a/dimension/lexer.l
+++ b/dimension/lexer.l
@@ -159,6 +159,7 @@ unsigned long wchar;
 "gray"          PUSH_TOKEN(DMNSN_T_GRAY);
 "grey"          PUSH_TOKEN(DMNSN_T_GRAY);
 "green"         PUSH_TOKEN(DMNSN_T_GREEN);
+"light_source"  PUSH_TOKEN(DMNSN_T_LIGHT_SOURCE);
 "pigment"       PUSH_TOKEN(DMNSN_T_PIGMENT);
 "red"           PUSH_TOKEN(DMNSN_T_RED);
 "rgb"           PUSH_TOKEN(DMNSN_T_RGB);
diff --git a/dimension/parse.h b/dimension/parse.h
index eeb4492..1bf4436 100644
--- a/dimension/parse.h
+++ b/dimension/parse.h
@@ -30,6 +30,7 @@ typedef enum {
   DMNSN_AST_TRANSLATION,
 
   DMNSN_AST_BOX,
+  DMNSN_AST_LIGHT_SOURCE,
   DMNSN_AST_SPHERE,
 
   DMNSN_AST_OBJECT_MODIFIERS,
diff --git a/dimension/realize.c b/dimension/realize.c
index 84d04c6..ac0231b 100644
--- a/dimension/realize.c
+++ b/dimension/realize.c
@@ -162,8 +162,7 @@ dmnsn_realize_pigment(dmnsn_astnode astnode, dmnsn_object *object)
   if (!object->texture) {
     object->texture = dmnsn_new_texture();
     if (!object->texture) {
-      dmnsn_delete_object(object);
-      return NULL;
+      dmnsn_error(DMNSN_SEVERITY_HIGH, "Couldn't create texture.");
     }
   }
   dmnsn_delete_pigment(object->texture->pigment);
@@ -180,8 +179,7 @@ dmnsn_realize_pigment(dmnsn_astnode astnode, dmnsn_object *object)
     color = dmnsn_realize_color(color_node);
     object->texture->pigment = dmnsn_new_solid_pigment(color);
     if (!object->texture->pigment) {
-      dmnsn_delete_object(object);
-      return NULL;
+      dmnsn_error(DMNSN_SEVERITY_HIGH, "Couldn't create pigment.");
     }
     break;
 
@@ -290,6 +288,28 @@ dmnsn_realize_box(dmnsn_astnode astnode)
   return box;
 }
 
+static dmnsn_light *
+dmnsn_realize_light_source(dmnsn_astnode astnode)
+{
+  if (astnode.type != DMNSN_AST_LIGHT_SOURCE) {
+    dmnsn_error(DMNSN_SEVERITY_HIGH, "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);
+  if (!light) {
+    dmnsn_error(DMNSN_SEVERITY_HIGH, "Couldn't allocate light.");
+  }
+
+  return light;
+}
+
 static dmnsn_object *
 dmnsn_realize_sphere(dmnsn_astnode astnode)
 {
@@ -309,18 +329,6 @@ dmnsn_realize_sphere(dmnsn_astnode astnode)
     dmnsn_error(DMNSN_SEVERITY_HIGH, "Couldn't allocate sphere.");
   }
 
-  sphere->texture = dmnsn_new_texture();
-  if (!sphere->texture) {
-    dmnsn_delete_object(sphere);
-    dmnsn_error(DMNSN_SEVERITY_HIGH, "Couldn't allocate sphere texture.");
-  }
-
-  sphere->texture->pigment = dmnsn_new_solid_pigment(dmnsn_white);
-  if (!sphere->texture->pigment) {
-    dmnsn_delete_object(sphere);
-    dmnsn_error(DMNSN_SEVERITY_HIGH, "Couldn't allocate sphere pigment.");
-  }
-
   sphere->trans = dmnsn_scale_matrix(dmnsn_new_vector(r, r, r));
   sphere->trans = dmnsn_matrix_mul(dmnsn_translation_matrix(x0), sphere->trans);
 
@@ -340,7 +348,7 @@ dmnsn_realize(const dmnsn_array *astree)
   }
 
   /* Default finish */
-  scene->default_texture->finish = dmnsn_new_phong_finish(1.0, 0.5, 50.0);
+  scene->default_texture->finish = dmnsn_new_phong_finish(1.0, 0.0, 1.0);
   if (!scene->default_texture->finish) {
     dmnsn_delete_scene(scene);
     return NULL;
@@ -382,18 +390,6 @@ dmnsn_realize(const dmnsn_array *astree)
   }
   dmnsn_set_perspective_camera_trans(scene->camera, trans);
 
-  /* Make a light */
-
-  dmnsn_light *light = dmnsn_new_point_light(
-    dmnsn_new_vector(-15.0, 20.0, 10.0),
-    dmnsn_white
-  );
-  if (!light) {
-    dmnsn_delete_scene(scene);
-    return NULL;
-  }
-  dmnsn_array_push(scene->lights, &light);
-
   /*
    * Now parse the abstract syntax tree
    */
@@ -404,6 +400,7 @@ dmnsn_realize(const dmnsn_array *astree)
   for (i = 0; i < dmnsn_array_size(astree); ++i) {
     dmnsn_array_get(astree, i, &astnode);
 
+    dmnsn_light  *light;
     dmnsn_object *object;
     switch (astnode.type) {
     case DMNSN_AST_BOX:
@@ -411,16 +408,18 @@ dmnsn_realize(const dmnsn_array *astree)
       dmnsn_array_push(scene->objects, &object);
       break;
 
+    case DMNSN_AST_LIGHT_SOURCE:
+      light = dmnsn_realize_light_source(astnode);
+      dmnsn_array_push(scene->lights, &light);
+      break;
+
     case DMNSN_AST_SPHERE:
       object = dmnsn_realize_sphere(astnode);
       dmnsn_array_push(scene->objects, &object);
       break;
 
     default:
-      fprintf(stderr, "Unrecognised syntax element '%s'.\n",
-              dmnsn_astnode_string(astnode.type));
-      dmnsn_delete_scene(scene);
-      return NULL;
+      dmnsn_error(DMNSN_SEVERITY_HIGH, "Unrecognised syntax element.");
     }
   }