Implement object modifiers and rotation.

4 files changed, 108 insertions, 37 deletions

diff --git a/dimension/grammar.y b/dimension/grammar.y
index 6bf6569..91d3852 100644
--- a/dimension/grammar.y
+++ b/dimension/grammar.y
@@ -188,6 +188,8 @@ yyerror(YYLTYPE *locp, dmnsn_array *astree, dmnsn_token_iterator *iterator,
 %error-verbose
 %token-table
 
+%expect 2
+
 %parse-param {dmnsn_array *astree}
 %parse-param {dmnsn_token_iterator *iterator}
 %lex-param {dmnsn_token_iterator *iterator}
@@ -550,7 +552,7 @@ yyerror(YYLTYPE *locp, dmnsn_array *astree, dmnsn_token_iterator *iterator,
 %token DMNSN_T_RGBT
 %token DMNSN_T_RIGHT
 %token DMNSN_T_RIPPLES
-%token DMNSN_T_ROTATE
+%token DMNSN_T_ROTATE                   "rotate"
 %token DMNSN_T_ROUGHNESS
 %token DMNSN_T_SAMPLES
 %token DMNSN_T_SAVE_FILE
@@ -699,12 +701,19 @@ yyerror(YYLTYPE *locp, dmnsn_array *astree, dmnsn_token_iterator *iterator,
 /* Top-level items */
 %type <astnode> SCENE_ITEM
 
+/* Transformations */
+%type <astnode> TRANSFORMATION
+
 /* Objects */
 %type <astnode> OBJECT
 %type <astnode> FINITE_SOLID_OBJECT
 %type <astnode> BOX
 %type <astnode> SPHERE
 
+/* Object modifiers */
+%type <astnode> OBJECT_MODIFIERS
+%type <astnode> OBJECT_MODIFIER
+
 /* Floats */
 %type <astnode> FLOAT
 %type <astnode> FLOAT_EXPR
@@ -719,6 +728,8 @@ yyerror(YYLTYPE *locp, dmnsn_array *astree, dmnsn_token_iterator *iterator,
 
 %%
 
+/* Start symbol */
+
 SCENE:    /* empty */ { }
         | SCENE SCENE_ITEM {
           dmnsn_array_push(astree, &$2);
@@ -728,6 +739,14 @@ SCENE:    /* empty */ { }
 SCENE_ITEM:       OBJECT
 ;
 
+/* Transformations */
+
+TRANSFORMATION:   "rotate" VECTOR {
+                  $$ = dmnsn_new_astnode1(DMNSN_AST_ROTATION, @$, $2);
+                }
+
+/* Objects */
+
 OBJECT:   FINITE_SOLID_OBJECT
 ;
 
@@ -737,20 +756,37 @@ FINITE_SOLID_OBJECT:      BOX
 
 BOX:      "box" "{"
             VECTOR "," VECTOR
+            OBJECT_MODIFIERS
           "}"
         {
-          $$ = dmnsn_new_astnode2(DMNSN_AST_BOX, @$, $3, $5);
+          $$ = dmnsn_new_astnode3(DMNSN_AST_BOX, @$, $3, $5, $6);
         }
 ;
 
 SPHERE:   "sphere" "{"
             VECTOR "," FLOAT
+            OBJECT_MODIFIERS
           "}"
         {
-          $$ = dmnsn_new_astnode2(DMNSN_AST_SPHERE, @$, $3, $5);
+          $$ = dmnsn_new_astnode3(DMNSN_AST_SPHERE, @$, $3, $5, $6);
         }
 ;
 
+/* Object modifiers */
+
+OBJECT_MODIFIERS:         /* empty */ {
+                          $$ = dmnsn_new_astnode(DMNSN_AST_OBJECT_MODIFIERS,
+                                                 @$);
+                        }
+                        | OBJECT_MODIFIERS OBJECT_MODIFIER {
+                          $$ = $1;
+                          dmnsn_array_push($$.children, &$2);
+                        }
+
+OBJECT_MODIFIER:  TRANSFORMATION
+
+/* Floats */
+
 FLOAT:    FLOAT_EXPR {
           $$ = dmnsn_eval_scalar($1);
           dmnsn_delete_astnode($1);
@@ -856,6 +892,8 @@ FLOAT_LITERAL:    "integer" {
                 }
 ;
 
+/* Vectors */
+
 VECTOR:   VECTOR_EXPR {
           $$ = dmnsn_eval_vector($1);
           dmnsn_delete_astnode($1);
@@ -1334,6 +1372,8 @@ dmnsn_astnode_string(dmnsn_astnode_type astnode_type)
   dmnsn_astnode_map(DMNSN_AST_BOX, "box");
   dmnsn_astnode_map(DMNSN_AST_VECTOR, "vector");
   dmnsn_astnode_map(DMNSN_AST_SPHERE, "sphere");
+  dmnsn_astnode_map(DMNSN_AST_OBJECT_MODIFIERS, "object-modifiers");
+  dmnsn_astnode_map(DMNSN_AST_ROTATION, "rotate");
 
   default:
     fprintf(stderr, "Warning: unrecognised astnode type %d.\n",
diff --git a/dimension/lexer.l b/dimension/lexer.l
index 50e9a8b..618bb7b 100644
--- a/dimension/lexer.l
+++ b/dimension/lexer.l
@@ -160,6 +160,7 @@ unsigned long wchar;
 "grey"          PUSH_TOKEN(DMNSN_T_GRAY);
 "green"         PUSH_TOKEN(DMNSN_T_GREEN);
 "red"           PUSH_TOKEN(DMNSN_T_RED);
+"rotate"        PUSH_TOKEN(DMNSN_T_ROTATE);
 "sphere"        PUSH_TOKEN(DMNSN_T_SPHERE);
 "t"             PUSH_TOKEN(DMNSN_T_T);
 "transmit"      PUSH_TOKEN(DMNSN_T_TRANSMIT);
diff --git a/dimension/parse.h b/dimension/parse.h
index 5801cdf..ea9ec87 100644
--- a/dimension/parse.h
+++ b/dimension/parse.h
@@ -33,6 +33,8 @@ typedef enum {
   DMNSN_AST_VECTOR,
   DMNSN_AST_BOX,
   DMNSN_AST_SPHERE,
+  DMNSN_AST_ROTATION,
+  DMNSN_AST_OBJECT_MODIFIERS,
 } dmnsn_astnode_type;
 
 typedef struct dmnsn_astnode dmnsn_astnode;
diff --git a/dimension/realize.c b/dimension/realize.c
index 264c4a7..2c5bd81 100644
--- a/dimension/realize.c
+++ b/dimension/realize.c
@@ -25,41 +25,14 @@
 static double
 dmnsn_realize_float(dmnsn_astnode astnode)
 {
-  dmnsn_astnode lhs, rhs;
-
   switch (astnode.type) {
   case DMNSN_AST_FLOAT:
     return *(double *)astnode.ptr;
-
   case DMNSN_AST_INTEGER:
     return *(long *)astnode.ptr;
 
-  case DMNSN_AST_NEGATE:
-    dmnsn_array_get(astnode.children, 0, &rhs);
-    return -dmnsn_realize_float(rhs);
-
-  case DMNSN_AST_ADD:
-    dmnsn_array_get(astnode.children, 0, &lhs);
-    dmnsn_array_get(astnode.children, 1, &rhs);
-    return dmnsn_realize_float(lhs) + dmnsn_realize_float(rhs);
-
-  case DMNSN_AST_SUB:
-    dmnsn_array_get(astnode.children, 0, &lhs);
-    dmnsn_array_get(astnode.children, 1, &rhs);
-    return dmnsn_realize_float(lhs) - dmnsn_realize_float(rhs);
-
-  case DMNSN_AST_MUL:
-    dmnsn_array_get(astnode.children, 0, &lhs);
-    dmnsn_array_get(astnode.children, 1, &rhs);
-    return dmnsn_realize_float(lhs) * dmnsn_realize_float(rhs);
-
-  case DMNSN_AST_DIV:
-    dmnsn_array_get(astnode.children, 0, &lhs);
-    dmnsn_array_get(astnode.children, 1, &rhs);
-    return dmnsn_realize_float(lhs) / dmnsn_realize_float(rhs);
-
   default:
-    dmnsn_error(DMNSN_SEVERITY_HIGH, "Invalid arithmetic expression.");
+    dmnsn_error(DMNSN_SEVERITY_HIGH, "Invalid float.");
     return 0; /* Silence compiler warning */
   }
 }
@@ -83,7 +56,58 @@ dmnsn_realize_vector(dmnsn_astnode astnode)
   return dmnsn_new_vector(x, y, z);
 }
 
-dmnsn_object *
+static dmnsn_object *
+dmnsn_realize_rotation(dmnsn_astnode astnode, dmnsn_object *object)
+{
+  const double deg2rad = atan(1.0)/45.0;
+
+  dmnsn_astnode angle_node;
+  dmnsn_array_get(astnode.children, 0, &angle_node);
+
+  dmnsn_vector angle = dmnsn_vector_mul(
+    deg2rad,
+    dmnsn_realize_vector(angle_node)
+  );
+
+  /* Rotations in POV-Ray are done about the X-axis first, then Y, then Z */
+  object->trans = dmnsn_matrix_mul(
+    dmnsn_rotation_matrix(dmnsn_new_vector(angle.x, 0.0, 0.0)),
+    object->trans
+  );
+  object->trans = dmnsn_matrix_mul(
+    dmnsn_rotation_matrix(dmnsn_new_vector(0.0, angle.y, 0.0)),
+    object->trans
+  );
+  object->trans = dmnsn_matrix_mul(
+    dmnsn_rotation_matrix(dmnsn_new_vector(0.0, 0.0, angle.z)),
+    object->trans
+  );
+
+  return object;
+}
+
+static dmnsn_object *
+dmnsn_realize_object_modifiers(dmnsn_astnode astnode, dmnsn_object *object)
+{
+  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:
+      object = dmnsn_realize_rotation(modifier, object);
+      break;
+
+    default:
+      dmnsn_error(DMNSN_SEVERITY_HIGH, "Invalid object modifier.");
+    }
+  }
+
+  return object;
+}
+
+static dmnsn_object *
 dmnsn_realize_box(dmnsn_astnode astnode)
 {
   if (astnode.type != DMNSN_AST_BOX) {
@@ -114,10 +138,14 @@ dmnsn_realize_box(dmnsn_astnode astnode)
     box->trans
   );
 
+  dmnsn_astnode modifiers;
+  dmnsn_array_get(astnode.children, 2, &modifiers);
+  box = dmnsn_realize_object_modifiers(modifiers, box);
+
   return box;
 }
 
-dmnsn_object *
+static dmnsn_object *
 dmnsn_realize_sphere(dmnsn_astnode astnode)
 {
   if (astnode.type != DMNSN_AST_SPHERE) {
@@ -151,6 +179,10 @@ dmnsn_realize_sphere(dmnsn_astnode astnode)
   sphere->trans = dmnsn_scale_matrix(dmnsn_new_vector(r, r, r));
   sphere->trans = dmnsn_matrix_mul(dmnsn_translation_matrix(x0), sphere->trans);
 
+  dmnsn_astnode modifiers;
+  dmnsn_array_get(astnode.children, 2, &modifiers);
+  sphere = dmnsn_realize_object_modifiers(modifiers, sphere);
+
   return sphere;
 }
 
@@ -188,10 +220,6 @@ dmnsn_realize(const dmnsn_array *astree)
     dmnsn_rotation_matrix(dmnsn_new_vector(0.0, 1.0, 0.0)),
     trans
   );
-  trans = dmnsn_matrix_mul(
-    dmnsn_rotation_matrix(dmnsn_new_vector(-0.75, 0.0, 0.0)),
-    trans
-  );
 
   /* Create a perspective camera */
   scene->camera = dmnsn_new_perspective_camera();