From 58e698772d6b48817fdff3a2d36f445c70e87ee3 Mon Sep 17 00:00:00 2001
From: Tavian Barnes <tavianator@gmail.com>
Date: Fri, 30 Oct 2009 11:10:23 -0400
Subject: Refactor parsing and realization a bit.

---
 dimension/parse.c       | 12 ++++++----
 dimension/realize.c     | 61 ++++++++++++++++++++++++++++++-------------------
 tests/dimension/box.pov |  5 +++-
 3 files changed, 49 insertions(+), 29 deletions(-)

diff --git a/dimension/parse.c b/dimension/parse.c
index c868d95..55ad78e 100644
--- a/dimension/parse.c
+++ b/dimension/parse.c
@@ -205,10 +205,11 @@ dmnsn_parse(const dmnsn_array *tokens)
   setlocale(LC_CTYPE, "C");
   setlocale(LC_NUMERIC, "C");
 
-  for (i = 0; i < dmnsn_array_size(tokens); ++i) {
+  while (i < dmnsn_array_size(tokens)) {
     dmnsn_array_get(tokens, i, &token);
 
-    if (token.type == DMNSN_T_BOX) {
+    switch (token.type) {
+    case DMNSN_T_BOX:
       if (dmnsn_parse_box(tokens, &i, astree) != 0) {
         dmnsn_diagnostic(token.filename, token.line, token.col,
                          "Invalid box",
@@ -216,10 +217,11 @@ dmnsn_parse(const dmnsn_array *tokens)
                          dmnsn_token_name(token.type));
         goto bailout;
       }
-    } else {
+      break;
+
+    default:
       dmnsn_diagnostic(token.filename, token.line, token.col,
-                       "Expected '%s', found '%s'",
-                       dmnsn_token_name(DMNSN_T_BOX),
+                       "Unexpected token '%s'",
                        dmnsn_token_name(token.type));
       goto bailout;
     }
diff --git a/dimension/realize.c b/dimension/realize.c
index 5df2648..286bae7 100644
--- a/dimension/realize.c
+++ b/dimension/realize.c
@@ -44,6 +44,35 @@ dmnsn_realize_vector(dmnsn_astnode astnode)
   return dmnsn_vector_construct(*x, *y, *z);
 }
 
+dmnsn_object *
+dmnsn_realize_box(dmnsn_astnode astnode)
+{
+  if (astnode.type != DMNSN_AST_BOX) {
+    dmnsn_error(DMNSN_SEVERITY_HIGH, "Expected a box.");
+  }
+
+  dmnsn_astnode corner1, corner2;
+  dmnsn_array_get(astnode.children, 0, &corner1);
+  dmnsn_array_get(astnode.children, 1, &corner2);
+
+  dmnsn_vector x1 = dmnsn_realize_vector(corner1),
+               x2 = dmnsn_realize_vector(corner2);
+
+  dmnsn_object *box = dmnsn_new_cube();
+  box->trans = dmnsn_scale_matrix(dmnsn_vector_construct((x2.x - x1.x)/2.0,
+                                                         (x2.y - x1.y)/2.0,
+                                                         (x2.z - x1.z)/2.0));
+  box->trans = dmnsn_matrix_mul(
+    dmnsn_translation_matrix(dmnsn_vector_construct((x2.x + x1.x)/2.0,
+                                                    (x2.y + x1.y)/2.0,
+                                                    (x2.z + x1.z)/2.0)),
+    box->trans
+  );
+  box->trans = dmnsn_matrix_inverse(box->trans);
+
+  return box;
+}
+
 dmnsn_scene *
 dmnsn_realize(const dmnsn_array *astree)
 {
@@ -75,7 +104,7 @@ dmnsn_realize(const dmnsn_array *astree)
     trans
   );
   trans = dmnsn_matrix_mul(
-    dmnsn_rotation_matrix(dmnsn_vector_construct(0.0, 1.0, 0.0)),
+    dmnsn_rotation_matrix(dmnsn_vector_construct(0.8, 0.7, 0.0)),
     trans
   );
 
@@ -97,30 +126,16 @@ dmnsn_realize(const dmnsn_array *astree)
   for (i = 0; i < dmnsn_array_size(astree); ++i) {
     dmnsn_array_get(astree, i, &astnode);
 
-    if (astnode.type != DMNSN_AST_BOX) {
+    dmnsn_object *object;
+    switch (astnode.type) {
+    case DMNSN_AST_BOX:
+      object = dmnsn_realize_box(astnode);
+      dmnsn_array_push(scene->objects, &object);
+      break;
+
+    default:
       dmnsn_error(DMNSN_SEVERITY_HIGH, "We only handle boxes right now.");
     }
-
-    dmnsn_astnode corner1, corner2;
-    dmnsn_array_get(astnode.children, 0, &corner1);
-    dmnsn_array_get(astnode.children, 1, &corner2);
-
-    dmnsn_vector x1 = dmnsn_realize_vector(corner1),
-                 x2 = dmnsn_realize_vector(corner2);
-
-    dmnsn_object *box = dmnsn_new_cube();
-    box->trans = dmnsn_scale_matrix(dmnsn_vector_construct((x2.x - x1.x)/2.0,
-                                                           (x2.y - x1.y)/2.0,
-                                                           (x2.z - x1.z)/2.0));
-    box->trans = dmnsn_matrix_mul(
-      dmnsn_translation_matrix(dmnsn_vector_construct((x2.x + x1.x)/2.0,
-                                                      (x2.y + x1.y)/2.0,
-                                                      (x2.z + x1.z)/2.0)),
-      box->trans
-    );
-    box->trans = dmnsn_matrix_inverse(box->trans);
-
-    dmnsn_array_push(scene->objects, &box);
   }
 
   return scene;
diff --git a/tests/dimension/box.pov b/tests/dimension/box.pov
index 6a75a9a..762e5df 100644
--- a/tests/dimension/box.pov
+++ b/tests/dimension/box.pov
@@ -20,5 +20,8 @@
 // Render a box
 
 box {
-  <-0.5, -1, -1>, <0.5, 1, 1>
+  <-0.125, -1, -1>, <0.125, 1, 1>
+}
+box {
+  <-1, -1, -0.125>, <1, 1, 0.125>
 }
-- 
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