Round out some edges in scene and obj parsing

scenes/dragons.json

@@ -15,7 +15,9 @@
  {
  "name": "dragon",
  "value": {
- "type": { "from-obj": "dragon.obj" },
+ "type": {
+ "from-obj": { "file": "dragon.obj", "normalize": false }
+ },
  "transform": [
  { "translate": [0, 0.1217, 0] },
  { "scale": [0.268, 0.268, 0.268] }

scenes/teapot.json

@@ -37,7 +37,9 @@
  }
  },
  {
- "type": { "from-obj": "teapot.obj" },
+ "type": {
+ "from-obj": { "file": "teapot.obj" }
+ },
  "transform": [
  { "translate": [0, 0.5, 0] },
  { "rotate-y": -0.4 }

src/parsing/obj.zig

@@ -98,7 +98,7 @@ pub fn ObjParser(comptime T: type) type {
  }
 
  fn handleFace(
- self: *Self, tokens: *std.mem.TokenIterator(u8, .scalar), material: ?Material(T)
+ self: *Self, tokens: *std.mem.TokenIterator(u8, .scalar), state: InheritedState
  ) !void {
  const first = try Self.handleFaceHelper(tokens.next() orelse { return Self.Error.IncompleteFace; });
 
@@ -139,7 +139,8 @@ pub fn ObjParser(comptime T: type) type {
  break :blk Shape(T).triangle(p1, p2, p3);
  };
 
- triangle.material = material orelse Material(T).new();
+ triangle.material = state.material orelse Material(T).new();
+ triangle.casts_shadow = state.casts_shadow orelse true;
 
  try self.active_group.addChild(triangle);
 
@@ -166,15 +167,15 @@ pub fn ObjParser(comptime T: type) type {
  self.active_group = g;
  }
 
- fn handleLine(self: *Self, line: []const u8, material: ?Material(T)) !void {
+ fn handleLine(self: *Self, line: []const u8, state: InheritedState) !void {
  var tokens = std.mem.tokenizeScalar(u8, line, ' ');
  if (tokens.next()) |first| {
  if (std.mem.eql(u8, first, "v")) {
  try self.handleVertex(&tokens);
  } else if (std.mem.eql(u8, first, "vn")) {
  try self.handleVertexNormal(&tokens);
  } else if (std.mem.eql(u8, first, "f")) {
- try self.handleFace(&tokens, material);
+ try self.handleFace(&tokens, state);
  } else if (std.mem.eql(u8, first, "g")) {
  try self.handleNamedGroup(&tokens);
  } else {
@@ -185,7 +186,12 @@ pub fn ObjParser(comptime T: type) type {
  }
  }
 
- pub fn loadObj(self: *Self, obj: []const u8, material: ?Material(T), normalize: bool) void {
+ const InheritedState = struct {
+ material: ?Material(T) = null,
+ casts_shadow: ?bool = null,
+ };
+
+ pub fn loadObj(self: *Self, obj: []const u8, state: InheritedState, normalize: bool) void {
  var lines = std.mem.tokenizeScalar(u8, obj, '\n');
 
  if (normalize) {
@@ -267,7 +273,7 @@ pub fn ObjParser(comptime T: type) type {
  var l = lines.next();
 
  while (l) |line| : (l = lines.next()) {
- self.handleLine(line, material) catch { self.lines_ignored += 1; };
+ self.handleLine(line, state) catch { self.lines_ignored += 1; };
  }
  }
 
@@ -294,7 +300,7 @@ test "Ignoring unrecognized lines" {
  var parser = try ObjParser(f32).new(allocator);
  defer parser.destroy();
 
- parser.loadObj(gibberish, null, false);
+ parser.loadObj(gibberish, .{}, false);
 
  try testing.expectEqual(parser.lines_ignored, 5);
 }
@@ -314,7 +320,7 @@ test "Vertex records" {
  var parser = try ObjParser(f32).new(allocator);
  defer parser.destroy();
 
- parser.loadObj(obj, null, false);
+ parser.loadObj(obj, .{}, false);
 
  try testing.expectEqual(parser.lines_ignored, 0);
 
@@ -349,7 +355,7 @@ test "Parsing triangle faces" {
  var parser = try ObjParser(f32).new(allocator);
  defer parser.destroy();
 
- parser.loadObj(obj, null, false);
+ parser.loadObj(obj, .{}, false);
 
  try testing.expectEqual(parser.lines_ignored, 0);
 
@@ -383,7 +389,7 @@ test "Triangulating polygons" {
  var parser = try ObjParser(f32).new(allocator);
  defer parser.destroy();
 
- parser.loadObj(obj, null, false);
+ parser.loadObj(obj, .{}, false);
 
  try testing.expectEqual(parser.lines_ignored, 0);
  try testing.expectEqual(parser.default_group.variant.group.children.items.len, 3);
@@ -422,7 +428,7 @@ test "Triangles in groups" {
  var parser = try ObjParser(f32).new(allocator);
  defer parser.destroy();
 
- parser.loadObj(obj, null, false);
+ parser.loadObj(obj, .{}, false);
 
  try testing.expectEqual(parser.lines_ignored, 0);
 
@@ -459,7 +465,7 @@ test "Converting an OBJ file to a group" {
  var parser = try ObjParser(f32).new(allocator);
  defer parser.destroy();
 
- parser.loadObj(obj, null, false);
+ parser.loadObj(obj, .{}, false);
 
  try testing.expectEqual(parser.lines_ignored, 0);
 
@@ -486,7 +492,7 @@ test "Vertex normal records" {
  var parser = try ObjParser(f32).new(allocator);
  defer parser.destroy();
 
- parser.loadObj(obj, null, false);
+ parser.loadObj(obj, .{}, false);
 
  try testing.expectEqual(parser.lines_ignored, 0);
 
@@ -520,7 +526,7 @@ test "Faces with normals" {
  var parser = try ObjParser(f32).new(allocator);
  defer parser.destroy();
 
- parser.loadObj(obj, null, false);
+ parser.loadObj(obj, .{}, false);
 
  try testing.expectEqual(parser.lines_ignored, 0);
 

src/parsing/scene.zig

@@ -80,7 +80,10 @@ fn ObjectConfig(comptime T: type) type {
  return struct {
  @"type": union(enum) {
  @"from-definition": []const u8,
- @"from-obj": []const u8,
+ @"from-obj": *struct {
+ file: []const u8,
+ normalize: bool = true
+ },
  sphere: void,
  cube: void,
  cylinder: *struct {
@@ -332,22 +335,22 @@ fn parseObject(
  return SceneParseError.UnknownDefinition;
  }
  },
- .@"from-obj" => |file_name| blk: {
+ .@"from-obj" => |from| blk: {
  if (target.cpu.arch == .wasm32) {
  return SceneParseError.NotImplemented;
  } else {
  var obj_dir = try std.fs.cwd().openDir("obj", .{});
  defer obj_dir.close();
 
  const obj = try obj_dir.readFileAlloc(
- allocator, file_name, std.math.pow(usize, 2, 32)
+ allocator, from.file, std.math.pow(usize, 2, 32)
  );
  defer allocator.free(obj);
 
  var parser = try ObjParser(T).new(allocator);
  defer parser.destroy();
 
- parser.loadObj(obj, material, false);
+ parser.loadObj(obj, .{ .material = material, .casts_shadow = casts_shadow }, from.normalize);
 
  break :blk parser.toGroup().*;
  }