Определение позиции дочернего объекта

src/toolbar/Tool.zig

@@ -1,6 +1,9 @@
-const Point2_f = @import("../models/basic_models.zig").Point2_f;
+const basic_models = @import("../models/basic_models.zig");
+const Point2_f = basic_models.Point2_f;
 const Canvas = @import("../Canvas.zig");
 const Document = @import("../models/Document.zig");
+const pipeline = @import("../render/cpu/pipeline.zig");
+const Transform = pipeline.Transform;
 
 pub const ToolContext = struct {
     canvas: *Canvas,
@@ -8,11 +11,41 @@ pub const ToolContext = struct {
     selected_object_id: ?u64,
 
     pub fn addObject(self: *const ToolContext, template: Document.Object) !void {
-        try self.canvas.document.addObjectUnderParentId(self.selected_object_id, template);
+        var obj = template;
+        const local_pos = self.computeLocalPosition();
+        try obj.setProperty(self.canvas.document.allocator, .{ .data = .{ .position = local_pos } });
+        try self.canvas.document.addObjectUnderParentId(self.selected_object_id, obj);
         self.canvas.requestRedraw();
     }
+
+    fn computeLocalPosition(self: *const ToolContext) Point2_f {
+        if (self.selected_object_id) |parent_id| {
+            if (findWorldTransformById(self.canvas.document, parent_id)) |parent_world| {
+                return pipeline.worldToLocalTransform(parent_world, self.document_point.x, self.document_point.y);
+            }
+        }
+        return self.document_point;
+    }
 };
 
+fn findWorldTransformById(doc: *Document, target_id: u64) ?Transform {
+    const identity = Transform{};
+    for (doc.objects.items) |*obj| {
+        if (findWorldTransformInTree(obj, identity, target_id)) |t| return t;
+    }
+    return null;
+}
+
+fn findWorldTransformInTree(obj: *const Document.Object, parent: Transform, target_id: u64) ?Transform {
+    const local = Transform.init(obj);
+    const world = Transform.compose(parent, local);
+    if (obj.id == target_id) return world;
+    for (obj.children.items) |*child| {
+        if (findWorldTransformInTree(child, world, target_id)) |t| return t;
+    }
+    return null;
+}
+
 pub const Tool = struct {
     onCanvasClick: *const fn (*const ToolContext) anyerror!void,
 };