`CurvePrim` draw an arrow representing a vector in 3D space.
| 338 | |
| 339 | # === Vector Primitive === |
| 340 | class VectorPrim(Primitive): |
| 341 | """ |
| 342 | `CurvePrim` draw an arrow representing a vector in 3D space. |
| 343 | """ |
| 344 | def __init__(self, vector, size=1.0, color=None): |
| 345 | super(VectorPrim, self).__init__() |
| 346 | self._size = size |
| 347 | self.color = color or COLOR_BLACK |
| 348 | |
| 349 | # body line |
| 350 | _points = ((0, 0, 0), vector) |
| 351 | self.body = CurvePrim(_points, color=self.color) |
| 352 | self.body.scale(self.size, self.size, self.size) |
| 353 | |
| 354 | # head line |
| 355 | m_vector = om2.MVector(*vector) |
| 356 | length = m_vector.length() |
| 357 | headSize = 0.1 * length |
| 358 | points = ((length - headSize, headSize, 0.0), |
| 359 | (length, 0.0, 0.0), |
| 360 | (length-headSize, -headSize, 0.0)) |
| 361 | self.head = CurvePrim(points, color=self.color) |
| 362 | self.isDirty = True # force to re-orient header |
| 363 | |
| 364 | # `size` represents the scale in which the vector is drawed on the screen |
| 365 | @property |
| 366 | def size(self): |
| 367 | return self._size |
| 368 | |
| 369 | @size.setter |
| 370 | def size(self, value): |
| 371 | self._size = value |
| 372 | self.isDirty = True |
| 373 | |
| 374 | def update(self): |
| 375 | super(VectorPrim, self).update() |
| 376 | # update the line along the length of the vector |
| 377 | self.body.color = self.color |
| 378 | self.body.transform = self.transform |
| 379 | self.body.transform.setScale((self.size, self.size, self.size), |
| 380 | om2.MSpace.kWorld) |
| 381 | self.body.update() |
| 382 | |
| 383 | # update the header of the vector (arrow) |
| 384 | self.head.color = self.color |
| 385 | self.head.transform = self.body.transform |
| 386 | m_vector = om2.MVector(self.body._drawPoints[1]) |
| 387 | m_vector -= self.transform.translation(om2.MSpace.kWorld) |
| 388 | m_vectorX = om2.MVector(1, 0, 0) |
| 389 | m_rot = m_vectorX.rotateTo(m_vector) |
| 390 | self.head.transform.setRotation(m_rot) |
| 391 | |
| 392 | def draw(self, view, renderer): |
| 393 | super(VectorPrim, self).draw(view, renderer) |
| 394 | self.body.draw(view, renderer) |
| 395 | self.head.draw(view, renderer) |
| 396 | |
| 397 |