这个工具允许我用鼠标为我的 QGraphicsView“雕刻”QGraphicsPathItems。但是每当我将路径项目移动到不同的位置时，我只能从原始位置雕刻该项目。例如，如果我将路径 A 从点 C 移动到点 B，我只能雕刻从点 C 开始的路径（就像它是不可见的一样）。
from PyQt5.QtWidgets import *
from PyQt5.QtCore import *
from PyQt5.QtGui import *
import sys
import math
class PathEditorGraphicsView(QGraphicsView):
def __init__(self, parent=None):
super().__init__(parent)
self.sculpting_item = None
self.sculpting_item_point_index = -1
self.sculpting_item_offset = QPointF()
self.undo_stack = QUndoStack(self)
self.initial_path = None
self.sculpt_radius = 10 # Radius for sculpting tool
self.setRenderHint(QPainter.Antialiasing)
def mousePressEvent(self, event):
if event.button() == Qt.LeftButton:
self.on_sculpt_start(event)
super().mousePressEvent(event)
def mouseMoveEvent(self, event):
self.on_sculpt(event)
super().mouseMoveEvent(event)
def mouseReleaseEvent(self, event):
if event.button() == Qt.LeftButton:
self.on_sculpt_end(event)
super().mouseReleaseEvent(event)
def on_sculpt_start(self, event):
pos = self.mapToScene(event.pos())
item = self.scene().itemAt(pos, self.transform())
if isinstance(item, QGraphicsPathItem):
self.sculpting_item = item
self.sculpting_item_point_index, self.sculpting_item_offset = self.find_closest_point(pos, item)
self.sculpting_initial_path = QPainterPath(item.path())
print(f"Sculpt Start: Item ID {id(item)}, Point Index {self.sculpting_item_point_index}")
def on_sculpt(self, event):
if self.sculpting_item is not None and self.sculpting_item_point_index != -1:
pos = self.mapToScene(event.pos()) - self.sculpting_item_offset
self.update_path_point(self.sculpting_item, self.sculpting_item_point_index, pos)
def on_sculpt_end(self, event):
self.sculpting_item = None
self.sculpting_item_point_index = -1
self.initial_path = None
def find_closest_point(self, pos, item):
path = item.path()
min_dist = float('inf')
closest_point_index = -1
closest_offset = QPointF()
for i in range(path.elementCount()):
point = path.elementAt(i)
point_pos = QPointF(point.x, point.y)
dist = QLineF(point_pos, pos).length()
if dist < min_dist:
min_dist = dist
closest_point_index = i
closest_offset = pos - point_pos
return closest_point_index, closest_offset
def update_path_point(self, item, index, new_pos):
path = item.path()
elements = [path.elementAt(i) for i in range(path.elementCount())]
if index < 0 or index >= len(elements):
return # Ensure the index is within bounds
old_pos = QPointF(elements[index].x, elements[index].y)
delta_pos = new_pos - old_pos
def calculate_influence(dist, radius):
return math.exp(-(dist**2) / (2 * (radius / 2.0)**2))
for i in range(len(elements)):
point = elements[i]
point_pos = QPointF(point.x, point.y)
dist = QLineF(point_pos, old_pos).length()
if dist <= self.sculpt_radius:
influence = calculate_influence(dist, self.sculpt_radius)
elements[i].x += delta_pos.x() * influence
elements[i].y += delta_pos.y() * influence
new_path = QPainterPath()
new_path.moveTo(elements[0].x, elements[0].y)
i = 1
while i < len(elements):
if i + 2 < len(elements):
new_path.cubicTo(elements[i].x, elements[i].y,
elements[i + 1].x, elements[i + 1].y,
elements[i + 2].x, elements[i + 2].y)
i += 3
else:
new_path.lineTo(elements[i].x, elements[i].y)
i += 1
item.setPath(new_path)
app = QApplication(sys.argv)
scene = QGraphicsScene()
view = PathEditorGraphicsView()
view.setScene(scene)
# Example path item
path = QPainterPath()
path.moveTo(50, 50)
path.cubicTo(70, 100, 130, 0, 150, 50)
path.cubicTo(70, 100, 130, 0, 150, 50)
path.cubicTo(170, 100, 230, 0, 250, 50)
path.cubicTo(270, 100, 330, 0, 350, 50)
path.cubicTo(370, 100, 430, 0, 450, 50)
path.cubicTo(470, 100, 530, 0, 550, 50)
path.cubicTo(570, 100, 630, 0, 650, 50)
path.cubicTo(670, 100, 730, 0, 750, 50)
path_item = QGraphicsPathItem(path)
scene.addItem(path_item)
# if we move the position of the path at all, the tool no longer works
path_item.setPos(100, 100)
view.show()
sys.exit(app.exec_())
我在该项目上尝试了
mapFromScene()通过使用地图方法解决了这个问题，这是最终的。我还添加了一个功能，因此当您双击时，路径会在该点变得平滑。
def on_sculpt_start(self, event):
pos = self.mapToScene(event.pos())
item = self.scene().itemAt(pos, self.transform())
if isinstance(item, CustomPathItem):
pos_in_item_coords = item.mapFromScene(pos)
self.sculpting_item = item
self.sculpting_item_point_index, self.sculpting_item_offset = self.find_closest_point(pos_in_item_coords,
item)
self.sculpting_initial_path = QPainterPath(item.path()) # Make a deep copy of the path
print(f"Sculpt Start: Item ID {id(item)}, Point Index {self.sculpting_item_point_index}")
self.canvas.addItem(self.sculpt_shape)
self.sculpt_shape.setPos(pos - self.sculpt_shape.boundingRect().center())
def on_sculpt(self, event):
if self.sculpting_item is not None and self.sculpting_item_point_index != -1:
pos = self.mapToScene(event.pos())
pos_in_item_coords = self.sculpting_item.mapFromScene(pos) - self.sculpting_item_offset
self.update_path_point(self.sculpting_item, self.sculpting_item_point_index, pos_in_item_coords)
print(f"Sculpt: Item ID {id(self.sculpting_item)}, Point Index {self.sculpting_item_point_index}")
self.sculpt_shape.setPos(self.mapToScene(event.pos()) - self.sculpt_shape.boundingRect().center())
def on_sculpt_end(self, event):
if self.sculpting_item is not None:
new_path = self.sculpting_item.path()
if new_path != self.sculpting_initial_path:
command = EditPathCommand(self.sculpting_item, self.sculpting_initial_path, new_path)
self.canvas.addCommand(command)
print(f"Sculpt End: Item ID {id(self.sculpting_item)}")
self.reset_sculpting_state()
def on_sculpt_double_click(self, event):
pos = self.mapToScene(event.pos())
item = self.scene().itemAt(pos, self.transform())
if isinstance(item, CustomPathItem):
pos_in_item_coords = item.mapFromScene(pos)
point_index, offset = self.find_closest_point(pos_in_item_coords, item)
if point_index != -1:
self.smooth_path_point(item, point_index)
def find_closest_point(self, pos, item):
path = item.path()
min_dist = float('inf')
closest_point_index = -1
closest_offset = QPointF()
for i in range(path.elementCount()):
point = path.elementAt(i)
point_pos = QPointF(point.x, point.y)
dist = QLineF(point_pos, pos).length()
if dist < min_dist:
min_dist = dist
closest_point_index = i
closest_offset = pos - point_pos
return closest_point_index, closest_offset
def update_path_point(self, item, index, new_pos):
path = item.path()
elements = [path.elementAt(i) for i in range(path.elementCount())]
if index < 0 or index >= len(elements):
return # Ensure the index is within bounds
old_pos = QPointF(elements[index].x, elements[index].y)
delta_pos = new_pos - old_pos
def calculate_influence(dist, radius):
return math.exp(-(dist ** 2) / (2 * (radius / 2.0) ** 2))
for i in range(len(elements)):
point = elements[i]
point_pos = QPointF(point.x, point.y)
dist = QLineF(point_pos, old_pos).length()
if dist <= self.sculpt_radius:
influence = calculate_influence(dist, self.sculpt_radius)
elements[i].x += delta_pos.x() * influence
elements[i].y += delta_pos.y() * influence
new_path = QPainterPath()
new_path.setFillRule(Qt.WindingFill)
new_path.moveTo(elements[0].x, elements[0].y)
i = 1
while i < len(elements):
if i + 2 < len(elements):
new_path.cubicTo(elements[i].x, elements[i].y,
elements[i + 1].x, elements[i + 1].y,
elements[i + 2].x, elements[i + 2].y)
i += 3
else:
new_path.lineTo(elements[i].x, elements[i].y)
i += 1
item.setPath(new_path)
item.smooth = False
def smooth_path_point(self, item, point_index):
path = item.path()
elements = [path.elementAt(i) for i in range(path.elementCount())]
if point_index > 0 and point_index + 1 < len(elements):
smoothed_x = (elements[point_index - 1].x + elements[point_index + 1].x) / 2
smoothed_y = (elements[point_index - 1].y + elements[point_index + 1].y) / 2
path.setElementPositionAt(point_index, smoothed_x, smoothed_y)
command = EditPathCommand(item, item.path(), path)
self.canvas.addCommand(command)
item.smooth = False
我还通过
EditPathCommand