added live updating of shown path

GUI_draft_live.py

+import sys
+import math
+import numpy as np
+
+# For smoothing the path
+from scipy.signal import savgol_filter
+
+from PyQt5.QtWidgets import (
+    QApplication, QMainWindow, QGraphicsView, QGraphicsScene,
+    QGraphicsEllipseItem, QGraphicsPixmapItem, QPushButton,
+    QHBoxLayout, QVBoxLayout, QWidget, QFileDialog, QGraphicsTextItem
+)
+from PyQt5.QtGui import QPixmap, QPen, QBrush, QColor, QFont
+from PyQt5.QtCore import Qt, QRectF
+
+from live_wire import compute_cost_image, find_path
+
+
+class LabeledPointItem(QGraphicsEllipseItem):
+    def __init__(self, x, y, label="", radius=4, color=Qt.red, removable=True, z_value=0, parent=None):
+        super().__init__(0, 0, 2*radius, 2*radius, parent)
+        self._x = x
+        self._y = y
+        self._r = radius
+        self._removable = removable
+
+        pen = QPen(color)
+        brush = QBrush(color)
+        self.setPen(pen)
+        self.setBrush(brush)
+        self.setZValue(z_value)
+
+        self._text_item = None
+        if label:
+            self._text_item = QGraphicsTextItem(self)
+            self._text_item.setPlainText(label)
+            self._text_item.setDefaultTextColor(QColor("black"))
+            font = QFont("Arial", 14)
+            font.setBold(True)
+            self._text_item.setFont(font)
+            self._scale_text_to_fit()
+
+        self.set_pos(x, y)
+
+    def _scale_text_to_fit(self):
+        if not self._text_item:
+            return
+        self._text_item.setScale(1.0)
+        circle_diam = 2 * self._r
+        raw_rect = self._text_item.boundingRect()
+        text_w = raw_rect.width()
+        text_h = raw_rect.height()
+        if text_w > circle_diam or text_h > circle_diam:
+            scale_factor = min(circle_diam / text_w, circle_diam / text_h)
+            self._text_item.setScale(scale_factor)
+        self._center_label()
+
+    def _center_label(self):
+        if not self._text_item:
+            return
+        ellipse_w = 2 * self._r
+        ellipse_h = 2 * self._r
+        raw_rect = self._text_item.boundingRect()
+        scale_factor = self._text_item.scale()
+        scaled_w = raw_rect.width() * scale_factor
+        scaled_h = raw_rect.height() * scale_factor
+        tx = (ellipse_w - scaled_w) * 0.5
+        ty = (ellipse_h - scaled_h) * 0.5
+        self._text_item.setPos(tx, ty)
+
+    def set_pos(self, x, y):
+        self._x = x
+        self._y = y
+        self.setPos(x - self._r, y - self._r)
+
+    def get_pos(self):
+        return (self._x, self._y)
+
+    def distance_to(self, x_other, y_other):
+        return math.sqrt((self._x - x_other)**2 + (self._y - y_other)**2)
+
+    def is_removable(self):
+        return self._removable
+
+
+class ImageGraphicsView(QGraphicsView):
+    def __init__(self, parent=None):
+        super().__init__(parent)
+        self.scene = QGraphicsScene(self)
+        self.setScene(self.scene)
+
+        # Allow zoom around mouse pointer
+        self.setTransformationAnchor(QGraphicsView.AnchorUnderMouse)
+
+        # Image display item
+        self.image_item = QGraphicsPixmapItem()
+        self.scene.addItem(self.image_item)
+
+        # Parallel lists
+        self.anchor_points = []  # List[(x, y)]
+        self.point_items = []    # List[LabeledPointItem]
+
+        self.editor_mode = False
+        self.dot_radius = 4
+        self.path_radius = 1
+        self.radius_cost_image = 2  # cost-lowering radius
+        self._img_w = 0
+        self._img_h = 0
+
+        # For pan/drag
+        self.setDragMode(QGraphicsView.ScrollHandDrag)
+        self.viewport().setCursor(Qt.ArrowCursor)
+
+        self._mouse_pressed = False
+        self._press_view_pos = None
+        self._drag_threshold = 5
+        self._was_dragging = False
+        self._dragging_idx = None
+        self._drag_offset = (0, 0)
+
+        # NEW: We'll count how many times we've updated the drag => partial path update
+        self._drag_counter = 0
+
+        # Keep original cost image to revert changes
+        self.cost_image_original = None
+        self.cost_image = None
+
+        # The path is displayed as small magenta circles in self.full_path_points
+        self.full_path_points = []
+
+    # --------------------------------------------------------------------
+    # LOADING
+    # --------------------------------------------------------------------
+    def load_image(self, path):
+        pixmap = QPixmap(path)
+        if not pixmap.isNull():
+            self.image_item.setPixmap(pixmap)
+            self.setSceneRect(QRectF(pixmap.rect()))
+
+            self._img_w = pixmap.width()
+            self._img_h = pixmap.height()
+
+            self._clear_all_points()
+            self.resetTransform()
+            self.fitInView(self.image_item, Qt.KeepAspectRatio)
+
+            # Create S/E
+            s_x, s_y = 0.15*self._img_w, 0.5*self._img_h
+            e_x, e_y = 0.85*self._img_w, 0.5*self._img_h
+
+            # S => not removable
+            self._insert_anchor_point(-1, s_x, s_y, label="S", removable=False, z_val=100, radius=6)
+            # E => not removable
+            self._insert_anchor_point(-1, e_x, e_y, label="E", removable=False, z_val=100, radius=6)
+
+    def set_editor_mode(self, mode: bool):
+        self.editor_mode = mode
+
+    # --------------------------------------------------------------------
+    # ANCHOR POINTS
+    # --------------------------------------------------------------------
+    def _insert_anchor_point(self, idx, x, y, label="", removable=True, z_val=0, radius=4):
+        """
+        Insert at index=idx, or -1 => append just before E if E exists.
+        """
+        if idx < 0:
+            # If we have at least 2 anchors, the last is E => insert before that
+            if len(self.anchor_points) >= 2:
+                idx = len(self.anchor_points) - 1
+            else:
+                idx = len(self.anchor_points)
+
+        self.anchor_points.insert(idx, (x, y))
+        color = Qt.green if label in ("S","E") else Qt.red
+        item = LabeledPointItem(x, y, label=label, radius=radius, color=color, 
+                                removable=removable, z_value=z_val)
+        self.point_items.insert(idx, item)
+        self.scene.addItem(item)
+
+    def _add_guide_point(self, x, y):
+        """
+        User added a red guide point => lower cost, insert anchor, rebuild path.
+        """
+        # 1) Revert cost
+        self._revert_cost_to_original()
+        # 2) Insert new anchor (removable)
+        self._insert_anchor_point(-1, x, y, label="", removable=True, z_val=1, radius=self.dot_radius)
+        # 3) Re-apply cost-lowering for all existing guide points
+        self._apply_all_guide_points_to_cost()
+        # 4) Rebuild path
+        self._rebuild_full_path()
+
+    # --------------------------------------------------------------------
+    # COST IMAGE
+    # --------------------------------------------------------------------
+    def _revert_cost_to_original(self):
+        """self.cost_image <- copy of self.cost_image_original"""
+        if self.cost_image_original is not None:
+            self.cost_image = self.cost_image_original.copy()
+
+    def _apply_all_guide_points_to_cost(self):
+        """Lower cost around every removable anchor."""
+        if self.cost_image is None:
+            return
+        for i, (ax, ay) in enumerate(self.anchor_points):
+            if self.point_items[i].is_removable():
+                self._lower_cost_in_circle(ax, ay, self.radius_cost_image)
+
+    def _lower_cost_in_circle(self, x_f, y_f, radius):
+        """Set cost_image row,col in circle of radius -> global min."""
+        if self.cost_image is None:
+            return
+        h, w = self.cost_image.shape
+        row_c = int(round(y_f))
+        col_c = int(round(x_f))
+        if not (0 <= row_c < h and 0 <= col_c < w):
+            return
+        global_min = self.cost_image.min()
+        r_s = max(0, row_c - radius)
+        r_e = min(h, row_c + radius + 1)
+        c_s = max(0, col_c - radius)
+        c_e = min(w, col_c + radius + 1)
+        for rr in range(r_s, r_e):
+            for cc in range(c_s, c_e):
+                dist = math.sqrt((rr - row_c)**2 + (cc - col_c)**2)
+                if dist <= radius:
+                    self.cost_image[rr, cc] = global_min
+
+    # --------------------------------------------------------------------
+    # PATH BUILDING
+    # --------------------------------------------------------------------
+    def _rebuild_full_path(self):
+        # Remove old path items
+        for item in self.full_path_points:
+            self.scene.removeItem(item)
+        self.full_path_points.clear()
+
+        # Build subpaths
+        if len(self.anchor_points) < 2 or self.cost_image is None:
+            return
+
+        big_xy = []
+        for i in range(len(self.anchor_points)-1):
+            xA, yA = self.anchor_points[i]
+            xB, yB = self.anchor_points[i+1]
+            sub_xy = self._compute_subpath_xy(xA, yA, xB, yB)
+            if i == 0:
+                big_xy.extend(sub_xy)
+            else:
+                # avoid duplicating the point between subpaths
+                if len(sub_xy) > 1:
+                    big_xy.extend(sub_xy[1:])
+
+        # Smoothing with Savitzky-Golay
+        if len(big_xy) >= 7:
+            arr_xy = np.array(big_xy)  # shape (N,2)
+            smoothed = savgol_filter(arr_xy, window_length=7, polyorder=1, axis=0)
+            big_xy = smoothed.tolist()
+
+        # Draw them
+        for (px, py) in big_xy:
+            path_item = LabeledPointItem(px, py, label="", radius=self.path_radius,
+                                         color=Qt.magenta, removable=False, z_value=0)
+            self.full_path_points.append(path_item)
+            self.scene.addItem(path_item)
+
+        # Ensure S/E stay on top
+        for p_item in self.point_items:
+            if p_item._text_item:
+                p_item.setZValue(100)
+
+    def _compute_subpath_xy(self, xA, yA, xB, yB):
+        if self.cost_image is None:
+            return []
+        h, w = self.cost_image.shape
+        rA, cA = int(round(yA)), int(round(xA))
+        rB, cB = int(round(yB)), int(round(xB))
+        rA = max(0, min(rA, h-1))
+        cA = max(0, min(cA, w-1))
+        rB = max(0, min(rB, h-1))
+        cB = max(0, min(cB, w-1))
+        try:
+            path_rc = find_path(self.cost_image, [(rA, cA), (rB, cB)])
+        except ValueError as e:
+            print("Error in find_path:", e)
+            return []
+        return [(c, r) for (r, c) in path_rc]
+
+    # --------------------------------------------------------------------
+    # MOUSE EVENTS (dragging, adding, removing points)
+    # --------------------------------------------------------------------
+    def mousePressEvent(self, event):
+        if event.button() == Qt.LeftButton:
+            self._mouse_pressed = True
+            self._was_dragging = False
+            self._press_view_pos = event.pos()
+
+            if self.editor_mode:
+                idx = self._find_item_near(event.pos(), 10)
+                if idx is not None:
+                    # drag existing anchor
+                    self._dragging_idx = idx
+                    # Reset drag counter
+                    self._drag_counter = 0
+
+                    scene_pos = self.mapToScene(event.pos())
+                    px, py = self.point_items[idx].get_pos()
+                    self._drag_offset = (scene_pos.x() - px, scene_pos.y() - py)
+                    self.setDragMode(QGraphicsView.NoDrag)
+                    self.viewport().setCursor(Qt.ClosedHandCursor)
+                    return
+                else:
+                    # If no anchor near, user might be panning
+                    self.setDragMode(QGraphicsView.ScrollHandDrag)
+                    self.viewport().setCursor(Qt.ClosedHandCursor)
+            else:
+                self.setDragMode(QGraphicsView.ScrollHandDrag)
+                self.viewport().setCursor(Qt.ClosedHandCursor)
+
+        elif event.button() == Qt.RightButton:
+            if self.editor_mode:
+                self._remove_point_by_click(event.pos())
+
+        super().mousePressEvent(event)
+
+    def mouseMoveEvent(self, event):
+        if self._dragging_idx is not None:
+            # dragging an anchor
+            scene_pos = self.mapToScene(event.pos())
+            x_new = scene_pos.x() - self._drag_offset[0]
+            y_new = scene_pos.y() - self._drag_offset[1]
+            r = self.point_items[self._dragging_idx]._r
+            x_clamped = self._clamp(x_new, r, self._img_w - r)
+            y_clamped = self._clamp(y_new, r, self._img_h - r)
+            self.point_items[self._dragging_idx].set_pos(x_clamped, y_clamped)
+
+            # THROTTLE: only recalc path every few frames
+            self._drag_counter += 1
+            if self._drag_counter >= 4:
+                self._drag_counter = 0
+                # do partial path update:
+                # (We won't revert cost if you want the user to see the “final” cost-lowered path only at the end
+                # or you can do the entire revert+reapply if you like)
+                self._revert_cost_to_original()
+                self._apply_all_guide_points_to_cost()
+                # update anchor_points
+                newX, newY = self.point_items[self._dragging_idx].get_pos()
+                self.anchor_points[self._dragging_idx] = (newX, newY)
+                self._rebuild_full_path()
+
+            return
+        else:
+            # if movement > threshold => pan
+            if self._mouse_pressed and (event.buttons() & Qt.LeftButton):
+                dist = (event.pos() - self._press_view_pos).manhattanLength()
+                if dist > self._drag_threshold:
+                    self._was_dragging = True
+            super().mouseMoveEvent(event)
+
+    def mouseReleaseEvent(self, event):
+        super().mouseReleaseEvent(event)
+        if event.button() == Qt.LeftButton and self._mouse_pressed:
+            self._mouse_pressed = False
+            self.viewport().setCursor(Qt.ArrowCursor)
+            if self._dragging_idx is not None:
+                idx = self._dragging_idx
+                self._dragging_idx = None
+                self._drag_offset = (0, 0)
+                self.setDragMode(QGraphicsView.ScrollHandDrag)
+
+                # Final big update
+                newX, newY = self.point_items[idx].get_pos()
+                self.anchor_points[idx] = (newX, newY)
+
+                self._revert_cost_to_original()
+                self._apply_all_guide_points_to_cost()
+                self._rebuild_full_path()
+
+            else:
+                if not self._was_dragging and self.editor_mode:
+                    # user clicked an empty spot => add a guide point
+                    scene_pos = self.mapToScene(event.pos())
+                    x, y = scene_pos.x(), scene_pos.y()
+                    self._add_guide_point(x, y)
+
+            self._was_dragging = False
+
+    def _remove_point_by_click(self, view_pos):
+        idx = self._find_item_near(view_pos, threshold=10)
+        if idx is None:
+            return
+        # check if removable => skip S/E
+        if not self.point_items[idx].is_removable():
+            return  # do nothing
+
+        # remove anchor
+        self.scene.removeItem(self.point_items[idx])
+        self.point_items.pop(idx)
+        self.anchor_points.pop(idx)
+
+        # revert + re-apply cost, rebuild path
+        self._revert_cost_to_original()
+        self._apply_all_guide_points_to_cost()
+        self._rebuild_full_path()
+
+    def _find_item_near(self, view_pos, threshold=10):
+        scene_pos = self.mapToScene(view_pos)
+        x_click, y_click = scene_pos.x(), scene_pos.y()
+        min_dist = float('inf')
+        closest_idx = None
+        for i, itm in enumerate(self.point_items):
+            d = itm.distance_to(x_click, y_click)
+            if d < min_dist:
+                min_dist = d
+                closest_idx = i
+        if closest_idx is not None and min_dist <= threshold:
+            return closest_idx
+        return None
+
+    # --------------------------------------------------------------------
+    # ZOOM
+    # --------------------------------------------------------------------
+    def wheelEvent(self, event):
+        """
+        Zoom in/out with mouse wheel
+        """
+        zoom_in_factor = 1.25
+        zoom_out_factor = 1 / zoom_in_factor
+
+        # If the user scrolls upward => zoom in. Otherwise => zoom out.
+        if event.angleDelta().y() > 0:
+            self.scale(zoom_in_factor, zoom_in_factor)
+        else:
+            self.scale(zoom_out_factor, zoom_out_factor)
+        event.accept()
+
+    # --------------------------------------------------------------------
+    # UTILS
+    # --------------------------------------------------------------------
+    def _clamp(self, val, mn, mx):
+        return max(mn, min(val, mx))
+
+    def _clear_all_points(self):
+        for it in self.point_items:
+            self.scene.removeItem(it)
+        self.point_items.clear()
+        self.anchor_points.clear()
+
+        for p in self.full_path_points:
+            self.scene.removeItem(p)
+        self.full_path_points.clear()
+
+    def clear_guide_points(self):
+        """
+        Removes all anchors that are 'removable' (guide points),
+        keeps S/E in place. Then reverts cost, re-applies, rebuilds path.
+        """
+        i = 0
+        while i < len(self.anchor_points):
+            if self.point_items[i].is_removable():
+                self.scene.removeItem(self.point_items[i])
+                del self.point_items[i]
+                del self.anchor_points[i]
+            else:
+                i += 1
+
+        for item in self.full_path_points:
+            self.scene.removeItem(item)
+        self.full_path_points.clear()
+
+        self._revert_cost_to_original()
+        self._apply_all_guide_points_to_cost()
+        self._rebuild_full_path()
+
+
+class MainWindow(QMainWindow):
+    def __init__(self):
+        super().__init__()
+        self.setWindowTitle("Test GUI")
+
+        main_widget = QWidget()
+        main_layout = QVBoxLayout(main_widget)
+
+        self.image_view = ImageGraphicsView()
+        main_layout.addWidget(self.image_view)
+
+        btn_layout = QHBoxLayout()
+
+        self.btn_load_image = QPushButton("Load Image")
+        self.btn_load_image.clicked.connect(self.load_image)
+        btn_layout.addWidget(self.btn_load_image)
+
+        self.btn_editor_mode = QPushButton("Editor Mode: OFF")
+        self.btn_editor_mode.setCheckable(True)
+        self.btn_editor_mode.setStyleSheet("background-color: lightgray;")
+        self.btn_editor_mode.clicked.connect(self.toggle_editor_mode)
+        btn_layout.addWidget(self.btn_editor_mode)
+
+        self.btn_export_points = QPushButton("Export Points")
+        self.btn_export_points.clicked.connect(self.export_points)
+        btn_layout.addWidget(self.btn_export_points)
+
+        self.btn_clear_points = QPushButton("Clear Points")
+        self.btn_clear_points.clicked.connect(self.clear_points)
+        btn_layout.addWidget(self.btn_clear_points)
+
+        main_layout.addLayout(btn_layout)
+        self.setCentralWidget(main_widget)
+        self.resize(900, 600)
+
+    def load_image(self):
+        options = QFileDialog.Options()
+        file_path, _ = QFileDialog.getOpenFileName(
+            self, "Open Image", "",
+            "Images (*.png *.jpg *.jpeg *.bmp *.tif)",
+            options=options
+        )
+        if file_path:
+            self.image_view.load_image(file_path)
+            cost_img = compute_cost_image(file_path)
+            self.image_view.cost_image_original = cost_img
+            self.image_view.cost_image = cost_img.copy()
+
+    def toggle_editor_mode(self):
+        is_checked = self.btn_editor_mode.isChecked()
+        self.image_view.set_editor_mode(is_checked)
+        if is_checked:
+            self.btn_editor_mode.setText("Editor Mode: ON")
+            self.btn_editor_mode.setStyleSheet("background-color: #ffcccc;")
+        else:
+            self.btn_editor_mode.setText("Editor Mode: OFF")
+            self.btn_editor_mode.setStyleSheet("background-color: lightgray;")
+
+    def export_points(self):
+        if not self.image_view.anchor_points:
+            print("No anchor points to export.")
+            return
+        options = QFileDialog.Options()
+        file_path, _ = QFileDialog.getSaveFileName(
+            self, "Export Points", "",
+            "NumPy Files (*.npy);;All Files (*)",
+            options=options
+        )
+        if file_path:
+            points_array = np.array(self.image_view.anchor_points)
+            np.save(file_path, points_array)
+            print(f"Exported {len(points_array)} points to {file_path}")
+
+    def clear_points(self):
+        """Remove all removable anchors (guide points), keep S/E in place."""
+        self.image_view.clear_guide_points()
+
+    def closeEvent(self, event):
+        super().closeEvent(event)
+
+
+def main():
+    app = QApplication(sys.argv)
+    window = MainWindow()
+    window.show()
+    sys.exit(app.exec_())
+
+
+if __name__ == "__main__":
+    main()