radar.py 文件源码

def _add_latest_input_line(self, angle):
        """Adds a line to the graphic scene that visualizes a scanned angle"""
        mx, my = self._get_middle()
        angle_rad = deg2rad(angle)
        angle_1_rad = deg2rad(angle - self.measurement_angle/2.0)
        angle_2_rad = deg2rad(angle + self.measurement_angle/2.0)
        length = max(self.width(), self.height())

        start_point = (mx, my)
        p1 = (mx + length * math.cos(angle_1_rad), my + length * math.sin(angle_1_rad))
        p2 = (mx + length * math.cos(angle_2_rad), my + length * math.sin(angle_2_rad))

        gradient_start_point, gradient_end_point = (mx, my), (mx + length * math.cos(angle_rad), my + length * math.sin(angle_rad))
        gradient = QLinearGradient(*gradient_start_point, *gradient_end_point)
        gradient.setColorAt(0, Qt.transparent)
        gradient.setColorAt(0.8, Qt.red)
        gradient.setColorAt(1, Qt.darkRed)

        triangle = QPolygonF()
        triangle.append(QPointF(*start_point))
        triangle.append(QPointF(*p1))
        triangle.append(QPointF(*p2))
        triangle.append(QPointF(*start_point))

        self.scene.addPolygon(triangle, pen=QPen(Qt.transparent), brush=QBrush(gradient))