首页 > 代码库 > 使用鼠标控制地图
使用鼠标控制地图
Tangram使用两种方式来控制地图:
- 使用Gesture API
- 使用Camera API
因为现在是在PC上控制, 因此使用了Camera API, 基本原理就是根据鼠标动作换算出camera变化量, 然后更新camera。
主要代码如下
Zoom在mouse wheelEvent里实现:
namespace Tangram { class Map { public: // Set the fractional zoom level of the view; if duration (in seconds) is provided, // zoom eases to the set value over the duration; calling either version of the setter // overrides all previous calls void setZoom(float _z); // Get the fractional zoom level of the view float getZoom(); }; void MapWidget::wheelEvent(QWheelEvent *event) { float zoom = m_map->getZoom(); if(event->delta() > 0){ zoom += 0.5; }else{ zoom -= 0.5; } if (zoom > Max_Zoom_Level) { zoom = Max_Zoom_Level; } if (zoom < Min_Zoom_Level) { zoom = Min_Zoom_Level; } m_map->setZoom(zoom); update(); } }
Rotate, Tilt和Pan在mouseMoveEvent里实现:
namespace Tangram { class Map { public: // Set the counter-clockwise rotation of the view in radians; 0 corresponds to // North pointing up; if duration (in seconds) is provided, rotation eases to the // the set value over the duration; calling either version of the setter overrides // all previous calls void setRotation(float _radians); // Get the counter-clockwise rotation of the view in radians; 0 corresponds to // North pointing up float getRotation();
// Set the tilt angle of the view in radians; 0 corresponds to straight down; // if duration (in seconds) is provided, tilt eases to the set value over the // duration; calling either version of the setter overrides all previous calls void setTilt(float _radians); void setTiltEased(float _radians, float _duration, EaseType _e = EaseType::quint); // Get the tilt angle of the view in radians; 0 corresponds to straight down float getTilt(); }; static float getTilt(QPoint p0, QPoint p1) { return p1.y() - p0.x(); } static float getRotation(QPoint p0, QPoint p1, QPoint center) { return QLineF(p1, center).angle() - QLineF(p0, center).angle(); } void MapWidget::mouseMoveEvent(QMouseEvent *event) { auto pos = event->pos(); if (m_gestureInprogress) { switch(m_gestureType) { case GESTURE_TAP: break; case GESTURE_PAN: { m_map->handlePanGesture(m_gestureStartPoint.x(), m_gestureStartPoint.y(), pos.x(), pos.y()); m_gestureStartPoint = pos; } break; case GESTURE_SHOVE:{ float currentTilt = toDegree(m_map->getTilt()); float newTilt = currentTilt + (pos.y() - m_gesturePreviousPoint.y()); if(newTilt>60){ newTilt = 60; } else if(newTilt<0) { newTilt = 0; } m_map->setTilt(toRadians(newTilt)); } break; case GESTURE_ROTATE:{ float currentRotation = m_map->getRotation(); m_map->setRotation(currentRotation + toRadians(getRotation(pos, m_gesturePreviousPoint, rect().center()))); } break; default: break; } } m_gesturePreviousPoint = pos; update(); } }
项目代码:
- https://github.com/tiangles/ltdmap
- https://github.com/tiangles/tangram-es
使用鼠标控制地图
声明:以上内容来自用户投稿及互联网公开渠道收集整理发布,本网站不拥有所有权,未作人工编辑处理,也不承担相关法律责任,若内容有误或涉及侵权可进行投诉: 投诉/举报 工作人员会在5个工作日内联系你,一经查实,本站将立刻删除涉嫌侵权内容。