CameraControl.cpp

#include "CameraControl.h"

namespace DirectGraphicalModels { namespace vis
{
    // Constructor
    CCameraControl::CCameraControl(GLFWwindow * window, float theta, float phi, float radius, float turnSpeed, float scrollSpeed, float panSpeed)
        : CTrackballCamera(theta, phi, radius)
        , m_mouseEvent(mouseEvent::none)
        , m_turnSpeed(turnSpeed)
        , m_scrollSpeed(scrollSpeed)
        , m_panSpeed(panSpeed)
    {
        glfwSetWindowUserPointer(window, this);
        glfwSetMouseButtonCallback(window, [](GLFWwindow *window, int button, int action, int mods) {
            static_cast<CCameraControl *>(glfwGetWindowUserPointer(window))->mouseButtonCallback(button, action, mods);
        });
        glfwSetCursorPosCallback(window, [](GLFWwindow *window, double x, double y) {
            static_cast<CCameraControl *>(glfwGetWindowUserPointer(window))->cursorPosCallback(x, y);
        });
        glfwSetScrollCallback(window, [](GLFWwindow *window, double x, double y) {
            static_cast<CCameraControl *>(glfwGetWindowUserPointer(window))->scrollCallback(x, y);
        });
    }

    // ------------------------------------- Callbacks -------------------------------------
    void CCameraControl::mouseButtonCallback(int button, int action, int mods)
    {
        if (button == GLFW_MOUSE_BUTTON_LEFT) {
            if (action == GLFW_PRESS)   m_mouseEvent = mouseEvent::start_turn;
            if (action == GLFW_RELEASE) m_mouseEvent = mouseEvent::none;
        }
        if (button == GLFW_MOUSE_BUTTON_MIDDLE) {
            if (action == GLFW_PRESS)   m_mouseEvent = mouseEvent::start_pan;
            if (action == GLFW_RELEASE) m_mouseEvent = mouseEvent::none;
        }
    }

    void CCameraControl::cursorPosCallback(double x, double y)
    {
        if (m_mouseEvent == mouseEvent::none) return;

        float dx = m_mouseLastPos.x - static_cast<float>(x);    // dTheta
        float dy = m_mouseLastPos.y - static_cast<float>(y);    // dPhi
        m_mouseLastPos.x = static_cast<float>(x);
        m_mouseLastPos.y = static_cast<float>(y);

        switch (m_mouseEvent) {
            case mouseEvent::start_turn: m_mouseEvent = mouseEvent::turn; break;
            case mouseEvent::turn: rotate(dx * m_turnSpeed, dy * m_turnSpeed); break;
            case mouseEvent::start_pan: m_mouseEvent = m_mouseEvent = mouseEvent::pan; break;
            case mouseEvent::pan: pan(-dx * m_panSpeed, dy * m_panSpeed); break;
            case mouseEvent::none: break;
        }
    }

    void CCameraControl::scrollCallback(double x, double y)
    {
        zoom(static_cast<float>(y) * m_scrollSpeed);
    }
} }