Transform.cpp

#include "Transform.h"

static const float MaxVerticalAngle = 89.0f; //must be less than 90 to avoid gimbal lock

void Transform::NormalizeAngles()
{
    m_Rotation.y = fmodf(m_Rotation.y, 360.0f);
    //fmodf can return negative values, but this will make them all positive
    if(m_Rotation.y < 0.0f)
        m_Rotation.y += 360.0f;

    if(m_Rotation.x > MaxVerticalAngle)
        m_Rotation.x = MaxVerticalAngle;
    else if(m_Rotation.x < -MaxVerticalAngle)
        m_Rotation.x = -MaxVerticalAngle;
}

void Transform::LookAt(glm::vec3 targetPosition)
{
    if((targetPosition - m_Position) == glm::vec3(0,0,0)) return;
    glm::vec3 direction = glm::normalize(targetPosition - m_Position);
    m_Rotation.x = asinf(-direction.y)* RadToDeg;
    m_Rotation.y = -atan2f(-direction.x, -direction.z)*RadToDeg;

    NormalizeAngles();
}

glm::mat4 Transform::GetOrientation() const
{
    glm::mat4 orientation;
    orientation = glm::rotate(orientation, m_Rotation.x, glm::vec3(1,0,0));
    orientation = glm::rotate(orientation, m_Rotation.y, glm::vec3(0,1,0));
    orientation = glm::rotate(orientation, m_Rotation.z, glm::vec3(0,0,1));
    return orientation;
}