procedural-3d-engine/base/camera.hpp

/*
* Basic camera class
*
* Copyright (C) 2016 by Sascha Willems - www.saschawillems.de
*
* This code is licensed under the MIT license (MIT) (http://opensource.org/licenses/MIT)
*/


#define GLM_FORCE_RADIANS
#define GLM_FORCE_DEPTH_ZERO_TO_ONE
#include <glm/glm.hpp>
#include <glm/gtc/quaternion.hpp>
#include <glm/gtx/quaternion.hpp>

class Camera
{
private:
	float fov;
	float znear, zfar;

	void updateViewMatrix()
	{
		glm::mat4 rotM = glm::mat4();
		glm::mat4 transM;

		rotM = glm::rotate(rotM, glm::radians(rotation.x), glm::vec3(1.0f, 0.0f, 0.0f));
		rotM = glm::rotate(rotM, glm::radians(rotation.y), glm::vec3(0.0f, 1.0f, 0.0f));
		rotM = glm::rotate(rotM, glm::radians(rotation.z), glm::vec3(0.0f, 0.0f, 1.0f));

		transM = glm::translate(glm::mat4(), position);

		if (type == CameraType::firstperson)
		{
			matrices.view = rotM * transM;
		}
		else
		{
			matrices.view = transM * rotM;
		}
	};
public:
	enum CameraType { lookat, firstperson };
	CameraType type = CameraType::lookat;

	glm::vec3 rotation = glm::vec3();
	glm::vec3 position = glm::vec3();

	float rotationSpeed = 1.0f;
	float movementSpeed = 1.0f;

	struct
	{
		glm::mat4 perspective;
		glm::mat4 view;
	} matrices;

	struct
	{
		bool left = false;
		bool right = false;
		bool up = false;
		bool down = false;
	} keys;

	bool moving()
	{
		return keys.left || keys.right || keys.up || keys.down;
	}

	void setPerspective(float fov, float aspect, float znear, float zfar)
	{
		this->fov = fov;
		this->znear = znear;
		this->zfar = zfar;
		matrices.perspective = glm::perspective(glm::radians(fov), aspect, znear, zfar);
	};

	void updateAspectRatio(float aspect)
	{
		matrices.perspective = glm::perspective(glm::radians(fov), aspect, znear, zfar);
	}

	void setRotation(glm::vec3 rotation)
	{
		this->rotation = rotation;
		updateViewMatrix();
	};

	void rotate(glm::vec3 delta)
	{
		this->rotation += delta;
		updateViewMatrix();
	}

	void setTranslation(glm::vec3 translation)
	{
		this->position = translation;
		updateViewMatrix();
	};

	void translate(glm::vec3 delta)
	{
		this->position += delta;
		updateViewMatrix();
	}

	void update(float deltaTime)
	{
		if (type == CameraType::firstperson)
		{
			if (moving())
			{
				glm::vec3 camFront;
				camFront.x = -cos(glm::radians(rotation.x)) * sin(glm::radians(rotation.y));
				camFront.y = sin(glm::radians(rotation.x));
				camFront.z = cos(glm::radians(rotation.x)) * cos(glm::radians(rotation.y));
				camFront = glm::normalize(camFront);

				float moveSpeed = deltaTime * movementSpeed;

				if (keys.up)
					position += camFront * moveSpeed;
				if (keys.down)
					position -= camFront * moveSpeed;
				if (keys.left)
					position -= glm::normalize(glm::cross(camFront, glm::vec3(0.0f, 1.0f, 0.0f))) * moveSpeed;
				if (keys.right)
					position += glm::normalize(glm::cross(camFront, glm::vec3(0.0f, 1.0f, 0.0f))) * moveSpeed;

				updateViewMatrix();
			}
		}
	};

};