character.cpp

#include "character.h"
#include "gameobject.h"
#include "glm/gtc/matrix_transform.hpp"

Character::Character(const glm::vec3& pos, const glm::vec3& siz, float radius) : GameObject{pos, siz}, Front{glm::vec3{0.0f, 0.0f, -1.0f}}, Forward{glm::vec3{0.0f, 0.0f, -1.0f}}, Up{glm::vec3{0.0f, 1.0f, 0.0f}}, Right{}, WorldUp{Up}, Yaw{-90.0f}, Pitch{0.0f}, MovementSpeed{0.035f}, MouseSensitivity{0.1f}, Fov{85.0f}, Radius{radius}, Grounded{false}
{
	updateDirectionVectors();
}

// Respond tp keyboard input received from game instance
void Character::processKeyboard(PlayerMovement direction)
{
	// Move the character on the 2D plane
	if (direction == PlayerMovement::FORWARD)
		addVelocity(Forward * MovementSpeed);
	if (direction == PlayerMovement::BACKWARD)
		addVelocity(-Forward * MovementSpeed);
	if (direction == PlayerMovement::RIGHT)
		addVelocity(Right * MovementSpeed);
	if (direction == PlayerMovement::LEFT)
		addVelocity(-Right * MovementSpeed);

	// Values for jumping logic
	constexpr auto startingJumpVel{0.25f};
	static auto jumping{false};
	static auto jumpPressed{false};
	static auto jumpCount{0};
	static auto jumpVel{startingJumpVel};

	if (direction == PlayerMovement::JUMP_PRESSED && Grounded && !jumpPressed)
	{
		jumping = true;

		Grounded = false;

		jumpPressed = true;
	}

	// If jump button is released at this point, it won't take affect until the next iteration
	if (direction == PlayerMovement::JUMP_RELEASED)
	{
		jumpPressed = false;
	}

	// Climb until velocity is lost
	if (jumping)
	{
		addVelocity(WorldUp * jumpVel);
		++jumpCount;
		jumpVel *= 0.95f;

		if (jumpCount >= 180)
		{
			jumping = false;
			jumpCount = 0;
			jumpVel = startingJumpVel;
		}
	}

	// If land early, reset jumping state
	if (Grounded)
	{
		jumping = false;
		jumpCount = 0;
		jumpVel = startingJumpVel;
	}
}

// Handle mouse input received from game instance
void Character::processMouseMovement(float xOffset, float yOffset)
{
	Yaw += xOffset * MouseSensitivity;
	Pitch += yOffset * MouseSensitivity;

	// Constrain pitch to prevent screen flipping
	constexpr auto pitchMax{89.0f};
	constexpr auto pitchMin{-89.0f};

	if (Pitch > pitchMax)
		Pitch = pitchMax;
	if (Pitch < pitchMin)
		Pitch = pitchMin;

	// Update Front, Right, and Up Vectors using the updated Euler angles
	updateDirectionVectors();
}

// Calculate and return the view matrix based on the player character's current state
glm::mat4 Character::getViewMatrix() const
{
	return lookAt(position_, position_ + Front, Up);
}

void Character::tick(float deltaTime)
{
	move();
}

// Update direction vectors for the camera view and player character movement
void Character::updateDirectionVectors()
{
	// Calculate new front vector for camera
	const auto dirX{cos(glm::radians(Yaw)) * cos(glm::radians(Pitch))};
	const auto dirY{sin(glm::radians(Pitch))};
	const auto dirZ{sin(glm::radians(Yaw)) * cos(glm::radians(Pitch))};
	const auto front{glm::vec3{dirX, dirY, dirZ}};
	Front = normalize(front);

	// Calculate new forward vector for character movement -- Y is zero to prevent flying
	const auto forward{glm::vec3{dirX, 0.0f, dirZ}};
	Forward = normalize(forward);

	// Calculate new the right and up vectors
	Right = normalize(cross(Front, WorldUp)); // Normalize the vectors, because their length gets closer to 0 the more you look up or down which results in slower movement
	Up = normalize(cross(Right, Front));
}