inferno/inferno/src/inferno/script/cameracontroller.cpp

#include "inferno/script/cameracontroller.h"

namespace Inferno {

	void CameraController::updateOrthographic(float deltaTime)
	{
		// Update camera rotation

		float cameraRotateSpeed = ROTATE_SPEED * deltaTime;

		if (Input::isKeyPressed(KeyCode("GLFW_KEY_Q"))) {
			transform->rotate.z += cameraRotateSpeed;
		}
		if (Input::isKeyPressed(KeyCode("GLFW_KEY_E"))) {
			transform->rotate.z -= cameraRotateSpeed;
		}

		if (transform->rotate.z > 180.0f) {
			transform->rotate.z -= 360.0f;
		}
		else if (transform->rotate.z <= -180.0f) {
			transform->rotate.z += 360.0f;
		}

		// Update camera translation

		float cameraTranslateSpeed = TRANSLATE_SPEED * deltaTime;

		// WASD movement
		if (Input::isKeyPressed(KeyCode("GLFW_KEY_W"))) {
			transform->translate.x += -sin(glm::radians(transform->rotate.z)) * cameraTranslateSpeed;
			transform->translate.y +=  cos(glm::radians(transform->rotate.z)) * cameraTranslateSpeed;
		}
		if (Input::isKeyPressed(KeyCode("GLFW_KEY_S"))) {
			transform->translate.x -= -sin(glm::radians(transform->rotate.z)) * cameraTranslateSpeed;
			transform->translate.y -=  cos(glm::radians(transform->rotate.z)) * cameraTranslateSpeed;
		}
		if (Input::isKeyPressed(KeyCode("GLFW_KEY_A"))) {
			transform->translate.x -= cos(glm::radians(transform->rotate.z)) * cameraTranslateSpeed;
			transform->translate.y -= sin(glm::radians(transform->rotate.z)) * cameraTranslateSpeed;
		}
		if (Input::isKeyPressed(KeyCode("GLFW_KEY_D"))) {
			transform->translate.x += cos(glm::radians(transform->rotate.z)) * cameraTranslateSpeed;
			transform->translate.y += sin(glm::radians(transform->rotate.z)) * cameraTranslateSpeed;
		}

		// Update camera zoom

		float zoomSpeed = ZOOM_SENSITIVITY * deltaTime;

		if (Input::isKeyPressed(KeyCode("GLFW_KEY_EQUAL"))) {
			m_camera->zoomLevel -= zoomSpeed;
		}
		if (Input::isKeyPressed(KeyCode("GLFW_KEY_MINUS"))) {
			m_camera->zoomLevel += zoomSpeed;
		}
		m_camera->zoomLevel = std::max(m_camera->zoomLevel, 0.25f);
		m_camera->zoomLevel = std::min(m_camera->zoomLevel, 10.0f);
	}

	void CameraController::updatePerspective(float deltaTime)
	{
		// Get mouse movement offset compared to last frame
		float xOffset = Input::getXOffset() * MOUSE_SENSITIVITY;
		float yOffset = Input::getYOffset() * MOUSE_SENSITIVITY;
		m_camera->yaw += xOffset;
		m_camera->pitch += yOffset;

		// Prevent gimbal lock
		if (m_camera->pitch > 89.0f) m_camera->pitch = 89.0f;
		if (m_camera->pitch < -89.0f) m_camera->pitch = -89.0f;

		// Update camera rotation, by calculating direction vector via yaw and pitch

		transform->rotate = {
			cos(glm::radians(m_camera->pitch)) * cos(glm::radians(m_camera->yaw)),
			sin(glm::radians(m_camera->pitch)),
			cos(glm::radians(m_camera->pitch)) * sin(glm::radians(m_camera->yaw))
		};
		transform->rotate = glm::normalize(transform->rotate);
		// The direction vector is based on
		// Camera direction (z): normalize(position - target)
		// Right axis       (x): normalize(cross(up, direction))
		// Up axis          (y): cross(direction, right)

		// Source: https://learnopengl.com/img/getting-started/camera_axes.png

		// Cross = combination of two vectors in 3D space,
		//         where result is always perpendicular to both of the vectors

		// Update camera translation

		float cameraSpeed = TRANSLATE_SPEED * deltaTime;
		// WASD movement
		if (Input::isKeyPressed(KeyCode("GLFW_KEY_W"))) {
			transform->translate = { transform->translate + cameraSpeed * transform->rotate };
		}
		if (Input::isKeyPressed(KeyCode("GLFW_KEY_S"))) {
			transform->translate = { transform->translate - cameraSpeed * transform->rotate };
		}
		if (Input::isKeyPressed(KeyCode("GLFW_KEY_A"))) {
			transform->translate = { transform->translate -
				glm::normalize(glm::cross(transform->rotate, m_camera->up)) * cameraSpeed };
		}
		if (Input::isKeyPressed(KeyCode("GLFW_KEY_D"))) {
			transform->translate = { transform->translate +
				glm::normalize(glm::cross(transform->rotate, m_camera->up)) * cameraSpeed };
		}
		// Up / down movement
		if (Input::isKeyPressed(KeyCode("GLFW_KEY_SPACE"))) {
			transform->translate = { transform->translate.x, transform->translate.y + cameraSpeed, transform->translate.z };
		}
		if (Input::isKeyPressed(KeyCode("GLFW_KEY_LEFT_SHIFT"))) {
			transform->translate = { transform->translate.x, transform->translate.y - cameraSpeed, transform->translate.z };
		}
	}
}