isle-portable/extensions/src/thirdpersoncamera/inputhandler.cpp

#include "extensions/thirdpersoncamera/inputhandler.h"

#include "extensions/thirdpersoncamera/orbitcamera.h"

#include <SDL3/SDL_stdinc.h>
#include <utility>

using namespace Extensions::ThirdPersonCamera;

InputHandler::InputHandler() : m_touch{}, m_wantsAutoDisable(false), m_wantsAutoEnable(false)
{
}

bool InputHandler::TryClaimFinger(const SDL_TouchFingerEvent& p_event, bool p_active)
{
	if (!p_active || m_touch.count >= 2 || p_event.x < CAMERA_ZONE_X) {
		return false;
	}

	int idx = m_touch.count;
	m_touch.id[idx] = p_event.fingerID;
	m_touch.x[idx] = p_event.x;
	m_touch.y[idx] = p_event.y;
	m_touch.count++;

	if (m_touch.count == 2) {
		float dx = m_touch.x[1] - m_touch.x[0];
		float dy = m_touch.y[1] - m_touch.y[0];
		m_touch.initialPinchDist = SDL_sqrtf(dx * dx + dy * dy);
	}

	return true;
}

bool InputHandler::TryReleaseFinger(SDL_FingerID p_id)
{
	for (int i = 0; i < m_touch.count; i++) {
		if (m_touch.id[i] == p_id) {
			if (i == 0 && m_touch.count == 2) {
				m_touch.id[0] = m_touch.id[1];
				m_touch.x[0] = m_touch.x[1];
				m_touch.y[0] = m_touch.y[1];
			}
			m_touch.count--;
			m_touch.initialPinchDist = 0.0f;
			return true;
		}
	}
	return false;
}

bool InputHandler::IsFingerTracked(SDL_FingerID p_id) const
{
	for (int i = 0; i < m_touch.count; i++) {
		if (m_touch.id[i] == p_id) {
			return true;
		}
	}
	return false;
}

bool InputHandler::ConsumeAutoDisable()
{
	return std::exchange(m_wantsAutoDisable, false);
}

bool InputHandler::ConsumeAutoEnable()
{
	return std::exchange(m_wantsAutoEnable, false);
}

void InputHandler::HandleSDLEvent(SDL_Event* p_event, OrbitCamera& p_orbit, bool p_active)
{
	switch (p_event->type) {
	case SDL_EVENT_MOUSE_WHEEL:
		if (!p_active) {
			if (p_event->wheel.y < 0) {
				m_wantsAutoEnable = true;
			}
			break;
		}
		if (p_orbit.GetOrbitDistance() <= OrbitCamera::MIN_DISTANCE && p_event->wheel.y > 0) {
			m_wantsAutoDisable = true;
			break;
		}
		p_orbit.AdjustDistance(-p_event->wheel.y * 0.5f);
		p_orbit.ClampDistance();
		break;

	case SDL_EVENT_MOUSE_MOTION:
		if (!p_active) {
			break;
		}
		if (p_event->motion.state & SDL_BUTTON_RMASK) {
			p_orbit.AdjustYaw(-p_event->motion.xrel * 0.005f);
			p_orbit.AdjustPitch(p_event->motion.yrel * 0.005f);
			p_orbit.ClampPitch();
		}
		break;

	case SDL_EVENT_MOUSE_BUTTON_DOWN:
	case SDL_EVENT_MOUSE_BUTTON_UP: {
		if (!p_active) {
			break;
		}
		SDL_Window* window = SDL_GetWindowFromID(p_event->button.windowID);
		if (window) {
			SDL_SetWindowRelativeMouseMode(window, SDL_GetMouseState(NULL, NULL) & SDL_BUTTON_RMASK);
		}
		break;
	}

	case SDL_EVENT_FINGER_DOWN: {
		if (!IsFingerTracked(p_event->tfinger.fingerID) && m_touch.count < 2 &&
			p_event->tfinger.x >= CAMERA_ZONE_X) {
			int idx = m_touch.count;
			m_touch.id[idx] = p_event->tfinger.fingerID;
			m_touch.x[idx] = p_event->tfinger.x;
			m_touch.y[idx] = p_event->tfinger.y;
			m_touch.count++;

			if (m_touch.count == 2) {
				float dx = m_touch.x[1] - m_touch.x[0];
				float dy = m_touch.y[1] - m_touch.y[0];
				m_touch.initialPinchDist = SDL_sqrtf(dx * dx + dy * dy);
			}
		}
		break;
	}

	case SDL_EVENT_FINGER_MOTION: {
		if (m_touch.count == 1) {
			if (!p_active) {
				break;
			}
			if (m_touch.id[0] == p_event->tfinger.fingerID) {
				float oldX = m_touch.x[0];
				float oldY = m_touch.y[0];
				m_touch.x[0] = p_event->tfinger.x;
				m_touch.y[0] = p_event->tfinger.y;

				float moveX = m_touch.x[0] - oldX;
				float moveY = m_touch.y[0] - oldY;
				p_orbit.AdjustYaw(-moveX * 2.0f);
				p_orbit.AdjustPitch(moveY * 2.0f);
				p_orbit.ClampPitch();
			}
		}
		else if (m_touch.count == 2) {
			int idx = -1;
			for (int i = 0; i < 2; i++) {
				if (m_touch.id[i] == p_event->tfinger.fingerID) {
					idx = i;
					break;
				}
			}
			if (idx < 0) {
				break;
			}

			float oldX = m_touch.x[idx];
			float oldY = m_touch.y[idx];
			m_touch.x[idx] = p_event->tfinger.x;
			m_touch.y[idx] = p_event->tfinger.y;

			float dx = m_touch.x[1] - m_touch.x[0];
			float dy = m_touch.y[1] - m_touch.y[0];
			float newDist = SDL_sqrtf(dx * dx + dy * dy);

			if (m_touch.initialPinchDist > 0.001f) {
				float pinchDelta = m_touch.initialPinchDist - newDist;

				if (!p_active) {
					if (pinchDelta > 0) {
						m_wantsAutoEnable = true;
					}
					m_touch.initialPinchDist = newDist;
					break;
				}

				if (p_orbit.GetOrbitDistance() <= OrbitCamera::MIN_DISTANCE && pinchDelta < 0) {
					m_wantsAutoDisable = true;
					m_touch.initialPinchDist = newDist;
					break;
				}

				p_orbit.AdjustDistance(pinchDelta * 15.0f);
				p_orbit.ClampDistance();
				m_touch.initialPinchDist = newDist;
			}

			float moveX = m_touch.x[idx] - oldX;
			float moveY = m_touch.y[idx] - oldY;
			p_orbit.AdjustYaw(-moveX * 2.0f);
			p_orbit.AdjustPitch(moveY * 2.0f);
			p_orbit.ClampPitch();
		}
		break;
	}

	case SDL_EVENT_FINGER_UP:
	case SDL_EVENT_FINGER_CANCELED: {
		TryReleaseFinger(p_event->tfinger.fingerID);
		break;
	}

	default:
		break;
	}
}