Method Process

Projects/Demo/source/Runtime/FreeCamera.cpp:52–123

------------------------------ FreeCameraSystem::Process Update a cameras position according to input

// Update a cameras position according to input
//
void FreeCameraSystem::Process(fw::ComponentRange<FreeCameraSystemView>& range)
{
	// common variables
	core::InputManager* const input = core::InputManager::GetInstance();
	float const dt = core::ContextManager::GetInstance()->GetActiveContext()->time->DeltaTime();

	for (FreeCameraSystemView& view : range)
	{
		// movement direction
		bool hasMoveInput = false;
		{
			vec3 move;

			move.x -= (input->GetKeyState(E_KbdKey::A) == E_KeyState::Down) ? 1.0f : 0.0f;
			move.x += (input->GetKeyState(E_KbdKey::D) == E_KeyState::Down) ? 1.0f : 0.0f;

			move.y -= (input->GetKeyState(E_KbdKey::Q) == E_KeyState::Down) ? 1.0f : 0.0f;
			move.y += (input->GetKeyState(E_KbdKey::E) == E_KeyState::Down) ? 1.0f : 0.0f;

			move.z += (input->GetKeyState(E_KbdKey::W) == E_KeyState::Down) ? 1.0f : 0.0f;
			move.z -= (input->GetKeyState(E_KbdKey::S) == E_KeyState::Down) ? 1.0f : 0.0f;

			if (!math::isZero(move))
			{
				move = math::normalize(move);
				hasMoveInput = true;
			}

			//Acceleration
			{
				vec3 const delta = move - view.camera->movement;
				float const acc = s_Accelleration * dt;
				view.camera->movement = view.camera->movement + (delta * math::Clamp01(acc));
			}
		}

		//handle scrolling to change camera speed
		if (hasMoveInput || input->GetMouseButton(E_MouseButton::Left) == E_KeyState::Down)
		{
			float const scroll = input->GetMouseWheelDelta().y;
			if (scroll > 0.0f)
			{
				view.camera->speedMultiplier *= 1.1f;
			}
			else if (scroll < -0.01f)
			{
				view.camera->speedMultiplier *= 0.9f;
			}
		}

		float const currSpeed = s_MoveSpeed * view.camera->speedMultiplier;

		// Calculate the view inverse in the same way the camera would do it
		vec3 const lookAt = view.transform->GetPosition() + view.transform->GetForward();
		mat3 const camMat = math::CreateFromMat4(math::inverse(math::lookAt(view.transform->GetPosition(), lookAt, view.transform->GetUp())));
		vec3 currPos = view.transform->GetPosition() + camMat * view.camera->movement * currSpeed * dt;
		view.transform->SetPosition(currPos);