h1-mod/src/client/component/movement.cpp

#include <std_include.hpp>
#include "loader/component_loader.hpp"
#include "game/game.hpp"
#include "game/dvars.hpp"

#include <utils/hook.hpp>
#include <utils/vector.hpp>

// https://github.com/xoxor4d/iw3xo-dev/blob/develop/src/components/modules/movement.cpp :)

namespace movement
{
	namespace
	{
		utils::hook::detour pm_airmove_hook;

		game::dvar_t* pm_cs_airAccelerate;
		game::dvar_t* pm_cs_airSpeedCap;
		game::dvar_t* pm_cs_strafing;

		void pm_air_accelerate(game::vec3_t wishdir, float wishspeed, game::mp::playerState_s* ps, game::mp::pml_t* pml)
		{
			float wishspd = wishspeed, accelspeed, currentspeed, addspeed;

			auto accel = pm_cs_airAccelerate->current.value;
			auto airspeedcap = pm_cs_airSpeedCap->current.value;

			if (wishspd > airspeedcap)
			{
				wishspd = airspeedcap;
			}

			currentspeed = utils::vector::product(ps->velocity, wishdir);
			addspeed = wishspd - currentspeed;

			if (addspeed > 0)
			{
				accelspeed = pml->frametime * accel * wishspeed * 1.0f;

				if (accelspeed > addspeed)
				{
					accelspeed = addspeed;
				}

				for (auto i = 0; i < 3; i++)
				{
					ps->velocity[i] += wishdir[i] * accelspeed;
				}
			}
		}

		void pm_clip_velocity(game::vec3_t in, game::vec3_t normal, game::vec3_t out, float overbounce)
		{
			float backoff, change, angle, adjust;

			angle = normal[2];
			backoff = utils::vector::product(in, normal) * overbounce;

			for (auto i = 0; i < 3; i++)
			{
				change = normal[i] * backoff;
				out[i] = in[i] - change;
			}

			adjust = utils::vector::product(out, normal);

			if (adjust < 0)
			{
				game::vec3_t reduce{};

				utils::vector::scale(normal, adjust, reduce);
				utils::vector::subtract(out, reduce, out);
			}
		}

		void pm_try_playermove(game::mp::pmove_t* pm, game::mp::pml_t* pml)
		{
			const auto surf_slope = 0.7f;
			const auto ps = pm->ps;

			game::vec3_t end{};
			game::trace_t trace{};

			if (utils::vector::length(ps->velocity) == 0)
			{
				return;
			}

			utils::vector::ma(ps->origin, pml->frametime, ps->velocity, end);
			utils::hook::invoke<void>(0x2D14C0_b, pm, &trace, ps->origin, end, 
				&pm->bounds, ps->clientNum, pm->tracemask); // PM_playerTrace

			if (trace.fraction == 1)
			{
				return;
			}

			if (trace.normal[2] > surf_slope)
			{
				return;
			}

			pm_clip_velocity(ps->velocity, trace.normal, ps->velocity, 1.0f);
		}

		void pm_airmove_stub(game::mp::pmove_t* pm, game::mp::pml_t* pml)
		{
			if (!pm_cs_strafing->current.enabled)
			{
				return pm_airmove_hook.invoke<void>(pm, pml);
			}

			const auto ps = pm->ps;

			ps->sprintButtonUpRequired = 1;

			float fmove{}, smove{}, wishspeed{};
			game::vec3_t wishvel{}, wishdir{};

			fmove = pm->cmd.forwardmove;
			smove = pm->cmd.rightmove;

			pml->forward[2] = 0.0f;
			pml->right[2] = 0.0f;

			utils::vector::normalize(pml->forward);
			utils::vector::normalize(pml->right);

			for (auto i = 0; i < 2; i++)
			{
				wishvel[i] = pml->forward[i] * fmove + pml->right[i] * smove;
			}

			wishvel[2] = 0;

			utils::vector::copy(wishvel, wishdir);
			wishspeed = utils::vector::normalize(wishdir);

			if (wishspeed != 0 && (wishspeed > 320.0f))
			{
				utils::vector::scale(wishvel, 320.0f / wishspeed, wishvel);
				wishspeed = 320.0f;
			}

			pm_air_accelerate(wishdir, wishspeed, ps, pml);

			utils::hook::invoke<void>(0x2D3380_b, pm, pml, 1, 1); // PM_StepSlideMove

			pm_try_playermove(pm, pml);
		}
	}

	class component final : public component_interface
	{
	public:
		void post_unpack() override
		{
			if (game::environment::is_sp())
			{
				return;
			}

			pm_airmove_hook.create(0x2C93B0_b, pm_airmove_stub);

			pm_cs_airAccelerate = dvars::register_float("pm_cs_airAccelerate", 100.0f, 1.0f, 500.0f,
				game::DvarFlags::DVAR_FLAG_REPLICATED,
				"Defines player acceleration mid-air");

			pm_cs_airSpeedCap = dvars::register_float("pm_cs_airSpeedCap", 30.0f, 1.0f, 500.0f,
				game::DvarFlags::DVAR_FLAG_REPLICATED,
				"Maximum speed mid-air");

			pm_cs_strafing = dvars::register_bool("pm_cs_strafing", false,
				game::DvarFlags::DVAR_FLAG_REPLICATED,
				"Enable CS like strafing");
		}
	};
}

REGISTER_COMPONENT(movement::component)