Properly set rotation data from LuaAI (#4406)

* Properly set rotation data from LuaAI

* Update Variable Name

Author: BMagnu

code/ai/ai.h

@@ -586,6 +586,7 @@ extern void ai_do_default_behavior(object *obj);
 extern void ai_start_waypoints(object *objp, waypoint_list *wp_list, int wp_flags);
 extern void ai_ship_hit(object *objp_ship, object *hit_objp, vec3d *hit_normal);
 extern void ai_ship_destroy(int shipnum);
+extern vec3d ai_get_acc_limit(vec3d* vel_limit, const object* objp);
 extern void ai_turn_towards_vector(vec3d *dest, object *objp, vec3d *slide_vec, vec3d *rel_pos, float bank_override, int flags, vec3d *rvec = nullptr, vec3d* turnrate_mod = nullptr);
 extern void init_ai_object(int objnum);
 extern void ai_init(void);				//	Call this one to parse ai.tbl.

code/ai/aicode.cpp

@@ -1261,43 +1261,7 @@ void ai_turn_towards_vector(vec3d* dest, object* objp, vec3d* slide_vec, vec3d*
 		}
 	}
 
-	//	Set rate at which ship can accelerate to its rotational velocity.
-	//	For now, weapons just go much faster.
-	acc_limit = vel_limit;
-	if (objp->type == OBJ_WEAPON)
-		acc_limit *= 8.0f;
-
-	// do _proper_ handling of acc_limit and vel_limit if this flag is set
-	if (Framerate_independent_turning) {
-		// handle modifications to rotdamp (that could affect acc_limit and vel_limit)
-		// handled in its entirety in physics_sim_rot 
-		float rotdamp = pip->rotdamp;
-		float shock_fraction_time_left = 0.f;
-		if (pip->flags & PF_IN_SHOCKWAVE) {
-			shock_fraction_time_left = timestamp_until(pip->shockwave_decay) / (float)SW_BLAST_DURATION;
-			if (shock_fraction_time_left > 0)
-				rotdamp = pip->rotdamp + pip->rotdamp * (SW_ROT_FACTOR - 1) * shock_fraction_time_left;
-		}
-
-		if (Ai_respect_tabled_turntime_rotdamp) {
-			// We're assuming the turn rate here is accurate so leave it as is
-			// but we'll use the ship's rotdamp to modify acc_limit
-			// (this is the polynomial approximation of the exponential effect rotdamp has on players)
-			if (rotdamp == 0.f)
-				acc_limit *= 1000.f;
-			else
-				acc_limit = vel_limit * (0.5f / rotdamp);
-		}
-		else { 
-			// else, calculate the retail-friendly vel and acc values
-			ai_compensate_for_retail_turning(&vel_limit, &acc_limit, rotdamp, objp->type == OBJ_WEAPON);
-
-			// handle missile turning accel (which is bundled into rotdamp)
-			if (objp->type == OBJ_WEAPON && rotdamp != 0.f) {
-				acc_limit = vel_limit * (0.5f / rotdamp);
-			}
-		}
-	}
+	acc_limit = ai_get_acc_limit(&vel_limit, objp);
 
 	// for formation flying
 	if ((flags & AITTV_SLOW_BANK_ACCEL)) {
@@ -1364,6 +1328,52 @@ void ai_turn_towards_vector(vec3d* dest, object* objp, vec3d* slide_vec, vec3d*
 
 }
 
+//vel_limit can be modified if the object is a weapon and retail behaviour is enabled
+vec3d ai_get_acc_limit(vec3d* vel_limit, const object* objp) {
+	//	Set rate at which ship can accelerate to its rotational velocity.
+	//	For now, weapons just go much faster.
+	vec3d acc_limit = *vel_limit;
+	if (objp->type == OBJ_WEAPON)
+		acc_limit *= 8.0f;
+
+	const physics_info* pip = &objp->phys_info;
+
+	// do _proper_ handling of acc_limit and vel_limit if this flag is set
+	if (Framerate_independent_turning) {
+		// handle modifications to rotdamp (that could affect acc_limit and vel_limit)
+		// handled in its entirety in physics_sim_rot 
+		float rotdamp = pip->rotdamp;
+		float shock_fraction_time_left = 0.f;
+		if (pip->flags & PF_IN_SHOCKWAVE) {
+			shock_fraction_time_left = timestamp_until(pip->shockwave_decay) / (float)SW_BLAST_DURATION;
+			if (shock_fraction_time_left > 0)
+				rotdamp = pip->rotdamp + pip->rotdamp * (SW_ROT_FACTOR - 1) * shock_fraction_time_left;
+		}
+
+		if (Ai_respect_tabled_turntime_rotdamp) {
+			// We're assuming the turn rate here is accurate so leave it as is
+			// but we'll use the ship's rotdamp to modify acc_limit
+			// (this is the polynomial approximation of the exponential effect rotdamp has on players)
+			if (rotdamp == 0.f)
+				acc_limit *= 1000.f;
+			else
+				acc_limit = *vel_limit * (0.5f / rotdamp);
+		}
+		else {
+			// else, calculate the retail-friendly vel and acc values
+			ai_compensate_for_retail_turning(vel_limit, &acc_limit, rotdamp, objp->type == OBJ_WEAPON);
+
+			// handle missile turning accel (which is bundled into rotdamp)
+			if (objp->type == OBJ_WEAPON && rotdamp != 0.f) {
+				acc_limit = *vel_limit * (0.5f / rotdamp);
+			}
+		}
+	}
+
+	return acc_limit;
+}
+
+
 //	Set aip->target_objnum to objnum
 //	Update aip->previous_target_objnum.
 //	If new target (objnum) is different than old target, reset target_time.

code/scripting/api/objs/ai_helper.cpp

@@ -6,6 +6,8 @@
 #include "vecmath.h"
 
 #include "ai/ai.h"
+#include "mission/missionparse.h"
+#include "ship/ship.h"
 
 namespace scripting {
 namespace api {
@@ -39,19 +41,65 @@ inline int aici_getset_helper(lua_State* L, float control_info::* value) {
 	return ade_set_args(L, "f", AI_ci.*value);
 }
 
-ADE_VIRTVAR(Pitch, l_AI_Helper, "number", "The pitch rate for the ship this frame, -1 to 1", "number", "The pitch rate, or 0 if the handle is invalid")
+inline int pi_rotation_getset_helper(lua_State* L, int axis) {
+	//Use with care! This works only if, as expected, the l_AI_Helper object is the one supplied to the luaai scripts this very frame
+	object_h ship;
+	float f = 0.0f;
+	if (!ade_get_args(L, "o|f", l_AI_Helper.Get(&ship), &f))
+		return ade_set_error(L, "f", 0.0f);
+
+	if (!ship.IsValid())
+		return ade_set_error(L, "f", 0.0f);
+
+	vec3d vel_limit;
+	// get the turn rate if we have Use_axial_turnrate_differences
+	if (The_mission.ai_profile->flags[AI::Profile_Flags::Use_axial_turnrate_differences]) {
+		vel_limit = Ship_info[Ships[ship.objp->instance].ship_info_index].max_rotvel;
+	}
+	else { // else get the turn time
+		float turn_time = Ship_info[Ships[ship.objp->instance].ship_info_index].srotation_time;
+
+		if (turn_time > 0.0f)
+		{
+			vel_limit.xyz.x = PI2 / turn_time;
+			vel_limit.xyz.y = PI2 / turn_time;
+			vel_limit.xyz.z = PI2 / turn_time;
+		}
+	}
+	vec3d acc_limit = ai_get_acc_limit(&vel_limit, ship.objp);
+
+	float currentThrustRate = ((ship.objp->phys_info.desired_rotvel.a1d[axis] - ship.objp->phys_info.rotvel.a1d[axis]) / AI_frametime) / acc_limit.a1d[axis];
+
+	if (ADE_SETTING_VAR) {
+		currentThrustRate = f;
+		float targetVel = currentThrustRate * acc_limit.a1d[axis] * AI_frametime + ship.objp->phys_info.rotvel.a1d[axis];
+		CLAMP(targetVel, -vel_limit.a1d[axis], vel_limit.a1d[axis]);
+		ship.objp->phys_info.desired_rotvel.a1d[axis] = targetVel;
+
+		vec3d rotstep = ship.objp->phys_info.desired_rotvel * AI_frametime;
+
+		matrix	rotmat;
+		angles rotangles{ rotstep.xyz.x, rotstep.xyz.z, rotstep.xyz.y };
+		vm_angles_2_matrix(&rotmat, &rotangles);
+		vm_matrix_x_matrix(&ship.objp->phys_info.ai_desired_orient, &ship.objp->orient, &rotmat);
+	}
+
+	return ade_set_args(L, "f", currentThrustRate);
+}
+
+ADE_VIRTVAR(Pitch, l_AI_Helper, "number", "The pitch thrust rate for the ship this frame, -1 to 1", "number", "The pitch rate, or 0 if the handle is invalid")
 {
-	return aici_getset_helper(L, &control_info::pitch);
+	return pi_rotation_getset_helper(L, 0);
 }
 
-ADE_VIRTVAR(Bank, l_AI_Helper, "number", "The bank rate for the ship this frame, -1 to 1", "number", "The bank rate, or 0 if the handle is invalid")
+ADE_VIRTVAR(Bank, l_AI_Helper, "number", "The bank thrust rate for the ship this frame, -1 to 1", "number", "The bank rate, or 0 if the handle is invalid")
 {
-	return aici_getset_helper(L, &control_info::bank);
+	return pi_rotation_getset_helper(L, 2);
 }
 
-ADE_VIRTVAR(Heading, l_AI_Helper, "number", "The heading rate for the ship this frame, -1 to 1", "number", "The heading rate, or 0 if the handle is invalid")
+ADE_VIRTVAR(Heading, l_AI_Helper, "number", "The heading thrust rate for the ship this frame, -1 to 1", "number", "The heading rate, or 0 if the handle is invalid")
 {
-	return aici_getset_helper(L, &control_info::heading);
+	return pi_rotation_getset_helper(L, 1);
 }
 
 ADE_VIRTVAR(ForwardThrust, l_AI_Helper, "number", "The forward thrust rate for the ship this frame, -1 to 1", "number", "The forward thrust rate, or 0 if the handle is invalid")