Add "Move End Position by target velocity" (#6760)

* add "Move End Position by target velocity"

* Enable the functionality for slashbeams as well

Author: BMagnu

code/weapon/beam.cpp

@@ -2471,7 +2471,9 @@ void beam_get_binfo(beam *b, float accuracy, int num_shots, int burst_seed, floa
 	if(b->weapon_info_index < 0){
 		return;
 	}
-	bwi = &Weapon_info[b->weapon_info_index].b_info;
+
+	auto& wi = Weapon_info[b->weapon_info_index];
+	bwi = &wi.b_info;
 
 	// stuff num shots even though its only used for antifighter beam weapons
 	b->binfo.shot_count = (ubyte)num_shots;
@@ -2519,6 +2521,11 @@ void beam_get_binfo(beam *b, float accuracy, int num_shots, int burst_seed, floa
 		vm_vec_sub(&b->binfo.dir_a, &pos1, &turret_point);
 		vm_vec_normalize(&b->binfo.dir_a);
 
+		if (b->target && wi.beam_curves.has_curve(weapon_info::BeamCurveOutputs::END_POSITION_BY_VELOCITY)) {
+			float velocity_mult = wi.beam_curves.get_output(weapon_info::BeamCurveOutputs::END_POSITION_BY_VELOCITY, *b, &b->modular_curves_instance);
+			pos2 += b->target->phys_info.vel * velocity_mult;
+		}
+
 		// point 2
 		vm_vec_sub(&b->binfo.dir_b, &pos2, &turret_point);
 		vm_vec_normalize(&b->binfo.dir_b);
@@ -2643,6 +2650,11 @@ void beam_get_binfo(beam *b, float accuracy, int num_shots, int burst_seed, floa
 				per_burst_rot_axis = b->target->pos;
 			if (bwi->t5info.burst_rot_axis == Type5BeamRotAxis::CENTER)
 				burst_rot_axis = b->target->pos;
+
+			if (wi.beam_curves.has_curve(weapon_info::BeamCurveOutputs::END_POSITION_BY_VELOCITY)) {
+				float velocity_mult = wi.beam_curves.get_output(weapon_info::BeamCurveOutputs::END_POSITION_BY_VELOCITY, *b, &b->modular_curves_instance);
+				pos2 += b->target->phys_info.vel * velocity_mult;
+			}
 
 		} else { // No usable target
 			vec3d center = vm_vec_new(0.f, 0.f, 0.f);

code/weapon/weapon.h

@@ -225,7 +225,7 @@ typedef struct type5_beam_info {
 	float continuous_rot;                        // radians per sec rotation over beam lifetime
 	int rot_curve_idx;
 	Type5BeamRotAxis continuous_rot_axis;		 // axis around which do continuous rotation
-	SCP_vector<float> burst_rot_pattern;         // radians to rotate for each beam in a burst, will also make spawned and ssb beams fire 
+	SCP_vector<float> burst_rot_pattern;         // radians to rotate for each beam in a burst, will also make spawned and ssb beams fire
 	                                             // this many beams simultaneously with the defined rotations
 	Type5BeamRotAxis burst_rot_axis;			 // axis around which to do burst rotation
 	float per_burst_rot;                         // radians to rotate for each burst, or each shot if no burst
@@ -256,7 +256,7 @@ typedef struct beam_weapon_info {
 	float beam_initial_width;		    // what percentage of total beam width the beam has initially
 	float beam_grow_factor;			    // what percentage of total beam lifetime when the beam starts growing
 	float beam_grow_pct;				// what percent/second the beam grows at
-	beam_weapon_section_info sections[MAX_BEAM_SECTIONS];	// info on the visible sections of the beam 	
+	beam_weapon_section_info sections[MAX_BEAM_SECTIONS];	// info on the visible sections of the beam
 	float range;						// how far it will shoot-Bobboau
 	float damage_threshold;				// point at wich damage will start being atenuated from 0.0 to 1.0
 	float beam_width;					// width of the beam (for certain collision checks)
@@ -833,6 +833,7 @@ struct weapon_info
 		GLOW_RADIUS_MULT,
 		GLOW_ALPHA_MULT,
 		GLOW_ANIM_STATE,
+		END_POSITION_BY_VELOCITY,
 
 		NUM_VALUES
 	};
@@ -846,6 +847,7 @@ struct weapon_info
 					std::pair {"Muzzle Glow Radius Mult", BeamCurveOutputs::GLOW_RADIUS_MULT},
 					std::pair {"Muzzle Glow Alpha Mult", BeamCurveOutputs::GLOW_ALPHA_MULT},
 					std::pair {"Muzzle Glow Anim State", BeamCurveOutputs::GLOW_ANIM_STATE},
+					std::pair {"Move End Position by Target Velocity", BeamCurveOutputs::END_POSITION_BY_VELOCITY}
 			},
 			std::pair {"Beam Lifetime", modular_curves_math_input<
 				modular_curves_math_input<
@@ -861,6 +863,7 @@ struct weapon_info
 				modular_curves_submember_input<&beam::life_left>,
 				ModularCurvesMathOperators::subtraction
 			>{}},
+			std::pair {"Beam Total Life", modular_curves_submember_input<&beam::life_total>{}},
 			std::pair {"Warmup Lifetime", modular_curves_functional_input<beam_get_warmup_lifetime_pct>{}},
 			std::pair {"Warmdown Lifetime", modular_curves_functional_input<beam_get_warmdown_lifetime_pct>{}},
 			std::pair {"Warmdown Age", modular_curves_functional_input<beam_get_warmdown_age>{}},