Added lerp_angles built-in function

Co-authored-by: Xrayez <https://github.com/Xrayez>
Co-authored-by: DleanJeans <https://github.com/DleanJeans>

core/math/expression.cpp

@@ -68,6 +68,7 @@ const char *Expression::func_name[Expression::FUNC_MAX] = {
 	"step_decimals",
 	"stepify",
 	"lerp",
+	"lerp_angle",
 	"inverse_lerp",
 	"range_lerp",
 	"smoothstep",
@@ -190,6 +191,7 @@ int Expression::get_func_argument_count(BuiltinFunc p_func) {
 		case COLORN:
 			return 2;
 		case MATH_LERP:
+		case MATH_LERP_ANGLE:
 		case MATH_INVERSE_LERP:
 		case MATH_SMOOTHSTEP:
 		case MATH_MOVE_TOWARD:
@@ -395,6 +397,13 @@ void Expression::exec_func(BuiltinFunc p_func, const Variant **p_inputs, Variant
 			VALIDATE_ARG_NUM(2);
 			*r_return = Math::lerp((double)*p_inputs[0], (double)*p_inputs[1], (double)*p_inputs[2]);
 		} break;
+		case MATH_LERP_ANGLE: {
+
+			VALIDATE_ARG_NUM(0);
+			VALIDATE_ARG_NUM(1);
+			VALIDATE_ARG_NUM(2);
+			*r_return = Math::lerp_angle((double)*p_inputs[0], (double)*p_inputs[1], (double)*p_inputs[2]);
+		} break;
 		case MATH_INVERSE_LERP: {
 
 			VALIDATE_ARG_NUM(0);

core/math/expression.h

@@ -67,6 +67,7 @@ public:
 		MATH_STEP_DECIMALS,
 		MATH_STEPIFY,
 		MATH_LERP,
+		MATH_LERP_ANGLE,
 		MATH_INVERSE_LERP,
 		MATH_RANGE_LERP,
 		MATH_SMOOTHSTEP,

core/math/math_funcs.h

@@ -215,6 +215,17 @@ public:
 	static _ALWAYS_INLINE_ double lerp(double p_from, double p_to, double p_weight) { return p_from + (p_to - p_from) * p_weight; }
 	static _ALWAYS_INLINE_ float lerp(float p_from, float p_to, float p_weight) { return p_from + (p_to - p_from) * p_weight; }
 
+	static _ALWAYS_INLINE_ double lerp_angle(double p_from, double p_to, double p_weight) {
+		double difference = fmod(p_to - p_from, Math_TAU);
+		double distance = fmod(2.0 * difference, Math_TAU) - difference;
+		return p_from + distance * p_weight;
+	}
+	static _ALWAYS_INLINE_ float lerp_angle(float p_from, float p_to, float p_weight) {
+		float difference = fmod(p_to - p_from, (float)Math_TAU);
+		float distance = fmod(2.0f * difference, (float)Math_TAU) - difference;
+		return p_from + distance * p_weight;
+	}
+
 	static _ALWAYS_INLINE_ double inverse_lerp(double p_from, double p_to, double p_value) { return (p_value - p_from) / (p_to - p_from); }
 	static _ALWAYS_INLINE_ float inverse_lerp(float p_from, float p_to, float p_value) { return (p_value - p_from) / (p_to - p_from); }
 

modules/gdscript/doc_classes/@GDScript.xml

@@ -604,6 +604,29 @@
 				[/codeblock]
 			</description>
 		</method>
+		<method name="lerp_angle">
+			<return type="float">
+			</return>
+			<argument index="0" name="from" type="float">
+			</argument>
+			<argument index="1" name="to" type="float">
+			</argument>
+			<argument index="2" name="weight" type="float">
+			</argument>
+			<description>
+				Linearly interpolates between two angles (in radians) by a normalized value.
+				Similar to [method lerp] but interpolate correctly when the angles wrap around [constant @GDScript.TAU].
+				[codeblock]
+				extends Sprite
+				var elapsed = 0.0
+				func _process(delta):
+					var min_angle = deg2rad(0.0)
+					var max_angle = deg2rad(90.0)
+					rotation = lerp_angle(min_angle, max_angle, elapsed)
+					elapsed += delta
+				[/codeblock]
+			</description>
+		</method>
 		<method name="linear2db">
 			<return type="float">
 			</return>

modules/gdscript/gdscript_functions.cpp

@@ -76,6 +76,7 @@ const char *GDScriptFunctions::get_func_name(Function p_func) {
 		"step_decimals",
 		"stepify",
 		"lerp",
+		"lerp_angle",
 		"inverse_lerp",
 		"range_lerp",
 		"smoothstep",
@@ -383,6 +384,13 @@ void GDScriptFunctions::call(Function p_func, const Variant **p_args, int p_arg_
 				} break;
 			}
 		} break;
+		case MATH_LERP_ANGLE: {
+			VALIDATE_ARG_COUNT(3);
+			VALIDATE_ARG_NUM(0);
+			VALIDATE_ARG_NUM(1);
+			VALIDATE_ARG_NUM(2);
+			r_ret = Math::lerp_angle((double)*p_args[0], (double)*p_args[1], (double)*p_args[2]);
+		} break;
 		case MATH_INVERSE_LERP: {
 			VALIDATE_ARG_COUNT(3);
 			VALIDATE_ARG_NUM(0);
@@ -1676,6 +1684,11 @@ MethodInfo GDScriptFunctions::get_info(Function p_func) {
 			mi.return_val.usage |= PROPERTY_USAGE_NIL_IS_VARIANT;
 			return mi;
 		} break;
+		case MATH_LERP_ANGLE: {
+			MethodInfo mi("lerp_angle", PropertyInfo(Variant::REAL, "from"), PropertyInfo(Variant::REAL, "to"), PropertyInfo(Variant::REAL, "weight"));
+			mi.return_val.type = Variant::REAL;
+			return mi;
+		} break;
 		case MATH_INVERSE_LERP: {
 			MethodInfo mi("inverse_lerp", PropertyInfo(Variant::REAL, "from"), PropertyInfo(Variant::REAL, "to"), PropertyInfo(Variant::REAL, "weight"));
 			mi.return_val.type = Variant::REAL;

modules/gdscript/gdscript_functions.h

@@ -67,6 +67,7 @@ public:
 		MATH_STEP_DECIMALS,
 		MATH_STEPIFY,
 		MATH_LERP,
+		MATH_LERP_ANGLE,
 		MATH_INVERSE_LERP,
 		MATH_RANGE_LERP,
 		MATH_SMOOTHSTEP,

modules/mono/glue/Managed/Files/Mathf.cs

@@ -185,6 +185,12 @@ namespace Godot
             return from + (to - from) * weight;
         }
 
+        public static real_t LerpAngle(real_t from, real_t to, real_t weight) {
+            real_t difference = (to - from) % Mathf.Tau;
+            real_t distance = ((2 * difference) % Mathf.Tau) - difference;
+            return from + distance * weight;
+        }
+
         public static real_t Log(real_t s)
         {
             return (real_t)Math.Log(s);

modules/visual_script/doc_classes/VisualScriptBuiltinFunc.xml

@@ -212,8 +212,11 @@
 			var t = clamp((weight - from) / (to - from), 0.0, 1.0)
 			return t * t * (3.0 - 2.0 * t)
 			[/codeblock]
+		<constant name="MATH_POSMOD" value="65" enum="BuiltinFunc">
 		</constant>
-		<constant name="FUNC_MAX" value="65" enum="BuiltinFunc">
+		<constant name="MATH_LERP_ANGLE" value="66" enum="BuiltinFunc">
+		</constant>
+		<constant name="FUNC_MAX" value="67" enum="BuiltinFunc">
 			Represents the size of the [enum BuiltinFunc] enum.
 		</constant>
 	</constants>

modules/visual_script/visual_script_builtin_funcs.cpp

@@ -105,6 +105,7 @@ const char *VisualScriptBuiltinFunc::func_name[VisualScriptBuiltinFunc::FUNC_MAX
 	"color_named",
 	"smoothstep",
 	"posmod",
+	"lerp_angle",
 };
 
 VisualScriptBuiltinFunc::BuiltinFunc VisualScriptBuiltinFunc::find_function(const String &p_string) {
@@ -207,6 +208,7 @@ int VisualScriptBuiltinFunc::get_func_argument_count(BuiltinFunc p_func) {
 		case COLORN:
 			return 2;
 		case MATH_LERP:
+		case MATH_LERP_ANGLE:
 		case MATH_INVERSE_LERP:
 		case MATH_SMOOTHSTEP:
 		case MATH_MOVE_TOWARD:
@@ -318,7 +320,9 @@ PropertyInfo VisualScriptBuiltinFunc::get_input_value_port_info(int p_idx) const
 				return PropertyInfo(Variant::REAL, "steps");
 		} break;
 		case MATH_LERP:
-		case MATH_INVERSE_LERP: {
+		case MATH_LERP_ANGLE:
+		case MATH_INVERSE_LERP:
+		case MATH_SMOOTHSTEP: {
 			if (p_idx == 0)
 				return PropertyInfo(Variant::REAL, "from");
 			else if (p_idx == 1)
@@ -338,14 +342,6 @@ PropertyInfo VisualScriptBuiltinFunc::get_input_value_port_info(int p_idx) const
 			else
 				return PropertyInfo(Variant::REAL, "ostop");
 		} break;
-		case MATH_SMOOTHSTEP: {
-			if (p_idx == 0)
-				return PropertyInfo(Variant::REAL, "from");
-			else if (p_idx == 1)
-				return PropertyInfo(Variant::REAL, "to");
-			else
-				return PropertyInfo(Variant::REAL, "weight");
-		} break;
 		case MATH_MOVE_TOWARD: {
 			if (p_idx == 0)
 				return PropertyInfo(Variant::REAL, "from");
@@ -532,6 +528,7 @@ PropertyInfo VisualScriptBuiltinFunc::get_output_value_port_info(int p_idx) cons
 		} break;
 		case MATH_STEPIFY:
 		case MATH_LERP:
+		case MATH_LERP_ANGLE:
 		case MATH_INVERSE_LERP:
 		case MATH_RANGE_LERP:
 		case MATH_SMOOTHSTEP:
@@ -856,6 +853,13 @@ void VisualScriptBuiltinFunc::exec_func(BuiltinFunc p_func, const Variant **p_in
 			VALIDATE_ARG_NUM(2);
 			*r_return = Math::lerp((double)*p_inputs[0], (double)*p_inputs[1], (double)*p_inputs[2]);
 		} break;
+		case VisualScriptBuiltinFunc::MATH_LERP_ANGLE: {
+
+			VALIDATE_ARG_NUM(0);
+			VALIDATE_ARG_NUM(1);
+			VALIDATE_ARG_NUM(2);
+			*r_return = Math::lerp_angle((double)*p_inputs[0], (double)*p_inputs[1], (double)*p_inputs[2]);
+		} break;
 		case VisualScriptBuiltinFunc::MATH_INVERSE_LERP: {
 
 			VALIDATE_ARG_NUM(0);
@@ -1369,6 +1373,7 @@ void VisualScriptBuiltinFunc::_bind_methods() {
 	BIND_ENUM_CONSTANT(BYTES_TO_VAR);
 	BIND_ENUM_CONSTANT(COLORN);
 	BIND_ENUM_CONSTANT(MATH_SMOOTHSTEP);
+	BIND_ENUM_CONSTANT(MATH_LERP_ANGLE);
 	BIND_ENUM_CONSTANT(FUNC_MAX);
 }
 
@@ -1422,6 +1427,7 @@ void register_visual_script_builtin_func_node() {
 	VisualScriptLanguage::singleton->add_register_func("functions/built_in/decimals", create_builtin_func_node<VisualScriptBuiltinFunc::MATH_DECIMALS>);
 	VisualScriptLanguage::singleton->add_register_func("functions/built_in/stepify", create_builtin_func_node<VisualScriptBuiltinFunc::MATH_STEPIFY>);
 	VisualScriptLanguage::singleton->add_register_func("functions/built_in/lerp", create_builtin_func_node<VisualScriptBuiltinFunc::MATH_LERP>);
+	VisualScriptLanguage::singleton->add_register_func("functions/built_in/lerp_angle", create_builtin_func_node<VisualScriptBuiltinFunc::MATH_LERP_ANGLE>);
 	VisualScriptLanguage::singleton->add_register_func("functions/built_in/inverse_lerp", create_builtin_func_node<VisualScriptBuiltinFunc::MATH_INVERSE_LERP>);
 	VisualScriptLanguage::singleton->add_register_func("functions/built_in/range_lerp", create_builtin_func_node<VisualScriptBuiltinFunc::MATH_RANGE_LERP>);
 	VisualScriptLanguage::singleton->add_register_func("functions/built_in/smoothstep", create_builtin_func_node<VisualScriptBuiltinFunc::MATH_SMOOTHSTEP>);

modules/visual_script/visual_script_builtin_funcs.h

@@ -105,6 +105,7 @@ public:
 		COLORN,
 		MATH_SMOOTHSTEP,
 		MATH_POSMOD,
+		MATH_LERP_ANGLE,
 		FUNC_MAX
 	};