Added smoothstep

generators/graph/voxel_generator_graph.cpp

@@ -706,6 +706,7 @@ void VoxelGeneratorGraph::_bind_methods() {
 	BIND_ENUM_CONSTANT(NODE_CLAMP);
 	BIND_ENUM_CONSTANT(NODE_MIX);
 	BIND_ENUM_CONSTANT(NODE_REMAP);
+	BIND_ENUM_CONSTANT(NODE_SMOOTHSTEP);
 	BIND_ENUM_CONSTANT(NODE_CURVE);
 	BIND_ENUM_CONSTANT(NODE_NOISE_2D);
 	BIND_ENUM_CONSTANT(NODE_NOISE_3D);

generators/graph/voxel_generator_graph.h

@@ -32,6 +32,7 @@ public:
 		NODE_CLAMP,
 		NODE_MIX,
 		NODE_REMAP,
+		NODE_SMOOTHSTEP,
 		NODE_CURVE,
 		NODE_NOISE_2D,
 		NODE_NOISE_3D,

generators/graph/voxel_graph_node_db.cpp

@@ -181,6 +181,14 @@ VoxelGraphNodeDB::VoxelGraphNodeDB() {
 		t.params.push_back(Param("min1", Variant::REAL, -1.f));
 		t.params.push_back(Param("max1", Variant::REAL, 1.f));
 	}
+	{
+		NodeType &t = types[VoxelGeneratorGraph::NODE_SMOOTHSTEP];
+		t.name = "Smoothstep";
+		t.inputs.push_back(Port("x"));
+		t.outputs.push_back(Port("out"));
+		t.params.push_back(Param("edge0", Variant::REAL, 0.f));
+		t.params.push_back(Param("edge1", Variant::REAL, 1.f));
+	}
 	{
 		NodeType &t = types[VoxelGeneratorGraph::NODE_CURVE];
 		t.name = "Curve";

generators/graph/voxel_graph_runtime.cpp

@@ -267,6 +267,13 @@ void VoxelGraphRuntime::compile(const ProgramGraph &graph) {
 						append(program, max1 - min1);
 					} break;
 
+					case VoxelGeneratorGraph::NODE_SMOOTHSTEP: {
+						float edge0 = node->params[0].operator float();
+						float edge1 = node->params[1].operator float();
+						append(program, edge0);
+						append(program, edge1);
+					} break;
+
 				} // switch special params
 
 #ifdef VOXEL_DEBUG_GRAPH_PROG_SENTINEL
@@ -355,6 +362,13 @@ struct PNodeRemap {
 	float p_m1;
 };
 
+struct PNodeSmoothstep {
+	uint16_t a_x;
+	uint16_t a_out;
+	float p_edge0;
+	float p_edge1;
+};
+
 struct PNodeCurve {
 	uint16_t a_in;
 	uint16_t a_out;
@@ -586,6 +600,11 @@ float VoxelGraphRuntime::generate_single(const Vector3i &position) {
 				memory[n.a_out] = ((memory[n.a_x] - n.p_c0) * n.p_m0) * n.p_m1 + n.p_c1;
 			} break;
 
+			case VoxelGeneratorGraph::NODE_SMOOTHSTEP: {
+				const PNodeSmoothstep &n = read<PNodeSmoothstep>(_program, pc);
+				memory[n.a_out] = smoothstep(n.p_edge0, n.p_edge1, memory[n.a_x]);
+			} break;
+
 			case VoxelGeneratorGraph::NODE_CURVE: {
 				const PNodeCurve &n = read<PNodeCurve>(_program, pc);
 				memory[n.a_out] = n.p_curve->interpolate_baked(memory[n.a_in]);
@@ -831,6 +850,14 @@ Interval VoxelGraphRuntime::analyze_range(Vector3i min_pos, Vector3i max_pos) {
 				max_memory[n.a_out] = r.max;
 			} break;
 
+			case VoxelGeneratorGraph::NODE_SMOOTHSTEP: {
+				const PNodeSmoothstep &n = read<PNodeSmoothstep>(_program, pc);
+				Interval x(min_memory[n.a_x], max_memory[n.a_x]);
+				Interval r = smoothstep(n.p_edge0, n.p_edge1, x);
+				min_memory[n.a_out] = r.min;
+				max_memory[n.a_out] = r.max;
+			} break;
+
 			case VoxelGeneratorGraph::NODE_CURVE: {
 				const PNodeCurve &n = read<PNodeCurve>(_program, pc);
 				if (min_memory[n.a_in] == max_memory[n.a_in]) {

math/interval.h

@@ -205,4 +205,18 @@ inline Interval wrapf(const Interval &x, const Interval &d) {
 	return x - (d * floor(x / d));
 }
 
+inline Interval smoothstep(float p_from, float p_to, Interval p_weight) {
+	if (Math::is_equal_approx(p_from, p_to)) {
+		return Interval::from_single_value(p_from);
+	}
+	// Smoothstep is monotonic
+	float v0 = smoothstep(p_from, p_to, p_weight.min);
+	float v1 = smoothstep(p_from, p_to, p_weight.max);
+	if (v0 <= v1) {
+		return Interval(v0, v1);
+	} else {
+		return Interval(v1, v0);
+	}
+}
+
 #endif // INTERVAL_H

util/utility.h

@@ -203,6 +203,15 @@ inline float wrapf(float x, float d) {
 	return Math::is_zero_approx(d) ? 0.f : x - (d * Math::floor(x / d));
 }
 
+// Similar to Math::smoothstep but doesn't use macro to clamp
+inline float smoothstep(float p_from, float p_to, float p_weight) {
+	if (Math::is_equal_approx(p_from, p_to)) {
+		return p_from;
+	}
+	float x = clamp((p_weight - p_from) / (p_to - p_from), 0.0f, 1.0f);
+	return x * x * (3.0f - 2.0f * x);
+}
+
 #if TOOLS_ENABLED
 namespace VoxelDebug {
 void create_debug_box_mesh();