feat(v3.4): CAM toolpath — contour + pocket + G-code

include/vde/core/cam_toolpath.h

@@ -0,0 +1,99 @@
+#pragma once
+#include "vde/core/point.h"
+#include <vector>
+#include <string>
+
+namespace vde::curves {
+class NurbsCurve;
+}
+
+namespace vde::core {
+
+using core::Point3D;
+using core::Vector3D;
+using core::Point2D = Eigen::Matrix<double, 2, 1>;
+
+/// Toolpath segment types
+enum class PathSegmentType {
+    Rapid,      ///< G0 — rapid traverse (不切削)
+    Linear,     ///< G1 — linear feed (直线切削)
+    ArcCW,      ///< G2 — clockwise arc
+    ArcCCW      ///< G3 — counter-clockwise arc
+};
+
+/// Single toolpath segment
+struct PathSegment {
+    Point3D start;
+    Point3D end;
+    Point3D center = Point3D::Zero();  ///< arc center (for G2/G3)
+    PathSegmentType type = PathSegmentType::Linear;
+    double feed_rate = 1000.0;  ///< mm/min
+    double z_depth = 0.0;       ///< Z cutting depth
+};
+
+/// Complete toolpath for one operation
+struct Toolpath {
+    std::string name;
+    std::vector<PathSegment> segments;
+    double safe_z = 10.0;    ///< safe retract height
+    double cut_z = -1.0;     ///< cutting depth
+    double step_down = 0.5;  ///< depth per pass
+};
+
+/// Offset a planar curve outward by a distance
+///
+/// Samples the curve at regular intervals, computes the normal at each sample,
+/// offsets each point, and fits a NURBS curve through the offset points.
+///
+/// @param curve Input curve (must lie in XY plane, Z coordinate ignored)
+/// @param distance Offset distance (> 0 for offset outward, < 0 for inward)
+/// @return Offset curve
+///
+/// @ingroup core
+[[nodiscard]] curves::NurbsCurve offset_contour(
+    const curves::NurbsCurve& curve, double distance);
+
+/// Generate contour toolpath (follow curve at cutting depth)
+///
+/// Creates multiple depth passes from safe_z stepping down to cut_depth.
+/// Adds rapid moves between passes.
+///
+/// @param curve Input contour curve
+/// @param cut_depth Cutting Z depth
+/// @param safe_z Safe retract Z height
+/// @param step_down Depth per pass
+/// @return Toolpath with spiral-down contour cuts
+///
+/// @ingroup core
+[[nodiscard]] Toolpath contour_toolpath(
+    const curves::NurbsCurve& curve,
+    double cut_depth, double safe_z = 10.0, double step_down = 1.0);
+
+/// Generate pocket toolpath (clear area inside contour, zigzag fill)
+///
+/// Computes the bounding box of the boundary, generates zigzag lines at the
+/// specified angle, clips them to the boundary and islands, then sorts
+/// segments for efficient tool movement.
+///
+/// @param boundary Outer boundary curve
+/// @param islands Interior island curves (optional)
+/// @param cut_depth Cutting Z depth
+/// @param step_over Tool step-over (fraction of tool diameter)
+/// @param angle Zigzag angle in degrees (0=horizontal, 90=vertical)
+/// @return Toolpath with spiral-down pocket cuts
+///
+/// @ingroup core
+[[nodiscard]] Toolpath pocket_toolpath(
+    const curves::NurbsCurve& boundary,
+    const std::vector<curves::NurbsCurve>& islands,
+    double cut_depth, double step_over = 0.5, double angle = 0.0);
+
+/// Export toolpath to G-code string (basic ISO format)
+///
+/// @param tp Toolpath to export
+/// @return G-code string
+///
+/// @ingroup core
+[[nodiscard]] std::string export_gcode(const Toolpath& tp);
+
+}  // namespace vde::core