Core API

The core layer owns 3D data and math. It does not know about TUI output, terminal aspect ratio correction, ANSI escape codes, or character backgrounds.

Types

struct QuadFace { a : Int; b : Int; c : Int; d : Int }
struct TriangleFace { a : Int; b : Int; c : Int }
struct Mesh { vertices : Array[@la.Vector[Double]]; faces : Array[QuadFace] }
struct Transform3 { matrix : @la.Matrix[Double] }

Mesh Construction

• cube_mesh(size : Double) -> Mesh: creates a cube centered at the origin.
• sphere_mesh(radius : Double, rings : Int, segments : Int) -> Mesh: creates a low-poly UV sphere represented as quad faces, with degenerate quads at the caps.
• torus_mesh(major_radius, minor_radius, major_segments, minor_segments) -> Mesh: creates an outward-wound quad torus suitable for backface culling.
• face_vertices(mesh : Mesh, face : QuadFace) -> Array[@la.Vector[Double]]: returns the four vertices referenced by a face.
• triangulate_quad(face : QuadFace) -> Array[TriangleFace]: splits a quad into two triangles for rasterization.

Vector Helpers

• vec3(x, y, z): constructs a 3D vector.
• sub_vec(a, b): subtracts two vectors.
• cross_vec(a, b): computes a 3D cross product.
• vec_length(v): computes Euclidean length.
• normalize_vec(v): returns a unit vector or zero vector for near-zero input.

Face Helpers

• face_center(vertices, face): average of the four face vertices.
• face_normal(vertices, face): normalized cross product from the first three face vertices.
• face_is_visible(vertices, face, camera_position): backface test using normal dot to_camera.
• face_intensity(vertices, face, light_direction): simple Lambert intensity clamped at zero.

Transform Helpers

• Transform3::identity(): identity 4x4 transform.
• Transform3::translation(x, y, z): point translation.
• Transform3::scale(x, y, z): non-uniform scale.
• rotation_x(angle), rotation_y(angle), rotation_z(angle): 4x4 rotation matrices.
• rotation_matrix(angle_x, angle_y, angle_z): combined Z * Y * X rotation.
• Transform3::rotation(angle_x, angle_y, angle_z): 4x4 rotation transform.
• Transform3::compose(next): applies self then next.
• Transform3::apply_point(point): applies the full homogeneous transform.
• Transform3::apply_direction(direction): ignores translation by using w = 0.
• Transform3::apply_vertex(vertex): applies the transform matrix to one vertex.
• Transform3::apply_mesh(mesh): transforms vertices and preserves face topology.