Data.CSG.Parser

Parser for CSG solid definition format. The format uses text files and is inspired by NETGEN 4.x .geo format.

Each definition may contain several solid definitions and ends with the top level object declaration. Right hand side of solid equations may reference other solids to allow composing of complex solids.

# comment

# define several primitives
solid b1 = sphere (0, 0, 0; 5);
solid p1 = plane (0, 0, 0; 1, 0, 0);

# define a composition
solid comp = b1 and p1;

# make it the top level object
tlo comp;

Statements must end with a semicolon (newlines are optional). Whitespace is ignored.

Multiple-solid compositions are right-associative, so b1 and b2 or b3 really means b1 and (b2 or b3). Keep simpler objects on the left and when in doubt stick to combining two solids at a time.

Top-level object line must reference a previously defined solid.

Syntax for primitives follows the signatures of CSG constructors for plane and sphere, but differs for cylinder and cone, as this module provides access only to frustums (cylinderFrustum and coneFrustum).

Half-space

plane (px, py, pz; nx, ny, nz), where (px, py, pz) is a point on a plane which defines the half-space and (nx, ny, nz) is a normal to the plane (outward to the half-space), not necessarily a unit vector.

Brick

orthobrick (ax, ay, az; bx, by, bz), where (ax, ay, az) is a vertex with minimum coordinates and (bx, by, bz) is a vertex with maximum coordinates.

Sphere

sphere (cx, cy, cz; r), where (cx, cy, cz) is a central point of a sphere and r is radius.

Right circular cylinder

cylinder (p1x, p1y, p1z; p2x, p2y, p2z; r) where (p1x, p1y, p1z) and (p2x, p2y, p2z) are bottom and top points on axis and r is radius.

Right circular conical frustum

cone (p1x, p1y, p1z; r1; p2x, p2y, p2z; r2) where (p1x, p1y, p1z) and (p2x, p2y, p2z) are bottom and top points on cone axis and r1, r2 are the corresponding radii.

Documentation

parseGeometry :: ByteString -> Either String Solid

Read solid definition. If parsing fails, return error message as a string.

parseGeometryFile :: FilePath -> IO (Either String Solid)

Read solid definition from a file. If parsing fails, return error message as a string.