Graphics.Rendering.OpenGL.GLU.Tessellation

This module corresponds to chapter 5 (Polygon Tessellation) of the GLU specs.

Polygon description

data AnnotatedVertex v

The basic building block in tessellation is a 3D vertex with an associated property, e.g. color, texture coordinates, etc.

Constructors

AnnotatedVertex (Vertex3 GLdouble) v

Instances

Eq v => Eq (AnnotatedVertex v)

Ord v => Ord (AnnotatedVertex v)

Storable v => Storable (AnnotatedVertex v)

newtype ComplexContour v

A complex contour, which can be self-intersecting and/or concave.

Constructors

ComplexContour [AnnotatedVertex v]

Instances

Eq v => Eq (ComplexContour v)

Ord v => Ord (ComplexContour v)

newtype ComplexPolygon v

A complex (possibly concave) polygon, represented by one or more complex and possibly intersecting contours.

Constructors

ComplexPolygon [ComplexContour v]

Instances

Eq v => Eq (ComplexPolygon v)

Ord v => Ord (ComplexPolygon v)

Combining vertices

data WeightedProperties v

Four vertex properties (cf. AnnotatedVertex) with associated weigths summing up to 1.0.

Constructors

WeightedProperties (GLfloat, v) (GLfloat, v) (GLfloat, v) (GLfloat, v)

Instances

Eq v => Eq (WeightedProperties v)

Ord v => Ord (WeightedProperties v)

type Combiner v = Vertex3 GLdouble -> WeightedProperties v -> v

A function combining given vertex properties into a property for a newly generated vertex

Tessellation parameters

data TessWinding

Constructors

TessWindingOdd

TessWindingNonzero

TessWindingPositive

TessWindingNegative

TessWindingAbsGeqTwo

Instances

Eq TessWinding

Ord TessWinding

Show TessWinding

type Tolerance = GLdouble

The relative tolerance under which two vertices can be combined (see Combiner). Multiplication with the largest coordinate magnitude of all polygon vertices yields the maximum distance between two mergeable vertices.

Note that merging is optional and the tolerance is only a hint.

Tessellator type

type Tessellator p v = TessWinding -> Tolerance -> Normal3 GLdouble -> Combiner v -> ComplexPolygon v -> IO (p v)

A general tessellator type.

Before tessellation of a complex polygon, all its vertices are projected into a plane perpendicular to the given normal. If the given normal is Normal3 0 0 0, a fitting plane of all vertices is used.

Contour extraction

newtype SimpleContour v

A simple, non-self-intersecting contour

Constructors

SimpleContour [AnnotatedVertex v]

Instances

Eq v => Eq (SimpleContour v)

Ord v => Ord (SimpleContour v)

newtype PolygonContours v

The contours of a complex polygon, represented by one or more non-intersecting simple contours

Constructors

PolygonContours [SimpleContour v]

Instances

Eq v => Eq (PolygonContours v)

Ord v => Ord (PolygonContours v)

extractContours :: Storable v => Tessellator PolygonContours v

Triangulation

type TriangleVertex v = AnnotatedVertex (v, EdgeFlag)

A triangle vertex with additional information about the edge it begins

data Triangle v

A triangle, represented by three triangle vertices

Constructors

Triangle (TriangleVertex v) (TriangleVertex v) (TriangleVertex v)

Instances

Eq v => Eq (Triangle v)

Ord v => Ord (Triangle v)

newtype Triangulation v

A triangulation of a complex polygon

Constructors

Triangulation [Triangle v]

Instances

Eq v => Eq (Triangulation v)

Ord v => Ord (Triangulation v)

triangulate :: Storable v => Tessellator Triangulation v

Tessellation into primitives

data Primitive v

Constructors

Primitive PrimitiveMode [AnnotatedVertex v]

Instances

Eq v => Eq (Primitive v)

Ord v => Ord (Primitive v)

newtype SimplePolygon v

Constructors

SimplePolygon [Primitive v]

Instances

Eq v => Eq (SimplePolygon v)

Ord v => Ord (SimplePolygon v)

tessellate :: Storable v => Tessellator SimplePolygon v