# nurbs

 Latest on Hackage: 0.1.1.0

This package is not currently in any snapshots. If you're interested in using it, we recommend adding it to Stackage Nightly. Doing so will make builds more reliable, and allow stackage.org to host generated Haddocks.

Maintained by

Simple NURBS library with support of NURBS, periodic NURBS, knot insertion-removal, NURBS split-joint

``````import Control.Lens
import Linear.NURBS
import Linear.V2
import Test.Hspec

-- | Simple NURBS of degree 3
test₁ ∷ NURBS V2 Double
test₁ = nurbs 3 [
V2 0.0 0.0,
V2 10.0 0.0,
V2 10.0 10.0,
V2 20.0 20.0,
V2 0.0 20.0,
V2 (-20.0) 0.0]

-- | Another NURBS of degree 3
test₂ ∷ NURBS V2 Double
test₂ = nurbs 3 [
V2 (-20.0) 0.0,
V2 (-20.0) (-20.0),
V2 0.0 (-40.0),
V2 20.0 20.0]

-- | Make test₁ periodic
testₒ ∷ NURBS V2 Double
testₒ = set periodic True test₁

main ∷ IO ()
main = hspec \$ do
describe "evaluate point" \$ do
it "should start from first control point" \$
(test₁ `eval` 0.0) ≃ (test₁ ^?! wpoints . _head . wpoint)
it "should end at last control point" \$
(test₁ `eval` 1.0) ≃ (test₁ ^?! wpoints . _last . wpoint)
describe "insert knot" \$ do
it "should not change nurbs curve" \$
insertKnots [(1, 0.1), (2, 0.3)] test₁ ≃ test₁
describe "remove knots" \$ do
it "should not change nurbs curve" \$
removeKnots [(1, 0.1), (2, 0.3)] (insertKnots [(1, 0.1), (2, 0.3)] test₁) ≃ test₁
describe "purge knots" \$ do
it "should not change nurbs curve" \$
purgeKnots (insertKnots [(1, 0.1), (2, 0.6)] test₁) ≃ test₁
describe "split" \$ do
it "should work as cut" \$
snd (split 0.4 test₁) ≃ cut (Span 0.4 1.0) test₁
describe "normalize" \$ do
it "should not affect curve" \$
cut (Span 0.2 0.8) test₁ ≃ normalizeKnot (cut (Span 0.2 0.8) test₁)
describe "joint" \$ do
it "should joint cutted nurbs" \$
uncurry joint (split 0.3 test₁) ≃ Just test₁
it "should cut jointed nurbs" \$
(cut (Span 0.0 1.0) <\$> (test₁ ⊕ test₂)) ≃ Just test₁
it "should cut jointed nurbs" \$
(cut (Span 1.0 2.0) <\$> (test₁ ⊕ test₂)) ≃ Just test₂
describe "periodic" \$ do
it "can be broken into simple nurbs" \$
breakLoop 0.0 testₒ ≃ testₒ
it "can be broken in any place" \$
uncurry (flip (⊕)) (split 0.5 (breakLoop 0.0 testₒ)) ≃ Just (breakLoop 0.5 testₒ)``````
Depends on 5 packages:
Used by 1 package: