## Changelog for diagrams-lib-0.7

## 0.7 (9 August 2013)

**New features**- New module
`Diagrams.TwoD.Curvature`

, for computing the curvature of 2D segments at any given point. - New module
`Diagrams.Offset`

, containing an`offsetSegment`

function that builds a trail a fixed distance from the original segment. This is a precursor to planned functions`offsetTrail`

and`offsetPath`

. - New function
`Diagrams.TwoD.Transform.onBasis`

, for extracting a matrix representation of a 2D transformation - New functions
`extrudeEnvelope`

and`intrudeEnvelope`

, for extending or shrinking an envelope only in a certain direction. - Generalize the
`Color`

class to absolute colors. This addresses concerns raised in issue #66 by letting the backend choose which color space to render`Color`

instances to. Functions are provided for backwards compatibility with the old semantics. - New function
`scaleInvPrim`

for creating a diagram from a single scale-invariant primitive. - New module
`Diagrams.Parametric`

, containing a collection of classes abstracting over "parametric" things:`Parametric`

,`DomainBounds`

,`EndValues`

,`Sectionable`

, and`HasArcLength`

, with instances for segments, trails, and related things. - A big refactoring of segments and trails:
- Segments can now be either "closed" or "open".
- There are now two types of trails: "lines" (which travel
from point A to point B) or "loops" (closed curves which end
where they started).
`Trail`

is now a wrapper type which can contain both loops and lines. - There is a new
`Located`

wrapper type for adding locations to translation-invariant things.`Path`

s now consist of a collection of`Located Trail`

s. - The
`PathLike`

class is now renamed to`TrailLike`

; the`trailLike`

function takes a`Located Trail`

as input.

- New convenience functions
`boundaryFrom`

and`boundaryFromMay`

, for computing boundaries of subdiagrams. - Re-export from
`diagrams-lib`

a lot of things defined in`diagrams-core`

, to make them easier for users to find. Several new modules have been created as a result:`Diagrams.Query`

,`Diagrams.Envelope`

,`Diagrams.Trace`

, and`Diagrams.Names`

. - Export the
`centroid`

function from`Diagrams.Prelude`

. `triangle`

is now a synonym for`eqTriangle`

.

- New module
**New instances**`IsPrim`

instances for`Path`

,`Ellipsoid`

,`Image`

,`Text`

, and`ScaleInv`

`Eq`

,`Ord`

, and`Show`

instances for`SizeSpec2D`

**API changes**`CircleFrac`

has been renamed`Turn`

(though`CircleFrac`

is retained as a deprecated synonym).`Diagrams.Coordinates`

is no longer exported from`Diagrams.Prelude`

. This is for compatibility with`lens`

, as`(&)`

is a rather important lens operator and clashes with`Diagrams.Coordinates`

. Users who want the`Coordinates`

stuff can import`Diagrams.Coordinates`

explicitly.

**Dependency/version changes**- allow
`base-4.7`

- upgrade to
`monoid-extras-0.3`

- depend on
`data-default-class`

instead of`data-default`

- Tested with GHC 7.7.

- allow
**Bug fixes**- Added a special case that was a not handled properly by the quadratic solver, resulting in bogus envelopes in certain cases (#88).
- Import only
`Data.NumInstances.Tuple`

instead of`Data.NumInstances`

. Previously,`Diagrams.Prelude`

exported`Eq`

,`Show`

, and`Num`

instances for functions and tuples; now it only exports tuple instances. Users wishing to use`Diagrams.CubicSpline`

with a vector space built over functions (!?) can import`Data.NumInstances.Function`

themselves. (#48) - Do scaling on a
`Path`

*before*constructing a`TrailLike`

in`rect`

(#43)

## 0.6.0.3 (4 May 2013)

- bump upper bound to allow
`NumInstances-1.3`

## 0.6.0.2 (28 March 2013)

bump upper bound to allow

`NumInstances-1.2`

Quadratic solver is now more numerically stable, getting rid of some incorrect behavior of

`juxtapose`

(#46)

## 0.6.0.1: 7 January 2013

- allow
`semigroups-0.9`

## 0.6: 11 December 2012

**New features**`boundingRect`

function for constructing a bounding rectangle`bg`

function for "setting the background color" (*i.e.*placing atop a colored bounding rectangle)New functions

`setDefault2DAttributes`

and`adjustDiaSize2D`

.`adjustDia2D`

does both --- so the behavior of`adjustDia2D`

has not changed, but it is now possible to apply just one of the two adjustments using the new functions.`Diagrams.TwoD.Transform`

now exports a`ScaleInv`

type for creating scale-invariant objects, which are only affected by rotational and translational components of transformations.The new

`Diagrams.Coordinates`

module provides nicer syntax for constructing and pattern-matching point and vector literals.New

`fromFixedSeg`

function in`Diagrams.Segment`

, which decomposes a`FixedSegment`

into a starting point and a`Segment`

.New

`withTrace`

function for setting the`Trace`

of a diagram.Three new size-related functions:

New

`sized`

function for scaling an object to a particular size. One particularly nice use of this is to obviate the need to keep fiddling with the line width to get diagrams to "look right"; just set the line width relative to some arbitrary scale (*e.g.*assuming the final diagram will fit into a 1x1 box) and then apply`sized`

to the final diagram to make it that given arbitrary size. It can also be used for easily making something (a diagram, path, trail, ...) the same size as something else, with the help of the new`sizeSpec2D`

function.New

`sizedAs`

function, for setting the size of some object to be "the same as" some other object.New

`sizeSpec2D`

function for conveniently calculating the size of an object as a`SizeSpec2D`

value (for use with the new`sized`

funtion).

New

`extrudeEnvelope`

and`intrudeEnvelope`

functions for modifying envelopes in a single direction only, as well as new functions`extrude{Left,Right,Bottom,Top}`

specializing`extrudeEnvelope`

to 2D.`arcCW`

draws clockwise arcs;`arc'`

draws arcs counterclockwise or clockwise as the radius is positive or negative, respectively.fill color attribute is generalized to support "recommended" and "committed" colors; text objects use a recommended fill color of black.

**New instances**The

`Show`

instance for`R2`

now produces something like`2 & 6`

instead of`R2 { unR2 = (2,6) }`

. The`Read`

instance has also been changed to match, so`read . show = id`

.`Enveloped`

instance for`FixedSegment`

`Traced`

instances for`Segment`

,`FixedSegment`

,`Trail`

, and`Path`

New derived

`Eq`

instances for`LineCapA`

,`LineJoinA`

,`Dashing`

,`DashingA`

,`FillRule`

,`Font`

,`FontSize`

,`FontSlant`

,`FontSlantA`

,`FontWeight`

, and`FontWeightA`

`Renderable Ellipsoid NullBackend`

instance

**API changes**`Data.Colour`

(minus`atop`

and`AffineSpace`

) is now re-exported from Diagrams.Prelude for convenience.The

`beneath`

function is now infixl 6.The

`BoundingBox`

module has had a complete overhaul. There is now a special empty bounding box, and bounding boxes are an instance of`Monoid`

.The type of

`withEnvelope`

has been slightly generalized.`Diagrams.TwoD.Adjust.adjustSize`

is now deprecated; it has been renamed and moved to`Diagrams.TwoD.Size.requiredScaleT`

.`expandPath`

has been renamed to`scalePath`

.

**Dependency/version changes**- Allow
`data-default`

0.4 and 0.5 - Allow
`base`

-4.6 - Allow
`containers`

-0.5

- Allow
**Bug fixes**`arc`

and`arcT`

functions now always produce counterclockwise arcs, as claimed.

## 0.5: 9 March 2012

**New features**`mkSizeSpec`

function for constructing a`SizeSpec2D`

from two`Maybe Double`

s`beneath`

as convenient synonym for`flip atop`

- Improvements and extensions to rounded rectangles by Peter Hall:
`roundedRect'`

allows rounded rectangles with a different radius specified for each corner- both
`roundedRect'`

and`roundedRect`

now allow negative radii, resulting in "inverted" circular corners

- #64: New
`Alignable`

class for things that can be aligned. `explodeTrail`

and`explodePath`

have been generalized to return any`PathLike`

type.- New path functions
`pathCentroid`

(compute the centroid of a path's vertices) and`expandPath`

(scale a path about its centroid). - Generalized
`centroid`

function now exported from new module`Diagrams.Points`

. - Initial (experimental) support for animation:
`Animation`

and`QAnimation`

defined as synonyms for`Active`

diagrams (see`active`

package)- Instances for
`Active`

:`V`

,`HasOrigin`

,`Transformable`

,`HasStyle`

,`PathLike`

,`Juxtaposable`

,`Alignable`

`animEnvelope`

and`animRect`

functions for automatic bounding of animations

`addClosingSegment`

function for making the implicit closing segment of a closed trail explicit- Improvements to
`BoundingBox`

module from Michael Sloan: querying of`BoundingBox`

bounds, corners, extents, and transformation of objects to fit within a given box. - Text alignment options from Michael Sloan
`view`

function for restricting a diagram's envelope to a rectangular region.`iterateN`

function for iterating a finite number of times`atAngle`

for placing two diagrams next to each other along a specified angle.`padX`

and`padY`

functions for padding in the X- and Y-directions independently.- generalized
`showOrigin`

function from Ian Ross - #40: add shears to
`Diagrams.TwoD.Transform`

**Performance improvements**- Use a balanced folding scheme for
`cat'`

, reducing time in some cases from \(O(n^2)\) to \(O(n \log n)\) - More efficient implementation of
`beside`

- Use a balanced folding scheme for
**New instances**`Alignable`

instances for`QDiagram`

,`Path`

,`Envelope`

,`Active`

,`Set`

,`Map`

,`[]`

`Renderable`

instances for`NullBackend`

(`Trail`

,`Path`

,`Segment`

,`Image`

,`Text`

)- Instances for
`Active`

:`V`

,`HasOrigin`

,`Transformable`

,`HasStyle`

,`PathLike`

,`Juxtaposable`

,`Alignable`

**API changes**`R2`

used to be a synonym for`(Double, Double)`

but is now abstract. To convert between pairs of`Doubles`

and`R2`

, use the new functions`r2`

and`unr2`

. There are two reasons for this change: 1. to allow for future changes to the implementation of`R2`

; 2.`(Double, Double)`

was an awkward special case getting in the way of useful tuple instances for classes like`HasOrigin`

,`Enveloped`

, and so on.`circlePath`

has been removed; its functionality has been subsumed by`circle`

.`adjustSegment`

now takes an extra tolerance option.- Ellipses are now represented using Bezier approximations rather than a separate special type.
`BoundingBox`

no longer has a`Transformable`

instance; the old instance was misleading at best.- Change semantics of
`beside`

(hence also`(|||)`

and`(===)`

) so the result's origin is the same as that of the first argument. `adjustDia2D`

now takes a`SizeSpec2D`

.`beside`

and related functions are now implemented in terms of`juxtapose`

.- Instead of taking an
`R2`

,`roundedRect`

now takes a pair of`Double`

s, to be more consistent with`rect`

.

**Dependency/version changes**- Support for GHC 7.4.1:
- depend on
`colour`

>= 2.3.2 - update
`base`

and`array`

upper bounds

- depend on
- bump
`vector-space`

upper bound

- Support for GHC 7.4.1:
**Bug fixes**- Avoid scale by zero error in
`showOrigin`

. - Base
`adjustDia2D`

translation on output size rather than diagram size.

- Avoid scale by zero error in

## 0.4.0.1: 30 October 2011

- bump
`data-default`

dependency to allow version 0.3

## 0.4: 23 October 2011

**documentation fixes****New functions and primitives**`wedge`

shape primitive`fromDirection`

function for converting angles to 2D unit vectors; inverse function`direction`

generalized to return any Angle type- New functions for computing and adjusting segment lengths
`scaleUToX`

and`scaleUToY`

for doing uniform scales resulting in a desired width or height.`circlePath`

,`reversePath`

,`decoratePath`

**New features**- Completely new and improved polygon generation API
- Cubic splines
- User-controllable path fill rules

**Bug fixes**- fix incorrect corner case in arc generation
- fix incorrect
`reverseTrail`

function

## 0.3: 18 June 2011

**New features**- new customizable
`stroke'`

function which lets you assign names to path vertices `circle`

and`square`

functions now take a size argument- function for adjusting 2D diagrams to requested size abstracted from cairo backend
- generalize
`PathLike`

class to include an instance for diagrams, and collapse things like`polygon`

/`polygonPath`

into a single polymorphic function - basic text support
- basic support for external images
- very sketchy initial proof-of-concept library of 3D primitives. See also diagrams-povray package.

- new customizable
**Bug fixes**- Issue 32 (
`mempty`

not behaving correctly within concatenations)

- Issue 32 (

## 0.2: 3 June 2011

**documentation fixes****New functions and primitives**`scaleToX`

and`scaleToY`

for scaling to an absolute width/height`reverseTrail`

- new
`Angle`

class and ability to use radians, degrees, or circle fractions for specifying angles `rotateAbout`

and`reflectAbout`

transformations based on new conjugation functions`rect`

and`roundedRect`

primitives`explodeTrail`

/`Path`

for breaking trails and paths into individual segments

**New features**- opacity attribute
- support for path clipping

**New modules**`Diagrams.BoundingBox`

**Fixes and updates**`withBounds`

now properly uses the new bounds instead of just combining them with the old

## 0.1.1: 18 May 2011

- minor documentation fixes
- link to new website

## 0.1: 17 May 2011

- initial preview release