dimen

Documentation

Overview

Package dimen implements dimensions and units.

BSD License

Copyright (c) 2017–21, Norbert Pillmayer (norbert@pillmayer.com)

All rights reserved.

Redistribution and use in source and binary forms, with or without modification, are permitted provided that the following conditions are met:

1. Redistributions of source code must retain the above copyright notice, this list of conditions and the following disclaimer.

2. Redistributions in binary form must reproduce the above copyright notice, this list of conditions and the following disclaimer in the documentation and/or other materials provided with the distribution.

3. Neither the name of this software nor the names of its contributors may be used to endorse or promote products derived from this software without specific prior written permission.

THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

Index

• Constants
• Variables
• type Dimen
  • func Max(a, b Dimen) Dimen
  • func Min(a, b Dimen) Dimen
  • func ParseDimen(s string) (Dimen, bool, error)
  • func (d Dimen) Points() float64
  • func (d Dimen) String() string
• type Point
  • func (p *Point) Shift(vector Point) *Point
• type Rect
  • func (r Rect) Height() Dimen
  • func (r Rect) Width() Dimen

Constants

const Infinity = math.MaxInt32

Infinity is the largest possible dimension

Variables

var DINA4 = Point{210 * MM, 297 * MM}

Some common paper sizes

var DINA5 = Point{148 * MM, 210 * MM}

var Origin = Point{0, 0}

Origin is origin

var USLegal = Point{216 * MM, 357 * MM}

var USLetter = Point{216 * MM, 279 * MM}

Types

type Dimen

type Dimen int32

Dimen is a dimension type. Values are in scaled big points (different from TeX).

const (
	Zero Dimen = 0
	SP   Dimen = 1       // scaled point = BP / 65536
	BP   Dimen = 65536   // big point (PDF) = 1/72 inch
	PX   Dimen = 65536   // "pixels"
	PT   Dimen = 65291   // printers point 1/72.27 inch
	MM   Dimen = 185771  // millimeters
	CM   Dimen = 1857710 // centimeters
	IN   Dimen = 4718592 // inch
)

Some pre-defined dimensions

const Fil Dimen = Infinity - 3

Some very stretchable dimensions

const Fill Dimen = Infinity - 2

const Filll Dimen = Infinity - 1

func Max

func Max(a, b Dimen) Dimen

Max returns the greater of two dimensions.

func Min

func Min(a, b Dimen) Dimen

Min returns the smaller of two dimensions.

func ParseDimen

func ParseDimen(s string) (Dimen, bool, error)

ParseDimen parses a string to return a dimension. Syntax is CSS Unit. If a percentage value is given (`80%`), the second return value will be true.

func (Dimen) Points

func (d Dimen) Points() float64

Points returns a dimension in big (PDF) points.

func (Dimen) String

func (d Dimen) String() string

Stringer implementation.

type Point

type Point struct {
	X, Y Dimen
}

Point is a point on a page.

TODO see methods in https://golang.org/pkg/image/#Point

func (*Point) Shift

func (p *Point) Shift(vector Point) *Point

Shift a point along a vector.

type Rect

type Rect struct {
	TopL, BotR Point
}

Rect is a rectangle (on a page).

func (Rect) Height

func (r Rect) Height() Dimen

Height returns the height of a rectangle, i.e. the difference between y-coordinates of bottom-right and top-left corner.

func (Rect) Width

func (r Rect) Width() Dimen

Width returns the width of a rectangle, i.e. the difference between x-coordinates of bottom-right and top-left corner.