graph

Documentation

Overview

Package graph is a suite of utilities for performing various operation's on an Image

Index

• func IsBlack(c color.Color) bool
• func IsNotBlack(c color.Color) bool
• func SetFont(gc *draw2dimg.GraphicContext, s string) error
• type Filter
  • func Of(filters ...Filter) Filter
  • func (f Filter) Do(src image.Image, dst Image, b image.Rectangle) error
  • func (f Filter) DoNew(src image.Image) (Image, error)
  • func (f Filter) DoOver(src Image) error
  • func (f Filter) Then(b Filter) Filter
• type Image
  • func AutoCrop(src image.Image) Image
  • func Crop(src image.Image, bounds image.Rectangle) Image
  • func DrawMask(img, mask, dest image.Image) (Image, error)
  • func DuplicateImage(img image.Image) Image
  • func Expand(src image.Image, top, left, bottom, right int) Image
  • func Immutable(img image.Image) Image
  • func Mask(img, mask image.Image) (Image, error)
  • func NewRGBA(img image.Image) Image
  • func NewRGBAImage(bounds image.Rectangle) Image
• type Mapper
  • func (m Mapper) Filter() Filter

Functions

func IsBlack

func IsBlack(c color.Color) bool

func IsNotBlack

func IsNotBlack(c color.Color) bool

func SetFont

func SetFont(gc *draw2dimg.GraphicContext, s string) error

Types

type Filter

type Filter func(x, y int, col color.Color) (color.Color, error)

Filter is a basic mapping function that is supplied with a Pixel and returns the new colour for that Pixel.

func Of

func Of(filters ...Filter) Filter

Of returns a Filter based on the supplied filters

func (Filter) Do

func (f Filter) Do(src image.Image, dst Image, b image.Rectangle) error

Do apply the filter against the source image, writing the result to the destination over the area defined by the supplied rectangle.

func (Filter) DoNew

func (f Filter) DoNew(src image.Image) (Image, error)

DoNew applies the filter against an image, returning a new mutable image with the result.

func (Filter) DoOver

func (f Filter) DoOver(src Image) error

DoOver applies the filter over the supplied mutable image, overwriting its previous state.

func (Filter) Then

func (f Filter) Then(b Filter) Filter

Then returns a Filter that will run this one then the subsequent one in sequence

type Image

type Image interface {
	image.Image
	Set(x, y int, c color.Color)
}

Image is an image.Image with a Set method to change a single pixel.

func AutoCrop

func AutoCrop(src image.Image) Image

AutoCrop will crop an image removing anything that is black around the image.

func Crop

func Crop(src image.Image, bounds image.Rectangle) Image

Crop will crop an image to fit the required bounds

func DrawMask

func DrawMask(img, mask, dest image.Image) (Image, error)

DrawMask draws img over dest using mask to select which pixels in img are to be copied over. This returns a new image

func DuplicateImage

func DuplicateImage(img image.Image) Image

DuplicateImage creates a new copy of an image which is also mutable

func Expand

func Expand(src image.Image, top, left, bottom, right int) Image

Expand will add the specified number of pixels to the edges of an Image

func Immutable

func Immutable(img image.Image) Image

Immutable returns an immutable image

func Mask

func Mask(img, mask image.Image) (Image, error)

func NewRGBA

func NewRGBA(img image.Image) Image

NewRGBA creates a new mutable image with the same dimensions of another image

func NewRGBAImage

func NewRGBAImage(bounds image.Rectangle) Image

type Mapper

type Mapper func(col color.Color) (color.Color, error)

Mapper is a function that can transform a color.Color to another

func (Mapper) Filter

func (m Mapper) Filter() Filter