sdf

package

v0.0.0-...-d2c143d Latest Latest Go to latest Published: Mar 30, 2019 License: MIT Imports: 4 Imported by: 0

Details

Valid go.mod file
Redistributable license
Tagged version
Stable version
Learn more about best practices

Repository

github.com/daveagill/go-sdf

Links

Open Source Insights

Documentation ¶

Overview ¶

Package sdf provides primitives for creating and manipulating Signed-Distance-Fields and Displacement-Fields with conversion utilities to and from images.

Index ¶

Constants
func DrawStencil(s Stencil, c color.Color, bg color.Color) *image.RGBA
func DrawStencilImage(s Stencil, srcImg image.Image, bg color.Color) *image.RGBA
type DisplacementField
- func Calculate(s Stencil) *DisplacementField
- func (df *DisplacementField) NearestBoundaryAt(x, y int) (int, int)
type ImageAlphaStencil
- func (s ImageAlphaStencil) Size() (int, int)
- func (s ImageAlphaStencil) Within(x, y int) bool
type ImplicitSurfaceStencil
- func (s ImplicitSurfaceStencil) Size() (int, int)
- func (s ImplicitSurfaceStencil) Within(x, y int) bool
type SDF
- func Lerp(a *SDF, b *SDF, t float64) (*SDF, error)
- func New(w, h int) *SDF
type Stencil

Constants ¶

View Source

const (
	// OpaqueAlpha is an alpha-threshold so only fully-opaque pixels will be within the stencil
	OpaqueAlpha = uint16(math.MaxUint16)
	// HalfAlpha is an alpha-threshold so 50% opaque pixels will be within the stencil
	HalfAlpha = uint16(math.MaxUint16 / 2)
)

Variables ¶

This section is empty.

Functions ¶

func DrawStencil ¶

func DrawStencil(s Stencil, c color.Color, bg color.Color) *image.RGBA

DrawStencil renders a Stencil into a 2-color image. Using color c for pixels within the stencil and color bg for pixels outside.

func DrawStencilImage ¶

func DrawStencilImage(s Stencil, srcImg image.Image, bg color.Color) *image.RGBA

DrawStencilImage stencils a given source image and returns a new image where pixels within the stencil are taken from the source image and pixels outside default to the given bg color.

Types ¶

type DisplacementField ¶

type DisplacementField struct {
	*SDF
	// contains filtered or unexported fields
}

DisplacementField is a vectorized Signed-Distance-Field where each field value is associated with its nearest boundary point.

func Calculate ¶

func Calculate(s Stencil) *DisplacementField

Calculate a new DisplacementField from the given Stencil

func (*DisplacementField) NearestBoundaryAt ¶

func (df *DisplacementField) NearestBoundaryAt(x, y int) (int, int)

NearestBoundaryAt returns X,Y coordinate of the nearest boundary point from the given point

type ImageAlphaStencil ¶

type ImageAlphaStencil struct {
	Image image.Image
	Alpha uint16
}

ImageAlphaStencil implements a Stencil where the alpha channel of an image is thresholded against the Alpha value

func (ImageAlphaStencil) Size ¶

func (s ImageAlphaStencil) Size() (int, int)

Size returns the width and height of the ImageAlphaStencil

func (ImageAlphaStencil) Within ¶

func (s ImageAlphaStencil) Within(x, y int) bool

Within predicates whether the given coordinate is inside or outside of the stencil surface

type ImplicitSurfaceStencil ¶

type ImplicitSurfaceStencil struct {
	SDF       *SDF
	Threshold float64
}

ImplicitSurfaceStencil implements a Stencil where a Signed-Distance-Field is thresholded against the Threshold value to define an implicit surface.

func (ImplicitSurfaceStencil) Size ¶

func (s ImplicitSurfaceStencil) Size() (int, int)

Size returns the width and height of the ImplicitSurfaceStencil

func (ImplicitSurfaceStencil) Within ¶

func (s ImplicitSurfaceStencil) Within(x, y int) bool

Within predicates whether the given coordinate is inside or outside of the stencil surface

type SDF ¶

type SDF struct {
	Field  []float64
	Width  int
	Height int
}

SDF models a rectangular & discretized Signed Distance Field

func Lerp ¶

func Lerp(a *SDF, b *SDF, t float64) (*SDF, error)

Lerp returns the linear interpolation between two SDFs, weighted by t in range [0, 1]

func New ¶

func New(w, h int) *SDF

New returns a zeroed SDF of the given size

func (*SDF) At ¶

func (sdf *SDF) At(x, y int) float64

At returns the field value at the given coordinate

func (*SDF) Draw ¶

func (sdf *SDF) Draw() *image.Gray

Draw returns an 8-bit grayscale representation of a Signed-Distance-Field

func (*SDF) Set ¶

func (sdf *SDF) Set(x, y int, v float64)

Set writes the field value at the given coordinate

type Stencil ¶

type Stencil interface {
	// Within predicates whether the given coordinate is inside or outside of the stencil surface
	Within(x, y int) bool
	// Size returns the width and height of the Stencil
	Size() (int, int)
}

Stencil defines a binary surface where pixels are either inside or outside the stencil

Source Files ¶

View all Source files

?	: This menu
/	: Search site
f or F	: Jump to
y or Y	: Canonical URL