ugfx

ugfx

Go programming helpers for common graphics and imaging needs.

Usage

func GammaToLinearSpace

func GammaToLinearSpace(f float64) float64

Converts the given value from gamma to linear color space.

func Index2D

func Index2D(x, y, ysize int) int

If 2 dimensions are represented in a 1-dimensional linear array, this function provides a way to return a 1D index addressing the specified 2D coordinate.

func Index3D

func Index3D(x, y, z, xsize, ysize int) int

If 3 dimensions are represented in a 1-dimensional linear array, this function provides a way to return a 1D index addressing the specified 3D coordinate.

func LinearToGammaSpace

func LinearToGammaSpace(f float64) float64

Converts the given value from linear to gamma color space.

func PreprocessImage

func PreprocessImage(src image.Image, dst Picture, flipY, toBgra, toLinear bool)

Processes the specified Image and writes the result to the specified Picture:

If flipY is true, all pixel rows are inverted (dst becomes src vertically mirrored).

If toBgra is true, all pixels' red and blue components are swapped.

If toLinear is true, all pixels are converted from gamma/sRGB to linear space -- only use this if you're certain that src is not already in linear space.

dst and src may point to the same Image object ONLY if flipY is false.

func SavePngImageFile

func SavePngImageFile(img image.Image, filePath string) error

Saves any given Image as a local PNG file.

type Picture

type Picture interface {
	image.Image

	//	Set pixel at `x, y` to the specified `Color`.
	Set(int, int, color.Color)
}

The "missing interface" from the image package: Set(x, y, color) is implemented by most (but not all) image types that also implement Image.

func CreateLike

func CreateLike(src image.Image, copyPixels bool) (dst Picture, pix []byte)

Creates and returns a Picture just like src:

If copyPixels is true, pixels in src are copied to dst, otherwise dst will be an empty/black Picture of the exact same dimensions, color format, stride/offset/etc as src.

The resulting dst will be of the same type as src if src is an *image.Alpha, *image.Alpha16, *image.Gray, *image.Gray16, *image.NRGBA, *image.NRGBA16, or *image.RGBA64 --- otherwise, dst will be an *image.RGBA.

type Rgba32

type Rgba32 struct {
	//	Red component
	R float32
	//	Green component
	G float32
	//	Blue component
	B float32
	//	Alpha component
	A float32
}

Describes a literal color using four 32-bit floating-point numbers in RGBA order.

func NewRgba32

func NewRgba32(vals ...float64) (me *Rgba32)

Converts the specified vals to a newly initialized Rgba32 instance.

The first 4 vals are used for R, G, B, and A in that order, if present. A is set to 1 if vals[3] is not present.

type Rgba64

type Rgba64 struct {
	//	Red component
	R float64
	//	Green component
	G float64
	//	Blue component
	B float64
	//	Alpha component
	A float64
}

Describes a literal color using four 64-bit floating-point numbers in RGBA order.

func NewRgba64

func NewRgba64(vals ...float64) (me *Rgba64)

Converts the specified vals to a newly initialized Rgba64 instance.

The first 4 vals are used for R, G, B, and A in that order, if present. A is set to 1 if vals[3] is not present.