graphics

Documentation

Index

• Constants
• func CopyImage(img image.Image) []byte
• func InternalImageSize(x int) int
• func MipmapLevel(det float32) int
• func QuadIndices() []uint16
• func QuadVertices(width, height int, sx0, sy0, sx1, sy1 int, a, b, c, d, tx, ty float32, ...) []float32
• type Address
• type CompositeMode
  • func (c CompositeMode) Operations() (src Operation, dst Operation)
• type Filter
• type Operation

Constants

const (
	IndicesNum     = (1 << 16) / 3 * 3 // Adjust num for triangles.
	VertexFloatNum = 12
)

const TexelAdjustmentFactor = 512.0

Functions

func CopyImage

func CopyImage(img image.Image) []byte

CopyImage copies img to a new RGBA image.

Basically CopyImage just calls draw.Draw. If img is a paletted image, an optimized copying method is used.

CopyImage is used only internally but it is exposed for testing.

func InternalImageSize

func InternalImageSize(x int) int

InternalImageSize returns a nearest appropriate size as an internal image.

func MipmapLevel

func MipmapLevel(det float32) int

MipmapLevel returns an appropriate mipmap level for the given determinant of a geometry matrix.

MipmapLevel returns -1 if det is 0.

MipmapLevel panics if det is NaN.

func QuadIndices

func QuadIndices() []uint16

func QuadVertices

func QuadVertices(width, height int, sx0, sy0, sx1, sy1 int, a, b, c, d, tx, ty float32, cr, cg, cb, ca float32) []float32

Types

type Address

type Address int

const (
	AddressClampToZero Address = iota
	AddressRepeat
)

type CompositeMode

type CompositeMode int

const (
	CompositeModeSourceOver CompositeMode = iota // This value must be 0 (= initial value)
	CompositeModeClear
	CompositeModeCopy
	CompositeModeDestination
	CompositeModeDestinationOver
	CompositeModeSourceIn
	CompositeModeDestinationIn
	CompositeModeSourceOut
	CompositeModeDestinationOut
	CompositeModeSourceAtop
	CompositeModeDestinationAtop
	CompositeModeXor
	CompositeModeLighter
	CompositeModeUnknown

	CompositeModeMax = CompositeModeLighter
)

func (CompositeMode) Operations

func (c CompositeMode) Operations() (src Operation, dst Operation)

type Filter

type Filter int

const (
	FilterDefault Filter = iota
	FilterNearest
	FilterLinear
	FilterScreen
)

type Operation

type Operation int

const (
	Zero Operation = iota
	One
	SrcAlpha
	DstAlpha
	OneMinusSrcAlpha
	OneMinusDstAlpha
)