graphicsutil

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 MipmapLevel ¶ added in v1.8.0

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 ¶ added in v1.8.0

func QuadIndices() []uint16

func QuadVertices ¶ added in v1.8.0

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

func Vertex ¶ added in v1.8.0

func Vertex(width, height int, dx, dy, sx, sy float32, cr, cg, cb, ca float32) []float32