package gg import ( "fmt" "image" "image/draw" "image/jpeg" _ "image/jpeg" "image/png" "io/ioutil" "math" "os" "strings" "github.com/golang/freetype/truetype" "golang.org/x/image/font" "golang.org/x/image/math/fixed" ) func Radians(degrees float64) float64 { return degrees * math.Pi / 180 } func Degrees(radians float64) float64 { return radians * 180 / math.Pi } func LoadImage(path string) (image.Image, error) { file, err := os.Open(path) if err != nil { return nil, err } defer file.Close() im, _, err := image.Decode(file) return im, err } func LoadPNG(path string) (image.Image, error) { file, err := os.Open(path) if err != nil { return nil, err } defer file.Close() return png.Decode(file) } func SavePNG(path string, im image.Image) error { file, err := os.Create(path) if err != nil { return err } defer file.Close() return png.Encode(file, im) } func LoadJPG(path string) (image.Image, error) { file, err := os.Open(path) if err != nil { return nil, err } defer file.Close() return jpeg.Decode(file) } func SaveJPG(path string, im image.Image, quality int) error { file, err := os.Create(path) if err != nil { return err } defer file.Close() var opt jpeg.Options opt.Quality = quality return jpeg.Encode(file, im, &opt) } func imageToRGBA(src image.Image) *image.RGBA { bounds := src.Bounds() dst := image.NewRGBA(bounds) draw.Draw(dst, bounds, src, bounds.Min, draw.Src) return dst } func parseHexColor(x string) (r, g, b, a int) { x = strings.TrimPrefix(x, "#") a = 255 if len(x) == 3 { format := "%1x%1x%1x" fmt.Sscanf(x, format, &r, &g, &b) r |= r << 4 g |= g << 4 b |= b << 4 } if len(x) == 6 { format := "%02x%02x%02x" fmt.Sscanf(x, format, &r, &g, &b) } if len(x) == 8 { format := "%02x%02x%02x%02x" fmt.Sscanf(x, format, &r, &g, &b, &a) } return } func fixp(x, y float64) fixed.Point26_6 { return fixed.Point26_6{fix(x), fix(y)} } func fix(x float64) fixed.Int26_6 { return fixed.Int26_6(x * 64) } func unfix(x fixed.Int26_6) float64 { const shift, mask = 6, 1<<6 - 1 if x >= 0 { return float64(x>>shift) + float64(x&mask)/64 } x = -x if x >= 0 { return -(float64(x>>shift) + float64(x&mask)/64) } return 0 } // LoadFontFace is a helper function to load the specified font file with // the specified point size. Note that the returned `font.Face` objects // are not thread safe and cannot be used in parallel across goroutines. // You can usually just use the Context.LoadFontFace function instead of // this package-level function. func LoadFontFace(path string, points float64) (font.Face, error) { fontBytes, err := ioutil.ReadFile(path) if err != nil { return nil, err } f, err := truetype.Parse(fontBytes) if err != nil { return nil, err } face := truetype.NewFace(f, &truetype.Options{ Size: points, // Hinting: font.HintingFull, }) return face, nil }