package drawing import ( "math" "golang.org/x/image/math/fixed" "git.gutmet.org/golang-freetype.git/raster" "git.gutmet.org/golang-freetype.git/truetype" ) // PixelsToPoints returns the points for a given number of pixels at a DPI. func PixelsToPoints(dpi, pixels float64) (points float64) { points = (pixels * 72.0) / dpi return } // PointsToPixels returns the pixels for a given number of points at a DPI. func PointsToPixels(dpi, points float64) (pixels float64) { pixels = (points * dpi) / 72.0 return } func abs(i int) int { if i < 0 { return -i } return i } func distance(x1, y1, x2, y2 float64) float64 { return vectorDistance(x2-x1, y2-y1) } func vectorDistance(dx, dy float64) float64 { return float64(math.Sqrt(dx*dx + dy*dy)) } func toFtCap(c LineCap) raster.Capper { switch c { case RoundCap: return raster.RoundCapper case ButtCap: return raster.ButtCapper case SquareCap: return raster.SquareCapper } return raster.RoundCapper } func toFtJoin(j LineJoin) raster.Joiner { switch j { case RoundJoin: return raster.RoundJoiner case BevelJoin: return raster.BevelJoiner } return raster.RoundJoiner } func pointToF64Point(p truetype.Point) (x, y float64) { return fUnitsToFloat64(p.X), -fUnitsToFloat64(p.Y) } func fUnitsToFloat64(x fixed.Int26_6) float64 { scaled := x << 2 return float64(scaled/256) + float64(scaled%256)/256.0 }