func drawMetrics(mw *imagick.MagickWand, dw *imagick.DrawingWand, dx *float64, text string) {
rotation := float64(random(-30, 30))
mw.AnnotateImage(dw, *dx, 35, rotation, text)
mw.DrawImage(dw)
// get the font metrics
fm := mw.QueryFontMetrics(dw, text)
if fm != nil {
// Adjust the new x coordinate
*dx += fm.TextWidth + 2
}
}
// The easiest (?) way to handle vertical text placement is
// not to use gravity at all because then you know that all the text is
// placed relative to ImageMagick's (0,0) coordinate which is the top left of
// the screen and the baseline will be y=0.
func draw_metrics(mw *imagick.MagickWand, dw *imagick.DrawingWand, dx *float64, dy, sx float64, text string) {
mw.AnnotateImage(dw, *dx, dy, 0, text)
mw.DrawImage(dw)
// get the font metrics
fm := mw.QueryFontMetrics(dw, text)
if fm != nil {
// Adjust the new x coordinate
*dx += fm.TextWidth + sx
}
}
func speedLine(mw *imagick.MagickWand, aw *imagick.MagickWand) error {
cols, rows := mw.GetImageHeight(), mw.GetImageWidth()
dw := imagick.NewDrawingWand()
defer dw.Destroy()
cw := imagick.NewPixelWand()
cw.SetColor(*color)
dw.SetFillColor(cw)
center := []float64{float64(rows) / 2.0, float64(cols) / 2.0}
const radiusCenter float64 = 0.75
const step float64 = 0.02
const bold float64 = 1.0
var theeta float64
for theeta < math.Pi*2 {
stepNoise := rand.Float64() + 0.5
theeta += step * stepNoise
radiusCenterNoise := rand.Float64()*0.3 + 1.0
boldNoise := rand.Float64() + 0.7 + 0.3
point0 := imagick.PointInfo{
X: math.Sin(theeta)*center[0]*radiusCenter*radiusCenterNoise + center[0],
Y: math.Cos(theeta)*center[1]*radiusCenter*radiusCenterNoise + center[1],
}
point1 := imagick.PointInfo{
X: math.Sin(theeta)*center[0]*2 + center[0],
Y: math.Cos(theeta)*center[1]*2 + center[1],
}
point2 := imagick.PointInfo{
X: math.Sin(theeta+step*bold*boldNoise)*center[0]*2 + center[0],
Y: math.Cos(theeta+step*bold*boldNoise)*center[1]*2 + center[1],
}
dw.Polygon([]imagick.PointInfo{point0, point1, point2})
}
if err := aw.DrawImage(dw); err != nil {
return err
}
return nil
}