// tokenSize retrieves the metrics from the internal cache, sizes.
// It is expensive to calculate the token sizes each frame and the
// sizes do not change often to justify the cost. Testing revealed
// this approach yields a slower rate of growth.
//
// TODO: maybe choose to disable cpu scaling for better performance
// > echo performance > /sys/devices/system/cpu/cpu0/cpufreq/scaling_governor
// or
// > sudo update-rc.d ondemand disable
func (self *Text) tokenBounds(i int, ctx *vg.Context) *ui.Rectangle {
bounds := self.bounds[i]
if bounds == nil {
x, y, w, h := ctx.TextBounds(self.tokens[i], 0, 0)
bounds = &ui.Rectangle{ui.Position{x, y}, ui.Size{w, h}}
self.bounds[i] = bounds
}
return bounds
}
func (self *Text) spaceWidth(ctx *vg.Context) float64 {
xmin, _, xmax, _ := ctx.TextBounds(".", 0, 0)
return xmax - xmin
}