/
main.go
155 lines (140 loc) · 2.94 KB
/
main.go
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package main
import (
"log"
"math"
"golang.org/x/mobile/app"
"golang.org/x/mobile/event"
"golang.org/x/mobile/geom"
"golang.org/x/mobile/gl"
)
var (
print = log.Print
printf = log.Printf
println = log.Println
)
var (
pressed = map[event.TouchSequenceID]key{}
scrollLoc = map[event.TouchSequenceID]geom.Pt{}
// fingers Fingers
)
func main() {
app.Run(app.Callbacks{
Start: start,
Stop: stop,
Touch: touch,
Draw: draw,
})
}
func start() {
initKeys()
startAudio()
}
func stop() {
stopAudio()
gl.DeleteProgram(program)
gl.DeleteBuffer(positionbuf)
gl.DeleteBuffer(pointsizebuf)
}
func touch(t event.Touch) {
// finger := fingers.touch(t)
if t.Type == event.TouchStart && t.Loc.Y < 8 {
scrollLoc[t.ID] = t.Loc.X
}
if _, ok := scrollLoc[t.ID]; ok {
avg0, stddev0 := scrollStats()
scrollLoc[t.ID] = t.Loc.X
avg1, stddev1 := scrollStats()
scale := 1.0
if stddev0 > 0 && stddev1 > 0 {
scale = float64(stddev1 / stddev0)
}
pitchOffset -= pitchRange * float64((avg1/geom.Pt(scale)-avg0)/geom.Width)
pitchRange /= scale
updateProjectionMatrix()
if t.Type == event.TouchEnd {
delete(scrollLoc, t.ID)
}
return
}
if t.Type == event.TouchStart {
if k := nearestKey(t.Loc); k != nil {
pressed[t.ID] = k
}
}
if k := pressed[t.ID]; k != nil {
switch t.Type {
case event.TouchStart:
k.press(t.Loc)
case event.TouchMove:
k.move(t.Loc)
case event.TouchEnd:
k.release(t.Loc)
delete(pressed, t.ID)
}
}
}
func scrollStats() (avg, stddev geom.Pt) {
n := geom.Pt(len(scrollLoc))
for _, x := range scrollLoc {
avg += x
}
avg /= n
for _, x := range scrollLoc {
stddev += (x - avg) * (x - avg)
}
return avg, geom.Pt(math.Sqrt(float64(stddev / n)))
}
func nearestKey(loc geom.Point) key {
var key key
dist := geom.Pt(math.MaxFloat32)
for _, k := range keys {
kb := k.base()
dx := geom.Pt((kb.pitch-pitchOffset)/pitchRange)*geom.Width - loc.X
dy := geom.Pt(1-kb.y)*geom.Height - loc.Y
d := geom.Pt(math.Hypot(float64(dx), float64(dy)))
if d < dist && d < geom.Pt(math.Max(8, kb.size/float64(geom.PixelsPerPt))) {
dist = d
key = k
}
}
return key
}
func draw() {
gl.ClearColor(0, 0, 0, 1)
gl.Clear(gl.COLOR_BUFFER_BIT)
drawKeys()
}
// type Fingers struct {
// fingers []*finger
// }
//
// func (f *Fingers) touch(t event.Touch) *finger {
// if t.Type == event.TouchStart {
// finger := &finger{t.Loc}
// f.fingers = append(f.fingers, finger)
// return finger
// }
// index := 0
// dist := geom.Pt(math.MaxFloat32)
// for i, finger := range f.fingers {
// dx := finger.loc.X - t.Loc.X
// dy := finger.loc.Y - t.Loc.Y
// d := dx*dx + dy*dy
// if d < dist {
// index = i
// dist = d
// }
// }
// finger := f.fingers[index]
// finger.loc = t.Loc
// if t.Type == event.TouchEnd {
// n := len(f.fingers)
// f.fingers[index] = f.fingers[n-1]
// f.fingers = f.fingers[:n-1]
// }
// return finger
// }
//
// type finger struct {
// loc geom.Point
// }