// Blend a new pixel over an old pixel - heeding their alpha chan values
//
// algorithm NOT according to http://en.wikipedia.org/wiki/Alpha_compositing
// but by my own trial and error
func blendPixelOverPixel(ic_old, ic_new uint8, al_new float64) (c_res uint8) {
al_old := float64(1)
_ = al_old
c_old := float64(ic_old)
c_new := float64(ic_new)
algo1 := c_old*(1-al_new) + c_new*al_new
c_res = uint8(util.Min(util.Round(algo1), 255))
//log.Printf("\t\t %3.1f + %3.1f = %3.1f", c_old*(1-al_new),c_new*al_new, algo1)
return
}
func logRetrieve(w http.ResponseWriter, r *http.Request) {
cgiRes := makeRequest(w, r, path_get_log)
sl := []string{cgiRes.Log0, cgiRes.Log1, cgiRes.Log2, cgiRes.Log3, cgiRes.Log4,
cgiRes.Log5, cgiRes.Log6, cgiRes.Log7, cgiRes.Log8, cgiRes.Log9}
for _, v := range sl {
sl1 := strings.Split(v, "%2B")
if len(sl1) < 4 {
continue
}
// time+user+ip+logID
unixTS := sl1[0]
usr := sl1[1]
ip := sl1[2]
eventId := sl1[3]
eventDesc := ""
switch eventId {
case "0":
eventDesc = "Power On"
case "1":
eventDesc = "Motion Alarm"
case "3":
eventDesc = "Login"
case "4":
eventDesc = "Logout"
case "5":
eventDesc = "Offline"
default:
eventDesc = "unkown event id: " + eventId
}
_, _, _ = eventDesc, usr, ip
ts := util.TimeFromUnix(unixTS)
tsf := ts.Format("2.1.2006 15:04:05")
tn := time.Now()
since := tn.Sub(ts)
iHours := int(math.Floor(since.Hours()))
iMinutes := util.Round(since.Minutes()) - iHours*60
if eventId == "1" {
wpf(w, "Last Alarm <b>%3vhrs %2vmin</b> ago (%v)<br>\n", iHours, iMinutes, tsf)
break
}
}
}
// returns a format string with as few as needed
// post-decimal digits ; 1000 => 1000 , but 0.0400 => 0.04
func practicalFormat(mv float64) (floatFormat string, exponent int) {
//Log x = Ln x / Ln 10
fExponent := math.Log(mv) / math.Log(10)
//exponent = int(fExponent)
exponent = util.Round(fExponent)
sExponent := fmt.Sprint(util.Abs(exponent) + 2)
floatFormat = "%12.0f"
if mv < 10 {
floatFormat = "%12.1f"
}
if mv < 1 {
floatFormat = "%12." + sExponent + "f"
}
return
}