boom

trm=peripheral.wrap("monitor_14")
trm.setTextScale(0.5)
trm1=peripheral.wrap("monitor_15")
trm1.setTextScale(2)
cb=peripheral.wrap("command_1")
fire="top"
pay="right"
start="68 73 207"

--// The elements of Basic graphical utility API (Written by: Bobby Lucero) were used
--// http://www.computercraft.info/forums2/index.php?/topic/20827-computercraft-graphics-library/

function pixel(x,y)
    trm.setCursorPos(x,y)
    trm.write(" ")
end

function line( startX, startY, endX, endY ) --Shamelessly borrowed from cc internal source
    startX = math.floor(startX+0.5)
    startY = math.floor(startY+0.5)
    endX = math.floor(endX+0.5)
    endY = math.floor(endY+0.5)

    if startX == endX and startY == endY then
        pixel( startX, startY )
        return
    end

    local minX = math.min( startX, endX )
    if minX == startX then
        minY = startY
        maxX = endX
        maxY = endY
    else
        minY = endY
        maxX = startX
        maxY = startY
    end

    local xDiff = maxX - minX
    local yDiff = maxY - minY

    if xDiff > math.abs(yDiff) then
        local y = minY
        local dy = yDiff / xDiff
        for x=minX,maxX do
            pixel( x, math.floor( y + 0.5 ) )
            y = y + dy
        end
    else
        local x = minX
        local dx = xDiff / yDiff
        if maxY >= minY then
            for y=minY,maxY do
                pixel( math.floor( x + 0.5 ), y )
                x = x + dx
            end
        else
            for y=minY,maxY,-1 do
                pixel( math.floor( x + 0.5 ), y )
                x = x - dx
            end
        end
    end
end

function fillRect(x,y,w,h)
  for i = y, y+h-1 do
    trm.setCursorPos(x,i)
    trm.write(string.rep(" ",w))
  end
end

stretch=1.4
function drawArc(x, y, radius, angle1, angle2)
    if angle1 == angle2 then return end
    if angle1 > angle2 then angle1,angle2=angle2,angle1 end
    local phi = angle1
    local k=1.5
    local x1,y1,x2,y2
    x1 = (stretch*radius * math.cos(math.rad(phi))) + x
    y1 = (radius * math.sin(math.rad(phi))) + y
    phi=phi+2
    while phi<angle2 do
      x2 = (stretch*radius * math.cos(math.rad(phi))) + x
      y2 = (radius * math.sin(math.rad(phi))) + y
      line(x1,y1,x2,y2)
      x1,y1=x2,y2
      phi=phi+2
    end
    x2 = (stretch*radius * math.cos(math.rad(angle2))) + x
    y2 = (radius * math.sin(math.rad(angle2))) + y
    line(x1,y1,x2,y2)
end

function makeArea(x,y,w,h)
  local area={X=x,Y=y,W=w,H=h}
  area.onMouse=function(clx,cly)
    return clx>=area.X and clx<area.X+area.W and cly>=area.Y and cly<area.Y+area.H
  end
  area.show=function(level,col1,col2)
    trm.setBackgroundColor(col1)
    fillRect(area.X,area.Y,area.W,area.H)
    trm.setBackgroundColor(col2)
    local hy=math.floor(level*(area.H)+0.5)
    fillRect(area.X,area.Y+area.H-hy,area.W,hy)
  end
  return area
end

function tostr(v)
  local s=tostring(v)
  if not s:find("%.") then s=s..".0" end
  return s
end

function boom(ax,ay,e)
  ay=math.rad(ay)
  ax=math.rad(ax)
  local v=math.sqrt(2*e)
  local vy=tostr(v*math.sin(ay))
  local vx=tostr(-v*math.cos(ay)*math.sin(ax))
  local vz=tostr(v*math.cos(ay)*math.cos(ax))
  cb.setCommand("playsound random.explode @a ~ ~ ~")
  cb.runCommand()
--  print("vx=",vx," vy=",vy," vz=",vz)
  cb.setCommand("summon PrimedTnt "..start.." {Motion:["..vx..","..vy..","..vz.."], Fuse:127}")
  cb.runCommand()
  bang=bang-1
  trm1.setCursorPos(1,1)
  trm1.write(' '..bang..'  ')
end

w,h=trm.getSize()
cx=math.floor(w/2+0.5)
cy=h
r=h-2.2
amax=45
aymax=45
pwmax=5
ax=0
ay=0
pw=2
bang=0
trm1.setCursorPos(1,1)
trm1.write(' '..bang..'  ')

function arrow()
  line(cx,cy,cx+stretch*r*math.sin(math.rad(ax)),cy-r*math.cos(math.rad(ax)))
end

trm.setBackgroundColor(colors.black)
trm.clear()
trm.setCursorBlink(false)

horizont=makeArea(7,1,45,cy,colors.black)
trm.setBackgroundColor(colors.white)
drawArc(cx,cy,cy-1,-90-amax,-90+amax)
trm.setBackgroundColor(colors.red)
arrow()

power=makeArea(1,1,6,cy,colors.yellow)
power.show((pw-1)/(pwmax-1),colors.yellow,colors.orange)

vertikal=makeArea(w-5,1,6,h,colors.green)
vertikal.show(ay/aymax,colors.green,colors.lime)

while true do
  event,but,mx,my=os.pullEvent()
--  print(event,' ',but,' ',mx,' ',my)
  if event=="mouse_click" and but==1 then
    clickx=mx
    clicky=my
  elseif event=="mouse_drag" and but==1 then
    dragx=mx-clickx
    dragy=my-clicky
    clickx=mx
    clicky=my
    if power.onMouse(mx,my) then
    end
    if horizont.onMouse(mx,my) then
      trm.setBackgroundColor(colors.black)
      arrow()
      ax=ax+dragx
      if ax>amax then ax=amax end
      if ax<-amax then ax=-amax end
      trm.setBackgroundColor(colors.red)
      arrow()
    end
    if vertikal.onMouse(mx,my) then
      ay=ay-dragy
      if ay>aymax then ay=aymax end
      if ay<0 then ay=0 end
      vertikal.show(ay/aymax,colors.green,colors.lime)
    end
    if power.onMouse(mx,my) then
      pw=pw-dragy/10
      if pw>pwmax then pw=pwmax end
      if pw<1 then pw=1 end
      power.show((pw-1)/(pwmax-1),colors.yellow,colors.orange)
    end
  elseif event=="monitor_touch" then
    if onDrag then
      os.queueEvent("mouse_drag",1,mx,my)
    else
      os.queueEvent("mouse_click",1,mx,my)
    end
    onDrag=true
    clicktimer=os.startTimer(0.5)
  elseif event=="timer" then
    if but==clicktimer then
      onDrag=false
    elseif but==boomtimer then
    end
  elseif event=="redstone" then
    if redstone.getInput(fire) then
      boom(ax,ay,pw)
    end
    if redstone.getInput(pay) then
      bang=bang+10
      trm1.setCursorPos(1,1)
      trm1.write(' '..bang..'  ')
    end
  end
end