angle problem

[shoobyman]

code:

setscreen ("offscreenonly") var angle : int := 1 var velx, vely := 0 var chars : array char of boolean var pic : array 1 .. 359 of int var shipx, shipy : int := 100 var linex1, liney1, linex2, liney2 : int var x, y, button : int linex1 := shipx + 23 linex2 := shipx + 23 liney1 := shipy + 38 liney2 := shipy + 28 for i : 1 .. 359     pic (i) := Pic.FileNew ("ship.bmp")     pic (i) := Pic.Rotate (pic (i), i, 23, 33)     drawfillbox (10, 200, (i + 10), 250, 12)     locate (12, 48)     put "Complete"     View.Update     locate (14, 18)     put "GENERATING PICTURES" end for loop     Input.KeyDown (chars)     mousewhere (x, y, button)     View.Update     delay (30)     cls     Pic.Draw (pic (angle), shipx, shipy, picCopy)     drawline (linex1, liney1, linex2, liney2, 7)     if x = 0 then         x := 1     end if     if y = 0 then         y := 1     end if     shipx += velx     shipy += vely     angle := arctan (y div x) div 1     if chars (KEY_UP_ARROW) then         velx := (linex1 - linex2) div 5         vely := (liney1 - liney2) div 5     end if     if button = 1 then         velx := (x - shipx) div 20         vely := (y - shipy) div 20     end if     if angle >= 360 then         angle := 1     end if     if angle < 1 then         angle := 358     end if     locate (1, 1)     put "Angle: ", angle     locate (2, 1)     put "x: ", x, "    y: ", y end loop

If you click, the ship moves properly, but can anyone help me with the formula for the way the ship is facing?
I want it to face the mouse, but I have tried a lot of different ways and i don't know how to do it. Anyone know the formula?

ps. Code is messy, but don't worry about that

[zylum]

this might help: http://www.compsci.ca/v2/viewtopic.php?t=14083

[richcash]

I assume you mean something like this :

code:

View.Set ("offscreenonly") var x1, y1, x2, y2, angle : real := 0 var x, y, button : int loop     Mouse.Where (x, y, button)     if button not= 0 then         x1 += sign (x - x1)     end if     angle := arctand ((y - y1) / (x - x1 + 1e-6))     if angle < 0 then         angle += 180     end if     x2 := x1 + cosd (angle) * 40     y2 := y1 + sind (angle) * 40     Draw.Line (round (x1), round (y1), round (x2), round (y2), 7)     View.Update     delay (5)     cls end loop

Get the angle and then use sine and cosine. In your case, you already have the rotated images, so you don't even have to use sine and cosine! Just draw the image that's at that angle.