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shadey

14

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Joined: 25th Jan 2010

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Posted: 8th Mar 2013 11:07 Edited at: 8th Mar 2013 11:27

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been trying to get good scrolling but using getspritex(cannon) and getspritey(cannon) with setviewoffset() aint good enough as it jumps straight to it of course, so consider i have a sprite called cannon and another called cannonball, how would i have it scroll nicely after the cannonball passes through the centre of the screen ?
here is what I have tried so far:

rem
rem AGK Application
rem

rem Landscape App
SetDisplayAspect( 1024.0 / 600.0 )
global brickcount = 0
global bricklimit= 800
global cannon=810
global cannonball = 811
global shot = 0
global y#
`setphysicsgravity(0,0)
type mybrick
    xloc as integer
    yloc as integer
    imagenum as integer
    spritenumber as integer
    sizex as integer
    sizey as integer
    physicstype as integer
    bangle as integer
    sprshape as integer

endtype
global dim brick[800] as mybrick
init()
`load_level()
SetPhysicsDebugOn()
do
    control()
    if getspriteexists(cannonball)
        xs#=getspritex(cannonball)-50
        ys#=getspritey(cannonball)-50
        SetViewOffset(xs#,ys#)
        FixSpritetoScreen(cannonball,0)
    endif
    Sync()
loop

function control()
    r=getvirtualbuttonpressed(1)
    t=getvirtualbuttonpressed(2)
    s=getvirtualbuttonpressed(3)
    y#=getspriteangle(cannon)
    if r = 1 and y#>0
        setspriteangle(cannon,getspriteangle(cannon)-2)
        sync()
    endif
    if t = 1
        setspriteangle(cannon,getspriteangle(cannon)+2)
    endif
    if s = 1 and shot = 0
        shot = 1
        createsprite(cannonball,0)
        setspritesize(cannonball,2,-1)
        setspriteshape(cannonball,1)
        setspriteposition(cannonball,getspritex(cannon),getspritey(cannon) )
        setspritephysicson(cannonball,2)
        setspritephysicsmass(cannonball,1.0)
        SetSpritePhysicsCanRotate(cannonball,0)
        angle#=getspriteangle(cannon)
        speed#=120.5
        vx#=cos(angle#)*speed#
        vy#=sin(angle#)*speed#
        setspritephysicsvelocity(cannonball,vx#,vy#)
    endif
    `if shot =1 and spritevelocityx
endfunction

function init()
    setclearcolor(10,200,10)
    clearscreen()
    `loadimage(1,"redbrick.png")
    `loadimage(2,"greenbrick.png")
    `loadimage(3,"bluebrick.png")
    `loadimage(4,"ball.png")
    `loadimage(5,"cannon.png")

createsprite(cannon,0)
    setspritesize(cannon,12,6)
    setspriteposition(cannon,10,76)
    addvirtualbutton(1,10,90,5)
    setvirtualbuttontext(1,"Angle -")
    addvirtualbutton(2,20,90,5)
    setvirtualbuttontext(2,"Angle +")
    addvirtualbutton(3,30,90,5)
    setvirtualbuttontext(3,"SHOOT!")

endfunction

`************************************************ Load Function *********************************
function load_level()
    myfile = OpenToread("Test2.dat")
    `brickcount = readinteger (myfile)
    for n = 1 to bricklimit
        xl = readinteger (myfile)
        yl = readinteger (myfile)
        im = readinteger (myfile)
        sn= readinteger (myfile)
        sx = readinteger (myfile)
        sy = readinteger (myfile)
        psm = readinteger (myfile)
        ba=readinteger (myfile)
        sprs= readinteger (myfile)
        brick[n].xloc = xl
        brick[n].yloc = yl
        brick[n].imagenum = im
        brick[n].spritenumber = sn
        brick[n].sizex = sx
        brick[n].sizey = sy
        brick[n].physicstype = psm
        brick[n].bangle = ba
        brick[n].sprshape = sprs
        if brick[n].spritenumber <> 0
            inc brickcount
            createsprite (brickcount,brick[n].imagenum)

setspriteshape(brickcount,brick[n].sprshape)
            SetSpriteGroup ( brickcount,brickgroup)
            SetSpriteOffset(brickcount,getspritewidth(brickcount)/2,getspriteheight(brickcount)/2)
            setspritesize(brickcount,sx,sy)
            setspriteangle(brickcount,brick[n].bangle)
            setspriteposition(brickcount,brick[n].xloc,brick[n].yloc)
            if brick[n].physicstype >0
                setSpritePhysicsOn(brickcount,brick[n].physicstype)
            endif
        endif
    next n

closefile (myfile)
    print("loaded!!")
    sync()
endfunction
`************************************************************************************************

+ Code Snippet


rem
rem AGK Application
rem

rem Landscape App
SetDisplayAspect( 1024.0 / 600.0 )
global brickcount = 0
global bricklimit= 800
global cannon=810
global cannonball = 811
global shot = 0
global y#
`setphysicsgravity(0,0)
type mybrick
    xloc as integer
    yloc as integer
    imagenum as integer
    spritenumber as integer
    sizex as integer
    sizey as integer
    physicstype as integer
    bangle as integer
    sprshape as integer

endtype
global dim brick[800] as mybrick
init()
`load_level()
SetPhysicsDebugOn()
do
    control()
    if getspriteexists(cannonball)
        xs#=getspritex(cannonball)-50
        ys#=getspritey(cannonball)-50
        SetViewOffset(xs#,ys#)
        FixSpritetoScreen(cannonball,0)
    endif
    Sync()
loop

function control()
    r=getvirtualbuttonpressed(1)
    t=getvirtualbuttonpressed(2)
    s=getvirtualbuttonpressed(3)
    y#=getspriteangle(cannon)
    if r = 1 and y#>0
        setspriteangle(cannon,getspriteangle(cannon)-2)
        sync()
    endif
    if t = 1
        setspriteangle(cannon,getspriteangle(cannon)+2)
    endif
    if s = 1 and shot = 0
        shot = 1
        createsprite(cannonball,0)
        setspritesize(cannonball,2,-1)
        setspriteshape(cannonball,1)
        setspriteposition(cannonball,getspritex(cannon),getspritey(cannon) )
        setspritephysicson(cannonball,2)
        setspritephysicsmass(cannonball,1.0)
        SetSpritePhysicsCanRotate(cannonball,0)
        angle#=getspriteangle(cannon)
        speed#=120.5
        vx#=cos(angle#)*speed#
        vy#=sin(angle#)*speed#
        setspritephysicsvelocity(cannonball,vx#,vy#)
    endif
    `if shot =1 and spritevelocityx
endfunction



function init()
    setclearcolor(10,200,10)
    clearscreen()
    `loadimage(1,"redbrick.png")
    `loadimage(2,"greenbrick.png")
    `loadimage(3,"bluebrick.png")
    `loadimage(4,"ball.png")
    `loadimage(5,"cannon.png")

    createsprite(cannon,0)
    setspritesize(cannon,12,6)
    setspriteposition(cannon,10,76)
    addvirtualbutton(1,10,90,5)
    setvirtualbuttontext(1,"Angle -")
    addvirtualbutton(2,20,90,5)
    setvirtualbuttontext(2,"Angle +")
    addvirtualbutton(3,30,90,5)
    setvirtualbuttontext(3,"SHOOT!")


endfunction

`************************************************ Load Function *********************************
function load_level()
    myfile = OpenToread("Test2.dat")
    `brickcount = readinteger (myfile)
    for n = 1 to bricklimit
        xl = readinteger (myfile)
        yl = readinteger (myfile)
        im = readinteger (myfile)
        sn= readinteger (myfile)
        sx = readinteger (myfile)
        sy = readinteger (myfile)
        psm = readinteger (myfile)
        ba=readinteger (myfile)
        sprs= readinteger (myfile)
        brick[n].xloc = xl
        brick[n].yloc = yl
        brick[n].imagenum = im
        brick[n].spritenumber = sn
        brick[n].sizex = sx
        brick[n].sizey = sy
        brick[n].physicstype = psm
        brick[n].bangle = ba
        brick[n].sprshape = sprs
        if brick[n].spritenumber <> 0
            inc brickcount
            createsprite (brickcount,brick[n].imagenum)

            setspriteshape(brickcount,brick[n].sprshape)
            SetSpriteGroup ( brickcount,brickgroup)
            SetSpriteOffset(brickcount,getspritewidth(brickcount)/2,getspriteheight(brickcount)/2)
            setspritesize(brickcount,sx,sy)
            setspriteangle(brickcount,brick[n].bangle)
            setspriteposition(brickcount,brick[n].xloc,brick[n].yloc)
            if brick[n].physicstype >0
                setSpritePhysicsOn(brickcount,brick[n].physicstype)
            endif
        endif
    next n

    closefile (myfile)
    print("loaded!!")
    sync()
endfunction
`************************************************************************************************

The code for what i need is in the main do-loop, most of the other functions are remmed out for the sake of not needing external media!

Hail to the king, baby!

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Grumpy Jedi

14

Years of Service

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Joined: 16th Jan 2010

Location:

Posted: 9th Mar 2013 00:01

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Maybe something like this is what you're looking for?...

`Find a value for MySpeedValue# that keeps up with the speed
`of your cannonballs and it should work nicely.
MySpeedValue# = YOURSPEEDVALUE

`For MyStopPoint# (assuming you have a max value you want the camera to stop moving at) insert your own value
MyStopPoint# = YOURSTOPPOINT

`if the cannonball is past halfway and the camera hasnt reached the furthest point you want it to travel then move the view.
if GetSpriteExists(cannonball) = 1 and GetSpriteXByOffset(cannonball) >= ScreenToWorldX(50) and GetViewOffsetX() < MyStopPoint#
SetViewOffset(GetViewOffsetX() + MySpeedValue#, GetViewOffsetY())
endif

`I'm guessing you may want to continue moving the camera to the stop point even after the cannonball
`is destroyed so you may want to add in some code that does that as well.
`Then perhaps a timer or event to trigger the camera resetting back to the cannons firing position
`for the next shot.

`This makes sure you don't go past where you want the camera to stop
if GetViewOffsetX() > MyStopPoint#
SetViewOffset(MyStopPoint#,GetViewOffsetY())
endif

+ Code Snippet

`Find a value for MySpeedValue# that keeps up with the speed
`of your cannonballs and it should work nicely.
MySpeedValue# = YOURSPEEDVALUE

`For MyStopPoint# (assuming you have a max value you want the camera to stop moving at) insert your own value
MyStopPoint# = YOURSTOPPOINT

`if the cannonball is past halfway and the camera hasnt reached the furthest point you want it to travel then move the view.
if GetSpriteExists(cannonball) = 1 and GetSpriteXByOffset(cannonball) >= ScreenToWorldX(50) and GetViewOffsetX() < MyStopPoint#
SetViewOffset(GetViewOffsetX() + MySpeedValue#, GetViewOffsetY())
endif

`I'm guessing you may want to continue moving the camera to the stop point even after the cannonball
`is destroyed so you may want to add in some code that does that as well.
`Then perhaps a timer or event to trigger the camera resetting back to the cannons firing position
`for the next shot.

`This makes sure you don't go past where you want the camera to stop
if GetViewOffsetX() > MyStopPoint#
SetViewOffset(MyStopPoint#,GetViewOffsetY())
endif

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Marl

13

Years of Service

User Offline

Joined: 19th Nov 2011

Location: Bradford, UK

Posted: 9th Mar 2013 14:06 Edited at: 9th Mar 2013 14:06

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There are a couple of ways I'd look at it. Both involve calculating the position of the middle of the screen.

1) you could position the middle of the screen at the mid point between the canon and the ball

This would put the canon in the middle of the screen until it fires and then the screen would scroll at half the speed of the ball until both reach the edge.

+ Code Snippet

// Screen 500 x 500
midx = 250
midY = ( getSpriteY( canon ) + getSpriteY( ball ) ) / 2
setViewOffset( midx - 250, midy - 250 )

What happens next is up to you.

2) Use a Smallest( valueA , valueB ) function - there's at least one in the community functions, but they're not hard.

Pass the default screen middle and the ball y position through this and use the result for the y position of the middle of the screen

+ Code Snippet

// Screen 500 x 500
midx = 250
midY = Smallest( 250 , getSpriteY( ball ))
setViewOffset( midx - 250, midy - 250 )

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lilpissywilly

AGK Developer

14

Years of Service

User Offline

Joined: 10th Sep 2010

Location: Office Chair

Posted: 9th Mar 2013 20:58 Edited at: 9th Mar 2013 21:08

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I would have a camera target x/y(cannonball) and take the difference between camera-target and camera-actual x/y, use a fraction of that to increase camera-actual each frame. How much of the fraction between target and actual camera position you want to use will determine the speed of the camera panning.

If you are only moving the camera on let's say X you don't need to complicate much:

+ Code Snippet

if cameraX# < cameraTargetX# then cameraX# = cameraX# + cameraSpeed#
if cameraX# > cameraTargetX# then cameraX# = cameraX# - cameraSpeed#

if you want to move on both x and y and keep it smooth, but also include code to set the viewpoint back to the cannon after the ball is gone I would do something like:

+ Code Snippet

if getSpriteExists(cannonball) = 1
   camTargetX# = (getSpriteX(cannonball) - camX#) / camSpeed
   camTargetY# = (getSpriteY(cannonball) - camY#) / camSpeed
        
else
   camTargetX# = (getSpriteX(cannon) - camX#) / camSpeed
   camTargetY# = (getSpriteY(cannon) - camY#) / camSpeed
        
endIf

  camX# = camX# + camTargetX#
  camY# = camY# + camTargetY#

  setViewOffset(camX# -50, camY# -50)

Try camSpeed to something like 10 or even 20

That's just me, and this is saturday night so I've had a couple of glasses of red wine already. Code not tested

Edit: And to prevent the screen to move before the cannonball hits the middle of the screen I would have something like:

+ Code Snippet

if camX# - 50 > 0 then setViewOffset(camX# -50, camY# -50)
      else setViewOffset(0,0)

My hovercraft is full of eels

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