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Alyce
Jul 11, 2011
=QCard DLL Lesson 10=
<span style="text-align: right;
display: block;
color: 0;">[[QCard09|Lesson 9]] [[QCard11|Lesson 11]]</span>
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[[user:Alyce]]
[[toc|flat]]
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See [[QCard01|Lesson 1]] for QCard DLL and WAV files needed for the demo code.
=More on Card Dragging=
In the previous demo we allowed the user to right-click on a card and drag it around. When the user released the button the card was dropped in a new position. We paid no attention to the card's status or to the location it was dropped. In a real game we'd need to monitor all such activity.
=Blocked Cards=
QCard has two functions to set and query the blocked status of a card. A card can be marked as blocked if it is covered or partially covered by another card. QCard lets us set the "blocked" status with AdjustCardBlocked. We can query the "blocked" status of a card with GetCardBlocked. The API calls look like this:
[[code format="lb"]]
calldll #qc, "AdjustCardBlocked",_
nC as long,_ 'index of card to block/unblock
bValue as long,_ '1=blocked, 0=unblocked
re as void 'no return
calldll #qc, "GetCardBlocked",_
nC as long,_ 'index of card to query
isBlocked as long '1=blocked, 0=unblocked
[[code]]
=Blocking Some Cards=
In our demo, we'll change the display so that the rows of cards overlap. Each row is 20 pixels below the previous row. When we deal the first three rows we'll also set the "blocked" status of each card in that row to "blocked". We will leave the cards in the fourth row with the default "unblocked" status. We've introduced a variable called "row" to keep track of the row being dealt.
[[code format="lb"]]
x=10:y=2:row=1
for i = 1 to 24
Call DealCard hBox,card(i),x,y
'When creating a row or pile of cards,
'only the topmost card should have an
'IsBlocked value of FALSE.
if row<4 then call AdjustCardBlocked card(i),1
x=x+100
if x>510 then 'move to next row
x=10
y=y+offset
row=row+1
end if
playwave "card.wav",sync
'pause 100 milliseconds between cards
call Pause 100
scan
next
[[code]]
=Aborting the Dragging Operation=
QCard DLL captures mouse events from the time InitDrag is called until EndDrag is called. If for any reason we need to abort the dragging procedure, we must call AbortDrag so that the DLL releases the capture of mouse events.
[[code format="lb"]]
calldll #qc, "AbortDrag", re as void
[[code]]
=Preventing the Drag of Blocked Cards=
When the user right-clicks the mouse we'll use InitDrag to discover which card in our card array was clicked. InitDrag returns the index of the card at the given x,y location. We then query its blocked status.
If the card is blocked we document that at the bottom of the display and halt the routine with AbortDrag. If it is not blocked, we begin the dragging procedure, as we did in the last lesson.
[[code format="lb"]]
[initDrag]
cardIndex=InitDrag(hBox,MouseX,MouseY)
isBlocked=GetCardBlocked(cardIndex) 'see if card is blocked
if isBlocked<>0 then
'if card is blocked, inform user and abort drag operation
call AbortDrag
#1.g "place 10 420;\BLOCKED Card Index is ";cardIndex;space$(100)
wait
end if
#1.g "place 10 420;\Drag Card Index is ";cardIndex;space$(100)
#1.g "when rightButtonMove [doDrag]"
wait
[[code]]
In a real game you'd want to set the blocked status of the newly uncovered card to 0. You'd also need to set the card that was just covered by the dragged card to "blocked". We did not complicate the code with these routines in order to keep the demo program short and understandable.
=Offset Value=
QCard has a default offset value of 16 pixels. The cards are 70x95 pixels and if one card is displayed 16 pixels lower thena the card beneath both card values will be visible. **This offset is important to the DLL when it discovers which card is at MouseX and MouseY.**
We can change the offset with SetOffSet. We change the offset to 20 pixels for this demo.
[[code format="lb"]]
calldll #qc, "SetOffSet",_ 'change pixel offset for vertical colums of cards
offset as long,_ 'number of pixels to offset
re as void
[[code]]
=DEMO=
See [[QCard01|Lesson 1]] for QCard DLL and WAV files needed for the demo code.
The demo deals the cards in four overlapped rows. It sets the blocked status of cards in the first three rows. It checks the blocked status of the card clicked by the user. It allows the user to drag the card if the designated card status is "unblocked". We've eliminated the shuffling routine to keep things simple for this demo.
[[code format="lb"]]
'An open project card game, begun by Alyce Watson, May 27, 2003.
'Uses Qcard32.dll, a freeware library of playing card images.
'DLL by Stephen Murphy. Qcard32.DLL website:
'http://www.telusplanet.net/public/stevem/
dim card(24) 'array to hold cards
gosub [fillCardArray] 'fill array with card values
[varSetup]
i=0 'i will be our counter var in for/next loops
offset=20 'offset for card vertical spacing for dragging purposes
nomainwin
WindowWidth=640:WindowHeight=480
UpperLeftX=1:UpperLeftY=1
menu #1, "&File", "&New",[new],"E&xit", [quit]
graphicbox #1.g, 0, 0, 640, 440
open "Dragging Cards" for window_nf as #1
#1 "trapclose [quit]"
'get graphicbox handle
hBox=hwnd(#1.g)
'open the dll
open "qcard32.dll" for dll as #qc
'initialize the deck
Call InitializeDeck hBox
[new]
Call SetDefaultValues
'draw a nice background
#1.g "down; fill 10 190 225"
#1.g "backcolor 10 190 225"
'temp message for this demo only
#1.g "place 10 420"
#1.g "\Right-click on a card, then move mouse to drag and drop it."
offset=20
call SetOffSet offset 'set offset to 20 pixels - default is 16
'set xy location to start deal
x=10:y=2:row=1
for i = 1 to 24
Call DealCard hBox,card(i),x,y
'When creating a row or pile of cards,
'only the topmost card should have an
'IsBlocked value of FALSE.
if row<4 then call AdjustCardBlocked card(i),1
x=x+100
if x>510 then 'move to next row
x=10
y=y+offset
row=row+1
end if
playwave "card.wav",sync
'pause 100 milliseconds between cards
call Pause 100
scan
next
#1.g "when rightButtonDown [initDrag]"
wait
[initDrag]
cardIndex=InitDrag(hBox,MouseX,MouseY)
isBlocked=GetCardBlocked(cardIndex) 'see if card is blocked
if isBlocked<>0 then
'if card is blocked, inform user and abort drag operation
call AbortDrag
#1.g "place 10 420;\BLOCKED Card Index is ";cardIndex;space$(100)
wait
end if
#1.g "place 10 420;\Drag Card Index is ";cardIndex;space$(100)
#1.g "when rightButtonMove [doDrag]"
wait
[doDrag]
call DoDrag hBox, MouseX, MouseY
#1.g "when rightButtonUp [endDrag]"
wait
[endDrag]
#1.g "when rightButtonUp"
cardIndex=EndDrag(hBox,MouseX,MouseY)
#1.g "place 10 420;\Destination Card Index is ";cardIndex;space$(100)
wait
[fillCardArray]
'fill card array
'cards 1 to 52 are in the first deck
'cards 53 to 104 are in the second deck
'use cards Jack through King in each suit, first deck
card(1)=11 'jack of clubs
card(2)=12 'queen
card(3)=13 'king
card(4)=24 'jack of diamonds
card(5)=25 'queen
card(6)=26 'king
card(7)=37 'jack of hearts
card(8)=38 'queen
card(9)=39 'king
card(10)=50 'jack of spades
card(11)=51 'queen
card(12)=52 'king
'now use second deck, to fill second half of array
for i = 1 to 12
card(i+12)=card(i)+52
next
RETURN
[quit] close #qc:close #1:end
''''''''''''''''''''
'subs and functions:
Sub Pause ms
'pause ms number of milliseconds
calldll #kernel32,"Sleep",_
ms as long, re as void
End Sub
Sub SetOffSet offset
calldll #qc, "SetOffSet",offset as long,_
re as void
end sub
Sub AdjustCardBlocked nC, bValue
calldll #qc, "AdjustCardBlocked",_
nC as long, bValue as long, re as void
end sub
Function GetCardBlocked(nC)
calldll #qc, "GetCardBlocked",nC as long,_
GetCardBlocked as long
end function
Function InitDrag(hndle, x, y)
calldll #qc, "InitDrag",_
hndle as ulong, x as long, y as long,_
InitDrag as long
end function
Sub AbortDrag
calldll #qc, "AbortDrag",re as void
end sub
Sub DoDrag hndle,x,y
calldll #qc, "DoDrag",hndle as ulong,_
x as long, y as long, r as void
end sub
Function EndDrag(hndle,x,y)
calldll #qc, "EndDrag",hndle as ulong,_
x as long, y as long, EndDrag as long
end function
Sub InitializeDeck hndle
calldll #qc, "InitializeDeck",_
hndle as ulong,r as long
End Sub
Sub DealCard hndle,nC,x,y
'places card on window whose handle is hndle at x,y
'nC is number of card - 1-52 in first deck and
'53-104 in second deck, if used
calldll #qc, "DealCard",hndle as ulong,nC as long,_
x as long,y as long,r as void
End Sub
Sub SetDefaultValues
'reset all card properties back to their default values.
calldll #qc, "SetDefaultValues",r as void
End Sub
[[code]]
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[[toc|flat]]
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<span style="text-align: right;
display: block;
color: 0;">[[QCard09|Lesson 9]] [[QCard11|Lesson 11]]</span>