[bb] RTS Drag Select by zoqfotpik [ 1+ years ago ]

[BlitzBot]

Title : RTS Drag Select
Author : zoqfotpik
Posted : 1+ years ago

Description : This is the drag select we're all familiar with from RTS games.  Knock yourselves out.

Code :

Code: BlitzBasic

1. ' RTS Drag Select
2. ' By ZoqFotPik
3.  
4.  
5. Type dragrect ' a mousedrag rect
6.         Field upperleft:Int, upperright:Int, lowerleft:Int, lowerright:Int
7. End Type
8.  
9. Global objects:TList = New TList
10.  
11. Type selectobject
12.         Field x:Int
13.         Field y:Int
14.         Field selected:Int
15.         Method draw()
16.                 SetColor 255,255,255
17.                 DrawRect x-5,y-5,10,10
18.                
19.                 If selected = 1
20.                         SetColor 0,255,0
21.                         DrawRect x-10,y-10,15,15
22.                 EndIf
23.         End Method
24. End Type
25.                
26. Graphics 640, 480
27.  
28. For i = 1 To 100
29.         Local tempobj:selectobject = New selectobject
30.         tempobj.x = Rand(640)
31.         tempobj.y = Rand(480)
32.         objects.addlast(tempobj)
33. Next
34.  
35. Global selectx:Int
36. Global selecty:Int ' these are the x and y origins of a select box
37. Global selectflag:Int ' is a selectbox active?
38.  
39. Print leastof(5,10)
40. Print greaterof(5,10)
41. While Not KeyHit(KEY_ESCAPE)
42.  
43. Cls
44.  
45. If MouseDown(1)
46.         If Selectflag = 0
47.                 selectflag = 1
48.                 selectx = MouseX()
49.                 selecty = MouseY()
50.         EndIf
51. EndIf
52.        
53.  
54. Local tempobj2:selectobject = New selectobject
55.  
56. For tempobj2 = EachIn objects
57.         tempobj2.draw()
58. Next
59.  
60. If selectflag = 1
61.         SetColor 0,255,0
62.         DrawLine selectx, selecty, MouseX(), selecty
63.         DrawLine MouseX(),selecty, MouseX(),MouseY()
64.         DrawLine MouseX(),MouseY(), selectx,MouseY()
65.         DrawLine selectx,MouseY(),selectx,selecty
66.        
67.         If Not MouseDown(1)
68.                 selectflag = 0
69.                 Local ux:Int = leastof (MouseX(),selectx)
70.                 Local uy:Int = leastof(MouseY(),selecty)
71.                 Local lx:Int = greaterof(MouseX(),selectx)
72.                 Local ly:Int = greaterof(MouseY(),selecty)
73.                 For tempobj2 = EachIn objects
74.                 If tempobj2.x > ux And tempobj2.y > uy And tempobj2.x<lx And tempobj2.y <ly
75.                         tempobj2.selected = 1
76.                 Else
77.                         tempobj2.selected = 0
78.                 EndIf
79.                 Next
80.         EndIf
81.                
82. EndIf
83.  
84. Flip
85. Wend
86. 'leastof and greaterof are necessary in case of a leftward or upward drag of the select box
87.  
88. Function leastof(n1:Int, n2:Int)  
89.         Local least:Int
90.         If n1>n2 least = n2
91.         If n2>n1 least = n1
92.         Return least
93. End Function
94.  
95. Function greaterof(n1:Int, n2:Int)
96.         Local greater:Int
97.         If n1>n2 greater= n1
98.         If n2>n1 greater= n2
99.         Return greater
100. End Function

Comments :


virtlands(Posted 1+ years ago)

 { The files are actually *.BMX files. }Color Cycling and Procedural Critters :: <font class="tiny"> <a href="http://uploadingit.com/file/xnrveey7fjoc93mk/Color Cycling and Procedural Critters_3089.bmx" target="_blank">http://uploadingit.com/file/xnrveey7fjoc93mk/Color%20Cycling%20and%20Procedural%20Critters_3089.bmx[/url] </font>RTS Drag Effect :: <font class="tiny"> <a href="http://uploadingit.com/file/dmoxb7q8pplmotpz/RTS Drag Select_3088.bmx" target="_blank">http://uploadingit.com/file/dmoxb7q8pplmotpz/RTS%20Drag%20Select_3088.bmx[/url] </font>Image Recursion :: <font class="tiny"> <a href="http://uploadingit.com/file/kv2u1husmv3ulyob/Image Recursion_3087.bmx" target="_blank">http://uploadingit.com/file/kv2u1husmv3ulyob/Image%20Recursion_3087.bmx[/url] </font>[ RTS Drag Effect screenshot: ][img]imagizer.imageshack.us/a/img802/8319/y4bf.html">  [img]imagizer.imageshack.us/a/img571/3012/gjjc.html">


_PJ_(Posted 1+ years ago)

 What might be of note, that whenever dragging a selection rectangle, the change of state between selected and non-selected only ever occurs when the rectangle boundary intersects with the dimensions of the position of the entities.Therefore, depending on how many potential selectable entities there are, it may be quicker to check for this 'collision' rather than continuous checks for the positions of every entity.