12-01-2024, 11:08 AM
Hi friends
I want to share these basical knowledges about scrolling background in graphic mode using the powerful _PUTIMAGE.
It is a basical 2D graphic mode 32bit.
I post the following 6 QB64pe code examples that start from a backgroung scrolling to right and leaving a black screen to arrive to a background scrolling in the 4 directions of a bidimensional field in which the user can start/stop the scrolling, change the directions of the scrolling and quit the program.
If you want to see the final result you must run the STEP 6.
If you want follow the tutorial you must go step by step from 1 to 6.
Happy enjoyment with this code.
STEP 1
STEP 2
STEP 3
STEP 4
STEP 5
STEP 6
Thanks for feedbacks
I want to share these basical knowledges about scrolling background in graphic mode using the powerful _PUTIMAGE.
It is a basical 2D graphic mode 32bit.
I post the following 6 QB64pe code examples that start from a backgroung scrolling to right and leaving a black screen to arrive to a background scrolling in the 4 directions of a bidimensional field in which the user can start/stop the scrolling, change the directions of the scrolling and quit the program.
If you want to see the final result you must run the STEP 6.
If you want follow the tutorial you must go step by step from 1 to 6.
Happy enjoyment with this code.
STEP 1
Code: (Select All)
Rem Demonstration of scrolling towards right or left of the background
Rem STEP 1 a background scrolling towards right in loop
' Global variables' declaration
Dim Back As Long, Scr As Long, x As Integer, y As Integer, w As Integer, h As Integer
Dim i As Integer, k As String
_Title " Demo of background scrolling: step 1" ' title on the titlebar of the application
' variables' initialization
w = 800: h = 600
y = 1
x = 1
Scr = _NewImage(w, h, 32)
Back = _NewImage(w, h, 32)
Screen Scr ' it creates window of the application
_Dest Back ' it sets the surface as destination of graphic output
' it draws a gradient background by using a FOR loop with graphic instructions (LINE and _RGBA)
For i = 1 To 10
Line ((w / 10) * (i - 1), y)-((w / 10) * (i + 1), h), _RGBA32(1 + (i - 1) * (255 / 10), 127, 127, 255), BF
Next i
_Dest 0 ' it sets the surface of destination of graphic output as the window of the application
' it manages the keyboard input of user and the scrolling towards right of background
While k <> "Q"
k = UCase$(InKey$) ' it takes the input from keyboard
Cls 'it clears previous screen
_PutImage (x, y), Back, Scr 'it paints screen now
_PrintString (1, 1), "Press Q to quit program" ' it shows instruction for user on the screen
x = x + 1 'it calculates the new position where starting to paint background, it is towards right
_Display ' it forces hardware to show image
_Limit 100 ' it reduces the number of cycles of CPU used by this application
Wend
End
STEP 2
Code: (Select All)
Rem Demonstration of scrolling towards right or left of the background
Rem STEP 2 a background scrolling towards right in loop
' Global variables' declaration
Dim Back As Long, Scr As Long, x As Integer, y As Integer, w As Integer, h As Integer
Dim i As Integer, k As String
_Title " Demo of background scrolling: step 2" ' title on the titlebar of the application
' variables' initialization
w = 800: h = 600
y = 1
x = 1
Scr = _NewImage(w, h, 32)
Back = _NewImage(w, h, 32)
Screen Scr ' it creates window of the application
_Dest Back ' it sets the surface as destination of graphic output
' it draws a gradient background by using a FOR loop with graphic instructions (LINE and _RGBA)
For i = 1 To 10
Line ((w / 10) * (i - 1), y)-((w / 10) * (i + 1), h), _RGBA32(1 + (i - 1) * (255 / 10), 127, 127, 255), BF
Next i
_Dest 0 ' it sets the surface of destination of graphic output as the window of the application
' it manages the keyboard input of user and the scrolling towards right of background
While k <> "Q"
k = UCase$(InKey$) ' it takes the input from keyboard
Cls 'it clears previous screen
_PutImage (x, y), Back, Scr 'it paints screen now
_PrintString (1, 1), "Press Q to quit program, A to restart" ' it shows instruction for user on the screen
x = x + 1 'it calculates the new position where starting to paint background, it is towards right
If k = "A" Then x = 1 ' it corrects x when user restarts
_Display ' it forces hardware to show image
_Limit 100 ' it reduces the number of cycles of CPU used by this application
Wend
End
STEP 3
Code: (Select All)
Rem Demonstration of scrolling towards right or left of the background
Rem STEP 3 a background scrolling towards right in loop
' Global variables' declaration
Dim Back As Long, Scr As Long, x As Integer, y As Integer, w As Integer, h As Integer
Dim i As Integer, k As String
_Title " Demo of background scrolling: step 3" ' title on the titlebar of the application
' variables' initialization
w = 800: h = 600
y = 1
x = 1
Scr = _NewImage(w, h, 32)
Back = _NewImage(w, h, 32)
Screen Scr ' it creates window of the application
_Dest Back ' it sets the surface as destination of graphic output
' it draws a gradient background by using a FOR loop with graphic instructions (LINE and _RGBA)
For i = 1 To 10
Line ((w / 10) * (i - 1), y)-((w / 10) * (i + 1), h), _RGBA32(1 + (i - 1) * (255 / 10), 127, 127, 255), BF
Next i
_Dest 0 ' it sets the surface of destination of graphic output as the window of the application
' it manages the keyboard input of user and the scrolling towards right of background
While k <> "Q"
k = UCase$(InKey$) ' it takes the input from keyboard
Cls 'it clears previous screen
_PutImage (x, y), Back, Scr 'it paints screen now
_PutImage (x - w, y), Back, Scr ' it completes the background on the left side
_PrintString (1, 1), "Press Q to quit program" ' it shows instruction for user on the screen
x = x + 1 'it calculates the new position where starting to paint background, it is towards right
If x > w Then x = 1 ' it corrects x when is over
_Display ' it forces hardware to show image
_Limit 100 ' it reduces the number of cycles of CPU used by this application
Wend
End
STEP 4
Code: (Select All)
Rem Demonstration of scrolling towards right or left of the background
Rem STEP 4 a background scrolling towards right in loop
' Global variables' declaration
Dim Back As Long, Scr As Long, x As Integer, y As Integer, w As Integer, h As Integer
Dim i As Integer, k As String, S As Integer
_Title " Demo of background scrolling: step 4" ' title on the titlebar of the application
' variables' initialization
w = 800: h = 600
y = 1
x = 1
Scr = _NewImage(w, h, 32)
Back = _NewImage(w, h, 32)
S = 1
Screen Scr ' it creates window of the application
_Dest Back ' it sets the surface as destination of graphic output
' it draws a gradient background by using a FOR loop with graphic instructions (LINE and _RGBA)
For i = 1 To 10
Line ((w / 10) * (i - 1), y)-((w / 10) * (i + 1), h), _RGBA32(1 + (i - 1) * (255 / 10), 127, 127, 255), BF
Next i
_Dest 0 ' it sets the surface of destination of graphic output as the window of the application
' it manages the keyboard input of user and the scrolling towards right of background
While k <> "Q"
k = UCase$(InKey$) ' it takes the input from keyboard
Cls 'it clears previous screen
_PutImage (x, y), Back, Scr 'it paints screen now
_PutImage (x - w, y), Back, Scr ' it completes the background on the left side
_PrintString (1, 1), "Press Q to quit program, S to stop/start demo" ' it shows instruction for user on the screen
If k = "S" Then If S > 0 Then S = -1 Else S = 1 ' it starts/stops the scrolling to right
If S > 0 Then x = x + 1 'it calculates the new position where starting to paint background, it is towards right
If x > w Then x = 1 ' it corrects x when is over
_Display ' it forces hardware to show image
_Limit 100 ' it reduces the number of cycles of CPU used by this application
Wend
End
STEP 5
Code: (Select All)
Rem Demonstration of scrolling towards right or left of the background
Rem STEP 5 a background scrolling towards right /left in loop
' Global variables' declaration
Dim Back As Long, Scr As Long, x As Integer, y As Integer, w As Integer, h As Integer
Dim i As Integer, k As String, S As Integer, d As Integer
_Title " Demo of background scrolling: step 5" ' title on the titlebar of the application
' variables' initialization
w = 800: h = 600
y = 1
x = 1
Scr = _NewImage(w, h, 32)
Back = _NewImage(w, h, 32)
S = 1
d = 1
Screen Scr ' it creates window of the application
_Dest Back ' it sets the surface as destination of graphic output
' it draws a gradient background by using a FOR loop with graphic instructions (LINE and _RGBA)
For i = 1 To 10
Line ((w / 10) * (i - 1), y)-((w / 10) * (i + 1), h), _RGBA32(1 + (i - 1) * (255 / 10), 127, 127, 255), BF
Next i
_Dest 0 ' it sets the surface of destination of graphic output as the window of the application
' it manages the keyboard input of user and the scrolling towards right of background
While k <> "Q"
k = UCase$(InKey$) ' it takes the input from keyboard
Cls 'it clears previous screen
_PutImage (x, y), Back, Scr 'it paints screen now
_PutImage (x - w, y), Back, Scr ' it completes the background on the left side
_PrintString (1, 1), "Press Q to quit program, S to stop/start demo, R to reverse direction" ' it shows instruction for user on the screen
If k = "S" Then If S > 0 Then S = -1 Else S = 1 ' it starts/stops the scrolling to right
If k = "R" Then d = d * -1 ' it changes the direction of scrolling +1 = to right / -1 = to left
If S > 0 Then x = x + d 'it calculates the new position where starting to paint background, it is towards right
If d > 0 And x > w Then x = 1 ' it corrects x when is over w and scrolling is to right
If d < 0 And x < 1 Then x = w ' it corrects x when is under 1 and scrolling is to left
_Display ' it forces hardware to show image
_Limit 100 ' it reduces the number of cycles of CPU used by this application
Wend
End
STEP 6
Code: (Select All)
Rem Demonstration of scrolling towards right or left of the background
Rem STEP 6 a background scrolling towards right /left & down/up in loop
' Global variables' declaration
Dim Back As Long, Scr As Long, x As Integer, y As Integer, w As Integer, h As Integer
Dim i As Integer, k As String, dx As Integer, dy As Integer, O As Integer, V As Integer, S As Integer
_Title " Demo of background scrolling: step 6" ' title on the titlebar of the application
' variables' initialization
w = 800: h = 600
y = 1
x = 1
Scr = _NewImage(w, h, 32)
Back = _NewImage(w, h, 32)
dx = 1
dy = 1
S = 1
O = 1
V = 1
Randomize Timer ' it starts the random generator of number
Screen Scr ' it creates window of the application
_Dest Back ' it sets the surface as destination of graphic output
' it draws a background by using a FOR loop with graphic instructions (LINE and _RGBA)
For i = 1 To 100
Line ((Rnd * (780) + 10), Rnd * (580) + 10)-(Rnd * (780) + 10, Rnd * (580) + 10), _RGBA32(Rnd * (255), Rnd * (255), Rnd * (255), 255), B
Next i
_Dest 0 ' it sets the surface of destination of graphic output as the window of the application
' it manages the keyboard input of user and the scrolling background
While k <> "Q"
k = UCase$(InKey$) ' it takes the input from keyboard
Cls 'it clears previous screen
_PutImage (x, y), Back, Scr 'it paints screen now
_PutImage (x - w, y), Back, Scr ' it completes the background on the left side
_PutImage (x, y - h), Back, Scr ' it completes the background on the upper side
_PutImage (x - w, y - h), Back, Scr ' it completes the background on the upper side
_PrintString (1, 1), "Press Q to quit program, S to stop/start demo, R to reverse directions" ' it shows instruction for user on the screen
_PrintString (1, 20), " O stop/start horizontal scrolling, V stop/start vertical scrolling"
' it starts/stops the scrolling
If k = "S" Then S = S * -1
If k = "R" Then
' it changes only scrolling activated
If O > 0 Then dx = dx * -1
If V > 0 Then dy = dy * -1
' it changes the direction of scrolling +1 = to right to bottom/ -1 = to left to up
End If
If k = "O" Then O = O * -1 'it sets the status of horizontal scrolling
If k = "V" Then V = V * -1 ' it sets the status of vertical scrolling
If S > 0 And O > 0 Then x = x + dx ' it scrolls only horizontal
If S > 0 And V > 0 Then y = y + dy ' it scrolls only vertical
If dx > 0 And x > w Then x = 1 ' it corrects x when it is over w and scrolling is to right
If dx < 0 And x < 1 Then x = w ' it corrects x when it is under 1 and scrolling is to left
If dy > 0 And y > h Then y = 1 ' it corrects y when it is over h and scrolling is to down
If dy < 0 And y < 1 Then y = h ' it corrects when it is under 1 and scrolling is to up
_Display ' it forces hardware to show image
_Limit 100 ' it reduces the number of cycles of CPU used by this application
Wend
End
Thanks for feedbacks