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Forum Index : Microcontroller and PC projects : Blit RESIZE abused ;-)

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Martin H.

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Joined: 04/06/2022
Location: Germany
Posts: 1407
Posted: 01:11pm 09 Mar 2026
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For PicoMite V6.02.01 RC 1 or later
Here is an example of using BLIT RESIZE somewhat outside its intended use.
BLIT RESIZE draws a floor similar to the game Ballblazer. At this speed, the simultaneous view for the second player/NPC would also not be a problem.
Movement is again controlled using the WS AD keys.
Dim integer mmb4w
Dim integer Bcl(16,160),speed=3
phase
' --- Initialisierung ---
CLS
' --- Init_Graphics: Setup 320x240 Resolution, Layer-Buffer).
If MM.DEVICE$ = "MMBasic for Windows" Then mmb4w = 1
If mmb4w Then
MODE 7
PAGE WRITE 1
CLS
Else
'Pico
MODE 2
FRAMEBUFFER create : FRAMEBUFFER write f
End If
' 2. Z-Table
Dim integer x,y, z_dist(38)
For y = 0 To 37
  Read scal:z_dist(y)=16+(scal/4)
Next y

CLS 'clear FRAMEBUFFER
Dim integer hh=120,hw=160,f,n,w
Dim integer c1=RGB(0,180,0),c2=RGB(White)
Dim Integer sky=RGB(0,85,255),sky1=RGB(0,170,255),sky2=RGB(cyan)
' --- Create_Checkerboard Source
For f =0 To 288 Step 32
Line f,hh-1,f+15,hh-1,,c1:Line f+16,hh-1,f+31,hh-1,,c2
Line f,hh,f+15,hh,,c2:Line f+16,hh,f+31,hh,,c1
Next
Box 8,16,304,72,,sky,sky
Line 8,51,311,51,,sky1:Line 8,52,311,52,,sky2
main:
p=0
Do
For y = 0 To 37
mult=y<<1
 f=z_dist(y):sy=y+53:w=200-f*2-y2'w=144-mult
 If mmb4w Then
    IMAGE RESIZE_FAST f+camX,hh-Bcl(p,y+50), w,1, 8, y+53,304,1
  Else
      BLIT RESIZE f,f,f+camX,hh-Bcl(p,y+50), w,1, 8, y+53,304,1
  End If
Next y
   ' --- Keyboard ---
   k$ = Inkey$
   Select Case k$
       Case "w", "W"
          Inc P,speed:p=p Mod 15   ' vorwrts

       Case "s", "S"
           p=p-speed:If p<0 Then p=15

       Case "a", "A"
           camX = camX - speed:If camX<0 Then camX=31

       Case "d", "D"
            camX = camX + speed:camX = camX Mod 32
   End Select
If mmb4w Then
Page copy 1,0
'Page write 0
Else
 FRAMEBUFFER copy f,n,b
End If
'pause 20
Loop
Sub phase
  'Precalculation pharse lookup table
   Local integer X,Y, SW = 120,CYCLES = 7
   Local C_VALUE = (2 * Pi * CYCLES) / (SW * SW),START_PHASE = 0,Agl
   For dst=0 To 15
     For X = 0 To 119
       Agl = C_VALUE * X * X + START_PHASE
       Y = Int(Sin(Agl)*5)
       bcl(dst,120-x)=Not(y>0)
     Next X
     Inc START_PHASE, 0.393
   Next
End Sub

Data 36, 39, 43, 46, 50, 54, 57, 61, 64, 68, 72,75, 79, 82, 86
Data 89, 93, 97, 100, 104, 107, 111, 115, 118, 122, 125, 129
Data 133, 136, 140, 143, 147, 151, 154, 158, 161, 165, 169

Runs faster smoother on Pico than on Windows  
Edited 2026-03-10 00:57 by Martin H.
'no comment
 
vegipete

Guru

Joined: 29/01/2013
Location: Canada
Posts: 1162
Posted: 08:08pm 09 Mar 2026
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That's fun! Runs pretty fast on MMB4W if your keyboard repeat rate is high.

Here's a modification with acceleration and friction: (still AWSD keys to move)
Only tested on MMB4W.
Dim integer mmb4w
Dim integer Bcl(16,160),speed=3
CONST SMAX=0.025
CONST FRICTION=0.9999
CONST ACCEL=0.005
phase
' --- Initialisierung ---
CLS
' --- Init_Graphics: Setup 320x240 Resolution, Layer-Buffer).
If MM.DEVICE$ = "MMBasic for Windows" Then mmb4w = 1
If mmb4w Then
 MODE 7
 PAGE WRITE 1
 CLS
Else
 'Pico
 MODE 2
 FRAMEBUFFER create : FRAMEBUFFER write f
End If
' 2. Z-Table
Dim integer x,y, z_dist(38)
For y = 0 To 37
 Read scal:z_dist(y)=16+(scal/4)
Next y

CLS 'clear FRAMEBUFFER
Dim float xpos=0,ypos=0,dx=0,dy=0
Dim integer hh=120,hw=160,f,n,w
Dim integer c1=RGB(0,180,0),c2=RGB(White)
Dim Integer sky=RGB(0,85,255),sky1=RGB(0,170,255),sky2=RGB(cyan)
' --- Create_Checkerboard Source
For f =0 To 288 Step 32
 Line f,hh-1,f+15,hh-1,,c1:Line f+16,hh-1,f+31,hh-1,,c2
 Line f,hh,f+15,hh,,c2:Line f+16,hh,f+31,hh,,c1
Next
Box 8,16,304,72,,sky,sky
Line 8,51,311,51,,sky1:Line 8,52,311,52,,sky2
main:
p=0
Do
 if abs(dx) < .0001 then
   dx = 0
 else
   dx = dx * FRICTION
   inc xpos,dx
 end if
 camX = xpos mod 32 : if camX < 0 then inc camX,32
 
 if abs(dy) < .0001 then
   dy = 0
 else
   dy = dy * FRICTION
   inc ypos,dy
 end if
 p = ypos mod 15 : if p < 0 then inc p,15
 
 For y = 0 To 37
   'y2 = y<<1
   'mult=y<<1
   f=z_dist(y):sy=y+53:w=200-f*2 '-y2 'w=144-mult
   If mmb4w Then
     IMAGE RESIZE_FAST f+camX,hh-Bcl(p,y+50), w,1, 8, y+53,304,1
   Else
     BLIT RESIZE f,f,f+camX,hh-Bcl(p,y+50), w,1, 8, y+53,304,1
   End If
 Next y
 ' --- Keyboard ---
 k$ = Inkey$
 Select Case k$
   Case "w", "W"
     'Inc P,speed:p=p Mod 15   ' vorwrts
     inc dy,ACCEL
     dy = min(dy, SMAX)

   Case "s", "S"
     'p=p-speed:If p<0 Then p=15
     inc dy,-ACCEL
     dy = max(dy,-SMAX)

   Case "a", "A"
     'camX = camX - speed:If camX<0 Then camX=31
     inc dx,-ACCEL
     dx = max(dx,-SMAX)

   Case "d", "D"
     'camX = camX + speed:camX = camX Mod 32
     inc dx,ACCEL
     dx = min(dx, SMAX)
     
 End Select
 If mmb4w Then
   Page copy 1,0
   'Page write 0
 Else
   FRAMEBUFFER copy f,n,b
 End If
 'pause 20
Loop
Sub phase
 'Precalculation pharse lookup table
  Local integer X,Y, SW = 120,CYCLES = 7
  Local C_VALUE = (2 * Pi * CYCLES) / (SW * SW),START_PHASE = 0,Agl
  For dst=0 To 15
    For X = 0 To 119
      Agl = C_VALUE * X * X + START_PHASE
      Y = Int(Sin(Agl)*5)
      bcl(dst,120-x)=Not(y>0)
    Next X
    Inc START_PHASE, 0.393
  Next
End Sub

Data 36, 39, 43, 46, 50, 54, 57, 61, 64, 68, 72,75, 79, 82, 86
Data 89, 93, 97, 100, 104, 107, 111, 115, 118, 122, 125, 129
Data 133, 136, 140, 143, 147, 151, 154, 158, 161, 165, 169

Visit Vegipete's *Mite Library for cool programs.
 
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