Locked Graphics Demo?

The forum is locked. These are the original blitzbasic.com forums, kept so they can still be read. No new topics, replies or edits can be made here. To join in, head over to the Blitz3D+ forums.

turtle1776

Okay, I *think* this might clarify how the faster B+ pixel drawing works.

Here is Mark's lock_graphics demo with a bit more added to show how to add the correct colors. The functions slow things down a bit, but you can easily optimize it. Comments are welcome.

[CODE]
;Note that this is B+ code.
Const FORMAT_RGB565=1 ;16 bit 565
Const FORMAT_XRGB1555=2 ;16 bit 555
Const FORMAT_RGB888=3 ;24 bit
Const FORMAT_XRGB8888=4 ;32 bit

Graphics 640,480,16,1;fullscreen!

timer=CreateTimer(60)

Repeat

Select WaitEvent()

Case $103 ;key down
If EventData()=27 End

Case $4001 ;timer tick

tm=MilliSecs()
LockBuffer
bank=LockedPixels()

For y=0 To 479
offset=y*LockedPitch()

Select LockedFormat()
Case FORMAT_RGB565
For x=0 To 319
PokeShort bank,offset+x*4,Get16Bit565RGB(255,0,255)
PokeShort bank,offset+x*4+2,Get16Bit565RGB(255,0,255)
Next
Case FORMAT_XRGB1555
For x=0 To 319
PokeShort bank,offset+x*4,Get16Bit555RGB(255,0,0)
PokeShort bank,offset+x*4+2,Get16Bit555RGB(255,0,0)
Next
Case FORMAT_RGB888
For x=0 To 639
PokeInt bank,offset+x*4,GetRGB(255,0,0)
Next
Case FORMAT_XRGB8888
For x=0 To 639
PokeInt bank,offset+x*4,GetRGB(255,0,0)
Next
End Select
Next

UnlockBuffer
tm=MilliSecs()-tm

Text 0,0,tm
Text 100,0,LockedFormat()
Flip

End Select

Forever
End

Function GetRGB(r,g,b)
;24/32 Bit Conversion - ignore first 8 bits, which are reserved for alpha info
;r 00000000111111110000000000000000 = 00FF0000
;g 00000000000000001111111100000000 = 0000FF00
;b 00000000000000000000000011111111 = 000000FF
;Note: 32 bits = 4 bytes = 2 shorts = 1 int

Return b Or (g Shl 8) Or (r Shl 16)
End Function

Function Get16Bit555RGB(r,g,b)
;16 bit 555 Conversion - 1st bit is empty
;r 0111110000000000 = 7C00 = 7*16^3 + 12*16^2 = 31744
;g 0000001111100000 = 03E0
;b 0000000000011111 = 001F = 31
;Note: 16 bits = 2 bytes = 1 short
Return (r/8 Shl 10) Or (g/8 Shl 5) Or (b Shr 3)
End Function
Function Get16Bit565RGB(r,g,b)
;16 bit 565 conversion - middle green value gets 6 bits
;r 1111100000000000 = F800 = 63488
;g 0000011111100000 = 07E0
;b 0000000000011111 = 001F = 31
;Note: 16 bits = 2 bytes = 1 short
Return (r/8 Shl 11) Or (g/4 Shl 5) Or (b Shr 3)
End Function
[/CODE]