[bb] TGA with alpha by Andres [ 1+ years ago ]

[BlitzBot]

Title : TGA with alpha
Author : Andres
Posted : 1+ years ago

Description : Supports 24 and 32 bpp and frames.

Functions:
image% = LoadTGA(path$)
DrawTGA(image%, x%, y%[, frames%, frame%])
TGAWidth%(image%)
TGAHeight%(image%)
FreeTGA%(image%)

Code :

Code (blitzbasic) Select Expand

Const TGAHeaderSize% = 6, TGAAlphaChannel% = True

Function LoadTGA(path$)
Local bank%, offset% = 0
Local file% = ReadFile(path$)

If file%
IDLenght% = ReadByte(file%)
ColorMapType% = ReadByte(file%)
ImageType% = ReadByte(file%)
ColorMapIndex% = ReadShort(file%)
ColorMapEntries% = ReadShort(file%)
ColorMapSize% = ReadByte(file%)
Xhandle% = ReadShort(file%)
YHandle% = ReadShort(file%)
Width% = ReadShort(file%)
Height% = ReadShort(file%)
BPP% = ReadByte(file%)
Attributes% = ReadByte(file%)

ImageID$ = ""
For i = 1 To IDLenght
ImageID$ = ImageID$ + Chr(ReadByte(RF))
Next

bank% = CreateBank(TGAHeaderSize% + Width% * Height% * 8)
image% = CreateImage(Width%, Height%)
MaskImage image%, 255, 0, 255

; HEADER
PokeShort bank%, 0, Width% * 4
PokeInt bank%, 2, image%

LockBuffer ImageBuffer(image%)

For y = 0 To height% - 1
For x = 0 To width% - 1
Select BPP%
Case 24
b% = ReadByte(file%)
g% = ReadByte(file%)
r% = ReadByte(file%)
a% = 255
Case 32
b% = ReadByte(file%)
g% = ReadByte(file%)
r% = ReadByte(file%)
a% = ReadByte(file%)
End Select
If TGAAlphaChannel%
Select a%
Case 0
WritePixelFast x, height% - y - 1, (255 Or (0 Shl 8) Or (255 Shl 16) Or ($FF000000)), ImageBuffer(image%)
Case 255
WritePixelFast x, height% - y - 1, (b% Or (g% Shl 8) Or (r% Shl 16) Or ($FF000000)), ImageBuffer(image%)
Default
WritePixelFast x, height% - y - 1, (255 Or (0 Shl 8) Or (255 Shl 16) Or ($FF000000)), ImageBuffer(image%)
PokeShort bank%, TGAHeaderSize% + offset + 0, x%
PokeShort bank%, TGAHeaderSize% + offset + 2, height% - y% - 1

PokeByte bank%, TGAHeaderSize% + offset + 4, r%
PokeByte bank%, TGAHeaderSize% + offset + 5, g%
PokeByte bank%, TGAHeaderSize% + offset + 6, b%
PokeByte bank%, TGAHeaderSize% + offset + 7, a%

offset = offset + 8
End Select
Else
Select a%
Case 0
WritePixelFast x, height% - y, (255 Or (0 Shl 8) Or (255 Shl 16) Or ($FF000000)), ImageBuffer(image%)
Default
WritePixelFast x, height% - y, (b% Or (g% Shl 8) Or (r% Shl 16) Or ($FF000000)), ImageBuffer(image%)
End Select
EndIf
Next
Next

ResizeBank bank%, TGAHeaderSize% + offset
UnlockBuffer ImageBuffer(image%)
CloseFile file%

Return bank%
EndIf
End Function

Function DrawTGA(screen%, bx%, by%, frames% = 1, frame% = 0)
Local width% = TGAWidth(screen%), height% = TGAHeight(screen%)
Local GWidth% = GraphicsWidth(), GHeight% = GraphicsHeight()

Local FrameWidth% = width% / frames%
Local StartX% = frame% * FrameWidth%

DrawImageRect PeekInt(screen%, 2), bx%, by%, StartX%, 0, FrameWidth%, height%

If Not TGAAlphaChannel% Then Return

Local bckgrnd% = LockedPixels(), bckgrndw% = LockedPitch() / 4

For i = 0 To BankSize(screen%) - (1 + TGAHeaderSize%) Step 8
x% = PeekShort(screen%, TGAHeaderSize% + i + 0)
y% = PeekShort(screen%, TGAHeaderSize% + i + 2)

If x% + bx% - StartX% => 0 And x% + bx% - StartX% < GWidth% And y% + by% => 0 And y% + by% < GHeight%
If x% => StartX And x% < StartX% + FrameWidth%
r% = PeekByte(screen%, TGAHeaderSize% + i + 4)
g% = PeekByte(screen%, TGAHeaderSize% + i + 5)
b% = PeekByte(screen%, TGAHeaderSize% + i + 6)
a# = Float PeekByte(screen%, TGAHeaderSize% + i + 7) / 255.0

br% = PeekByte(bckgrnd%, ((by% + y%) * bckgrndw% + (bx% + x% - StartX%)) * 4 + 2)
bg% = PeekByte(bckgrnd%, ((by% + y%) * bckgrndw% + (bx% + x% - StartX%)) * 4 + 1)
bb% = PeekByte(bckgrnd%, ((by% + y%) * bckgrndw% + (bx% + x% - StartX%)) * 4 + 0)

r% = Float br% + (r% - br%) * a#
g% = Float bg% + (g% - bg%) * a#
b% = Float bb% + (b% - bb%) * a#

PokeInt bckgrnd%, ((by% + y%) * bckgrndw% + (bx% + x% - StartX%)) * 4 + 0, (b% Or (g% Shl 8) Or (r% Shl 16) Or ($FF000000))
EndIf
EndIf
Next
End Function

Function TGAWidth%(screen%)
Return PeekShort(screen%, 0) / 4
End Function

Function TGAHeight%(screen%)
Return ImageHeight(PeekInt(screen%, 2))
End Function

Function FreeTGA(screen%)
If PeekInt(screen%, 2) Then FreeImage PeekInt(screen%, 2)
FreeBank screen%
End Function

Comments :


MikeP (Dark Mist Software)(Posted 1+ years ago)

 This doesn't work, it says "Function LockedPixels() not found"


Beaker(Posted 1+ years ago)

 Which version of Blitz are you using? LockedPixels() is only in BlitzPlus.


puki(Posted 1+ years ago)

 I'm hedging my bets on B+ then.


Matty(Posted 1+ years ago)

 You will need to change the following lines if you are using b3d/blitzbasic as opposed to blitzplus:

Code Select Expand

;br% = PeekByte(bckgrnd%, ((by% + y%) * bckgrndw% + (bx% + x% - StartX%)) * 4 + 2)

;bg% = PeekByte(bckgrnd%, ((by% + y%) * bckgrndw% + (bx% + x% - StartX%)) * 4 + 1)

;bb% = PeekByte(bckgrnd%, ((by% + y%) * bckgrndw% + (bx% + x% - StartX%)) * 4 + 0)


;to this
brgb%=readpixelfast(bx%+x%-StartX%,by%+y%
br%=(brgb shr 16) and 255
bg%=(brgb shr 8) and 255
bb%=(brgb) and 255
and this line

Code Select Expand

;PokeInt bckgrnd%, ((by% + y%) * bckgrndw% + (bx% + x% - StartX%)) * 4 + 0, (b% Or (g% Shl 8) Or (r% Shl 16) Or ($FF000000))

;and change that to this:
writepixelfast bx%+x%-startx%,by%+y%,b% or (g% shl 8) or (r% shl 16)


However I'd imagine in b3d it would be dog slow compared to blitzplus, can't remember what it would be like in blitzbasic,


_PJ_(Posted 1+ years ago)

 <div class="quote"> You will need to change the following lines if you are using b3d/blitzbasic as opposed to blitzplusblahblahblah </div>You missed a ) off the end in this line

Code Select Expand

brgb%=readpixelfast(bx%+x%-StartX%,by%+y%) [/i]