Need to load 8-bits images *AS 8-BITS IMAGES* in my 24-bits DX game!

[Jotaf98]

Hi!

In my DX game (24-bits), I need to load a surface as 8-bits. But it won't let me - the surface appears as 24-bits! How can I specify the color depth to use, or use the color depth of the file?

If you can't help me, please post some code chunks to load images in DX and I might be able to figure it out

[Sastraxi]

[DDSURFACEDESC2].ddpfPixelFormat.lFlags = DDPF_PALETTEINDEXED8

This will denote it as a paletted surface. To get the palette entries (which isn't working for me, grrr ), you use this chunk of code:

Dim Pal(0 to 255) As PALETTEENTRY
Dim dPal As DirectDrawPalette
Set dPal = [DIRECTDRAWSURFACE7].GetPalette
Call dPal.GetEntries(0, 256, Pal())

To set the palette (which actually works, ), use this code:

Dim Pal(0 to 255) As PALETTEENTRY
Dim dPal As DirectDrawPalette
Call dPal.SetEntries(0, 256, Pal())
[DIRECTDRAWSURFACE7].SetPalette dPal

[Sastraxi]

BTW, why do you need to load them as 8-bit images?

[Jotaf98]

Thanks!

I'd help you out with getting the palette entries, but VB doesn't seem to work now

Can you please post here again so I get e-mailed and remember to check back tomorrow?

[Sastraxi]

Well, if you want me to post here I am

I looked this up (in a hurry!) because I want to be able to add a tinge to all of my sprites (to simulate sunset/sunrise/nighttime/daytime). The method that I (have tried!!) to use would be fast, but I dont know if it would be fast enough...

[Jotaf98]

Hum... in exactly which line does it crash? It will be easier to find the source of the problem if we know that.

[Sastraxi]

.GetPalette

[Jotaf98]

Hum DDraw usually crashes the whole comp with a small error... here are the 2 most likely causes of your problem:

DDERR_NOEXCLUSIVEMODE
The operation requires the application to have exclusive mode, but the application does not have exclusive mode.

DDERR_NOPALETTEATTACHED
No palette object is attached to this surface.

The first one is, I think, what is happening - is your game running in exclusive mode?

Just a wild guess

[Sastraxi]

Yes, it is. And I set the surface with the palette indexed 8 flag...

Call dd.SetCooperativeLevel(Me.hWnd, DDSCL_FULLSCREEN Or DDSCL_EXCLUSIVE Or DDSCL_ALLOWREBOOT)

Here is the surface loading:

Public Function LoadBitm(ByRef Surf As DirectDrawSurface7, ByRef desc As DDSURFACEDESC2, File As String, Optional Paletted As Boolean = False)
 
    If Paletted = True Then desc.ddpfPixelFormat.lFlags = DDPF_PALETTEINDEXED8
    desc.lFlags = DDSD_CAPS
    desc.ddsCaps.lCaps = DDSCAPS_OFFSCREENPLAIN
    Set Surf = dd.CreateSurfaceFromFile(File, desc)
    
End Function

Call LoadBitm(mySurf,myDesc,App.Path & "\chara.bmp",True)

And I use this:

Set PPal = mySurf.GetPalette

If I use this code, I get an AUTOMATION error.

[Jotaf98]

Well, if you need to NOT be in exclusive mode to use that function, simply don't run your program in exclusive mode

[Sastraxi]

Oh you're evil >=)
I've decided to drop palettes, in order to use getlockedarray

[Jotaf98]

You can use that with palettes too, it's just gonna be a bit harder to use special effects or something (palettes is where lookup tables are the ONLY fast method to use).

In 8-bits, each byte is a pixel (the palette index); in 16-bits, each 2 bytes are a pixel (this is a bit hard to use since you'll need to find out if the method is 555 or 556, and you'll have to use bitshifts to figure out the RGB values); in 24-bits, each 3 bytes are a pixel (each RGB value is a byte); and 32-bits is just like 24-bits, except that the fourth byte isn't used.

Remember that a greater color depth means looping trough more bytes, so it's slower.

[Sastraxi]

I know that, for some reason my GeForce is lightning fast with that stupid Set/GetLockedPixel method (1/2 a second for 320x240), that's for my gradient function. Anyways I wont be toying with palettes for a long time, bring on the full-screen clippers >=(

[Jotaf98]

Then you should ask MS about it!

BTW, I need to load them as 8-bits for the damage indicator in my Tyrian game... I can't tell you here because someone could steal my idea

You could also have the whole game in 8-bits mode and change the palette of the front surface or something... it would be a lot easier because this way you only have 1 palette so you can load it from a file