Sorry your browser is not supported!

Hi all,

I've been playing around with DarkGDK and VS2008 and hit a problem, I don't know if it's a bug or I'm doing something wrong.

I set the colour key to red using dbSetImageColorKey(255,0,0) and if I load an image with dbLoadImage(),assign it to a sprite with dbSetSpriteImage() and display it with dbSprite(), the transparency works as expected.

But if I create an image from a memblock (I used the code posted by IanM some time ago), then display it, the transparency doesn't work i.e. I can see the red colour around the image.

Any ideas?

Where are you getting your memblock data from? Are you using dbGetImage()? If so don't forget the extra 1 to grab image without anti-aliasing.

Also, if making a image from memblocks why not use the alpha channel?

You're RIGHT! But I found a book called Gullible's Travels... I'm going to make a MMORPG based on it

Seriously, Flashing Blade is correct. I did that BitMap Font (Newletter 59 I tink) and went through it fowards, backwards, and that part wasn't so bad - but getting into the Image format, dealing with RGB and the Alpha... Paid off!

You can do some neat things just loading images with an Alpha Channel, but its prety fun to play with them programmatically to.

You should check out the MakeImageFromMemblock thing and MakeMemblockFrom Image.....

format for memblock made this way is:

First Four Bytes (DWORD, Offset 0) : Image Width
Next Four Bytes (DWORD, Offset 4) : Image Height
Next Four Bytes (DWORD, Offset 8) : Image Depth (usually 32)
from there, its a grid of DWORD, therefore each pixel is 4 bytes..

PixelOffset = 12 + ((x + ( Y * Width))*4)

To Get Individual "channels", using that PixelOffset Value:

dbWriteMemblockByte(MemID, PixelOffset+0, Blue);
dbWriteMemblockByte(MemID, PixelOffset+1, Green);
dbWriteMemblockByte(MemID, PixelOffset+2, Red);
dbWriteMemblockByte(MemID, PixelOffset+3, Alpha);

Good Luck!

Thanks for input guys.

@Flashing Blade - I'm loading the data from a resource that was compiled into the exe, I'm not sure how to load an alpha channel separately, but I'll google about for it.

@jason p sage - I used those functions to make the image, and it worked OK, it's just the transparency thing.