[Lazarus] fpimage use of Lazarus

[Mattias Gaertner]

On Sat, 16 Feb 2008 01:19:28 +0100
Marco van de Voort <marcov at stack.nl> wrote:

> 
> I post this msg because I see fpimage units used in Lazarus' graphics
> unit. I plan to enhance tmemoryimage with scanline support, and adapt
> the readers and writers.
> 
> The consequences are:
> - standard fpimage readers and writers might get extra methods for
> tmemoryimages. There might be an extra inheritance level involved.
> (if img is TMemory then)
> - tmemoryimage internal representation changes (and won't be always 4
> bytes per pixel), lowering mem usage somewhat for lower bpp pictures.

Sounds like what TLazIntfImage is doing. It maps Get/SetColor to a
memory image pixel format. See graphtype.pp TRawImageDescription for
supported formats.

 
> For now I'm only playing ad exploring, and even if I start to get
> serious, it will be a branch at first. So no panic and running for
> the door please :-)
> 
> Does sb know on what fpimage properties lazarus exactly depends? 

If you mean TFPCustomImage: Almost every property. The Extra*
properties are used only by some readers/writers that are used by the
LCL. So this is an indirect dependency.

 
> I now have the feeling the readers, writers and canvas are used but
> not the core image classes itself (tfpcustomimage)?

TLazIntfImage = class(TFPCustomImage)

 
> Are there hidden assumptions on internal format (mostly being it
> always 32bpp?)

I didn't even know that fpimage has an internal format.

Mattias