Image format in HBitmap
lazarus / 39-Graphics

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wile64 · 2007-05-21 13:38

Hello,

How are to store the images in HBitmap of TBitmap?
In what format?

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antonio · 2007-05-21 17:18

You create a bitmap (format: bitmap) at run time, set height and width
and you can load from file, save to file, etc, or simply draw or write
to it.

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wile64 · 2007-05-21 19:13

I can use a bitmap, thank you !

My question is, Which is the format of the data in HBitmap :!:

ex :
header, Image Data (rgb, bgr, rgba...) ?   :?:

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antonio · 2007-05-21 20:45

I found this link:
http://www.fortunecity.com/skyscraper/windows/364/bmpffrmt.html , have
a look at it.

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wile64 · 2007-05-21 21:22

thank you,

I seek information on pointer of data HBITMAP not on the files Bitmap
(bmp)

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antonio · 2007-05-21 21:52

You could search on MSDN, http://msdn2.microsoft.com/fr-
fr/default.aspx

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Marc · 2007-05-22 08:46

That info will be only for real HBITMAP handles returned by windows.
There is no guarantee what so ever that it is compatible with lazarus.
A handle is an abstract pointer so some object. How it is internally
structured is of no importance to a user of that handle.

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wile64 · 2007-05-22 09:19

How to reach directly the data image in TBitmap ?  :twisted:

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theo · 2007-05-22 09:47

You can access individual Pixels using TLazIntfImage.
See http://wiki.lazarus.freepascal.org/Developing_with_Graphics#A_fadi
ng_example .

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Marc · 2007-05-22 09:47

What data do you mean ?

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wile64 · 2007-05-22 10:00

it seems to me:
an image is to charge by the SetHandles procedure in FHandle

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Marc · 2007-05-22 16:17

the Handle of a TBitmap is only a "utility" for the LCL to communicate
with the Widgetset. For normal usage you don't need to worry about it
(like every other handle)
If you want to draw something, create a TBitmap, set its Width/Height
and start drawing using a canvas.
If you want to load an image, use LoadFrom... functions.
If you want a TBitmap to display on a form, put a TImage on a form,
and assign its picture property.
If you want the RawImagedata, use a TLazIntfImage.GetRawImage

This is why I ask what you want to do with the handle.

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wile64 · 2007-06-15 19:16

Thank Marc,

In me classes :

TFPReaderPCX = class (TFPCustomImageReader)

procedure InternalRead  (Stream:TStream; Img:TFPCustomImage);
override;

Or go my image after on load in Img ?

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Marc · 2007-06-18 08:32

the imagereaders are used by FPImage (or LazIntfImage). For each
pixel, FPImage.Setpixel is called. LazIntfImage writes those to
memory, which you can retrieve/access using a rawimage.
This is internally used by bitmap to load some graphic formats.

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wile64 · 2007-06-18 10:06

Hello Marc,

I have to create units of loading of file image pass from there by
from TFPCustomImageReader and TFPCustomImagewriter.

My question is to know if I can charge of the images more directly ?

One can like Delphi with scanline and of being able to reach it for
the modifiers.

It also seems to to me that the pallets are not to support ?

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felipemdc · 2007-06-18 11:58

Quote from: "wile64"My question is to know if I can charge of the
images more directly ?

The support for this is only partial. You can use TLazIntfImage as
already said.

Or, use another graphics component, such as:

http://wiki.lazarus.freepascal.org/LazRGBGraphics

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wile64 · 2007-06-20 15:29

Thanks Sekel,

I already saw component it LazRGBGraphics but I do not believe that it
functions on all the platform.

And I prefer to await Graphics32 ! :lol: