Pictures in an Internal Database

[Alfred]

Hi,

I would like to include pictures into an internal database like (Name, FirstName, Picture etc.). How can I insert pictures into such a database

Thanks for your reply

[Thomas Linder Puls]

What do you mean by "picture"?

[Alfred]

That means a visual representation of a person. See as follows:

class facts - db_pic
db_pic : (string Name,string FirstName, picture Picture).

predicates
onPaint : drawWindow::paintResponder.

clauses
onPaint(_Source, Rectangle, GDI):-
retractAll(db_pic(_,_,_)),
FileName="Hydrangeas1.bmp",
Pic=vpi::pictLoad(fileName(FileName),100,100,0x0020),
file::delete("db_pic.bmp"),
assert(db_pic("Meier","Tom",Pic)),
file::save("db_pic.bmp",db_pic),
GDI:pictDraw(Pic, pnt(250,10), rop_SrcCopy),
W= pictOpen(Rectangle),
Pic= pictClose(W),
retractAll(db_pic(_,_,_)),!.

onPaint(_Source, _Rectangle, _GDI).

Picture appears into the dialog; but it seems to be, that the picture is not included into the database as mentioned. When database is reloaded, there is no picture at all.

[Thomas Linder Puls]

OK, so the problem is saving and loading the vpiDomains::picture.

However a vpiDomains::picture is actually a pointer to "something":

Code: Select all

domains
    picture = pointer.
    % @short Handle to a picture.
    % @end

If you save a pointer and load it again "another day" it will point to something different (or nothing at all).

You can however obtain a binary that represents the image, and that binary can be saved and loaded and reconverted into a picture (in the vpi class):

Code: Select all

predicates
    pictToBin : (vpiDomains::picture Picture) -> binary Binary language c as runtimeLinknamesVpi::pict_ToBin.
    % @short Converts the #Picture picture into the #Binary binary format.
    % @detail Binary has exactly the same format as BMP file.
    % @end
 
predicates
    pictFromBin : (binary Binary) -> vpiDomains::picture Picture language c as runtimeLinknamesVpi::pict_FromBin.
    % @short Retrieves the #Picture picture from the #Binary binary. <br>
    % @detail Binary has exactly the same format as BMP file.
    % @end

So if you let the database contain the binary-picture instead of the pointer-picture it can be saved and loaded.

(It will however use a lot of disk space)

[Alfred]

OK, so the problem is saving and loading the vpiDomains::picture.

However a vpiDomains::picture is actually a pointer to "something":

Code: Select all

domains
    picture = pointer.
    % @short Handle to a picture.
    % @end

If you save a pointer and load it again "another day" it will point to something different (or nothing at all).

You can however obtain a binary that represents the image, and that binary can be saved and loaded and reconverted into a picture (in the vpi class):

Code: Select all

predicates
    pictToBin : (vpiDomains::picture Picture) -> binary Binary language c as runtimeLinknamesVpi::pict_ToBin.
    % @short Converts the #Picture picture into the #Binary binary format.
    % @detail Binary has exactly the same format as BMP file.
    % @end
 
predicates
    pictFromBin : (binary Binary) -> vpiDomains::picture Picture language c as runtimeLinknamesVpi::pict_FromBin.
    % @short Retrieves the #Picture picture from the #Binary binary. <br>
    % @detail Binary has exactly the same format as BMP file.
    % @end

So if you let the database contain the binary-picture instead of the pointer-picture it can be saved and loaded.

(It will however use a lot of disk space)

Thanks Thomas, any other way using pictures at the least possible disk space.

Regards

[Tonton Luc]

Hi,

as you can see in the help file :

Code: Select all

binary::compress/1-> 
compress : (binary Input)
    -> binary Output 
    language c.