Interested to Buy Any Domain ? << Click Here >> for more details...
Answer Posted / editcdc
Found this write-up online:
n general terms, the algorithm goes like this:
1.
We adjust the form to the dimensions of the BMP file.
This is simple. For the purpose, the following two lines
will do it:
// Ajustar el área / to Ajust the area
ClientWidth := Image1.Width;
ClientHeight:= Image1.Height;
2.
We read the first pixel of the form and take it as
"transparent".
3.
We search for the first "non-transparent" pixel and
from this point we generate a polygon with the silhouette of
the "non-transparent" part (see GenRegion in the file
ffigura.pas).
4.
We get rid of the title bar (if it's still bothering
us). To do it:
BorderStyle := bsNone; // Titulo estorba / no Title
5.
We change the shape of the form according to the
polygon. To do it we make use of the CreatePolygonRgn and
SetWindowRgn API functions (see ActiveSkin in ffigura.pas).
Unlike the example of the first part of this article, in
this one we don't define an elliptical (circular) region.
6.
We set from the TImage the necessary events for
dragging the form like we did in the example of the first
article.
Except for the third step, nothing seems too difficult. To
generate the polygonal region we just look for the frontier
of the figure, then we advance thru all the outline of the
figure until we reach the starting point (or run out of
memory, in this case 1024 points). This series of points
define a polygon used to generate a region with the function
CreatePolygonRgn. Then we use SetWindowRgn y we get the form
with the given shape. It works but it has limitations: our
figure must have only one frontier, therefore it can't be a
figure with a hole in the middle (in any case the algorithm
will ignore the hole in the middle).
| Is This Answer Correct ? | 0 Yes | 0 No |
Post New Answer View All Answers
How to Trap scrolling messages for the ScrollBars of a TScrollBox ?
How to Determine if a combobox is in dropped state?
'Translate error, value out of bounds' error what does these errors mean?
How to use Access97 drivers with BDE 4.51 ?
How to Use the WinApi GetObject to get a bitmap?
what are the Differences between Create(Self) and Create(Application)?
How to Use Visual Basic arrays in Delphi ?
How to Add accelerator characters to TTabsheets?
How to Display a 24 bit True Color bitmap image on a 256 color display?
How to create Data Link File with Windows 2000?
How to prevent closing of an undocked ToolBar?
How to Use Variables & For Loops in Delphi?
Define PRIMARYLANGID(), SUBLANGID(), and MAKELANGID() macros?
How to Simulate a mouse move in code?
How to Print a TStringGrid / TDBGrid?
