>When you use the Windows GDI font engine, you don't have to specify the
>location of the font - that is done for you in the font engine.
> Also you specify the font name like windows programs do, you don't specify
> the font filename.
Thank you the information
I finally partially figured out the red / blue color problem.
After single stepping through tons of the aggpas code for hours (it's quite
complicated even to draw a line) with a sample program that just made a red
line at the top, I discovered that it's actually doing everything exactly
correct! The problem is not with rendering with rgb565, the problem is
something in the original that was patched with the setcolor function:
Line 122 of agg_color pas has:
constructor rgba8.Construct;
begin
b{*}:=int8u(r_ );
g:=int8u(g_ );
r:=int8u(b_ );
a:=int8u(a_ );
end;
This switches red and blue... if I correct it to:
constructor rgba8.Construct;
begin
b{*}:=int8u(b_ );
g:=int8u(g_ );
r:=int8u(r_ );
a:=int8u(a_ );
end;
now my colors with rgb565 are correct. Since this is no logical reason to
make b:=R_ and r:=B_ it seems more likely that with the rgba format somewhere
along the way someone got lazy and just switched red and blue instead of fixing
the pixelformat.
It became obvious that the original was the thing that was backwards, not the
RGB565 patch because I kept stepping through things like:
constructor aggclr.Construct(rgba : rgba8 );
begin
v:=(rgba.r * 77 + rgba.g * 150 + rgba.b * 29 ) shr 8;
r:=rgba.r;
g:=rgba.g;
b:=rgba.b;
a:=rgba.a;
end;
When I evaluated the variables
R=0
G=0
B=255
A=255
But I defined a RED line, not a blue one.
I used
agg^.lineColor($FF, 0, 0, 255);
and according to:
procedure Agg2D.lineColor(r ,g ,b : unsigned; a : unsigned = 255 );
var
clr : Color;
begin
clr.Construct(r ,g ,b ,a );
lineColor (clr );
end;
This should be red.
Every other function or procedure I came across with elements for red, green
and blue kept coming up like this, so technically are incorrect. Where the
inconsistency come from to fix it properly. For now I just made a compiler
directive {$DEFINE AGG2D_USE_RGB565 } and use it to fix things in both agg_2D
and agg_color.
I've committed these to a custom branch on my github fork of fpGUI at:
https://github.com/Zaaphod/fpGUI/tree/Zaaphod_Custom
I looked at the file history in fpGUI and it looks like red and blue have been
reversed like this since the initial import of aggpas into fpGUI, when I look
at the original example agg2dconsole.dpr, it has in it:
c.red := getBufItemAsWord(2);
c.green := getBufItemAsWord(1);
c.blue := getBufItemAsWord(0);
c.alpha := getBufItemAsWord(3);
but it should have been
c.red := getBufItemAsWord(0);
c.green := getBufItemAsWord(1);
c.blue := getBufItemAsWord(2);
c.alpha := getBufItemAsWord(3);
and would have been if constructor rgba8.Construct; was correct... instead it
was just re-reversed to compensate for the error in agg_color.pas. My point
here is that it may be too late to just correct it now, because then everyone
who has programs that already 'fix' the problem will then all be wrong, so I'm
not sure what the best way to fix this is.
James
-----Original Message-----
From: fpc-pascal [mailto:[email protected]] On Behalf Of
Graeme Geldenhuys
Sent: Sunday, June 18, 2017 12:32 PM
To: [email protected]
Subject: Re: [fpc-pascal] Implementing AggPas with PtcGraph
On 2017-06-16 18:49, James Richters wrote:
> agg^.Font('C:\Windows\Fonts\ConsolaB.ttf' ,45 ) works fine, but as I
> mentioned I can't be sure windows is installed in C:\Windows
When you use the Windows GDI font engine, you don't have to specify the
location of the font - that is done for you in the font engine. Also you
specify the font name like windows programs do, you don't specify the font
filename.
For example:
agg^.LineWidth(1);
agg^.Font('Consola' ,45, True); // Bold
agg^.Text(300 ,100 ,'Consola font here.' );
agg^.Font('Courier New' ,45, False, True ); // Italics
agg^.Text(300 ,150 ,'Courier New font here.' );
Regards,
Graeme
--
fpGUI Toolkit - a cross-platform GUI toolkit using Free Pascal
http://fpgui.sourceforge.net/
My public PGP key: http://tinyurl.com/graeme-pgp
_______________________________________________
fpc-pascal maillist - [email protected]
http://lists.freepascal.org/cgi-bin/mailman/listinfo/fpc-pascal
_______________________________________________
fpc-pascal maillist - [email protected]
http://lists.freepascal.org/cgi-bin/mailman/listinfo/fpc-pascal
