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| author | Graeme Geldenhuys <graeme@mastermaths.co.za> | 2012-02-27 19:53:35 +0200 |
|---|---|---|
| committer | Graeme Geldenhuys <graeme@mastermaths.co.za> | 2012-03-07 22:44:08 +0200 |
| commit | b50c7fe536960a49349475f5c361044b097f24dc (patch) | |
| tree | eb74f0624ebaca3b6ee64a08b3edb63883eb06c2 /src/corelib/render/software/ctrl/agg_gamma_spline.pas | |
| parent | a955b0e4833ba419478be83523fe433d645cd789 (diff) | |
| download | fpGUI-b50c7fe536960a49349475f5c361044b097f24dc.tar.xz | |
initial import of AggPas 2.4 RM3
The AggPas demos will not compile at this time, because I have restructured
the directories a bit. I wanted a pristine checkin though. The demos will be
fixed in the next few commits.
Diffstat (limited to 'src/corelib/render/software/ctrl/agg_gamma_spline.pas')
| -rw-r--r-- | src/corelib/render/software/ctrl/agg_gamma_spline.pas | 265 |
1 files changed, 265 insertions, 0 deletions
diff --git a/src/corelib/render/software/ctrl/agg_gamma_spline.pas b/src/corelib/render/software/ctrl/agg_gamma_spline.pas new file mode 100644 index 00000000..7be50692 --- /dev/null +++ b/src/corelib/render/software/ctrl/agg_gamma_spline.pas @@ -0,0 +1,265 @@ +//----------------------------------------------------------------------------
+// Anti-Grain Geometry - Version 2.4 (Public License)
+// Copyright (C) 2002-2005 Maxim Shemanarev (http://www.antigrain.com)
+//
+// Anti-Grain Geometry - Version 2.4 Release Milano 3 (AggPas 2.4 RM3)
+// Pascal Port By: Milan Marusinec alias Milano
+// milan@marusinec.sk
+// http://www.aggpas.org
+// Copyright (c) 2005-2006
+//
+// Permission to copy, use, modify, sell and distribute this software
+// is granted provided this copyright notice appears in all copies.
+// This software is provided "as is" without express or implied
+// warranty, and with no claim as to its suitability for any purpose.
+//
+//----------------------------------------------------------------------------
+// Contact: mcseem@antigrain.com
+// mcseemagg@yahoo.com
+// http://www.antigrain.com
+//
+// [Pascal Port History] -----------------------------------------------------
+//
+// 30.01.2006-Milano: Unit port establishment
+//
+{ agg_gamma_spline.pas }
+unit
+ agg_gamma_spline ;
+
+INTERFACE
+
+{$I agg_mode.inc }
+
+uses
+ agg_basics ,
+ agg_bspline ,
+ agg_vertex_source ;
+
+{ TYPES DEFINITION }
+type
+// Class-helper for calculation gamma-correction arrays. A gamma-correction
+// array is an array of 256 unsigned chars that determine the actual values
+// of Anti-Aliasing for each pixel coverage value from 0 to 255. If all the
+// values in the array are equal to its index, i.e. 0,1,2,3,... there's
+// no gamma-correction. Class agg::polyfill allows you to use custom
+// gamma-correction arrays. You can calculate it using any approach, and
+// class gamma_spline allows you to calculate almost any reasonable shape
+// of the gamma-curve with using only 4 values - kx1, ky1, kx2, ky2.
+//
+// kx2
+// +----------------------------------+
+// | | | . |
+// | | | . | ky2
+// | | . ------|
+// | | . |
+// | | . |
+// |----------------.|----------------|
+// | . | |
+// | . | |
+// |-------. | |
+// ky1 | . | | |
+// | . | | |
+// +----------------------------------+
+// kx1
+//
+// Each value can be in range [0...2]. Value 1.0 means one quarter of the
+// bounding rectangle. Function values() calculates the curve by these
+// 4 values. After calling it one can get the gamma-array with call gamma().
+// Class also supports the vertex source interface, i.e rewind() and
+// vertex(). It's made for convinience and used in class gamma_ctrl.
+// Before calling rewind/vertex one must set the bounding box
+// box() using pixel coordinates.
+ gamma_spline = object(vertex_source )
+ m_gamma : array[0..255 ] of char;
+
+ m_x ,
+ m_y : array[0..3 ] of double;
+ m_x1 ,
+ m_y1 ,
+ m_x2 ,
+ m_y2 ,
+
+ m_cur_x : double;
+ m_spline : bspline;
+
+ constructor Construct;
+ destructor Destruct; virtual;
+
+ procedure values(kx1 ,ky1 ,kx2 ,ky2 : double ); overload;
+ procedure values(kx1 ,ky1 ,kx2 ,ky2 : double_ptr ); overload;
+
+ function gamma : char_ptr;
+ function _y (x : double ) : double;
+ procedure box(x1 ,y1 ,x2 ,y2 : double );
+
+ procedure rewind(path_id : unsigned ); virtual;
+ function vertex(x ,y : double_ptr ) : unsigned; virtual;
+
+ end;
+
+{ GLOBAL PROCEDURES }
+
+
+IMPLEMENTATION
+{ LOCAL VARIABLES & CONSTANTS }
+{ UNIT IMPLEMENTATION }
+{ CONSTRUCT }
+constructor gamma_spline.Construct;
+begin
+ m_spline.Construct;
+
+ m_x1:=0;
+ m_y1:=0;
+ m_x2:=10;
+ m_y2:=10;
+
+ m_cur_x:=0.0;
+
+ values(1.0 ,1.0 ,1.0 ,1.0 );
+
+end;
+
+{ DESTRUCT }
+destructor gamma_spline.Destruct;
+begin
+ m_spline.Destruct;
+
+end;
+
+{ VALUES }
+procedure gamma_spline.values(kx1 ,ky1 ,kx2 ,ky2 : double );
+var
+ i : int;
+
+begin
+ if kx1 < 0.001 then
+ kx1:=0.001;
+
+ if kx1 > 1.999 then
+ kx1:=1.999;
+
+ if ky1 < 0.001 then
+ ky1:=0.001;
+
+ if ky1 > 1.999 then
+ ky1:=1.999;
+
+ if kx2 < 0.001 then
+ kx2:=0.001;
+
+ if kx2 > 1.999 then
+ kx2:=1.999;
+
+ if ky2 < 0.001 then
+ ky2:=0.001;
+
+ if ky2 > 1.999 then
+ ky2:=1.999;
+
+ m_x[0 ]:=0.0;
+ m_y[0 ]:=0.0;
+ m_x[1 ]:=kx1 * 0.25;
+ m_y[1 ]:=ky1 * 0.25;
+ m_x[2 ]:=1.0 - kx2 * 0.25;
+ m_y[2 ]:=1.0 - ky2 * 0.25;
+ m_x[3 ]:=1.0;
+ m_y[3 ]:=1.0;
+
+ m_spline.init(4 ,@m_x ,@m_y );
+
+ for i:=0 to 255 do
+ m_gamma[i ]:=char(trunc(_y(i / 255.0 ) * 255.0 ) );
+
+end;
+
+{ VALUES }
+procedure gamma_spline.values(kx1 ,ky1 ,kx2 ,ky2 : double_ptr );
+begin
+ kx1^:=m_x[1 ] * 4.0;
+ ky1^:=m_y[1 ] * 4.0;
+ kx2^:=(1.0 - m_x[2 ] ) * 4.0;
+ ky2^:=(1.0 - m_y[2 ] ) * 4.0;
+
+end;
+
+{ GAMMA }
+function gamma_spline.gamma;
+begin
+ result:=@m_gamma[0 ];
+
+end;
+
+{ _Y }
+function gamma_spline._y;
+var
+ val : double;
+
+begin
+ if x < 0.0 then
+ x:=0.0;
+
+ if x > 1.0 then
+ x:=1.0;
+
+ val:=m_spline.get(x );
+
+ if val < 0.0 then
+ val:=0.0;
+
+ if val > 1.0 then
+ val:=1.0;
+
+ result:=val;
+
+end;
+
+{ BOX }
+procedure gamma_spline.box;
+begin
+ m_x1:=x1;
+ m_y1:=y1;
+ m_x2:=x2;
+ m_y2:=y2;
+
+end;
+
+{ REWIND }
+procedure gamma_spline.rewind;
+begin
+ m_cur_x:=0.0;
+
+end;
+
+{ VERTEX }
+function gamma_spline.vertex;
+begin
+ if m_cur_x = 0.0 then
+ begin
+ x^:=m_x1;
+ y^:=m_y1;
+
+ m_cur_x:=m_cur_x + (1.0 / (m_x2 - m_x1 ) );
+ result :=path_cmd_move_to;
+
+ exit;
+
+ end;
+
+ if m_cur_x > 1.0 then
+ begin
+ result:=path_cmd_stop;
+
+ exit;
+
+ end;
+
+ x^:=m_x1 + m_cur_x * (m_x2 - m_x1 );
+ y^:=m_y1 + _y(m_cur_x ) * (m_y2 - m_y1 );
+
+ m_cur_x:=m_cur_x + (1.0 / (m_x2 - m_x1 ) );
+ result :=path_cmd_line_to;
+
+end;
+
+END.
+
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