lazarus/components/aggpas/src/agg_span_allocator.pas
mattias 36a2b1ea07 added aggpas
git-svn-id: trunk@21942 -
2009-10-01 12:24:32 +00:00

106 lines
2.3 KiB
ObjectPascal

//----------------------------------------------------------------------------
// 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] -----------------------------------------------------
//
// 27.01.2006-Milano: Unit port establishment
//
{ agg_span_allocator.pas }
unit
agg_span_allocator ;
INTERFACE
{$I agg_mode.inc }
uses
agg_basics ,
agg_color ;
{ TYPES DEFINITION }
type
span_allocator_ptr = ^span_allocator;
span_allocator = object
m_max_span_len : unsigned;
m_span : aggclr_ptr;
constructor Construct;
destructor Destruct;
function allocate(max_span_len : unsigned ) : aggclr_ptr;
function span : aggclr_ptr;
end;
{ GLOBAL PROCEDURES }
IMPLEMENTATION
{ LOCAL VARIABLES & CONSTANTS }
{ UNIT IMPLEMENTATION }
{ CONSTRUCT }
constructor span_allocator.Construct;
begin
m_max_span_len:=0;
m_span:=NIL;
end;
{ DESTRUCT }
destructor span_allocator.Destruct;
begin
agg_freemem(pointer(m_span ) ,m_max_span_len * sizeof(aggclr ) );
end;
{ ALLOCATE }
function span_allocator.allocate;
begin
if max_span_len > m_max_span_len then
begin
agg_freemem(pointer(m_span ) ,m_max_span_len * sizeof(aggclr ) );
// To reduce the number of reallocs we align the
// span_len to 256 color elements.
// Well, I just like this number and it looks reasonable.
max_span_len:=((max_span_len + 255 ) shr 8 ) shl 8;
agg_getmem(pointer(m_span ) ,max_span_len * sizeof(aggclr ) );
m_max_span_len:=max_span_len;
end;
result:=m_span;
end;
{ SPAN }
function span_allocator.span;
begin
result:=m_span;
end;
END.