fpc/fcl/image/fpcolhash.pas
2005-09-25 12:35:11 +00:00

412 lines
12 KiB
ObjectPascal

{*****************************************************************************}
{
This file is part of the Free Pascal's "Free Components Library".
Copyright (c) 2005 by Giulio Bernardi
This file contains a color hash table.
See the file COPYING.FPC, included in this distribution,
for details about the copyright.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
}
{*****************************************************************************}
{$mode objfpc}{$h+}
unit FPColHash;
interface
uses sysutils, classes, fpimage;
type TFPColorHashException = class(Exception);
type
PColHashSubNode = ^TColHashSubNode;
TColHashSubNode = packed record
index : byte;
data : pointer;
next : PColHashSubNode;
end;
type
PColHashMainNode = ^TColHashMainNode;
TColHashMainNode = packed record
childs : array[0..16] of pointer; { can be either another MainNode or a SubNode }
end;
{
HashMap configuration:
childs[MSN(A)] level 0
|_childs[LSN(A)] level 1
|_childs[LSN(R)] level 2
|_childs[LSN(G)] level 3
|_childs[LSN(B)] level 4
|_childs[(MSN(R) MSN(G) MSN (B)) div 256] level 5
|_element [(MSN(R) MSN(G) MSN (B)) mod 256]
Very low accesses to reach an element, not much memory occupation if alpha is rarely used, event with
images with 500.000 colors.
For extremely colorful images (near 2^24 colors used) using only 5 bits per channel keeps the map
small and efficient
}
type
TFPPackedColor = record
R, G, B, A : byte;
end;
type
TFPColorWeight = record
Col : TFPPackedColor;
Num : integer;
end;
PFPColorWeight = ^TFPColorWeight;
TFPColorWeightArray = array of PFPColorWeight;
type
TFPColorHashTable = class
private
Root : PColHashMainNode;
AllIntegers : boolean;
procedure FreeAllData;
FCount : longword;
function AllocateMainNode : PColHashMainNode;
function AllocateSubNode : PColHashSubNode;
procedure DeallocateLinkedList(node : PColHashSubNode);
procedure DeallocateMainNode(node : PColHashMainNode; level : byte);
procedure CalculateIndexes(Col : TFPPackedColor; var ahi, alo, ri, gi, bi, partial, sub : byte);
function CalculateColor(const ahi, alo, ri, gi, bi, partial, sub : byte) : TFPPackedColor;
function SearchSubNode(start : PColHashSubNode; const index : byte ) : PColHashSubNode;
function SearchSubNodeAllocate(var start : PColHashSubNode; const index : byte ) : PColHashSubNode;
function Search(const Col : TFPPackedColor) : PColHashSubNode;
function SearchAllocate(const Col : TFPPackedColor) : PColHashSubNode;
protected
public
procedure Insert(const Col : TFPColor; const Value : integer);
procedure Insert(const Col : TFPColor; const Value : pointer);
procedure Add(const Col : TFPColor; const Value : integer);
function Get(const Col : TFPColor) : pointer;
procedure Clear;
function GetArray : TFPColorWeightArray;
property Count : longword read FCount;
constructor Create;
destructor Destroy; override;
end;
function FPColor2Packed(Col : TFPColor) : TFPPackedColor;
function Packed2FPColor(Col : TFPPackedColor) : TFPColor;
implementation
function FPColor2Packed(Col : TFPColor) : TFPPackedColor;
begin
Result.R:=(Col.Red and $FF00) shr 8;
Result.G:=(Col.Green and $FF00) shr 8;
Result.B:=(Col.Blue and $FF00) shr 8;
Result.A:=(Col.Alpha and $FF00) shr 8;
end;
function Packed2FPColor(Col : TFPPackedColor) : TFPColor;
begin
Result.Red:=(Col.R shl 8) + Col.R;
Result.Green:=(Col.G shl 8) + Col.G;
Result.Blue:=(Col.B shl 8) + Col.B;
Result.Alpha:=(Col.A shl 8) + Col.A;
end;
constructor TFPColorHashTable.Create;
begin
Fcount:=0;
AllIntegers:=true;
Root:=nil;
end;
destructor TFPColorHashTable.Destroy;
begin
FreeAllData;
inherited Destroy;
end;
procedure TFPColorHashTable.CalculateIndexes(Col : TFPPackedColor; var ahi, alo, ri, gi, bi, partial, sub : byte);
var tmp : longword;
begin
ahi := (Col.A and $F0) shr 4;
alo := (Col.A and $F);
ri := (Col.R and $F);
gi := (Col.G and $F);
bi := (Col.B and $F);
tmp:=((Col.R and $F0) shl 4) or (Col.G and $F0) or ((Col.B and $F0) shr 4);
partial:=tmp div 256;
sub:=tmp mod 256;
end;
function TFPColorHashTable.CalculateColor(const ahi, alo, ri, gi, bi, partial, sub : byte) : TFPPackedColor;
var tmp : longword;
col : TFPPackedColor;
begin
tmp:=(partial shl 8) + sub; //partial*256 + sub;
col.A:=(ahi shl 4) or alo;
col.R:=((tmp and $F00) shr 4) + ri;
col.G:=(tmp and $0F0) + gi;
col.B:=((tmp and $00F) shl 4) + bi;
Result:=col;
end;
procedure TFPColorHashTable.FreeAllData;
begin
DeallocateMainNode(Root,0);
Root:=nil;
FCount:=0;
AllIntegers:=true;
end;
function TFPColorHashTable.AllocateMainNode : PColHashMainNode;
var tmp : PColHashMainNode;
i : byte;
begin
Result:=nil;
tmp:=getmem(sizeof(TColHashMainNode));
if tmp=nil then raise TFPColorHashException.Create('Out of memory');
for i:=0 to high(tmp^.childs) do
tmp^.childs[i]:=nil;
Result:=tmp;
end;
function TFPColorHashTable.AllocateSubNode : PColHashSubNode;
var tmp : PColHashSubNode;
begin
Result:=nil;
tmp:=getmem(sizeof(TColHashSubNode));
if tmp=nil then raise TFPColorHashException.Create('Out of memory');
tmp^.index:=0;
tmp^.data:=nil;
tmp^.next:=nil;
inc(FCount);
Result:=tmp;
end;
procedure TFPColorHashTable.DeallocateLinkedList(node : PColHashSubNode);
var tmp : PColHashSubNode;
begin
while (node<>nil) do
begin
tmp:=node^.next;
if node^.data<>nil then
FreeMem(node^.data);
FreeMem(node);
node:=tmp;
end;
end;
procedure TFPColorHashTable.DeallocateMainNode(node : PColHashMainNode; level : byte);
var i : byte;
begin
if node=nil then exit;
if level=5 then
begin
for i:=0 to high(node^.childs) do
DeallocateLinkedList(node^.childs[i]);
end
else
for i:=0 to high(node^.childs) do
DeallocateMainNode(node^.childs[i],level+1);
FreeMem(node);
end;
function TFPColorHashTable.SearchSubNode(start : PColHashSubNode; const index : byte ) : PColHashSubNode;
var cur : PColHashSubNode;
begin
Result:=nil;
cur:=start;
while cur<>nil do
begin
if cur^.index=index then break
else if cur^.index>index then exit; { exit and returns nil}
cur:=cur^.next;
end;
Result:=cur;
end;
function TFPColorHashTable.SearchSubNodeAllocate(var start : PColHashSubNode; const index : byte ) : PColHashSubNode;
var tmp, cur, prev : PColHashSubNode;
begin
Result:=nil;
prev:=nil;
cur:=start;
while cur<>nil do
begin
if cur^.index=index then break
else if cur^.index>index then {whoops, we must insert the new node before this one}
begin
tmp:=AllocateSubNode;
tmp^.index:=index;
tmp^.next:=cur;
if prev<>nil then prev^.next:=tmp
else start:=tmp;
cur:=tmp;
break;
end;
prev:=cur;
cur:=cur^.next;
end;
if cur=nil then { not found! append to the end }
begin
cur:=AllocateSubNode;
cur^.index:=index;
prev^.next:=cur { start is always <> nil}
end;
Result:=cur;
end;
function TFPColorHashTable.Search(const Col : TFPPackedColor) : PColHashSubNode;
var ahi, alo, ri, gi, bi, partial, sub : byte;
tmpmain : PColHashMainNode;
begin
Result:=nil;
CalculateIndexes(Col, ahi, alo, ri, gi, bi, partial, sub);
if Root=nil then exit;
if Root^.childs[ahi]=nil then exit;
tmpmain:=Root^.childs[ahi];
if tmpmain^.childs[alo]=nil then exit;
tmpmain:=tmpmain^.childs[alo];
if tmpmain^.childs[ri]=nil then exit;
tmpmain:=tmpmain^.childs[ri];
if tmpmain^.childs[gi]=nil then exit;
tmpmain:=tmpmain^.childs[gi];
if tmpmain^.childs[bi]=nil then exit;
tmpmain:=tmpmain^.childs[bi];
if tmpmain^.childs[partial]=nil then exit;
Result:=SearchSubNode(tmpmain^.childs[partial],sub);
end;
{ get the node; if there isn't, build the part of the tree }
function TFPColorHashTable.SearchAllocate(const Col : TFPPackedColor) : PColHashSubNode;
var ahi, alo, ri, gi, bi, partial, sub : byte;
tmpmain : PColHashMainNode;
begin
Result:=nil;
CalculateIndexes(Col, ahi, alo, ri, gi, bi, partial, sub);
if Root=nil then Root:=AllocateMainNode;
if Root^.childs[ahi]=nil then Root^.childs[ahi]:=AllocateMainNode;
tmpmain:=Root^.childs[ahi];
if tmpmain^.childs[alo]=nil then tmpmain^.childs[alo]:=AllocateMainNode;
tmpmain:=tmpmain^.childs[alo];
if tmpmain^.childs[ri]=nil then tmpmain^.childs[ri]:=AllocateMainNode;
tmpmain:=tmpmain^.childs[ri];
if tmpmain^.childs[gi]=nil then tmpmain^.childs[gi]:=AllocateMainNode;
tmpmain:=tmpmain^.childs[gi];
if tmpmain^.childs[bi]=nil then tmpmain^.childs[bi]:=AllocateMainNode;
tmpmain:=tmpmain^.childs[bi];
if tmpmain^.childs[partial]=nil then { newly-created linked list. }
begin
tmpmain^.childs[partial]:=AllocateSubNode;
Result:=tmpmain^.childs[partial];
Result^.index:=sub;
exit;
end;
Result:=SearchSubNodeAllocate(tmpmain^.childs[partial],sub)
end;
procedure TFPColorHashTable.Insert(const Col : TFPColor; const Value : integer);
var node : PColHashSubNode;
begin
node:=SearchAllocate(FPColor2Packed(col));
node^.data:=getmem(sizeof(Value));
integer(node^.data^):=value;
end;
procedure TFPColorHashTable.Insert(const Col : TFPColor; const Value : pointer);
var node : PColHashSubNode;
begin
node:=SearchAllocate(FPColor2Packed(col));
node^.data:=Value;
AllIntegers:=false;
end;
procedure TFPColorHashTable.Add(const Col : TFPColor; const Value : integer);
var node : PColHashSubNode;
begin
node:=SearchAllocate(FPColor2Packed(col));
if node^.data=nil then
begin
node^.data:=getmem(sizeof(Value));
integer(node^.data^):=0;
end;
inc(integer(node^.data^),value);
end;
function TFPColorHashTable.Get(const Col : TFPColor) : pointer;
var node : PColHashSubNode;
begin
node:=Search(FPColor2Packed(col));
if node<>nil then
Result:=node^.data
else
Result:=nil;
end;
procedure TFPColorHashTable.Clear;
begin
FreeAllData;
end;
function TFPColorHashTable.GetArray : TFPColorWeightArray;
var ahi, alo, ri, gi, bi, partial : byte;
node : PColHashSubNode;
i : longword;
cw : PFPColorWeight;
tmp1,tmp2,tmp3,tmp4,tmp5 : PColHashMainNode;
begin
if not AllIntegers then
raise TFPColorHashException.Create('Hashtable data is not made by integers.');
SetLength(Result,FCount);
if Root=nil then exit;
i:=0;
for ahi:=0 to 15 do
begin
if Root^.childs[ahi]=nil then continue;
tmp1:=Root^.childs[ahi];
for alo:=0 to 15 do
begin
if tmp1^.childs[alo]=nil then continue;
tmp2:=tmp1^.childs[alo];
for ri:=0 to 15 do
begin
if tmp2^.childs[ri]=nil then continue;
tmp3:=tmp2^.childs[ri];
for gi:=0 to 15 do
begin
if tmp3^.childs[gi]=nil then continue;
tmp4:=tmp3^.childs[gi];
for bi:=0 to 15 do
begin
if tmp4^.childs[bi]=nil then continue;
tmp5:=tmp4^.childs[bi];
for partial:=0 to 15 do
begin
node:=tmp5^.childs[partial];
while (node<>nil) do
begin
getmem(cw,sizeof(TFPColorWeight));
if cw=nil then
raise TFPColorHashException.Create('Out of memory');
cw^.Col:=CalculateColor(ahi,alo,ri,gi,bi,partial,node^.index);
cw^.Num:=integer(node^.data^);
Result[i]:=cw;
inc(i);
node:=node^.next;
end;
end;
end;
end;
end;
end;
end;
end;
end.