grafX2/src/colorred.h
Adrien Destugues 32ec828835 Group all copyright statements in a single file.
This gives a much clearer overview of the licensing.

It also shows there are some problems:
- Some files are under GPLv3 only
- Some files have no known license at all.
2020-12-19 21:56:33 +00:00

83 lines
2.2 KiB
C

/* vim:expandtab:ts=2 sw=2:
*/
/* Grafx2 - The Ultimate 256-color bitmap paint program
Copyright owned by various GrafX2 authors, see COPYRIGHT.txt for details.
Grafx2 is free software; you can redistribute it and/or
modify it under the terms of the GNU General Public License
as published by the Free Software Foundation; version 2
of the License.
Grafx2 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. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with Grafx2; if not, see <http://www.gnu.org/licenses/>
*/
#include "struct.h"
/**
* @file colorred.h
* 24bit RGB to 8bit indexed functions
*
* Octree for mapping RGB to color. A bit slower than a plain conversion table in theory,
but :
* Faster than running a search in the palette
* Takes less memory than the huge conversion table
* No loss of precision
*/
#ifndef __COLORRED_H
#define __COLORRED_H
/**
* Color Tree node
*/
typedef struct CT_Node_s
{
// min
byte Rmin;
byte Gmin;
byte Bmin;
// max
byte Rmax;
byte Gmax;
byte Bmax;
// possible optimization: a cluster has either two childs or a color index.
// if the first child is NULL, then the other can be used to store the index
// when the tree is being built, a node may have child0 set and not child1, but not the reverse)
// possible optimization: there can't be more than 511 clusters in the tree
// for a 256 color picture, so use int16 as pointers and store everything in a table :
// * makes them smaller
// * helps with cache locality
// Child nodes :
// Either two indices in the colorTree array, or
// 0 and a palette index
// 0 is not a valid array index, because no node points to the root !
word children[2];
} CT_Node;
/**
* Color Tree
*/
typedef struct ColorTree_S {
short nodecount;
CT_Node nodes[511];
} CT_Tree;
CT_Tree* CT_new();
void CT_delete(CT_Tree* t);
byte CT_get(CT_Tree* t,byte r,byte g,byte b);
void CT_set(CT_Tree* colorTree, byte Rmin, byte Gmin, byte Bmin,
byte Rmax, byte Gmax, byte Bmax, byte index);
#endif