WIP on new color reduction data structures.

The 8megabytes conversion table is replaced by an octree taking 10kbytes (800 times better !)
The conversion is done with full 24bit precision instead of 19 bits (8 green, 6 red, 5 blue) previously.

Not added to makefile and integrated yet, because I need to bugfix first.


git-svn-id: svn://pulkomandy.tk/GrafX2/trunk@1873 416bcca6-2ee7-4201-b75f-2eb2f807beb1

src/colorred.c

@@ -0,0 +1,126 @@
+/* vim:expandtab:ts=2 sw=2:
+*/
+/*  Grafx2 - The Ultimate 256-color bitmap paint program
+
+    Copyright 2011 Adrien Destugues
+
+    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/>
+
+********************************************************************************
+
+    24bit RGB to 8bit indexed functions
+*/
+
+#include <stdlib.h>
+
+#include "colorred.h"
+
+/* 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
+*/
+
+CT_Node* CT_new() {return NULL;}
+
+void CT_set(CT_Node* colorTree, byte Rmin, byte Gmin, byte Bmin,
+	byte Rmax, byte Gmax, byte Bmax, byte index)
+{
+	int i;
+	CT_Node* parent = colorTree;
+	// Create and setup node
+	CT_Node* node = malloc(sizeof(CT_Node));
+	
+	node->Rmin = Rmin;
+	node->Gmin = Gmin;
+	node->Bmin = Bmin;
+	node->Rmax = Rmax;
+	node->Gmax = Gmax;
+	node->Bmax = Bmax;
+	node->index = index;
+	
+	for(i = 0; i < 7; i++)
+		node->children[i] = NULL;
+	
+	// Now insert it in tree
+	
+	if (parent == NULL) {
+		// This is our first node.
+		colorTree = node;
+	} else for(;;) {
+		// Find where to insert ourselves
+		// (clusters are non-intersecting, so there is no need to check for that)
+		int where = 0;
+		if (parent->Rmin < node->Rmin)
+			where += 4;
+		if (parent->Gmin < node->Gmin)
+			where += 2;
+		if (parent->Bmin < node->Bmin)
+			where += 1;
+			
+		// TODO - we always insert downwards, maybe we should try to keep
+		// the tree balanced...
+			
+		if (parent->children[where] == NULL)
+		{
+			// insert!	
+			parent->children[where] = node;
+			break;
+		} else {
+			// recurse
+			parent = parent->children[where];	
+		}
+	}
+}
+
+byte CT_get(CT_Node* node, byte r, byte g, byte b)
+{	
+	int wheremin = 0;
+	int wheremax = 0;
+	
+	if (node->Rmin < r)
+		wheremin += 4;
+	if (node->Gmin < g)
+		wheremin += 2;
+	if (node->Bmin < b)
+		wheremin += 1;
+		
+	if (node->Rmax < r)
+		wheremin += 4;
+	if (node->Gmax < g)
+		wheremin += 2;
+	if (node->Bmax < b)
+		wheremin += 1;
+		
+	if (wheremin == 7 && wheremax == 0)
+	{
+		// Found it!
+		return node->index;	
+	} else {
+		return CT_get(node->children[wheremin], r, g, b);	
+	}
+}
+
+void CT_delete(CT_Node* tree)
+{
+	int i;
+	if (tree == NULL)
+		return;
+	for	(i = 0; i < 8; i++)
+	{
+		CT_delete(tree->children[i]);
+	}
+	free(tree);
+}

src/colorred.h

@@ -0,0 +1,63 @@
+/* vim:expandtab:ts=2 sw=2:
+*/
+/*  Grafx2 - The Ultimate 256-color bitmap paint program
+
+    Copyright 2011 Adrien Destugues
+
+    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/>
+
+********************************************************************************
+
+    24bit RGB to 8bit indexed functions
+*/
+
+#include "struct.h"
+
+/* 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
+
+typedef struct CT_Node_s
+{
+	// min
+	byte Rmin;
+	byte Gmin;
+	byte Bmin;
+	
+	// max
+	byte Rmax;
+	byte Gmax;
+	byte Bmax;
+	
+	// palette index (valid iff any child is NULL)
+	byte index;
+	
+	// child nodes
+	struct CT_Node_s* children[8];
+	//rgb rgB rGb rGB Rgb RgB RGb RGB
+} CT_Node;
+
+CT_Node* CT_new();
+void CT_delete(CT_Node* t);
+byte CT_get(CT_Node* t,byte r,byte g,byte b);
+void CT_set(CT_Node* colorTree, byte Rmin, byte Gmin, byte Bmin,
+	byte Rmax, byte Gmax, byte Bmax, byte index);
+
+#endif