pjs/modules/libimg/public_com/il_utilp.h

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C

/* -*- Mode: C; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 2 -*-
*
* The contents of this file are subject to the Netscape Public License
* Version 1.0 (the "NPL"); you may not use this file except in
* compliance with the NPL. You may obtain a copy of the NPL at
* http://www.mozilla.org/NPL/
*
* Software distributed under the NPL is distributed on an "AS IS" basis,
* WITHOUT WARRANTY OF ANY KIND, either express or implied. See the NPL
* for the specific language governing rights and limitations under the
* NPL.
*
* The Initial Developer of this code under the NPL is Netscape
* Communications Corporation. Portions created by Netscape are
* Copyright (C) 1998 Netscape Communications Corporation. All Rights
* Reserved.
*/
/* -*- Mode: C; tab-width: 4 -*-
* il_utilp.h Colormap and colorspace utilities - types and definitions
* private to Image Library.
*
* $Id: il_utilp.h,v 1.2 1999-04-19 22:42:56 pnunn%netscape.com Exp $
*/
/************************* Colormap utilities ********************************/
/* Parameters for building a color cube and its associated lookup table. */
#define LOOKUP_TABLE_SIZE 32768
#define LOOKUP_TABLE_RED 32
#define LOOKUP_TABLE_GREEN 32
#define LOOKUP_TABLE_BLUE 32
#define CUBE_MAX_SIZE 256
/* Macro to convert 8-bit/channel RGB data into an 8-bit colormap index. */
#define COLORMAP_INDEX(lookup_table, red, green, blue) \
lookup_table[LOOKUP_TABLE_INDEX(red, green, blue)]
/* Macro to convert 8-bit/channel RGB data into a 16-bit lookup table index.
The lookup table value is the index to the colormap. */
#define LOOKUP_TABLE_INDEX(red, green, blue) \
((USE_5_BITS(red) << 10) | \
(USE_5_BITS(green) << 5) | \
USE_5_BITS(blue))
/* Take the 5 most significant bits of an 8-bit value. */
#define USE_5_BITS(x) ((x) >> 3)
/* Scaling macro for creating color cubes. */
#define CUBE_SCALE(val, double_new_size_minus1, old_size_minus1, \
double_old_size_minus1) \
((val) * (double_new_size_minus1) + (old_size_minus1)) / \
(double_old_size_minus1)
/************************** Colorspace utilities *****************************/
/* Image Library private part of an IL_ColorSpace structure. */
typedef struct il_ColorSpaceData {
/* RGB24 to RGBN depth conversion maps. Each of these maps take an
8-bit input for a color channel and converts it into that channel's
contribution to a depth N pixmap e.g. for a 24 to 16-bit color
conversion, the output pixel is given by
uint8 red, green, blue;
uint16 output_pixel;
output_pixel = r8torgbn[red] + g8torgbn[green] + b8torgbn[blue];
Depth conversion maps are created for the following destination image
pixmap depths: N = 8, 16 and 32. The type of the array elements is a
uintN. */
void *r8torgbn;
void *g8torgbn;
void *b8torgbn;
} il_ColorSpaceData;