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kimageformats/src/imageformats/gimp_p.h

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#ifndef GIMP_H
#define GIMP_H
/* -*- c++ -*-
* gimp.h: Header for a Qt 3 plug-in for reading GIMP XCF image files
* Copyright (C) 2001 lignum Computing, Inc. <allen@lignumcomputing.com>
* Copyright (C) 2004 Melchior FRANZ <mfranz@kde.org>
*
* This plug-in is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* This library 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
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*
*/
typedef unsigned char uchar;
/*
* These are the constants and functions I extracted from The GIMP source
* code. If the reader fails to work, this is probably the place to start
* looking for discontinuities.
*/
// From GIMP "tile.h" v1.2
const uint TILE_WIDTH = 64; //!< Width of a tile in the XCF file.
const uint TILE_HEIGHT = 64; //!< Height of a tile in the XCF file.
// From GIMP "paint_funcs.c" v1.2
const int RANDOM_TABLE_SIZE = 4096; //!< Size of dissolve random number table.
const int RANDOM_SEED = 314159265; //!< Seed for dissolve random number table.
const double EPSILON = 0.0001; //!< Roundup in alpha blending.
// From GIMP "paint_funcs.h" v1.2
const uchar OPAQUE_OPACITY = 255; //!< Opaque value for 8-bit alpha component.
// From GIMP "apptypes.h" v1.2
//! Basic GIMP image type. QImage converter may produce a deeper image
//! than is specified here. For example, a grayscale image with an
//! alpha channel must (currently) use a 32-bit Qt image.
typedef enum {
RGB,
GRAY,
INDEXED
} GimpImageBaseType;
//! Type of individual layers in an XCF file.
typedef enum {
RGB_GIMAGE,
RGBA_GIMAGE,
GRAY_GIMAGE,
GRAYA_GIMAGE,
INDEXED_GIMAGE,
INDEXEDA_GIMAGE
} GimpImageType;
// From GIMP "libgimp/gimpenums.h" v2.4
//! Effect to apply when layers are merged together.
typedef enum {
NORMAL_MODE,
DISSOLVE_MODE,
BEHIND_MODE,
MULTIPLY_MODE,
SCREEN_MODE,
OVERLAY_MODE,
DIFFERENCE_MODE,
ADDITION_MODE,
SUBTRACT_MODE,
DARKEN_ONLY_MODE,
LIGHTEN_ONLY_MODE,
HUE_MODE,
SATURATION_MODE,
COLOR_MODE,
VALUE_MODE,
DIVIDE_MODE,
DODGE_MODE,
BURN_MODE,
HARDLIGHT_MODE,
SOFTLIGHT_MODE,
GRAIN_EXTRACT_MODE,
GRAIN_MERGE_MODE
} LayerModeEffects;
// From GIMP "xcf.c" v1.2
//! Properties which can be stored in an XCF file.
typedef enum {
PROP_END = 0,
PROP_COLORMAP = 1,
PROP_ACTIVE_LAYER = 2,
PROP_ACTIVE_CHANNEL = 3,
PROP_SELECTION = 4,
PROP_FLOATING_SELECTION = 5,
PROP_OPACITY = 6,
PROP_MODE = 7,
PROP_VISIBLE = 8,
PROP_LINKED = 9,
PROP_PRESERVE_TRANSPARENCY = 10,
PROP_APPLY_MASK = 11,
PROP_EDIT_MASK = 12,
PROP_SHOW_MASK = 13,
PROP_SHOW_MASKED = 14,
PROP_OFFSETS = 15,
PROP_COLOR = 16,
PROP_COMPRESSION = 17,
PROP_GUIDES = 18,
PROP_RESOLUTION = 19,
PROP_TATTOO = 20,
PROP_PARASITES = 21,
PROP_UNIT = 22,
PROP_PATHS = 23,
PROP_USER_UNIT = 24,
MAX_SUPPORTED_PROPTYPE // should always be at the end so its value is last + 1
} PropType;
// From GIMP "xcf.c" v1.2
//! Compression type used in layer tiles.
typedef enum {
COMPRESS_NONE = 0,
COMPRESS_RLE = 1,
COMPRESS_ZLIB = 2,
COMPRESS_FRACTAL = 3 /* Unused. */
} CompressionType;
// From GIMP "paint_funcs.c" v1.2
/*!
* Multiply two color components. Really expects the arguments to be
* 8-bit quantities.
* \param a first minuend.
* \param b second minuend.
* \return product of arguments.
*/
inline int INT_MULT(int a, int b)
{
int c = a * b + 0x80;
return ((c >> 8) + c) >> 8;
}
/*!
* Blend the two color components in the proportion alpha:
*
* result = alpha a + ( 1 - alpha ) b
*
* \param a first component.
* \param b second component.
* \param alpha blend proportion.
* \return blended color components.
*/
inline int INT_BLEND(int a, int b, int alpha)
{
return INT_MULT(a - b, alpha) + b;
}
// From GIMP "gimpcolorspace.c" v1.2
/*!
* Convert a color in RGB space to HSV space (Hue, Saturation, Value).
* \param red the red component (modified in place).
* \param green the green component (modified in place).
* \param blue the blue component (modified in place).
*/
static void RGBTOHSV(uchar &red, uchar &green, uchar &blue)
{
int r, g, b;
double h, s, v;
int min, max;
h = 0.;
r = red;
g = green;
b = blue;
if (r > g) {
max = qMax(r, b);
min = qMin(g, b);
} else {
max = qMax(g, b);
min = qMin(r, b);
}
v = max;
if (max != 0) {
s = ((max - min) * 255) / (double)max;
} else {
s = 0;
}
if (s == 0) {
h = 0;
} else {
int delta = max - min;
if (r == max) {
h = (g - b) / (double)delta;
} else if (g == max) {
h = 2 + (b - r) / (double)delta;
} else if (b == max) {
h = 4 + (r - g) / (double)delta;
}
h *= 42.5;
if (h < 0) {
h += 255;
}
if (h > 255) {
h -= 255;
}
}
red = (uchar)h;
green = (uchar)s;
blue = (uchar)v;
}
/*!
* Convert a color in HSV space to RGB space.
* \param hue the hue component (modified in place).
* \param saturation the saturation component (modified in place).
* \param value the value component (modified in place).
*/
static void HSVTORGB(uchar &hue, uchar &saturation, uchar &value)
{
if (saturation == 0) {
hue = value;
saturation = value;
//value = value;
} else {
double h = hue * 6. / 255.;
double s = saturation / 255.;
double v = value / 255.;
double f = h - (int)h;
double p = v * (1. - s);
double q = v * (1. - (s * f));
double t = v * (1. - (s * (1. - f)));
// Worth a note here that gcc 2.96 will generate different results
// depending on optimization mode on i386.
switch ((int)h) {
case 0:
hue = (uchar)(v * 255);
saturation = (uchar)(t * 255);
value = (uchar)(p * 255);
break;
case 1:
hue = (uchar)(q * 255);
saturation = (uchar)(v * 255);
value = (uchar)(p * 255);
break;
case 2:
hue = (uchar)(p * 255);
saturation = (uchar)(v * 255);
value = (uchar)(t * 255);
break;
case 3:
hue = (uchar)(p * 255);
saturation = (uchar)(q * 255);
value = (uchar)(v * 255);
break;
case 4:
hue = (uchar)(t * 255);
saturation = (uchar)(p * 255);
value = (uchar)(v * 255);
break;
case 5:
hue = (uchar)(v * 255);
saturation = (uchar)(p * 255);
value = (uchar)(q * 255);
}
}
}
/*!
* Convert a color in RGB space to HLS space (Hue, Lightness, Saturation).
* \param red the red component (modified in place).
* \param green the green component (modified in place).
* \param blue the blue component (modified in place).
*/
static void RGBTOHLS(uchar &red, uchar &green, uchar &blue)
{
int r = red;
int g = green;
int b = blue;
int min, max;
if (r > g) {
max = qMax(r, b);
min = qMin(g, b);
} else {
max = qMax(g, b);
min = qMin(r, b);
}
double h;
double l = (max + min) / 2.;
double s;
if (max == min) {
s = 0.;
h = 0.;
} else {
int delta = max - min;
if (l < 128) {
s = 255 * (double)delta / (double)(max + min);
} else {
s = 255 * (double)delta / (double)(511 - max - min);
}
if (r == max) {
h = (g - b) / (double)delta;
} else if (g == max) {
h = 2 + (b - r) / (double)delta;
} else {
h = 4 + (r - g) / (double)delta;
}
h *= 42.5;
if (h < 0) {
h += 255;
} else if (h > 255) {
h -= 255;
}
}
red = (uchar)h;
green = (uchar)l;
blue = (uchar)s;
}
/*!
* Implement the HLS "double hex-cone".
* \param n1 lightness fraction (?)
* \param n2 saturation fraction (?)
* \param hue hue "angle".
* \return HLS value.
*/
static int HLSVALUE(double n1, double n2, double hue)
{
double value;
if (hue > 255) {
hue -= 255;
} else if (hue < 0) {
hue += 255;
}
if (hue < 42.5) {
value = n1 + (n2 - n1) * (hue / 42.5);
} else if (hue < 127.5) {
value = n2;
} else if (hue < 170) {
value = n1 + (n2 - n1) * ((170 - hue) / 42.5);
} else {
value = n1;
}
return (int)(value * 255);
}
/*!
* Convert a color in HLS space to RGB space.
* \param hue the hue component (modified in place).
* \param lightness the lightness component (modified in place).
* \param saturation the saturation component (modified in place).
*/
static void HLSTORGB(uchar &hue, uchar &lightness, uchar &saturation)
{
double h = hue;
double l = lightness;
double s = saturation;
if (s == 0) {
hue = (uchar)l;
lightness = (uchar)l;
saturation = (uchar)l;
} else {
double m1, m2;
if (l < 128) {
m2 = (l * (255 + s)) / 65025.;
} else {
m2 = (l + s - (l * s) / 255.) / 255.;
}
m1 = (l / 127.5) - m2;
hue = HLSVALUE(m1, m2, h + 85);
lightness = HLSVALUE(m1, m2, h);
saturation = HLSVALUE(m1, m2, h - 85);
}
}
#endif
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