KImgIO

gimp.h

00001 #ifndef GIMP_H
00002 #define GIMP_H
00003 /* -*- c++ -*-
00004  * gimp.h: Header for a Qt 3 plug-in for reading GIMP XCF image files
00005  * Copyright (C) 2001 lignum Computing, Inc. <allen@lignumcomputing.com>
00006  * Copyright (C) 2004 Melchior FRANZ <mfranz@kde.org>
00007  *
00008  * This plug-in is free software; you can redistribute it and/or
00009  * modify it under the terms of the GNU Lesser General Public
00010  * License as published by the Free Software Foundation; either
00011  * version 2.1 of the License, or (at your option) any later version.
00012  *
00013  * This library is distributed in the hope that it will be useful,
00014  * but WITHOUT ANY WARRANTY; without even the implied warranty of
00015  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
00016  * Lesser General Public License for more details.
00017  *
00018  * You should have received a copy of the GNU Lesser General Public
00019  * License along with this library; if not, write to the Free Software
00020  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
00021  *
00022  */
00023 
00024 #include <kglobal.h>
00025 
00026 /*
00027  * These are the constants and functions I extracted from The GIMP source
00028  * code. If the reader fails to work, this is probably the place to start
00029  * looking for discontinuities.
00030  */
00031 
00032 // From GIMP "tile.h" v1.2
00033 
00034 const uint TILE_WIDTH = 64; 
00035 const uint TILE_HEIGHT = 64;    
00036 
00037 // From GIMP "paint_funcs.c" v1.2
00038 
00039 const int RANDOM_TABLE_SIZE = 4096; 
00040 const int RANDOM_SEED = 314159265; 
00041 const double EPSILON = 0.0001;  
00042 
00043 // From GIMP "paint_funcs.h" v1.2
00044 
00045 const uchar OPAQUE_OPACITY = 255; 
00046 
00047 // From GIMP "apptypes.h" v1.2
00048 
00052 
00053 typedef enum
00054 {
00055   RGB,
00056   GRAY,
00057   INDEXED
00058 } GimpImageBaseType;
00059 
00061 
00062 typedef enum
00063 {
00064   RGB_GIMAGE,
00065   RGBA_GIMAGE,
00066   GRAY_GIMAGE,
00067   GRAYA_GIMAGE,
00068   INDEXED_GIMAGE,
00069   INDEXEDA_GIMAGE
00070 } GimpImageType;
00071 
00073 
00074 typedef enum
00075 {
00076   NORMAL_MODE,
00077   DISSOLVE_MODE,
00078   BEHIND_MODE,
00079   MULTIPLY_MODE,
00080   SCREEN_MODE,
00081   OVERLAY_MODE,
00082   DIFFERENCE_MODE,
00083   ADDITION_MODE,
00084   SUBTRACT_MODE,
00085   DARKEN_ONLY_MODE,
00086   LIGHTEN_ONLY_MODE,
00087   HUE_MODE,
00088   SATURATION_MODE,
00089   COLOR_MODE,
00090   VALUE_MODE,
00091   DIVIDE_MODE,
00092   ERASE_MODE,
00093   REPLACE_MODE,
00094   ANTI_ERASE_MODE
00095 } LayerModeEffects;
00096 
00097 // From GIMP "xcf.c" v1.2
00098 
00100 
00101 typedef enum
00102 {
00103   PROP_END = 0,
00104   PROP_COLORMAP = 1,
00105   PROP_ACTIVE_LAYER = 2,
00106   PROP_ACTIVE_CHANNEL = 3,
00107   PROP_SELECTION = 4,
00108   PROP_FLOATING_SELECTION = 5,
00109   PROP_OPACITY = 6,
00110   PROP_MODE = 7,
00111   PROP_VISIBLE = 8,
00112   PROP_LINKED = 9,
00113   PROP_PRESERVE_TRANSPARENCY = 10,
00114   PROP_APPLY_MASK = 11,
00115   PROP_EDIT_MASK = 12,
00116   PROP_SHOW_MASK = 13,
00117   PROP_SHOW_MASKED = 14,
00118   PROP_OFFSETS = 15,
00119   PROP_COLOR = 16,
00120   PROP_COMPRESSION = 17,
00121   PROP_GUIDES = 18,
00122   PROP_RESOLUTION = 19,
00123   PROP_TATTOO = 20,
00124   PROP_PARASITES = 21,
00125   PROP_UNIT = 22,
00126   PROP_PATHS = 23,
00127   PROP_USER_UNIT = 24
00128 } PropType;
00129 
00130 // From GIMP "xcf.c" v1.2
00131 
00133 
00134 typedef enum
00135 {
00136   COMPRESS_NONE = 0,
00137   COMPRESS_RLE = 1,
00138   COMPRESS_ZLIB = 2,
00139   COMPRESS_FRACTAL = 3  /* Unused. */
00140 } CompressionType;
00141 
00142 // From GIMP "paint_funcs.c" v1.2
00143 
00151 inline int INT_MULT ( int a, int b )
00152 {
00153   int c = a * b + 0x80;
00154   return ( ( c >> 8 ) + c ) >> 8;
00155 }
00156 
00168 inline int INT_BLEND ( int a, int b, int alpha )
00169 {
00170   return INT_MULT( a - b, alpha ) + b;
00171 }
00172 
00173 // From GIMP "gimpcolorspace.c" v1.2
00174 
00181 void RGBTOHSV ( uchar& red, uchar& green, uchar& blue )
00182 {
00183   int r, g, b;
00184   double h, s, v;
00185   int min, max;
00186 
00187   h = 0.;
00188 
00189   r = red;
00190   g = green;
00191   b = blue;
00192 
00193   if ( r > g ) {
00194     max = KMAX( r, b );
00195     min = KMIN( g, b );
00196   }
00197   else {
00198     max = KMAX( g, b );
00199     min = KMIN( r, b );
00200   }
00201 
00202   v = max;
00203 
00204   if ( max != 0 )
00205     s = ( ( max - min ) * 255 ) / (double)max;
00206   else
00207     s = 0;
00208 
00209   if ( s == 0 )
00210     h = 0;
00211   else {
00212     int delta = max - min;
00213     if ( r == max )
00214       h = ( g - b ) / (double)delta;
00215     else if ( g == max )
00216       h = 2 + ( b - r ) / (double)delta;
00217     else if ( b == max )
00218       h = 4 + ( r - g ) / (double)delta;
00219     h *= 42.5;
00220 
00221     if ( h < 0 )
00222       h += 255;
00223     if ( h > 255 )
00224       h -= 255;
00225   }
00226 
00227   red   = (uchar)h;
00228   green = (uchar)s;
00229   blue  = (uchar)v;
00230 }
00231 
00238 void HSVTORGB ( uchar& hue, uchar& saturation, uchar& value )
00239 {
00240   if ( saturation == 0 ) {
00241     hue        = value;
00242     saturation = value;
00243     value      = value;
00244   }
00245   else {
00246     double h = hue * 6. / 255.;
00247     double s = saturation / 255.;
00248     double v = value / 255.;
00249 
00250     double f = h - (int)h;
00251     double p = v * ( 1. - s );
00252     double q = v * ( 1. - ( s * f ) );
00253     double t = v * ( 1. - ( s * ( 1. - f ) ) );
00254 
00255     // Worth a note here that gcc 2.96 will generate different results
00256     // depending on optimization mode on i386.
00257 
00258     switch ((int)h) {
00259     case 0:
00260       hue        = (uchar)( v * 255 );
00261       saturation = (uchar)( t * 255 );
00262       value      = (uchar)( p * 255 );
00263       break;
00264     case 1:
00265       hue        = (uchar)( q * 255 );
00266       saturation = (uchar)( v * 255 );
00267       value      = (uchar)( p * 255 );
00268       break;
00269     case 2:
00270       hue        = (uchar)( p * 255 );
00271       saturation = (uchar)( v * 255 );
00272       value      = (uchar)( t * 255 );
00273       break;
00274     case 3:
00275       hue        = (uchar)( p * 255 );
00276       saturation = (uchar)( q * 255 );
00277       value      = (uchar)( v * 255 );
00278       break;
00279     case 4:
00280       hue        = (uchar)( t * 255 );
00281       saturation = (uchar)( p * 255 );
00282       value      = (uchar)( v * 255 );
00283       break;
00284     case 5:
00285       hue        = (uchar)( v * 255 );
00286       saturation = (uchar)( p * 255 );
00287       value      = (uchar)( q * 255 );
00288     }
00289   }
00290 }
00291 
00298 void RGBTOHLS ( uchar& red, uchar& green, uchar& blue )
00299 {
00300   int r = red;
00301   int g = green;
00302   int b = blue;
00303 
00304   int min, max;
00305 
00306   if ( r > g ) {
00307     max = KMAX( r, b );
00308     min = KMIN( g, b );
00309   }
00310   else {
00311     max = KMAX( g, b );
00312     min = KMIN( r, b );
00313   }
00314 
00315   double h;
00316   double l = ( max + min ) / 2.;
00317   double s;
00318 
00319   if ( max == min ) {
00320     s = 0.;
00321     h = 0.;
00322   }
00323   else {
00324     int delta = max - min;
00325 
00326     if ( l < 128 )
00327       s = 255 * (double)delta / (double)( max + min );
00328     else
00329       s = 255 * (double)delta / (double)( 511 - max - min );
00330 
00331     if ( r == max )
00332       h = ( g - b ) / (double)delta;
00333     else if ( g == max )
00334       h = 2 + ( b - r ) / (double)delta;
00335     else
00336       h = 4 + ( r - g ) / (double)delta;
00337 
00338     h *= 42.5;
00339 
00340     if ( h < 0 )
00341       h += 255;
00342     else if ( h > 255 )
00343       h -= 255;
00344   }
00345 
00346   red   = (uchar)h;
00347   green = (uchar)l;
00348   blue  = (uchar)s;
00349 }
00350 
00358 int HLSVALUE ( double n1, double n2, double hue )
00359 {
00360   double value;
00361 
00362   if ( hue > 255 )
00363     hue -= 255;
00364   else if ( hue < 0 )
00365     hue += 255;
00366 
00367   if ( hue < 42.5 )
00368     value = n1 + ( n2 - n1 ) * ( hue / 42.5 );
00369   else if ( hue < 127.5 )
00370     value = n2;
00371   else if ( hue < 170 )
00372     value = n1 + ( n2 - n1 ) * ( ( 170 - hue ) / 42.5 );
00373   else
00374     value = n1;
00375 
00376   return (int)( value * 255 );
00377 }
00378 
00385 void HLSTORGB ( uchar& hue, uchar& lightness, uchar& saturation )
00386 {
00387   double h = hue;
00388   double l = lightness;
00389   double s = saturation;
00390 
00391   if ( s == 0 ) {
00392     hue        = (uchar)l;
00393     lightness  = (uchar)l;
00394     saturation = (uchar)l;
00395   }
00396   else {
00397     double m1, m2;
00398 
00399     if ( l < 128 )
00400       m2 = ( l * ( 255 + s ) ) / 65025.;
00401     else
00402       m2 = ( l + s - ( l * s ) / 255. ) / 255.;
00403 
00404     m1 = ( l / 127.5 ) - m2;
00405 
00406     hue        = HLSVALUE( m1, m2, h + 85 );
00407     lightness  = HLSVALUE( m1, m2, h );
00408     saturation = HLSVALUE( m1, m2, h - 85 );
00409   }
00410 }
00411 #endif
KImgIO

gimp.h

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