1 /* dodge.cpp
2  * Copyright (C) 2006 Jean-Sebastien Senecal (js@drone.ws)
3  * This file is a Frei0r plugin.
4  * The code is a modified version of code from the Gimp.
5  *
6  * This program is free software; you can redistribute it and/or modify
7  * it under the terms of the GNU General Public License as published by
8  * the Free Software Foundation; either version 2 of the License, or
9  * (at your option) any later version.
10  *
11  * This program is distributed in the hope that it will be useful,
12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
14  * GNU General Public License for more details.
15  *
16  * You should have received a copy of the GNU General Public License
17  * along with this program; if not, write to the Free Software
18  * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
19  */
20 
21 #include "frei0r.hpp"
22 #include "frei0r_math.h"
23 
24 #define NBYTES 4
25 #define ALPHA 3
26 
27 class dodge : public frei0r::mixer2
28 {
29 public:
dodge(unsigned int width,unsigned int height)30   dodge(unsigned int width, unsigned int height)
31   {
32   }
33 
34   /**
35    *
36    * Perform an RGB[A] dodge operation between the pixel sources
37    * in1 and in2, using the generalised algorithm:
38    *
39    * D = saturation of 255 or (A * 256) / (256 - B)
40    *
41    **/
update(double time,uint32_t * out,const uint32_t * in1,const uint32_t * in2)42   void update(double time,
43               uint32_t* out,
44               const uint32_t* in1,
45               const uint32_t* in2)
46   {
47     const uint8_t *src1 = reinterpret_cast<const uint8_t*>(in1);
48     const uint8_t *src2 = reinterpret_cast<const uint8_t*>(in2);
49     uint8_t *dst = reinterpret_cast<uint8_t*>(out);
50     uint32_t sizeCounter = size;
51 
52     uint32_t b, tmp;
53 
54     while (sizeCounter--)
55       {
56         for (b = 0; b < ALPHA; b++)
57           {
58             tmp = src1[b] << 8;
59             tmp /= 256 - src2[b];
60             dst[b] = MAX255(tmp);
61           }
62 
63         dst[ALPHA] = MIN (src1[ALPHA], src2[ALPHA]);
64 
65         src1 += NBYTES;
66         src2 += NBYTES;
67         dst += NBYTES;
68       }
69   }
70 
71 };
72 
73 frei0r::construct<dodge> plugin("dodge",
74                                 "Perform an RGB[A] dodge operation between the pixel sources, using the generalised algorithm:\n"
75                                 "D = saturation of 255 or (A * 256) / (256 - B)",
76                                 "Jean-Sebastien Senecal",
77                                 0,2,
78                                 F0R_COLOR_MODEL_RGBA8888);
79 
80