1 /* darken.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 darken : public frei0r::mixer2
28 {
29 public:
darken(unsigned int width,unsigned int height)30   darken(unsigned int width, unsigned int height)
31   {
32   }
33 
34   /**
35    *
36    * Perform a darken operation between sources in1 and in2, using
37    * the generalised algorithm:
38    * D_r = min(A_r, B_r);
39    * D_g = min(A_g, B_g);
40    * D_b = min(A_b, B_b);
41    * D_a = min(A_a, B_a);
42    *
43    **/
update(double time,uint32_t * out,const uint32_t * in1,const uint32_t * in2)44   void update(double time,
45               uint32_t* out,
46               const uint32_t* in1,
47               const uint32_t* in2)
48   {
49     const uint8_t *src1 = reinterpret_cast<const uint8_t*>(in1);
50     const uint8_t *src2 = reinterpret_cast<const uint8_t*>(in2);
51     uint8_t *dst = reinterpret_cast<uint8_t*>(out);
52     uint32_t sizeCounter = size;
53 
54     uint32_t b;
55     uint8_t s1, s2;
56 
57     while (sizeCounter--)
58       {
59         for (b = 0; b < ALPHA; b++)
60           {
61             s1 = src1[b];
62             s2 = src2[b];
63             dst[b] = MIN(s1,s2);
64           }
65 
66         dst[ALPHA] = MIN(src1[ALPHA], src2[ALPHA]);
67 
68         src1 += NBYTES;
69         src2 += NBYTES;
70         dst += NBYTES;
71       }
72   }
73 
74 
75 };
76 
77 
78 frei0r::construct<darken> plugin("darken",
79                                   "Perform a darken operation between two sources (minimum value of both sources).",
80                                   "Jean-Sebastien Senecal",
81                                   0,2,
82                                   F0R_COLOR_MODEL_RGBA8888);
83 
84