ColorTranslator.cc 7.05 KB
Newer Older
Jan Möbius's avatar
Jan Möbius committed
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
/*===========================================================================*\
 *                                                                           *
 *                              OpenFlipper                                  *
 *           Copyright (c) 2001-2015, RWTH-Aachen University                 *
 *           Department of Computer Graphics and Multimedia                  *
 *                          All rights reserved.                             *
 *                            www.openflipper.org                            *
 *                                                                           *
 *---------------------------------------------------------------------------*
 * This file is part of OpenFlipper.                                         *
 *---------------------------------------------------------------------------*
 *                                                                           *
 * Redistribution and use in source and binary forms, with or without        *
 * modification, are permitted provided that the following conditions        *
 * are met:                                                                  *
 *                                                                           *
 * 1. Redistributions of source code must retain the above copyright notice, *
 *    this list of conditions and the following disclaimer.                  *
 *                                                                           *
 * 2. Redistributions in binary form must reproduce the above copyright      *
 *    notice, this list of conditions and the following disclaimer in the    *
 *    documentation and/or other materials provided with the distribution.   *
 *                                                                           *
 * 3. Neither the name of the copyright holder nor the names of its          *
 *    contributors may be used to endorse or promote products derived from   *
 *    this software without specific prior written permission.               *
 *                                                                           *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS       *
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED *
 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A           *
 * PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER *
 * OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,  *
 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,       *
 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR        *
 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF    *
 * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING      *
 * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS        *
 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.              *
 *                                                                           *
\*===========================================================================*/

//=============================================================================
//
//  CLASS ColorTranslator - IMPLEMENTATION
//
//=============================================================================


//== INCLUDES =================================================================


#include "ColorTranslator.hh"
53
#include <ACG/GL/GLState.hh>
Jan Möbius's avatar
Jan Möbius committed
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
#include <iostream>
#include <limits>


//== NAMESPACES ===============================================================


namespace ACG {


//== IMPLEMENTATION ========================================================== 


void
ColorTranslator::
69
initialize(ACG::GLState* _state)
Jan Möbius's avatar
Jan Möbius committed
70
{
71
72
73
74
75
76
77
78
79
80
81
82
83
84
    if(_state->compatibilityProfile())
    {
        glGetIntegerv( GL_RED_BITS,   &red_bits_   );
        glGetIntegerv( GL_GREEN_BITS, &green_bits_ );
        glGetIntegerv( GL_BLUE_BITS,  &blue_bits_  );
        glGetIntegerv( GL_ALPHA_BITS,  &alpha_bits_ );
    }
    else
    {   //only up to 8 bits are supported as of now, so hardcode them for core profiles
        red_bits_   = 8;
        green_bits_ = 8;
        blue_bits_  = 8;
        alpha_bits_ = 8;
    }
Jan Möbius's avatar
Jan Möbius committed
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
  // We currently only support up to 8 bits per channel (
  if (red_bits_   > 8)  red_bits_   = 8;
  if (green_bits_ > 8)  green_bits_ = 8;
  if (blue_bits_  > 8)  blue_bits_  = 8;
  if (alpha_bits_ > 8)  alpha_bits_ = 8;

  // Compute the mask to extract the component
  red_mask_    = ((1 << red_bits_)   - 1);
  green_mask_  = ((1 << green_bits_) - 1);
  blue_mask_   = ((1 << blue_bits_)  - 1);
  alpha_mask_  = ((1 << alpha_bits_) - 1);

  // Shift required to move the component to the lowest bits
  red_shift_   = 8 - red_bits_;
  green_shift_ = 8 - green_bits_;
  blue_shift_  = 8 - blue_bits_;
  alpha_shift_ = 8 - alpha_bits_;


  red_round_   = 1 << (red_shift_   - 1);
  green_round_ = 1 << (green_shift_ - 1);
  blue_round_  = 1 << (blue_shift_  - 1);
  alpha_round_ = 1 << (alpha_shift_ - 1);

  initialized_ = true;
}

  
//-----------------------------------------------------------------------------


Vec4uc
ColorTranslator::
index2color(const size_t _idx) const
{
  assert(initialized());
  unsigned char  r, g, b, a;
  
  // Make sure that the number fits
  if ( _idx > std::numeric_limits<unsigned int>::max() ) {
    std::cerr << "Can't convert index " << _idx << " to RGBA. Number too large for unsigned int \n";
    return Vec4uc(0, 0, 0, 0);
  }

  unsigned int idx = ( static_cast<unsigned int>(_idx) + 1);

  b = ((idx & blue_mask_)  << blue_shift_)  | blue_round_;  
  idx >>= blue_bits_;
  g = ((idx & green_mask_) << green_shift_) | green_round_;  
  idx >>= green_bits_;
  r = ((idx & red_mask_)   << red_shift_)   | red_round_;  
  idx >>= red_bits_;
  a = ((idx & alpha_mask_) << alpha_shift_) | alpha_round_;
  idx >>= alpha_bits_;

  if (!idx) 
    return  Vec4uc(r, g, b, a);

  else 
  {
    std::cerr << "Can't convert index " << _idx << " to RGBA\n";
    return Vec4uc(0, 0, 0, 0);
  }
}

  
//-----------------------------------------------------------------------------


size_t
ColorTranslator::
color2index(const Vec4uc _rgba) const
{


  assert(initialized());

  // Work internally with#include <iostream> unsigned int for now
  unsigned int result;

  // Combine the single unsigned chars according to masks
  result =   _rgba[3] >> alpha_shift_;
  result <<= red_bits_;
168
  result |=  _rgba[0] >> red_shift_;
Jan Möbius's avatar
Jan Möbius committed
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
  result <<= green_bits_;
  result |=  _rgba[1] >> green_shift_;
  result <<= blue_bits_;
  result |=  _rgba[2] >> blue_shift_;    

  // Return size_t Here
  return ( static_cast<size_t>(result-1) );
}


//-----------------------------------------------------------------------------


size_t
ColorTranslator::max_index() const 
{
  assert(initialized());
  if (red_bits_+green_bits_+blue_bits_+alpha_bits_ == 32)
    return 0xffffffff;
  else
    return (1 << (red_bits_+green_bits_+blue_bits_+alpha_bits_))-1;
}


//=============================================================================
} // namespace ACG
//=============================================================================