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
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
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
168
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
197
198
199
200
201
202
203
204
205
206
|
/* -----------------------------------------------------------------------------
Copyright (c) 2006 Simon Brown si@sjbrown.co.uk
Permission is hereby granted, free of charge, to any person obtaining
a copy of this software and associated documentation files (the
"Software"), to deal in the Software without restriction, including
without limitation the rights to use, copy, modify, merge, publish,
distribute, sublicense, and/or sell copies of the Software, and to
permit persons to whom the Software is furnished to do so, subject to
the following conditions:
The above copyright notice and this permission notice shall be included
in all copies or substantial portions of the Software.
THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
-------------------------------------------------------------------------- */
/*! @file
@brief This program tests the error for 1 and 2-colour DXT compression.
This tests the effectiveness of the DXT compression algorithm for all
possible 1 and 2-colour blocks of pixels.
*/
#include <squish.h>
#include <iostream>
#include <cmath>
#include <cfloat>
#include <cstdlib>
using namespace squish;
double GetColourError( u8 const* a, u8 const* b )
{
double error = 0.0;
for( int i = 0; i < 16; ++i )
{
for( int j = 0; j < 3; ++j )
{
int index = 4*i + j;
int diff = ( int )a[index] - ( int )b[index];
error += ( double )( diff*diff );
}
}
return error / 16.0;
}
void TestOneColour( int flags )
{
u8 input[4*16];
u8 output[4*16];
u8 block[16];
double avg = 0.0, min = DBL_MAX, max = -DBL_MAX;
int counter = 0;
// test all single-channel colours
for( int i = 0; i < 16*4; ++i )
input[i] = ( ( i % 4 ) == 3 ) ? 255 : 0;
for( int channel = 0; channel < 3; ++channel )
{
for( int value = 0; value < 255; ++value )
{
// set the channnel value
for( int i = 0; i < 16; ++i )
input[4*i + channel] = ( u8 )value;
// compress and decompress
Compress( input, block, flags );
Decompress( output, block, flags );
// test the results
double rm = GetColourError( input, output );
double rms = std::sqrt( rm );
// accumulate stats
min = std::min( min, rms );
max = std::max( max, rms );
avg += rm;
++counter;
}
// reset the channel value
for( int i = 0; i < 16; ++i )
input[4*i + channel] = 0;
}
// finish stats
avg = std::sqrt( avg/counter );
// show stats
std::cout << "one colour error (min, max, avg): "
<< min << ", " << max << ", " << avg << std::endl;
}
void TestOneColourRandom( int flags )
{
u8 input[4*16];
u8 output[4*16];
u8 block[16];
double avg = 0.0, min = DBL_MAX, max = -DBL_MAX;
int counter = 0;
// test all single-channel colours
for( int test = 0; test < 1000; ++test )
{
// set a constant random colour
for( int channel = 0; channel < 3; ++channel )
{
u8 value = ( u8 )( rand() & 0xff );
for( int i = 0; i < 16; ++i )
input[4*i + channel] = value;
}
for( int i = 0; i < 16; ++i )
input[4*i + 3] = 255;
// compress and decompress
Compress( input, block, flags );
Decompress( output, block, flags );
// test the results
double rm = GetColourError( input, output );
double rms = std::sqrt( rm );
// accumulate stats
min = std::min( min, rms );
max = std::max( max, rms );
avg += rm;
++counter;
}
// finish stats
avg = std::sqrt( avg/counter );
// show stats
std::cout << "random one colour error (min, max, avg): "
<< min << ", " << max << ", " << avg << std::endl;
}
void TestTwoColour( int flags )
{
u8 input[4*16];
u8 output[4*16];
u8 block[16];
double avg = 0.0, min = DBL_MAX, max = -DBL_MAX;
int counter = 0;
// test all single-channel colours
for( int i = 0; i < 16*4; ++i )
input[i] = ( ( i % 4 ) == 3 ) ? 255 : 0;
for( int channel = 0; channel < 3; ++channel )
{
for( int value1 = 0; value1 < 255; ++value1 )
{
for( int value2 = value1 + 1; value2 < 255; ++value2 )
{
// set the channnel value
for( int i = 0; i < 16; ++i )
input[4*i + channel] = ( u8 )( ( i < 8 ) ? value1 : value2 );
// compress and decompress
Compress( input, block, flags );
Decompress( output, block, flags );
// test the results
double rm = GetColourError( input, output );
double rms = std::sqrt( rm );
// accumulate stats
min = std::min( min, rms );
max = std::max( max, rms );
avg += rm;
++counter;
}
}
// reset the channel value
for( int i = 0; i < 16; ++i )
input[4*i + channel] = 0;
}
// finish stats
avg = std::sqrt( avg/counter );
// show stats
std::cout << "two colour error (min, max, avg): "
<< min << ", " << max << ", " << avg << std::endl;
}
int main()
{
TestOneColourRandom( kDxt1 | kColourRangeFit );
TestOneColour( kDxt1 );
TestTwoColour( kDxt1 );
}
|
