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comparison data/model/PowerOfSqrtTwoZoomConstraint.cpp @ 1527:710e6250a401 zoom

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Merge from default branch
author Chris Cannam
date Mon, 17 Sep 2018 13:51:14 +0100
parents d4a28d1479a8 48e9f538e6e9
children c1c45c5146bb
comparison
equal deleted inserted replaced
1324:d4a28d1479a8 1527:710e6250a401
19 #include <cmath> 19 #include <cmath>
20 20
21 21
22 ZoomLevel 22 ZoomLevel
23 PowerOfSqrtTwoZoomConstraint::getNearestZoomLevel(ZoomLevel requested, 23 PowerOfSqrtTwoZoomConstraint::getNearestZoomLevel(ZoomLevel requested,
24 RoundingDirection dir) const 24 RoundingDirection dir) const
25 { 25 {
26 int type, power; 26 int type, power;
27 int blockSize; 27 int blockSize;
28 28
29 if (requested.zone == ZoomLevel::FramesPerPixel) { 29 if (requested.zone == ZoomLevel::FramesPerPixel) {
45 } 45 }
46 } 46 }
47 47
48 int 48 int
49 PowerOfSqrtTwoZoomConstraint::getNearestBlockSize(int blockSize, 49 PowerOfSqrtTwoZoomConstraint::getNearestBlockSize(int blockSize,
50 int &type, 50 int &type,
51 int &power, 51 int &power,
52 RoundingDirection dir) const 52 RoundingDirection dir) const
53 { 53 {
54 // cerr << "given " << blockSize << endl; 54 // cerr << "given " << blockSize << endl;
55 55
56 int minCachePower = getMinCachePower(); 56 int minCachePower = getMinCachePower();
57 57
58 if (blockSize < (1 << minCachePower)) { 58 if (blockSize < (1 << minCachePower)) {
59 type = -1; 59 type = -1;
60 power = 0; 60 power = 0;
61 float val = 1.0, prevVal = 1.0; 61 float val = 1.0, prevVal = 1.0;
62 while (val + 0.01 < blockSize) { 62 while (val + 0.01 < blockSize) {
63 prevVal = val; 63 prevVal = val;
64 val *= sqrtf(2.f); 64 val *= sqrtf(2.f);
65 } 65 }
66 int rval; 66 int rval;
67 if (dir == RoundUp) rval = int(val + 0.01f); 67 if (dir == RoundUp) rval = int(val + 0.01f);
68 else if (dir == RoundDown) rval = int(prevVal + 0.01f); 68 else if (dir == RoundDown) rval = int(prevVal + 0.01f);
69 else if (val - float(blockSize) < 69 else if (val - float(blockSize) <
70 float(blockSize) - prevVal) rval = int(val + 0.01f); 70 float(blockSize) - prevVal) rval = int(val + 0.01f);
71 else rval = int(prevVal + 0.01); 71 else rval = int(prevVal + 0.01);
72 // SVDEBUG << "returning " << rval << endl; 72 // SVDEBUG << "returning " << rval << endl;
73 return rval; 73 return rval;
74 } 74 }
75 75
76 int prevBase = (1 << minCachePower); 76 int prevBase = (1 << minCachePower);
77 int prevPower = minCachePower; 77 int prevPower = minCachePower;
78 int prevType = 0; 78 int prevType = 0;
79 79
80 int result = 0; 80 int result = 0;
81 81
82 for (unsigned int i = 0; ; ++i) { 82 for (unsigned int i = 0; ; ++i) {
83 83
84 power = minCachePower + i/2; 84 power = minCachePower + i/2;
85 type = i % 2; 85 type = i % 2;
86 86
87 int base; 87 int base;
88 if (type == 0) { 88 if (type == 0) {
89 base = (1 << power); 89 base = (1 << power);
90 } else { 90 } else {
91 base = (((unsigned int)((1 << minCachePower) * sqrt(2.) + 0.01)) 91 base = (((unsigned int)((1 << minCachePower) * sqrt(2.) + 0.01))
92 << (power - minCachePower)); 92 << (power - minCachePower));
93 } 93 }
94 94
95 // SVDEBUG << "Testing base " << base << endl; 95 // SVDEBUG << "Testing base " << base << endl;
96 96
97 if (base == blockSize) { 97 if (base == blockSize) {
98 result = base; 98 result = base;
99 break; 99 break;
100 } 100 }
101 101
102 if (base > blockSize) { 102 if (base > blockSize) {
103 if (dir == RoundNearest) { 103 if (dir == RoundNearest) {
104 if (base - blockSize < blockSize - prevBase) { 104 if (base - blockSize < blockSize - prevBase) {
105 dir = RoundUp; 105 dir = RoundUp;
106 } else { 106 } else {
107 dir = RoundDown; 107 dir = RoundDown;
108 } 108 }
109 } 109 }
110 if (dir == RoundUp) { 110 if (dir == RoundUp) {
111 result = base; 111 result = base;
112 break; 112 break;
113 } else { 113 } else {
114 type = prevType; 114 type = prevType;
115 power = prevPower; 115 power = prevPower;
116 result = prevBase; 116 result = prevBase;
117 break; 117 break;
118 } 118 }
119 } 119 }
120 120
121 prevType = type; 121 prevType = type;
122 prevPower = power; 122 prevPower = power;
123 prevBase = base; 123 prevBase = base;
124 } 124 }
125 125
126 if (result > getMaxZoomLevel().level) { 126 if (result > getMaxZoomLevel().level) {
127 result = getMaxZoomLevel().level; 127 result = getMaxZoomLevel().level;
128 } 128 }