| 1 | #include "../integer.hpp" |
| 2 | |
| 3 | namespace glm{ |
| 4 | namespace detail |
| 5 | { |
| 6 | template<length_t L, typename T, qualifier Q, bool compute = false> |
| 7 | struct compute_ceilShift |
| 8 | { |
| 9 | GLM_FUNC_QUALIFIER static vec<L, T, Q> call(vec<L, T, Q> const& v, T) |
| 10 | { |
| 11 | return v; |
| 12 | } |
| 13 | }; |
| 14 | |
| 15 | template<length_t L, typename T, qualifier Q> |
| 16 | struct compute_ceilShift<L, T, Q, true> |
| 17 | { |
| 18 | GLM_FUNC_QUALIFIER static vec<L, T, Q> call(vec<L, T, Q> const& v, T Shift) |
| 19 | { |
| 20 | return v | (v >> Shift); |
| 21 | } |
| 22 | }; |
| 23 | |
| 24 | template<length_t L, typename T, qualifier Q, bool isSigned = true> |
| 25 | struct compute_ceilPowerOfTwo |
| 26 | { |
| 27 | GLM_FUNC_QUALIFIER static vec<L, T, Q> call(vec<L, T, Q> const& x) |
| 28 | { |
| 29 | static_assert(!std::numeric_limits<T>::is_iec559 || GLM_CONFIG_UNRESTRICTED_FLOAT, "'ceilPowerOfTwo' only accept integer scalar or vector inputs"); |
| 30 | |
| 31 | vec<L, T, Q> const Sign(sign(x)); |
| 32 | |
| 33 | vec<L, T, Q> v(abs(x)); |
| 34 | |
| 35 | v = v - static_cast<T>(1); |
| 36 | v = v | (v >> static_cast<T>(1)); |
| 37 | v = v | (v >> static_cast<T>(2)); |
| 38 | v = v | (v >> static_cast<T>(4)); |
| 39 | v = compute_ceilShift<L, T, Q, sizeof(T) >= 2>::call(v, 8); |
| 40 | v = compute_ceilShift<L, T, Q, sizeof(T) >= 4>::call(v, 16); |
| 41 | v = compute_ceilShift<L, T, Q, sizeof(T) >= 8>::call(v, 32); |
| 42 | return (v + static_cast<T>(1)) * Sign; |
| 43 | } |
| 44 | }; |
| 45 | |
| 46 | template<length_t L, typename T, qualifier Q> |
| 47 | struct compute_ceilPowerOfTwo<L, T, Q, false> |
| 48 | { |
| 49 | GLM_FUNC_QUALIFIER static vec<L, T, Q> call(vec<L, T, Q> const& x) |
| 50 | { |
| 51 | static_assert(!std::numeric_limits<T>::is_iec559 || GLM_CONFIG_UNRESTRICTED_FLOAT, "'ceilPowerOfTwo' only accept integer scalar or vector inputs"); |
| 52 | |
| 53 | vec<L, T, Q> v(x); |
| 54 | |
| 55 | v = v - static_cast<T>(1); |
| 56 | v = v | (v >> static_cast<T>(1)); |
| 57 | v = v | (v >> static_cast<T>(2)); |
| 58 | v = v | (v >> static_cast<T>(4)); |
| 59 | v = compute_ceilShift<L, T, Q, sizeof(T) >= 2>::call(v, 8); |
| 60 | v = compute_ceilShift<L, T, Q, sizeof(T) >= 4>::call(v, 16); |
| 61 | v = compute_ceilShift<L, T, Q, sizeof(T) >= 8>::call(v, 32); |
| 62 | return v + static_cast<T>(1); |
| 63 | } |
| 64 | }; |
| 65 | |
| 66 | template<bool is_float, bool is_signed> |
| 67 | struct compute_ceilMultiple{}; |
| 68 | |
| 69 | template<> |
| 70 | struct compute_ceilMultiple<true, true> |
| 71 | { |
| 72 | template<typename genType> |
| 73 | GLM_FUNC_QUALIFIER static genType call(genType Source, genType Multiple) |
| 74 | { |
| 75 | if(Source > genType(0)) |
| 76 | return Source + (Multiple - std::fmod(Source, Multiple)); |
| 77 | else |
| 78 | return Source + std::fmod(-Source, Multiple); |
| 79 | } |
| 80 | }; |
| 81 | |
| 82 | template<> |
| 83 | struct compute_ceilMultiple<false, false> |
| 84 | { |
| 85 | template<typename genType> |
| 86 | GLM_FUNC_QUALIFIER static genType call(genType Source, genType Multiple) |
| 87 | { |
| 88 | genType Tmp = Source - genType(1); |
| 89 | return Tmp + (Multiple - (Tmp % Multiple)); |
| 90 | } |
| 91 | }; |
| 92 | |
| 93 | template<> |
| 94 | struct compute_ceilMultiple<false, true> |
| 95 | { |
| 96 | template<typename genType> |
| 97 | GLM_FUNC_QUALIFIER static genType call(genType Source, genType Multiple) |
| 98 | { |
| 99 | assert(Multiple > genType(0)); |
| 100 | if(Source > genType(0)) |
| 101 | { |
| 102 | genType Tmp = Source - genType(1); |
| 103 | return Tmp + (Multiple - (Tmp % Multiple)); |
| 104 | } |
| 105 | else |
| 106 | return Source + (-Source % Multiple); |
| 107 | } |
| 108 | }; |
| 109 | |
| 110 | template<bool is_float, bool is_signed> |
| 111 | struct compute_floorMultiple{}; |
| 112 | |
| 113 | template<> |
| 114 | struct compute_floorMultiple<true, true> |
| 115 | { |
| 116 | template<typename genType> |
| 117 | GLM_FUNC_QUALIFIER static genType call(genType Source, genType Multiple) |
| 118 | { |
| 119 | if(Source >= genType(0)) |
| 120 | return Source - std::fmod(Source, Multiple); |
| 121 | else |
| 122 | return Source - std::fmod(Source, Multiple) - Multiple; |
| 123 | } |
| 124 | }; |
| 125 | |
| 126 | template<> |
| 127 | struct compute_floorMultiple<false, false> |
| 128 | { |
| 129 | template<typename genType> |
| 130 | GLM_FUNC_QUALIFIER static genType call(genType Source, genType Multiple) |
| 131 | { |
| 132 | if(Source >= genType(0)) |
| 133 | return Source - Source % Multiple; |
| 134 | else |
| 135 | { |
| 136 | genType Tmp = Source + genType(1); |
| 137 | return Tmp - Tmp % Multiple - Multiple; |
| 138 | } |
| 139 | } |
| 140 | }; |
| 141 | |
| 142 | template<> |
| 143 | struct compute_floorMultiple<false, true> |
| 144 | { |
| 145 | template<typename genType> |
| 146 | GLM_FUNC_QUALIFIER static genType call(genType Source, genType Multiple) |
| 147 | { |
| 148 | if(Source >= genType(0)) |
| 149 | return Source - Source % Multiple; |
| 150 | else |
| 151 | { |
| 152 | genType Tmp = Source + genType(1); |
| 153 | return Tmp - Tmp % Multiple - Multiple; |
| 154 | } |
| 155 | } |
| 156 | }; |
| 157 | }//namespace detail |
| 158 | |
| 159 | template<typename genIUType> |
| 160 | GLM_FUNC_QUALIFIER bool isPowerOfTwo(genIUType Value) |
| 161 | { |
| 162 | static_assert(std::numeric_limits<genIUType>::is_integer, "'isPowerOfTwo' only accept integer inputs"); |
| 163 | |
| 164 | genIUType const Result = glm::abs(Value); |
| 165 | return !(Result & (Result - 1)); |
| 166 | } |
| 167 | |
| 168 | template<typename genIUType> |
| 169 | GLM_FUNC_QUALIFIER genIUType nextPowerOfTwo(genIUType value) |
| 170 | { |
| 171 | static_assert(std::numeric_limits<genIUType>::is_integer, "'nextPowerOfTwo' only accept integer inputs"); |
| 172 | |
| 173 | return detail::compute_ceilPowerOfTwo<1, genIUType, defaultp, std::numeric_limits<genIUType>::is_signed>::call(vec<1, genIUType, defaultp>(value)).x; |
| 174 | } |
| 175 | |
| 176 | template<typename genIUType> |
| 177 | GLM_FUNC_QUALIFIER genIUType prevPowerOfTwo(genIUType value) |
| 178 | { |
| 179 | static_assert(std::numeric_limits<genIUType>::is_integer, "'prevPowerOfTwo' only accept integer inputs"); |
| 180 | |
| 181 | return isPowerOfTwo(value) ? value : static_cast<genIUType>(static_cast<genIUType>(1) << static_cast<genIUType>(findMSB(value))); |
| 182 | } |
| 183 | |
| 184 | template<typename genIUType> |
| 185 | GLM_FUNC_QUALIFIER bool isMultiple(genIUType Value, genIUType Multiple) |
| 186 | { |
| 187 | static_assert(std::numeric_limits<genIUType>::is_integer, "'isMultiple' only accept integer inputs"); |
| 188 | |
| 189 | return isMultiple(vec<1, genIUType>(Value), vec<1, genIUType>(Multiple)).x; |
| 190 | } |
| 191 | |
| 192 | template<typename genIUType> |
| 193 | GLM_FUNC_QUALIFIER genIUType nextMultiple(genIUType Source, genIUType Multiple) |
| 194 | { |
| 195 | static_assert(std::numeric_limits<genIUType>::is_integer, "'nextMultiple' only accept integer inputs"); |
| 196 | |
| 197 | return detail::compute_ceilMultiple<std::numeric_limits<genIUType>::is_iec559, std::numeric_limits<genIUType>::is_signed>::call(Source, Multiple); |
| 198 | } |
| 199 | |
| 200 | template<typename genIUType> |
| 201 | GLM_FUNC_QUALIFIER genIUType prevMultiple(genIUType Source, genIUType Multiple) |
| 202 | { |
| 203 | static_assert(std::numeric_limits<genIUType>::is_integer, "'prevMultiple' only accept integer inputs"); |
| 204 | |
| 205 | return detail::compute_floorMultiple<std::numeric_limits<genIUType>::is_iec559, std::numeric_limits<genIUType>::is_signed>::call(Source, Multiple); |
| 206 | } |
| 207 | |
| 208 | template<typename genIUType> |
| 209 | GLM_FUNC_QUALIFIER int findNSB(genIUType x, int significantBitCount) |
| 210 | { |
| 211 | static_assert(std::numeric_limits<genIUType>::is_integer, "'findNSB' only accept integer inputs"); |
| 212 | |
| 213 | if(bitCount(x) < significantBitCount) |
| 214 | return -1; |
| 215 | |
| 216 | genIUType const One = static_cast<genIUType>(1); |
| 217 | int bitPos = 0; |
| 218 | |
| 219 | genIUType key = x; |
| 220 | int nBitCount = significantBitCount; |
| 221 | int Step = sizeof(x) * 8 / 2; |
| 222 | while (key > One) |
| 223 | { |
| 224 | genIUType Mask = static_cast<genIUType>((One << Step) - One); |
| 225 | genIUType currentKey = key & Mask; |
| 226 | int currentBitCount = bitCount(currentKey); |
| 227 | if (nBitCount > currentBitCount) |
| 228 | { |
| 229 | nBitCount -= currentBitCount; |
| 230 | bitPos += Step; |
| 231 | key >>= static_cast<genIUType>(Step); |
| 232 | } |
| 233 | else |
| 234 | { |
| 235 | key = key & Mask; |
| 236 | } |
| 237 | |
| 238 | Step >>= 1; |
| 239 | } |
| 240 | |
| 241 | return static_cast<int>(bitPos); |
| 242 | } |
| 243 | }//namespace glm |