int.h 3.5 KB

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  1. /*
  2. * Copyright (c) 2002-2007, Communications and Remote Sensing Laboratory, Universite catholique de Louvain (UCL), Belgium
  3. * Copyright (c) 2002-2007, Professor Benoit Macq
  4. * Copyright (c) 2001-2003, David Janssens
  5. * Copyright (c) 2002-2003, Yannick Verschueren
  6. * Copyright (c) 2003-2007, Francois-Olivier Devaux and Antonin Descampe
  7. * Copyright (c) 2005, Herve Drolon, FreeImage Team
  8. * All rights reserved.
  9. *
  10. * Redistribution and use in source and binary forms, with or without
  11. * modification, are permitted provided that the following conditions
  12. * are met:
  13. * 1. Redistributions of source code must retain the above copyright
  14. * notice, this list of conditions and the following disclaimer.
  15. * 2. Redistributions in binary form must reproduce the above copyright
  16. * notice, this list of conditions and the following disclaimer in the
  17. * documentation and/or other materials provided with the distribution.
  18. *
  19. * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS `AS IS'
  20. * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  21. * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  22. * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
  23. * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
  24. * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
  25. * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
  26. * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
  27. * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
  28. * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
  29. * POSSIBILITY OF SUCH DAMAGE.
  30. */
  31. #ifndef __INT_H
  32. #define __INT_H
  33. /**
  34. @file int.h
  35. @brief Implementation of operations on integers (INT)
  36. The functions in INT.H have for goal to realize operations on integers.
  37. */
  38. /** @defgroup INT INT - Implementation of operations on integers */
  39. /*@{*/
  40. /** @name Exported functions (see also openjpeg.h) */
  41. /*@{*/
  42. /* ----------------------------------------------------------------------- */
  43. /**
  44. Get the minimum of two integers
  45. @return Returns a if a < b else b
  46. */
  47. static INLINE int int_min(int a, int b) {
  48. return a < b ? a : b;
  49. }
  50. /**
  51. Get the maximum of two integers
  52. @return Returns a if a > b else b
  53. */
  54. static INLINE int int_max(int a, int b) {
  55. return (a > b) ? a : b;
  56. }
  57. /**
  58. Clamp an integer inside an interval
  59. @return
  60. <ul>
  61. <li>Returns a if (min < a < max)
  62. <li>Returns max if (a > max)
  63. <li>Returns min if (a < min)
  64. </ul>
  65. */
  66. static INLINE int int_clamp(int a, int min, int max) {
  67. if (a < min)
  68. return min;
  69. if (a > max)
  70. return max;
  71. return a;
  72. }
  73. /**
  74. @return Get absolute value of integer
  75. */
  76. static INLINE int int_abs(int a) {
  77. return a < 0 ? -a : a;
  78. }
  79. /**
  80. Divide an integer and round upwards
  81. @return Returns a divided by b
  82. */
  83. static INLINE int int_ceildiv(int a, int b) {
  84. return (a + b - 1) / b;
  85. }
  86. /**
  87. Divide an integer by a power of 2 and round upwards
  88. @return Returns a divided by 2^b
  89. */
  90. static INLINE int int_ceildivpow2(int a, int b) {
  91. return (a + (1 << b) - 1) >> b;
  92. }
  93. /**
  94. Divide an integer by a power of 2 and round downwards
  95. @return Returns a divided by 2^b
  96. */
  97. static INLINE int int_floordivpow2(int a, int b) {
  98. return a >> b;
  99. }
  100. /**
  101. Get logarithm of an integer and round downwards
  102. @return Returns log2(a)
  103. */
  104. static INLINE int int_floorlog2(int a) {
  105. int l;
  106. for (l = 0; a > 1; l++) {
  107. a >>= 1;
  108. }
  109. return l;
  110. }
  111. /* ----------------------------------------------------------------------- */
  112. /*@}*/
  113. /*@}*/
  114. #endif