JasPer: jas_fix.h Source File

JasPer 2.0.25 |

jas_fix.h
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1 /*
2 * Copyright (c) 1999-2000 Image Power, Inc. and the University of
3 * British Columbia.
4 * Copyright (c) 2001-2002 Michael David Adams.
5 * All rights reserved.
6 */
7
8 /* __START_OF_JASPER_LICENSE__
9 *
10 * JasPer License Version 2.0
11 *
12 * Copyright (c) 2001-2006 Michael David Adams
13 * Copyright (c) 1999-2000 Image Power, Inc.
14 * Copyright (c) 1999-2000 The University of British Columbia
15 *
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60 *
61 * __END_OF_JASPER_LICENSE__
62 */
63
69 #ifndef JAS_FIX_H
70 #define JAS_FIX_H
71
72 /******************************************************************************\
73 * Includes.
74 \******************************************************************************/
75
76 /* The configuration header file should be included first. */
77 #include <jasper/jas_config.h> /* IWYU pragma: keep */
78
79 #include <jasper/jas_types.h>
80
81 #ifdef __cplusplus
82 extern "C" {
83 #endif
84
85 /******************************************************************************\
86 * Constants.
87 \******************************************************************************/
88
89 /* The representation of the value zero. */
90 #define JAS_FIX_ZERO(fix_t, fracbits) \
91 JAS_INTTOFIX(fix_t, fracbits, 0)
92
93 /* The representation of the value one. */
94 #define JAS_FIX_ONE(fix_t, fracbits) \
95 JAS_INTTOFIX(fix_t, fracbits, 1)
96
97 /* The representation of the value one half. */
98 #define JAS_FIX_HALF(fix_t, fracbits) \
99 (JAS_CAST(fix_t, 1) << ((fracbits) - 1))
100
101 /******************************************************************************\
102 * Conversion operations.
103 \******************************************************************************/
104
105 /* Convert an int to a fixed-point number. */
106 #define JAS_INTTOFIX(fix_t, fracbits, x) \
107 (JAS_CAST(fix_t, x) << (fracbits))
108
109 /* Convert a fixed-point number to an int. */
110 #define JAS_FIXTOINT(fix_t, fracbits, x) \
111 JAS_CAST(int, (x) >> (fracbits))
112
113 /* Convert a fixed-point number to a double. */
114 #define JAS_FIXTODBL(fix_t, fracbits, x) \
115 (JAS_CAST(double, x) / JAS_FIX_ONE(fix_t, fracbits))
116
117 /* Convert a double to a fixed-point number. */
118 #define JAS_DBLTOFIX(fix_t, fracbits, x) \
119 JAS_CAST(fix_t, ((x) * JAS_CAST(double, JAS_FIX_ONE(fix_t, fracbits))))
120
121 /******************************************************************************\
122 * Basic arithmetic operations.
123 * All other arithmetic operations are synthesized from these basic operations.
124 * There are three macros for each type of arithmetic operation.
125 * One macro always performs overflow/underflow checking, one never performs
126 * overflow/underflow checking, and one is generic with its behavior
127 * depending on compile-time flags.
128 * Only the generic macros should be invoked directly by application code.
129 \******************************************************************************/
130
131 /* Calculate the sum of two fixed-point numbers. */
132 #if !defined(DEBUG_OVERFLOW)
133 #define JAS_FIX_ADD JAS_FIX_ADD_FAST
134 #else
135 #define JAS_FIX_ADD JAS_FIX_ADD_OFLOW
136 #endif
137
138 /* Calculate the sum of two fixed-point numbers without overflow checking. */
139 #define JAS_FIX_ADD_FAST(fix_t, fracbits, x, y) ((x) + (y))
140
141 /* Calculate the sum of two fixed-point numbers with overflow checking. */
142 #define JAS_FIX_ADD_OFLOW(fix_t, fracbits, x, y) \
143 ((x) >= 0) ? \
144 (((y) >= 0) ? ((x) + (y) >= 0 || JAS_FIX_OFLOW(), (x) + (y)) : \
145 ((x) + (y))) : \
146 (((y) >= 0) ? ((x) + (y)) : ((x) + (y) < 0 || JAS_FIX_OFLOW(), \
147 (x) + (y)))
148
149 /* Calculate the product of two fixed-point numbers. */
150 #if !defined(DEBUG_OVERFLOW)
151 #define JAS_FIX_MUL JAS_FIX_MUL_FAST
152 #else
153 #define JAS_FIX_MUL JAS_FIX_MUL_OFLOW
154 #endif
155
156 /* Calculate the product of two fixed-point numbers without overflow
157 checking. */
158 #define JAS_FIX_MUL_FAST(fix_t, fracbits, bigfix_t, x, y) \
159 JAS_CAST(fix_t, (JAS_CAST(bigfix_t, x) * JAS_CAST(bigfix_t, y)) >> \
160 (fracbits))
161
162 /* Calculate the product of two fixed-point numbers with overflow
163 checking. */
164 #define JAS_FIX_MUL_OFLOW(fix_t, fracbits, bigfix_t, x, y) \
165 ((JAS_CAST(bigfix_t, x) * JAS_CAST(bigfix_t, y) >> (fracbits)) == \
166 JAS_CAST(fix_t, (JAS_CAST(bigfix_t, x) * JAS_CAST(bigfix_t, y) >> \
167 (fracbits))) ? \
168 JAS_CAST(fix_t, (JAS_CAST(bigfix_t, x) * JAS_CAST(bigfix_t, y) >> \
169 (fracbits))) : JAS_FIX_OFLOW())
170
171 /* Calculate the product of a fixed-point number and an int. */
172 #if !defined(DEBUG_OVERFLOW)
173 #define JAS_FIX_MULBYINT JAS_FIX_MULBYINT_FAST
174 #else
175 #define JAS_FIX_MULBYINT JAS_FIX_MULBYINT_OFLOW
176 #endif
177
178 /* Calculate the product of a fixed-point number and an int without overflow
179 checking. */
180 #define JAS_FIX_MULBYINT_FAST(fix_t, fracbits, x, y) \
181 JAS_CAST(fix_t, ((x) * (y)))
182
183 /* Calculate the product of a fixed-point number and an int with overflow
184 checking. */
185 #define JAS_FIX_MULBYINT_OFLOW(fix_t, fracbits, x, y) \
186 JAS_FIX_MULBYINT_FAST(fix_t, fracbits, x, y)
187
188 /* Calculate the quotient of two fixed-point numbers. */
189 #if !defined(DEBUG_OVERFLOW)
190 #define JAS_FIX_DIV JAS_FIX_DIV_FAST
191 #else
192 #define JAS_FIX_DIV JAS_FIX_DIV_UFLOW
193 #endif
194
195 /* Calculate the quotient of two fixed-point numbers without underflow
196 checking. */
197 #define JAS_FIX_DIV_FAST(fix_t, fracbits, bigfix_t, x, y) \
198 JAS_CAST(fix_t, (JAS_CAST(bigfix_t, x) << (fracbits)) / (y))
199
200 /* Calculate the quotient of two fixed-point numbers with underflow
201 checking. */
202 #define JAS_FIX_DIV_UFLOW(fix_t, fracbits, bigfix_t, x, y) \
203 JAS_FIX_DIV_FAST(fix_t, fracbits, bigfix_t, x, y)
204
205 /* Negate a fixed-point number. */
206 #if !defined(DEBUG_OVERFLOW)
207 #define JAS_FIX_NEG JAS_FIX_NEG_FAST
208 #else
209 #define JAS_FIX_NEG JAS_FIX_NEG_OFLOW
210 #endif
211
212 /* Negate a fixed-point number without overflow checking. */
213 #define JAS_FIX_NEG_FAST(fix_t, fracbits, x) \
214 (-(x))
215
216 /* Negate a fixed-point number with overflow checking. */
217 /* Yes, overflow is actually possible for two's complement representations,
218 although highly unlikely to occur. */
219 #define JAS_FIX_NEG_OFLOW(fix_t, fracbits, x) \
220 (((x) < 0) ? (-(x) > 0 || JAS_FIX_OFLOW(), -(x)) : (-(x)))
221
222 /* Perform an arithmetic shift left of a fixed-point number. */
223 #if !defined(DEBUG_OVERFLOW)
224 #define JAS_FIX_ASL JAS_FIX_ASL_FAST
225 #else
226 #define JAS_FIX_ASL JAS_FIX_ASL_OFLOW
227 #endif
228
229 /* Perform an arithmetic shift left of a fixed-point number without overflow
230 checking. */
231 #define JAS_FIX_ASL_FAST(fix_t, fracbits, x, n) \
232 ((x) << (n))
233
234 /* Perform an arithmetic shift left of a fixed-point number with overflow
235 checking. */
236 #define JAS_FIX_ASL_OFLOW(fix_t, fracbits, x, n) \
237 ((((x) << (n)) >> (n)) == (x) || JAS_FIX_OFLOW(), (x) << (n))
238
239 /* Perform an arithmetic shift right of a fixed-point number. */
240 #if !defined(DEBUG_OVERFLOW)
241 #define JAS_FIX_ASR JAS_FIX_ASR_FAST
242 #else
243 #define JAS_FIX_ASR JAS_FIX_ASR_UFLOW
244 #endif
245
246 /* Perform an arithmetic shift right of a fixed-point number without underflow
247 checking. */
248 #define JAS_FIX_ASR_FAST(fix_t, fracbits, x, n) \
249 ((x) >> (n))
250
251 /* Perform an arithmetic shift right of a fixed-point number with underflow
252 checking. */
253 #define JAS_FIX_ASR_UFLOW(fix_t, fracbits, x, n) \
254 JAS_FIX_ASR_FAST(fix_t, fracbits, x, n)
255
256 /******************************************************************************\
257 * Other basic arithmetic operations.
258 \******************************************************************************/
259
260 /* Calculate the difference between two fixed-point numbers. */
261 #define JAS_FIX_SUB(fix_t, fracbits, x, y) \
262 JAS_FIX_ADD(fix_t, fracbits, x, JAS_FIX_NEG(fix_t, fracbits, y))
263
264 /* Add one fixed-point number to another. */
265 #define JAS_FIX_PLUSEQ(fix_t, fracbits, x, y) \
266 ((x) = JAS_FIX_ADD(fix_t, fracbits, x, y))
267
268 /* Subtract one fixed-point number from another. */
269 #define JAS_FIX_MINUSEQ(fix_t, fracbits, x, y) \
270 ((x) = JAS_FIX_SUB(fix_t, fracbits, x, y))
271
272 /* Multiply one fixed-point number by another. */
273 #define JAS_FIX_MULEQ(fix_t, fracbits, bigfix_t, x, y) \
274 ((x) = JAS_FIX_MUL(fix_t, fracbits, bigfix_t, x, y))
275
276 /******************************************************************************\
277 * Miscellaneous operations.
278 \******************************************************************************/
279
280 /* Calculate the absolute value of a fixed-point number. */
281 #define JAS_FIX_ABS(fix_t, fracbits, x) \
282 (((x) >= 0) ? (x) : (JAS_FIX_NEG(fix_t, fracbits, x)))
283
284 /* Is a fixed-point number an integer? */
285 #define JAS_FIX_ISINT(fix_t, fracbits, x) \
286 (JAS_FIX_FLOOR(fix_t, fracbits, x) == (x))
287
288 /* Get the sign of a fixed-point number. */
289 #define JAS_FIX_SGN(fix_t, fracbits, x) \
290 ((x) >= 0 ? 1 : (-1))
291
292 /******************************************************************************\
293 * Relational operations.
294 \******************************************************************************/
295
296 /* Compare two fixed-point numbers. */
297 #define JAS_FIX_CMP(fix_t, fracbits, x, y) \
298 ((x) > (y) ? 1 : (((x) == (y)) ? 0 : (-1)))
299
300 /* Less than. */
301 #define JAS_FIX_LT(fix_t, fracbits, x, y) \
302 ((x) < (y))
303
304 /* Less than or equal. */
305 #define JAS_FIX_LTE(fix_t, fracbits, x, y) \
306 ((x) <= (y))
307
308 /* Greater than. */
309 #define JAS_FIX_GT(fix_t, fracbits, x, y) \
310 ((x) > (y))
311
312 /* Greater than or equal. */
313 #define JAS_FIX_GTE(fix_t, fracbits, x, y) \
314 ((x) >= (y))
315
316 /******************************************************************************\
317 * Rounding functions.
318 \******************************************************************************/
319
320 /* Round a fixed-point number to the nearest integer. */
321 #define JAS_FIX_ROUND(fix_t, fracbits, x) \
322 (((x) < 0) ? JAS_FIX_FLOOR(fix_t, fracbits, JAS_FIX_ADD(fix_t, fracbits, \
323 (x), JAS_FIX_HALF(fix_t, fracbits))) : \
324 JAS_FIX_NEG(fix_t, fracbits, JAS_FIX_FLOOR(fix_t, fracbits, \
325 JAS_FIX_ADD(fix_t, fracbits, (-(x)), JAS_FIX_HALF(fix_t, fracbits)))))
326
327 /* Round a fixed-point number to the nearest integer in the direction of
328 negative infinity (i.e., the floor function). */
329 #define JAS_FIX_FLOOR(fix_t, fracbits, x) \
330 ((x) & (~(JAS_FIX_ONE(fix_t, fracbits) - 1)))
331
332 /******************************************************************************\
333 * The below macros are for internal library use only. Do not invoke them
334 * directly in application code.
335 \******************************************************************************/
336
337 /* Handle overflow. */
338 #define JAS_FIX_OFLOW() \
339 jas_eprintf("overflow error: file %s, line %d\n", __FILE__, __LINE__)
340
341 /* Handle underflow. */
342 #define JAS_FIX_UFLOW() \
343 jas_eprintf("underflow error: file %s, line %d\n", __FILE__, __LINE__)
344
345 #ifdef __cplusplus
346 }
347 #endif
348
349 #endif
jas_types.h
Primitive Types.