source/libs/pixman/pixman-src/pixman/pixman-utils.c

   1 /*
   2  * Copyright © 2000 SuSE, Inc.
   3  * Copyright © 1999 Keith Packard
   4  *
   5  * Permission to use, copy, modify, distribute, and sell this software and its
   6  * documentation for any purpose is hereby granted without fee, provided that
   7  * the above copyright notice appear in all copies and that both that
   8  * copyright notice and this permission notice appear in supporting
   9  * documentation, and that the name of SuSE not be used in advertising or
  10  * publicity pertaining to distribution of the software without specific,
  11  * written prior permission.  SuSE makes no representations about the
  12  * suitability of this software for any purpose.  It is provided "as is"
  13  * without express or implied warranty.
  14  *
  15  * SuSE DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE, INCLUDING ALL
  16  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS, IN NO EVENT SHALL SuSE
  17  * BE LIABLE FOR ANY SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
  18  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION
  19  * OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN
  20  * CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
  21  *
  22  * Author:  Keith Packard, SuSE, Inc.
  23  */
  24
  25 #ifdef HAVE_CONFIG_H
  26 #include <config.h>
  27 #endif
  28 #include <stdio.h>
  29 #include <stdlib.h>
  30
  31 #include "pixman-private.h"
  32
  33 pixman_bool_t
  34 _pixman_multiply_overflows_size (size_t a, size_t b)
  35 {
  36     return a >= SIZE_MAX / b;
  37 }
  38
  39 pixman_bool_t
  40 _pixman_multiply_overflows_int (unsigned int a, unsigned int b)
  41 {
  42     return a >= INT32_MAX / b;
  43 }
  44
  45 pixman_bool_t
  46 _pixman_addition_overflows_int (unsigned int a, unsigned int b)
  47 {
  48     return a > INT32_MAX - b;
  49 }
  50
  51 void *
  52 pixman_malloc_ab_plus_c (unsigned int a, unsigned int b, unsigned int c)
  53 {
  54     if (!b || a >= INT32_MAX / b || (a * b) > INT32_MAX - c)
  55         return NULL;
  56
  57     return malloc (a * b + c);
  58 }
  59
  60 void *
  61 pixman_malloc_ab (unsigned int a,
  62                   unsigned int b)
  63 {
  64     if (a >= INT32_MAX / b)
  65         return NULL;
  66
  67     return malloc (a * b);
  68 }
  69
  70 void *
  71 pixman_malloc_abc (unsigned int a,
  72                    unsigned int b,
  73                    unsigned int c)
  74 {
  75     if (a >= INT32_MAX / b)
  76         return NULL;
  77     else if (a * b >= INT32_MAX / c)
  78         return NULL;
  79     else
  80         return malloc (a * b * c);
  81 }
  82
  83 static force_inline uint16_t
  84 float_to_unorm (float f, int n_bits)
  85 {
  86     uint32_t u;
  87
  88     if (f > 1.0)
  89         f = 1.0;
  90     if (f < 0.0)
  91         f = 0.0;
  92
  93     u = f * (1 << n_bits);
  94     u -= (u >> n_bits);
  95
  96     return u;
  97 }
  98
  99 static force_inline float
 100 unorm_to_float (uint16_t u, int n_bits)
 101 {
 102     uint32_t m = ((1 << n_bits) - 1);
 103
 104     return (u & m) * (1.f / (float)m);
 105 }
 106
 107 /*
 108  * This function expands images from a8r8g8b8 to argb_t.  To preserve
 109  * precision, it needs to know from which source format the a8r8g8b8 pixels
 110  * originally came.
 111  *
 112  * For example, if the source was PIXMAN_x1r5g5b5 and the red component
 113  * contained bits 12345, then the 8-bit value is 12345123.  To correctly
 114  * expand this to floating point, it should be 12345 / 31.0 and not
 115  * 12345123 / 255.0.
 116  */
 117 void
 118 pixman_expand_to_float (argb_t               *dst,
 119                         const uint32_t       *src,
 120                         pixman_format_code_t  format,
 121                         int                   width)
 122 {
 123     static const float multipliers[16] = {
 124         0.0f,
 125         1.0f / ((1 <<  1) - 1),
 126         1.0f / ((1 <<  2) - 1),
 127         1.0f / ((1 <<  3) - 1),
 128         1.0f / ((1 <<  4) - 1),
 129         1.0f / ((1 <<  5) - 1),
 130         1.0f / ((1 <<  6) - 1),
 131         1.0f / ((1 <<  7) - 1),
 132         1.0f / ((1 <<  8) - 1),
 133         1.0f / ((1 <<  9) - 1),
 134         1.0f / ((1 << 10) - 1),
 135         1.0f / ((1 << 11) - 1),
 136         1.0f / ((1 << 12) - 1),
 137         1.0f / ((1 << 13) - 1),
 138         1.0f / ((1 << 14) - 1),
 139         1.0f / ((1 << 15) - 1),
 140     };
 141     int a_size, r_size, g_size, b_size;
 142     int a_shift, r_shift, g_shift, b_shift;
 143     float a_mul, r_mul, g_mul, b_mul;
 144     uint32_t a_mask, r_mask, g_mask, b_mask;
 145     int i;
 146
 147     if (!PIXMAN_FORMAT_VIS (format))
 148         format = PIXMAN_a8r8g8b8;
 149
 150     /*
 151      * Determine the sizes of each component and the masks and shifts
 152      * required to extract them from the source pixel.
 153      */
 154     a_size = PIXMAN_FORMAT_A (format);
 155     r_size = PIXMAN_FORMAT_R (format);
 156     g_size = PIXMAN_FORMAT_G (format);
 157     b_size = PIXMAN_FORMAT_B (format);
 158
 159     a_shift = 32 - a_size;
 160     r_shift = 24 - r_size;
 161     g_shift = 16 - g_size;
 162     b_shift =  8 - b_size;
 163
 164     a_mask = ((1 << a_size) - 1);
 165     r_mask = ((1 << r_size) - 1);
 166     g_mask = ((1 << g_size) - 1);
 167     b_mask = ((1 << b_size) - 1);
 168
 169     a_mul = multipliers[a_size];
 170     r_mul = multipliers[r_size];
 171     g_mul = multipliers[g_size];
 172     b_mul = multipliers[b_size];
 173
 174     /* Start at the end so that we can do the expansion in place
 175      * when src == dst
 176      */
 177     for (i = width - 1; i >= 0; i--)
 178     {
 179         const uint32_t pixel = src[i];
 180
 181         dst[i].a = a_mask? ((pixel >> a_shift) & a_mask) * a_mul : 1.0f;
 182         dst[i].r = ((pixel >> r_shift) & r_mask) * r_mul;
 183         dst[i].g = ((pixel >> g_shift) & g_mask) * g_mul;
 184         dst[i].b = ((pixel >> b_shift) & b_mask) * b_mul;
 185     }
 186 }
 187
 188 uint16_t
 189 pixman_float_to_unorm (float f, int n_bits)
 190 {
 191     return float_to_unorm (f, n_bits);
 192 }
 193
 194 float
 195 pixman_unorm_to_float (uint16_t u, int n_bits)
 196 {
 197     return unorm_to_float (u, n_bits);
 198 }
 199
 200 void
 201 pixman_contract_from_float (uint32_t     *dst,
 202                             const argb_t *src,
 203                             int           width)
 204 {
 205     int i;
 206
 207     for (i = 0; i < width; ++i)
 208     {
 209         uint8_t a, r, g, b;
 210
 211         a = float_to_unorm (src[i].a, 8);
 212         r = float_to_unorm (src[i].r, 8);
 213         g = float_to_unorm (src[i].g, 8);
 214         b = float_to_unorm (src[i].b, 8);
 215
 216         dst[i] = (a << 24) | (r << 16) | (g << 8) | (b << 0);
 217     }
 218 }
 219
 220 uint32_t *
 221 _pixman_iter_get_scanline_noop (pixman_iter_t *iter, const uint32_t *mask)
 222 {
 223     return iter->buffer;
 224 }
 225
 226 void
 227 _pixman_iter_init_bits_stride (pixman_iter_t *iter, const pixman_iter_info_t *info)
 228 {
 229     pixman_image_t *image = iter->image;
 230     uint8_t *b = (uint8_t *)image->bits.bits;
 231     int s = image->bits.rowstride * 4;
 232
 233     iter->bits = b + s * iter->y + iter->x * PIXMAN_FORMAT_BPP (info->format) / 8;
 234     iter->stride = s;
 235 }
 236
 237 #define N_TMP_BOXES (16)
 238
 239 pixman_bool_t
 240 pixman_region16_copy_from_region32 (pixman_region16_t *dst,
 241                                     pixman_region32_t *src)
 242 {
 243     int n_boxes, i;
 244     pixman_box32_t *boxes32;
 245     pixman_box16_t *boxes16;
 246     pixman_bool_t retval;
 247
 248     boxes32 = pixman_region32_rectangles (src, &n_boxes);
 249
 250     boxes16 = pixman_malloc_ab (n_boxes, sizeof (pixman_box16_t));
 251
 252     if (!boxes16)
 253         return FALSE;
 254
 255     for (i = 0; i < n_boxes; ++i)
 256     {
 257         boxes16[i].x1 = boxes32[i].x1;
 258         boxes16[i].y1 = boxes32[i].y1;
 259         boxes16[i].x2 = boxes32[i].x2;
 260         boxes16[i].y2 = boxes32[i].y2;
 261     }
 262
 263     pixman_region_fini (dst);
 264     retval = pixman_region_init_rects (dst, boxes16, n_boxes);
 265     free (boxes16);
 266     return retval;
 267 }
 268
 269 pixman_bool_t
 270 pixman_region32_copy_from_region16 (pixman_region32_t *dst,
 271                                     pixman_region16_t *src)
 272 {
 273     int n_boxes, i;
 274     pixman_box16_t *boxes16;
 275     pixman_box32_t *boxes32;
 276     pixman_box32_t tmp_boxes[N_TMP_BOXES];
 277     pixman_bool_t retval;
 278
 279     boxes16 = pixman_region_rectangles (src, &n_boxes);
 280
 281     if (n_boxes > N_TMP_BOXES)
 282         boxes32 = pixman_malloc_ab (n_boxes, sizeof (pixman_box32_t));
 283     else
 284         boxes32 = tmp_boxes;
 285
 286     if (!boxes32)
 287         return FALSE;
 288
 289     for (i = 0; i < n_boxes; ++i)
 290     {
 291         boxes32[i].x1 = boxes16[i].x1;
 292         boxes32[i].y1 = boxes16[i].y1;
 293         boxes32[i].x2 = boxes16[i].x2;
 294         boxes32[i].y2 = boxes16[i].y2;
 295     }
 296
 297     pixman_region32_fini (dst);
 298     retval = pixman_region32_init_rects (dst, boxes32, n_boxes);
 299
 300     if (boxes32 != tmp_boxes)
 301         free (boxes32);
 302
 303     return retval;
 304 }
 305
 306 /* This function is exported for the sake of the test suite and not part
 307  * of the ABI.
 308  */
 309 PIXMAN_EXPORT pixman_implementation_t *
 310 _pixman_internal_only_get_implementation (void)
 311 {
 312     return get_implementation ();
 313 }
 314
 315 void
 316 _pixman_log_error (const char *function, const char *message)
 317 {
 318     static int n_messages = 0;
 319
 320     if (n_messages < 10)
 321     {
 322         fprintf (stderr,
 323                  "*** BUG ***\n"
 324                  "In %s: %s\n"
 325                  "Set a breakpoint on '_pixman_log_error' to debug\n\n",
 326                  function, message);
 327
 328         n_messages++;
 329     }
 330 }