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/* quirc -- QR-code recognition library
* Copyright (C) 2010-2012 Daniel Beer <dlbeer@gmail.com>
*
* Permission to use, copy, modify, and/or distribute this software for any
* purpose with or without fee is hereby granted, provided that the above
* copyright notice and this permission notice appear in all copies.
*
* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
* ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
* ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
* OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
*/
#include <stdlib.h>
#include <string.h>
#include "quirc_internal.h"
const char *quirc_version(void)
{
return "1.0";
}
struct quirc *quirc_new(void)
{
struct quirc *q = QUIRC_MALLOC(sizeof(*q));
if (!q)
return NULL;
memset(q, 0, sizeof(*q));
return q;
}
void quirc_destroy(struct quirc *q)
{
QUIRC_FREE(q->image);
/* q->pixels may alias q->image when their type representation is of the
same size, so we need to be careful here to avoid a double QUIRC_FREE */
if (!QUIRC_PIXEL_ALIAS_IMAGE)
QUIRC_FREE(q->pixels);
QUIRC_FREE(q->flood_fill_vars);
QUIRC_FREE(q);
}
int quirc_resize(struct quirc *q, int w, int h)
{
uint8_t *image = NULL;
quirc_pixel_t *pixels = NULL;
size_t num_vars;
size_t vars_byte_size;
struct quirc_flood_fill_vars *vars = NULL;
/*
* XXX: w and h should be size_t (or at least unsigned) as negatives
* values would not make much sense. The downside is that it would break
* both the API and ABI. Thus, at the moment, let's just do a sanity
* check.
*/
if (w < 0 || h < 0)
goto fail;
/*
* alloc a new buffer for q->image. We avoid realloc(3) because we want
* on failure to be leave `q` in a consistant, unmodified state.
*/
image = QUIRC_CALLOC(w, h);
if (!image)
goto fail;
/* compute the "old" (i.e. currently allocated) and the "new"
(i.e. requested) image dimensions */
size_t olddim = q->w * q->h;
size_t newdim = w * h;
size_t min = (olddim < newdim ? olddim : newdim);
/*
* copy the data into the new buffer, avoiding (a) to read beyond the
* old buffer when the new size is greater and (b) to write beyond the
* new buffer when the new size is smaller, hence the min computation.
*/
(void)memcpy(image, q->image, min);
/* alloc a new buffer for q->pixels if needed */
if (!QUIRC_PIXEL_ALIAS_IMAGE) {
pixels = QUIRC_CALLOC(newdim, sizeof(quirc_pixel_t));
if (!pixels)
goto fail;
}
/*
* alloc the work area for the flood filling logic.
*
* the size was chosen with the following assumptions and observations:
*
* - rings are the regions which requires the biggest work area.
* - they consumes the most when they are rotated by about 45 degree.
* in that case, the necessary depth is about (2 * height_of_the_ring).
* - the maximum height of rings would be about 1/3 of the image height.
*/
if ((size_t)h * 2 / 2 != (size_t)h) {
goto fail; /* size_t overflow */
}
num_vars = (size_t)h * 2 / 3;
if (num_vars == 0) {
num_vars = 1;
}
vars_byte_size = sizeof(*vars) * num_vars;
if (vars_byte_size / sizeof(*vars) != num_vars) {
goto fail; /* size_t overflow */
}
vars = QUIRC_MALLOC(vars_byte_size);
if (!vars)
goto fail;
/* alloc succeeded, update `q` with the new size and buffers */
q->w = w;
q->h = h;
QUIRC_FREE(q->image);
q->image = image;
if (!QUIRC_PIXEL_ALIAS_IMAGE) {
QUIRC_FREE(q->pixels);
q->pixels = pixels;
}
QUIRC_FREE(q->flood_fill_vars);
q->flood_fill_vars = vars;
q->num_flood_fill_vars = num_vars;
return 0;
/* NOTREACHED */
fail:
QUIRC_FREE(image);
QUIRC_FREE(pixels);
QUIRC_FREE(vars);
return -1;
}
int quirc_count(const struct quirc *q)
{
return q->num_grids;
}
static const char *const error_table[] = {
[QUIRC_SUCCESS] = "Success",
[QUIRC_ERROR_INVALID_GRID_SIZE] = "Invalid grid size",
[QUIRC_ERROR_INVALID_VERSION] = "Invalid version",
[QUIRC_ERROR_FORMAT_ECC] = "Format data ECC failure",
[QUIRC_ERROR_DATA_ECC] = "ECC failure",
[QUIRC_ERROR_UNKNOWN_DATA_TYPE] = "Unknown data type",
[QUIRC_ERROR_DATA_OVERFLOW] = "Data overflow",
[QUIRC_ERROR_DATA_UNDERFLOW] = "Data underflow"
};
const char *quirc_strerror(quirc_decode_error_t err)
{
if (err >= 0 && err < sizeof(error_table) / sizeof(error_table[0]))
return error_table[err];
return "Unknown error";
}
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