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#include <assert.h>
#include <limits.h>
#include <stdlib.h>
#include <qr/bitmap.h>
#include <qr/bitstream.h>
#include <qr/code.h>
#include <qr/common.h>
#include "constants.h"
void qr_code_destroy(struct qr_code * code)
{
if (code) {
qr_bitmap_destroy(code->modules);
free(code);
}
}
int qr_code_width(const struct qr_code * code)
{
return code->version * 4 + 17;
}
size_t qr_code_total_capacity(int version)
{
int side = version * 4 + 17;
int alignment_side = version > 1 ? (version / 7) + 2 : 0;
int alignment_count = alignment_side >= 2 ?
alignment_side * alignment_side - 3 : 0;
int locator_bits = 8*8*3;
int format_bits = 8*4 - 1 + (version >= 7 ? 6*3*2 : 0);
int timing_bits = 2 * (side - 8*2 -
(alignment_side > 2 ? (alignment_side - 2) * 5 : 0));
int function_bits = timing_bits + format_bits + locator_bits
+ alignment_count * 5*5;
return side * side - function_bits;
}
void qr_get_rs_block_sizes(int version,
enum qr_ec_level ec,
int block_count[2],
int data_length[2],
int ec_length[2])
{
/* FIXME: rather than using a big static table, better to
* calculate these values.
*/
int total_words = qr_code_total_capacity(version) / 8;
int data_words = QR_DATA_WORD_COUNT[version - 1][ec ^ 0x1];
int ec_words = total_words - data_words;
int total_blocks;
block_count[0] = QR_RS_BLOCK_COUNT[version - 1][ec ^ 0x1][0];
block_count[1] = QR_RS_BLOCK_COUNT[version - 1][ec ^ 0x1][1];
total_blocks = block_count[0] + block_count[1];
data_length[0] = data_words / total_blocks;
data_length[1] = data_length[0] + 1;
assert(data_length[0] * block_count[0] +
data_length[1] * block_count[1] == data_words);
ec_length[0] = ec_length[1] = ec_words / total_blocks;
assert(ec_length[0] * block_count[0] +
ec_length[1] * block_count[1] == ec_words);
assert(data_words + ec_words == total_words);
}
void qr_mask_apply(struct qr_bitmap * bmp, int mask)
{
int i, j;
assert((mask & 0x7) == mask);
mask &= 0x7;
/* Slow version for now; we can optimize later */
for (i = 0; i < bmp->height; ++i) {
unsigned char * p = bmp->bits + i * bmp->stride;
for (j = 0; j < bmp->width; ++j) {
int bit = j % CHAR_BIT;
size_t off = j / CHAR_BIT;
int t;
switch (mask) {
case 0: t = (i + j) % 2; break;
case 1: t = i % 2; break;
case 2: t = j % 3; break;
case 3: t = (i + j) % 3; break;
case 4: t = (i/2 + j/3) % 2; break;
case 5: t = ((i*j) % 2) + ((i*j) % 3); break;
case 6: t = (((i*j) % 2) + ((i*j) % 3)) % 2; break;
case 7: t = (((i*j) % 3) + ((i+j) % 2)) % 2; break;
}
p[off] ^= (t == 0) << bit;
}
}
}
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