static int blits_intersect_or_touch(mdjvu_image_t image, int32 b1, int32 b2)
{
int32 x1 = mdjvu_image_get_blit_x(image, b1);
int32 x2 = mdjvu_image_get_blit_x(image, b2);
int32 y1 = mdjvu_image_get_blit_y(image, b1);
int32 y2 = mdjvu_image_get_blit_y(image, b2);
mdjvu_bitmap_t bitmap1 = mdjvu_image_get_blit_bitmap(image, b1);
mdjvu_bitmap_t bitmap2 = mdjvu_image_get_blit_bitmap(image, b2);
int32 w1 = mdjvu_bitmap_get_width(bitmap1);
int32 w2 = mdjvu_bitmap_get_width(bitmap2);
int32 h1 = mdjvu_bitmap_get_height(bitmap1);
int32 h2 = mdjvu_bitmap_get_height(bitmap2);
return segments_intersect_or_touch(x1, w1, x2, w2)
&& segments_intersect_or_touch(y1, h1, y2, h2);
}
MDJVU_IMPLEMENT void mdjvu_sort_blits(mdjvu_image_t img)
{
/* We're going to sort only blits with `is_a_letter' flag set. */
int32 char_blit_count = 0;
int32 blit_count, i, j, maxtopchange, ccno;
BlitPassport *bps;
int32 *bottoms, *passport_of_blit;
if (!mdjvu_image_has_not_a_letter_flags(img))
mdjvu_calculate_not_a_letter_flags(img);
/* Count letter blits */
blit_count = mdjvu_image_get_blit_count(img);
for (i = 0; i < blit_count; i++)
{
mdjvu_bitmap_t bmp = mdjvu_image_get_blit_bitmap(img, i);
if (!mdjvu_image_get_not_a_letter_flag(img, bmp))
char_blit_count++;
}
if (char_blit_count < 2) return;
/* Allocate `bps' and `bottoms' arrays */
bps = (BlitPassport *) malloc(char_blit_count * sizeof(BlitPassport));
bottoms = (int32 *) malloc(char_blit_count * sizeof(int32));
/* Fill in `bps' with character blit passports */
j = 0;
for (i = 0; i < blit_count; i++)
{
mdjvu_bitmap_t bmp = mdjvu_image_get_blit_bitmap(img, i);
if (!mdjvu_image_get_not_a_letter_flag(img, bmp))
{
int32 x = bps[j].left = mdjvu_image_get_blit_x(img, i);
int32 y = bps[j].top = mdjvu_image_get_blit_y(img, i);;
bps[j].right = x + mdjvu_bitmap_get_width(bmp) - 1;
bps[j].bottom = y + mdjvu_bitmap_get_height(bmp) - 1;
bps[j].original_index = i;
j++;
}
}
/* Sort the BlitPassports list in top-to-bottom order. */
qsort(bps, char_blit_count, sizeof(BlitPassport),
&compare_top_edges_downward);
/* Subdivide the ccarray list roughly into text lines [LYB] */
/* Determine maximal top deviation */
maxtopchange = mdjvu_image_get_width(img) / 40;
if (maxtopchange < 32) maxtopchange = 32;
/* Loop until processing all ccs */
ccno = 0;
while (ccno < char_blit_count) /* ccno will be increasing constantly */
{
/* Gather first line approximation */
int32 sublist_top = bps[ccno].top;
int32 sublist_bottom = bps[ccno].bottom;
int32 nccno;
/* nccno will be at least ccno + 1,
* or otherwise we're hung.
*/
for (nccno = ccno; nccno < char_blit_count; nccno++)
{
int32 bottom;
if (bps[nccno].top > sublist_bottom) break;
if (bps[nccno].top > sublist_top + maxtopchange) break;
bottom = bps[nccno].bottom;
bottoms[nccno - ccno] = bottom;
if (bottom > sublist_bottom)
sublist_bottom = bottom;
}
/* If more than one candidate cc for the line */
if (nccno > ccno + 1)
{
/* Compute median bottom */
int32 bottom;
qsort(bottoms, nccno - ccno, sizeof(int32),
&compare_integers_reversed);
bottom = bottoms[ (nccno - ccno - 1) / 2 ];
/* Compose final line */
for (nccno = ccno; nccno < char_blit_count; nccno++)
if (bps[nccno].top > bottom)
break;
/* Sort final line */
qsort(bps + ccno, nccno - ccno, sizeof(BlitPassport),
&compare_left_edges_rightward);
}
/* Next line */
ccno = nccno;
}
/* Permute the blits according to `bps' */
passport_of_blit = (int32 *) malloc(blit_count * sizeof(int32));
for (i = 0; i < blit_count; i++)
passport_of_blit[i] = -1;
for (i = 0; i < char_blit_count; i++)
passport_of_blit[bps[i].original_index] = i;
/* We'll maintain that bps[i].original_index points to the same blit */
for (i = 0; i < char_blit_count; i++)
{
int32 blit_to_put_here = bps[i].original_index;
mdjvu_image_exchange_blits(img, blit_to_put_here, i);
if (passport_of_blit[i] != -1)
bps[passport_of_blit[i]].original_index = blit_to_put_here;
passport_of_blit[blit_to_put_here] = passport_of_blit[i];
}
free(passport_of_blit);
free(bps);
free(bottoms);
}
