-
Notifications
You must be signed in to change notification settings - Fork 0
/
tile-generator.cc
97 lines (79 loc) · 3.08 KB
/
tile-generator.cc
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
// Copyright 2021 Ellogon BV.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
#include <cassert>
#include <cstring>
#include <memory>
#include <sstream>
#include <type_traits>
#include <vips/vips.h>
#include <vips/vips8>
#include <cstring>
#include "utils.h"
#include "tile-generator.h"
using namespace vips;
VipsImageTileGenerator::VipsImageTileGenerator(
const VImage &source, unsigned tile_width, unsigned tile_height)
: source_(source), tile_width_(tile_width), tile_height_(tile_height),
num_tiles_width_(partition(source.width(), tile_width)),
num_total_tiles_(num_tiles_width_ * partition(source.height(), tile_height)) {}
std::optional<Tile> VipsImageTileGenerator::Next(
const std::optional<Tile> &prev, bool *end) const {
assert(!*end);
const unsigned tile_index = (prev) ? (*prev).index + 1 : 0;
if (tile_index + 1 > num_total_tiles_) {
*end = true;
return {};
}
const VipsImageTileGenerator &ref = *this;
return ref[tile_index];
}
const bool VipsImageTileGenerator::ExtractTile(int x, int y, Buffer *out) const {
UniqueVipsRegion region(vips_region_new(source_.get_image()));
const unsigned bands = source_.bands();
const unsigned x_end = x + tile_width_;
const unsigned y_end = y + tile_height_;
const unsigned width = source_.width();
const unsigned height = source_.height();
int region_valid_width = (x_end > width) ? width - x : tile_width_;
int region_valid_height = (y_end > height) ? height - y : tile_height_;
VipsRect r = { x, y, region_valid_width, region_valid_height };
if (vips_region_prepare(region.get(), &r))
return false;
const size_t tile_line_size = tile_width_ * bands;
const size_t tile_size = tile_line_size * tile_height_;
size_t region_line_size = VIPS_REGION_SIZEOF_LINE(region.get());
size_t region_stride = VIPS_REGION_LSKIP(region.get());
uint8_t *c = VIPS_REGION_ADDR_TOPLEFT(region.get());
uint8_t *data = new uint8_t[tile_size]{};
for (int i = 0; i < region_valid_height; ++i) {
const size_t dst_offset = tile_line_size * i;
const size_t src_offset = region_stride * i;
memcpy(data + dst_offset, c + src_offset, region_line_size);
}
out->data.reset(data);
out->size = tile_size;
return true;
}
const std::optional<Tile> VipsImageTileGenerator::operator[](unsigned int i) const {
const unsigned row = i / (num_tiles_width_);
const unsigned column = i % num_tiles_width_;
const int y = row * tile_height_;
const int x = column * tile_width_;
Tile tile{{}, i};
if (!ExtractTile(x, y, &tile.buffer)) {
fprintf(stderr, "Unable to extract tile.");
return {};
}
return tile;
}