godot/scene/resources/bit_map.cpp
Ninni Pipping 249784ed53 Fix size error in BitMap.opaque_to_polygons
Previous estimate of upper limit on size was incorrect
2023-04-28 19:01:02 +02:00

733 lines
19 KiB
C++

/**************************************************************************/
/* bit_map.cpp */
/**************************************************************************/
/* This file is part of: */
/* GODOT ENGINE */
/* https://godotengine.org */
/**************************************************************************/
/* Copyright (c) 2014-present Godot Engine contributors (see AUTHORS.md). */
/* Copyright (c) 2007-2014 Juan Linietsky, Ariel Manzur. */
/* */
/* Permission is hereby granted, free of charge, to any person obtaining */
/* a copy of this software and associated documentation files (the */
/* "Software"), to deal in the Software without restriction, including */
/* without limitation the rights to use, copy, modify, merge, publish, */
/* distribute, sublicense, and/or sell copies of the Software, and to */
/* permit persons to whom the Software is furnished to do so, subject to */
/* the following conditions: */
/* */
/* The above copyright notice and this permission notice shall be */
/* included in all copies or substantial portions of the Software. */
/* */
/* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, */
/* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF */
/* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. */
/* IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY */
/* CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, */
/* TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE */
/* SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. */
/**************************************************************************/
#include "bit_map.h"
#include "core/io/image_loader.h"
#include "core/variant/typed_array.h"
void BitMap::create(const Size2i &p_size) {
ERR_FAIL_COND(p_size.width < 1);
ERR_FAIL_COND(p_size.height < 1);
ERR_FAIL_COND(static_cast<int64_t>(p_size.width) * static_cast<int64_t>(p_size.height) > INT32_MAX);
Error err = bitmask.resize((((p_size.width * p_size.height) - 1) / 8) + 1);
ERR_FAIL_COND(err != OK);
width = p_size.width;
height = p_size.height;
memset(bitmask.ptrw(), 0, bitmask.size());
}
void BitMap::create_from_image_alpha(const Ref<Image> &p_image, float p_threshold) {
ERR_FAIL_COND(p_image.is_null() || p_image->is_empty());
Ref<Image> img = p_image->duplicate();
img->convert(Image::FORMAT_LA8);
ERR_FAIL_COND(img->get_format() != Image::FORMAT_LA8);
create(Size2i(img->get_width(), img->get_height()));
const uint8_t *r = img->get_data().ptr();
uint8_t *w = bitmask.ptrw();
for (int i = 0; i < width * height; i++) {
int bbyte = i / 8;
int bbit = i % 8;
if (r[i * 2 + 1] / 255.0 > p_threshold) {
w[bbyte] |= (1 << bbit);
}
}
}
void BitMap::set_bit_rect(const Rect2i &p_rect, bool p_value) {
Rect2i current = Rect2i(0, 0, width, height).intersection(p_rect);
uint8_t *data = bitmask.ptrw();
for (int i = current.position.x; i < current.position.x + current.size.x; i++) {
for (int j = current.position.y; j < current.position.y + current.size.y; j++) {
int ofs = width * j + i;
int bbyte = ofs / 8;
int bbit = ofs % 8;
uint8_t b = data[bbyte];
if (p_value) {
b |= (1 << bbit);
} else {
b &= ~(1 << bbit);
}
data[bbyte] = b;
}
}
}
int BitMap::get_true_bit_count() const {
int ds = bitmask.size();
const uint8_t *d = bitmask.ptr();
int c = 0;
// Fast, almost branchless version.
for (int i = 0; i < ds; i++) {
c += (d[i] & (1 << 7)) >> 7;
c += (d[i] & (1 << 6)) >> 6;
c += (d[i] & (1 << 5)) >> 5;
c += (d[i] & (1 << 4)) >> 4;
c += (d[i] & (1 << 3)) >> 3;
c += (d[i] & (1 << 2)) >> 2;
c += (d[i] & (1 << 1)) >> 1;
c += d[i] & 1;
}
return c;
}
void BitMap::set_bitv(const Point2i &p_pos, bool p_value) {
set_bit(p_pos.x, p_pos.y, p_value);
}
void BitMap::set_bit(int p_x, int p_y, bool p_value) {
ERR_FAIL_INDEX(p_x, width);
ERR_FAIL_INDEX(p_y, height);
int ofs = width * p_y + p_x;
int bbyte = ofs / 8;
int bbit = ofs % 8;
uint8_t b = bitmask[bbyte];
if (p_value) {
b |= (1 << bbit);
} else {
b &= ~(1 << bbit);
}
bitmask.write[bbyte] = b;
}
bool BitMap::get_bitv(const Point2i &p_pos) const {
return get_bit(p_pos.x, p_pos.y);
}
bool BitMap::get_bit(int p_x, int p_y) const {
ERR_FAIL_INDEX_V(p_x, width, false);
ERR_FAIL_INDEX_V(p_y, height, false);
int ofs = width * p_y + p_x;
int bbyte = ofs / 8;
int bbit = ofs % 8;
return (bitmask[bbyte] & (1 << bbit)) != 0;
}
Size2i BitMap::get_size() const {
return Size2i(width, height);
}
void BitMap::_set_data(const Dictionary &p_d) {
ERR_FAIL_COND(!p_d.has("size"));
ERR_FAIL_COND(!p_d.has("data"));
create(p_d["size"]);
bitmask = p_d["data"];
}
Dictionary BitMap::_get_data() const {
Dictionary d;
d["size"] = get_size();
d["data"] = bitmask;
return d;
}
Vector<Vector<Vector2>> BitMap::_march_square(const Rect2i &p_rect, const Point2i &p_start) const {
int stepx = 0;
int stepy = 0;
int prevx = 0;
int prevy = 0;
int startx = p_start.x;
int starty = p_start.y;
int curx = startx;
int cury = starty;
unsigned int count = 0;
HashMap<Point2i, int> cross_map;
Vector<Vector2> _points;
int points_size = 0;
Vector<Vector<Vector2>> ret;
// Add starting entry at start of return.
ret.resize(1);
do {
int sv = 0;
{ // Square value
/*
checking the 2x2 pixel grid, assigning these values to each pixel, if not transparent
+---+---+
| 1 | 2 |
+---+---+
| 4 | 8 | <- current pixel (curx,cury)
+---+---+
*/
Point2i tl = Point2i(curx - 1, cury - 1);
sv += (p_rect.has_point(tl) && get_bitv(tl)) ? 1 : 0;
Point2i tr = Point2i(curx, cury - 1);
sv += (p_rect.has_point(tr) && get_bitv(tr)) ? 2 : 0;
Point2i bl = Point2i(curx - 1, cury);
sv += (p_rect.has_point(bl) && get_bitv(bl)) ? 4 : 0;
Point2i br = Point2i(curx, cury);
sv += (p_rect.has_point(br) && get_bitv(br)) ? 8 : 0;
ERR_FAIL_COND_V(sv == 0 || sv == 15, Vector<Vector<Vector2>>());
}
switch (sv) {
case 1:
case 5:
case 13:
/* going UP with these cases:
1 5 13
+---+---+ +---+---+ +---+---+
| 1 | | | 1 | | | 1 | |
+---+---+ +---+---+ +---+---+
| | | | 4 | | | 4 | 8 |
+---+---+ +---+---+ +---+---+
*/
stepx = 0;
stepy = -1;
break;
case 8:
case 10:
case 11:
/* going DOWN with these cases:
8 10 11
+---+---+ +---+---+ +---+---+
| | | | | 2 | | 1 | 2 |
+---+---+ +---+---+ +---+---+
| | 8 | | | 8 | | | 8 |
+---+---+ +---+---+ +---+---+
*/
stepx = 0;
stepy = 1;
break;
case 4:
case 12:
case 14:
/* going LEFT with these cases:
4 12 14
+---+---+ +---+---+ +---+---+
| | | | | | | | 2 |
+---+---+ +---+---+ +---+---+
| 4 | | | 4 | 8 | | 4 | 8 |
+---+---+ +---+---+ +---+---+
*/
stepx = -1;
stepy = 0;
break;
case 2:
case 3:
case 7:
/* going RIGHT with these cases:
2 3 7
+---+---+ +---+---+ +---+---+
| | 2 | | 1 | 2 | | 1 | 2 |
+---+---+ +---+---+ +---+---+
| | | | | | | 4 | |
+---+---+ +---+---+ +---+---+
*/
stepx = 1;
stepy = 0;
break;
case 9:
/* Going DOWN if coming from the LEFT, otherwise go UP.
9
+---+---+
| 1 | |
+---+---+
| | 8 |
+---+---+
*/
if (prevx == 1) {
stepx = 0;
stepy = 1;
} else {
stepx = 0;
stepy = -1;
}
break;
case 6:
/* Going RIGHT if coming from BELOW, otherwise go LEFT.
6
+---+---+
| | 2 |
+---+---+
| 4 | |
+---+---+
*/
if (prevy == -1) {
stepx = 1;
stepy = 0;
} else {
stepx = -1;
stepy = 0;
}
break;
default:
ERR_PRINT("this shouldn't happen.");
}
// Handle crossing points.
if (sv == 6 || sv == 9) {
const Point2i cur_pos(curx, cury);
// Find if this point has occurred before.
if (HashMap<Point2i, int>::Iterator found = cross_map.find(cur_pos)) {
// Add points after the previous crossing to the result.
ret.push_back(_points.slice(found->value + 1, points_size));
// Remove points after crossing point.
points_size = found->value + 1;
// Erase trailing map elements.
while (cross_map.last() != found) {
cross_map.remove(cross_map.last());
}
cross_map.erase(cur_pos);
} else {
// Add crossing point to map.
cross_map.insert(cur_pos, points_size - 1);
}
}
// Small optimization:
// If the previous direction is same as the current direction,
// then we should modify the last vector to current.
curx += stepx;
cury += stepy;
if (stepx == prevx && stepy == prevy) {
_points.set(points_size - 1, Vector2(curx, cury) - p_rect.position);
} else {
_points.resize(MAX(points_size + 1, _points.size()));
_points.set(points_size, Vector2(curx, cury) - p_rect.position);
points_size++;
}
count++;
prevx = stepx;
prevy = stepy;
ERR_FAIL_COND_V((int)count > 2 * (width * height + 1), Vector<Vector<Vector2>>());
} while (curx != startx || cury != starty);
// Add remaining points to result.
_points.resize(points_size);
ret.set(0, _points);
return ret;
}
static float perpendicular_distance(const Vector2 &i, const Vector2 &start, const Vector2 &end) {
float res;
float slope;
float intercept;
if (start.x == end.x) {
res = Math::absf(i.x - end.x);
} else if (start.y == end.y) {
res = Math::absf(i.y - end.y);
} else {
slope = (end.y - start.y) / (end.x - start.x);
intercept = start.y - (slope * start.x);
res = Math::absf(slope * i.x - i.y + intercept) / Math::sqrt(Math::pow(slope, 2.0f) + 1.0);
}
return res;
}
static Vector<Vector2> rdp(const Vector<Vector2> &v, float optimization) {
if (v.size() < 3) {
return v;
}
int index = -1;
float dist = 0.0;
// Not looping first and last point.
for (size_t i = 1, size = v.size(); i < size - 1; ++i) {
float cdist = perpendicular_distance(v[i], v[0], v[v.size() - 1]);
if (cdist > dist) {
dist = cdist;
index = static_cast<int>(i);
}
}
if (dist > optimization) {
Vector<Vector2> left, right;
left.resize(index);
for (int i = 0; i < index; i++) {
left.write[i] = v[i];
}
right.resize(v.size() - index);
for (int i = 0; i < right.size(); i++) {
right.write[i] = v[index + i];
}
Vector<Vector2> r1 = rdp(left, optimization);
Vector<Vector2> r2 = rdp(right, optimization);
int middle = r1.size();
r1.resize(r1.size() + r2.size());
for (int i = 0; i < r2.size(); i++) {
r1.write[middle + i] = r2[i];
}
return r1;
} else {
Vector<Vector2> ret;
ret.push_back(v[0]);
ret.push_back(v[v.size() - 1]);
return ret;
}
}
static Vector<Vector2> reduce(const Vector<Vector2> &points, const Rect2i &rect, float epsilon) {
int size = points.size();
// If there are less than 3 points, then we have nothing.
ERR_FAIL_COND_V(size < 3, Vector<Vector2>());
// If there are less than 9 points (but more than 3), then we don't need to reduce it.
if (size < 9) {
return points;
}
float maxEp = MIN(rect.size.width, rect.size.height);
float ep = CLAMP(epsilon, 0.0, maxEp / 2);
Vector<Vector2> result = rdp(points, ep);
Vector2 last = result[result.size() - 1];
if (last.y > result[0].y && last.distance_to(result[0]) < ep * 0.5f) {
result.write[0].y = last.y;
result.resize(result.size() - 1);
}
return result;
}
struct FillBitsStackEntry {
Point2i pos;
int i = 0;
int j = 0;
};
static void fill_bits(const BitMap *p_src, Ref<BitMap> &p_map, const Point2i &p_pos, const Rect2i &rect) {
// Using a custom stack to work iteratively to avoid stack overflow on big bitmaps.
Vector<FillBitsStackEntry> stack;
// Tracking size since we won't be shrinking the stack vector.
int stack_size = 0;
Point2i pos = p_pos;
int next_i = 0;
int next_j = 0;
bool reenter = true;
bool popped = false;
do {
if (reenter) {
next_i = pos.x - 1;
next_j = pos.y - 1;
reenter = false;
}
for (int i = next_i; i <= pos.x + 1; i++) {
for (int j = next_j; j <= pos.y + 1; j++) {
if (popped) {
// The next loop over j must start normally.
next_j = pos.y - 1;
popped = false;
// Skip because an iteration was already executed with current counter values.
continue;
}
if (i < rect.position.x || i >= rect.position.x + rect.size.x) {
continue;
}
if (j < rect.position.y || j >= rect.position.y + rect.size.y) {
continue;
}
if (p_map->get_bit(i, j)) {
continue;
} else if (p_src->get_bit(i, j)) {
p_map->set_bit(i, j, true);
FillBitsStackEntry se = { pos, i, j };
stack.resize(MAX(stack_size + 1, stack.size()));
stack.set(stack_size, se);
stack_size++;
pos = Point2i(i, j);
reenter = true;
break;
}
}
if (reenter) {
break;
}
}
if (!reenter) {
if (stack_size) {
FillBitsStackEntry se = stack.get(stack_size - 1);
stack_size--;
pos = se.pos;
next_i = se.i;
next_j = se.j;
popped = true;
}
}
} while (reenter || popped);
}
Vector<Vector<Vector2>> BitMap::clip_opaque_to_polygons(const Rect2i &p_rect, float p_epsilon) const {
Rect2i r = Rect2i(0, 0, width, height).intersection(p_rect);
Point2i from;
Ref<BitMap> fill;
fill.instantiate();
fill->create(get_size());
Vector<Vector<Vector2>> polygons;
for (int i = r.position.y; i < r.position.y + r.size.height; i++) {
for (int j = r.position.x; j < r.position.x + r.size.width; j++) {
if (!fill->get_bit(j, i) && get_bit(j, i)) {
fill_bits(this, fill, Point2i(j, i), r);
for (Vector<Vector2> polygon : _march_square(r, Point2i(j, i))) {
polygon = reduce(polygon, r, p_epsilon);
if (polygon.size() < 3) {
print_verbose("Invalid polygon, skipped");
continue;
}
polygons.push_back(polygon);
}
}
}
}
return polygons;
}
void BitMap::grow_mask(int p_pixels, const Rect2i &p_rect) {
if (p_pixels == 0) {
return;
}
bool bit_value = p_pixels > 0;
p_pixels = Math::abs(p_pixels);
Rect2i r = Rect2i(0, 0, width, height).intersection(p_rect);
Ref<BitMap> copy;
copy.instantiate();
copy->create(get_size());
copy->bitmask = bitmask;
for (int i = r.position.y; i < r.position.y + r.size.height; i++) {
for (int j = r.position.x; j < r.position.x + r.size.width; j++) {
if (bit_value == get_bit(j, i)) {
continue;
}
bool found = false;
for (int y = i - p_pixels; y <= i + p_pixels; y++) {
for (int x = j - p_pixels; x <= j + p_pixels; x++) {
bool outside = false;
if ((x < p_rect.position.x) || (x >= p_rect.position.x + p_rect.size.x) || (y < p_rect.position.y) || (y >= p_rect.position.y + p_rect.size.y)) {
// Outside of rectangle counts as bit not set.
if (!bit_value) {
outside = true;
} else {
continue;
}
}
float d = Point2(j, i).distance_to(Point2(x, y)) - CMP_EPSILON;
if (d > p_pixels) {
continue;
}
if (outside || (bit_value == copy->get_bit(x, y))) {
found = true;
break;
}
}
if (found) {
break;
}
}
if (found) {
set_bit(j, i, bit_value);
}
}
}
}
void BitMap::shrink_mask(int p_pixels, const Rect2i &p_rect) {
grow_mask(-p_pixels, p_rect);
}
TypedArray<PackedVector2Array> BitMap::_opaque_to_polygons_bind(const Rect2i &p_rect, float p_epsilon) const {
Vector<Vector<Vector2>> result = clip_opaque_to_polygons(p_rect, p_epsilon);
// Convert result to bindable types.
TypedArray<PackedVector2Array> result_array;
result_array.resize(result.size());
for (int i = 0; i < result.size(); i++) {
const Vector<Vector2> &polygon = result[i];
PackedVector2Array polygon_array;
polygon_array.resize(polygon.size());
{
Vector2 *w = polygon_array.ptrw();
for (int j = 0; j < polygon.size(); j++) {
w[j] = polygon[j];
}
}
result_array[i] = polygon_array;
}
return result_array;
}
void BitMap::resize(const Size2i &p_new_size) {
ERR_FAIL_COND(p_new_size.width < 0 || p_new_size.height < 0);
if (p_new_size == get_size()) {
return;
}
Ref<BitMap> new_bitmap;
new_bitmap.instantiate();
new_bitmap->create(p_new_size);
// also allow for upscaling
int lw = (width == 0) ? 0 : p_new_size.width;
int lh = (height == 0) ? 0 : p_new_size.height;
float scale_x = ((float)width / p_new_size.width);
float scale_y = ((float)height / p_new_size.height);
for (int x = 0; x < lw; x++) {
for (int y = 0; y < lh; y++) {
bool new_bit = get_bit(x * scale_x, y * scale_y);
new_bitmap->set_bit(x, y, new_bit);
}
}
width = new_bitmap->width;
height = new_bitmap->height;
bitmask = new_bitmap->bitmask;
}
Ref<Image> BitMap::convert_to_image() const {
Ref<Image> image = Image::create_empty(width, height, false, Image::FORMAT_L8);
for (int i = 0; i < width; i++) {
for (int j = 0; j < height; j++) {
image->set_pixel(i, j, get_bit(i, j) ? Color(1, 1, 1) : Color(0, 0, 0));
}
}
return image;
}
void BitMap::blit(const Vector2i &p_pos, const Ref<BitMap> &p_bitmap) {
ERR_FAIL_COND_MSG(p_bitmap.is_null(), "It's not a reference to a valid BitMap object.");
int x = p_pos.x;
int y = p_pos.y;
int w = p_bitmap->get_size().width;
int h = p_bitmap->get_size().height;
for (int i = 0; i < w; i++) {
for (int j = 0; j < h; j++) {
int px = x + i;
int py = y + j;
if (px < 0 || px >= width) {
continue;
}
if (py < 0 || py >= height) {
continue;
}
if (p_bitmap->get_bit(i, j)) {
set_bit(px, py, true);
}
}
}
}
void BitMap::_bind_methods() {
ClassDB::bind_method(D_METHOD("create", "size"), &BitMap::create);
ClassDB::bind_method(D_METHOD("create_from_image_alpha", "image", "threshold"), &BitMap::create_from_image_alpha, DEFVAL(0.1));
ClassDB::bind_method(D_METHOD("set_bitv", "position", "bit"), &BitMap::set_bitv);
ClassDB::bind_method(D_METHOD("set_bit", "x", "y", "bit"), &BitMap::set_bit);
ClassDB::bind_method(D_METHOD("get_bitv", "position"), &BitMap::get_bitv);
ClassDB::bind_method(D_METHOD("get_bit", "x", "y"), &BitMap::get_bit);
ClassDB::bind_method(D_METHOD("set_bit_rect", "rect", "bit"), &BitMap::set_bit_rect);
ClassDB::bind_method(D_METHOD("get_true_bit_count"), &BitMap::get_true_bit_count);
ClassDB::bind_method(D_METHOD("get_size"), &BitMap::get_size);
ClassDB::bind_method(D_METHOD("resize", "new_size"), &BitMap::resize);
ClassDB::bind_method(D_METHOD("_set_data", "data"), &BitMap::_set_data);
ClassDB::bind_method(D_METHOD("_get_data"), &BitMap::_get_data);
ClassDB::bind_method(D_METHOD("grow_mask", "pixels", "rect"), &BitMap::grow_mask);
ClassDB::bind_method(D_METHOD("convert_to_image"), &BitMap::convert_to_image);
ClassDB::bind_method(D_METHOD("opaque_to_polygons", "rect", "epsilon"), &BitMap::_opaque_to_polygons_bind, DEFVAL(2.0));
ADD_PROPERTY(PropertyInfo(Variant::DICTIONARY, "data", PROPERTY_HINT_NONE, "", PROPERTY_USAGE_NO_EDITOR | PROPERTY_USAGE_INTERNAL), "_set_data", "_get_data");
}
BitMap::BitMap() {}