godot/editor/editor_atlas_packer.cpp

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/*************************************************************************/
/* editor_atlas_packer.cpp */
/*************************************************************************/
/* This file is part of: */
/* GODOT ENGINE */
/* https://godotengine.org */
/*************************************************************************/
/* Copyright (c) 2007-2022 Juan Linietsky, Ariel Manzur. */
/* Copyright (c) 2014-2022 Godot Engine contributors (cf. AUTHORS.md). */
/* */
/* 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 "editor_atlas_packer.h"
#include "core/math/geometry_2d.h"
#include "core/math/vector2.h"
#include "core/math/vector2i.h"
void EditorAtlasPacker::chart_pack(Vector<Chart> &charts, int &r_width, int &r_height, int p_atlas_max_size, int p_cell_resolution) {
int divide_by = MIN(64, p_cell_resolution);
Vector<PlottedBitmap> bitmaps;
int max_w = 0;
for (int i = 0; i < charts.size(); i++) {
const Chart &chart = charts[i];
//generate aabb
Rect2i aabb;
int vertex_count = chart.vertices.size();
const Vector2 *vertices = chart.vertices.ptr();
for (int j = 0; j < vertex_count; j++) {
if (j == 0) {
aabb.position = vertices[j];
} else {
aabb.expand_to(vertices[j]);
}
}
Ref<BitMap> src_bitmap;
src_bitmap.instantiate();
src_bitmap->create(aabb.size / divide_by);
int w = src_bitmap->get_size().width;
int h = src_bitmap->get_size().height;
//plot triangles, using divisor
for (int j = 0; j < chart.faces.size(); j++) {
Vector2i v[3];
for (int k = 0; k < 3; k++) {
Vector2 vtx = chart.vertices[chart.faces[j].vertex[k]];
vtx -= aabb.position;
vtx /= divide_by;
vtx.x = MIN(vtx.x, w - 1);
vtx.y = MIN(vtx.y, h - 1);
v[k] = vtx;
}
for (int k = 0; k < 3; k++) {
int l = k == 0 ? 2 : k - 1;
Vector<Point2i> points = Geometry2D::bresenham_line(v[k], v[l]);
for (Point2i point : points) {
src_bitmap->set_bit(point, true);
}
}
}
//src_bitmap->convert_to_image()->save_png("bitmap" + itos(i) + ".png");
//grow by 1 for each side
int bmw = src_bitmap->get_size().width + 2;
int bmh = src_bitmap->get_size().height + 2;
int heights_size = -1;
bool transpose = false;
if (chart.can_transpose && bmh > bmw) {
heights_size = bmh;
transpose = true;
} else {
heights_size = bmw;
}
max_w = MAX(max_w, heights_size);
Vector<int> top_heights;
Vector<int> bottom_heights;
top_heights.resize(heights_size);
bottom_heights.resize(heights_size);
for (int x = 0; x < heights_size; x++) {
top_heights.write[x] = -1;
bottom_heights.write[x] = 0x7FFFFFFF;
}
for (int x = 0; x < bmw; x++) {
for (int y = 0; y < bmh; y++) {
bool found_pixel = false;
for (int lx = x - 1; lx < x + 2 && !found_pixel; lx++) {
for (int ly = y - 1; ly < y + 2 && !found_pixel; ly++) {
int px = lx - 1;
if (px < 0 || px >= w) {
continue;
}
int py = ly - 1;
if (py < 0 || py >= h) {
continue;
}
if (src_bitmap->get_bit(Vector2(px, py))) {
found_pixel = true;
}
}
}
if (found_pixel) {
if (transpose) {
if (x > top_heights[y]) {
top_heights.write[y] = x;
}
if (x < bottom_heights[y]) {
bottom_heights.write[y] = x;
}
} else {
if (y > top_heights[x]) {
top_heights.write[x] = y;
}
if (y < bottom_heights[x]) {
bottom_heights.write[x] = y;
}
}
}
}
}
String row;
for (int j = 0; j < top_heights.size(); j++) {
row += "(" + itos(top_heights[j]) + "-" + itos(bottom_heights[j]) + "),";
}
PlottedBitmap plotted_bitmap;
plotted_bitmap.offset = aabb.position;
plotted_bitmap.top_heights = top_heights;
plotted_bitmap.bottom_heights = bottom_heights;
plotted_bitmap.chart_index = i;
plotted_bitmap.transposed = transpose;
plotted_bitmap.area = bmw * bmh;
bitmaps.push_back(plotted_bitmap);
}
bitmaps.sort();
int atlas_max_width = nearest_power_of_2_templated(p_atlas_max_size) / divide_by;
int atlas_w = nearest_power_of_2_templated(max_w);
int atlas_h;
while (true) {
atlas_h = 0;
//do a tetris
Vector<int> heights;
heights.resize(atlas_w);
for (int i = 0; i < atlas_w; i++) {
heights.write[i] = 0;
}
int *atlas_ptr = heights.ptrw();
for (int i = 0; i < bitmaps.size(); i++) {
int best_height = 0x7FFFFFFF;
int best_height_offset = -1;
int w = bitmaps[i].top_heights.size();
const int *top_heights = bitmaps[i].top_heights.ptr();
const int *bottom_heights = bitmaps[i].bottom_heights.ptr();
for (int j = 0; j <= atlas_w - w; j++) {
int height = 0;
for (int k = 0; k < w; k++) {
int pixmap_h = bottom_heights[k];
if (pixmap_h == 0x7FFFFFFF) {
continue; //no pixel here, anything is fine
}
int h = MAX(0, atlas_ptr[j + k] - pixmap_h);
if (h > height) {
height = h;
}
}
if (height < best_height) {
best_height = height;
best_height_offset = j;
}
}
for (int j = 0; j < w; j++) { //add
if (top_heights[j] == -1) { //unused
continue;
}
int height = best_height + top_heights[j] + 1;
atlas_ptr[j + best_height_offset] = height;
atlas_h = MAX(atlas_h, height);
}
// set
Vector2 offset = bitmaps[i].offset;
if (bitmaps[i].transposed) {
SWAP(offset.x, offset.y);
}
Vector2 final_pos = Vector2(best_height_offset * divide_by, best_height * divide_by) + Vector2(divide_by, divide_by) - offset;
charts.write[bitmaps[i].chart_index].final_offset = final_pos;
charts.write[bitmaps[i].chart_index].transposed = bitmaps[i].transposed;
}
if (atlas_h <= atlas_w * 2 || atlas_w >= atlas_max_width) {
break; //ok this one is enough
}
//try again
atlas_w *= 2;
}
r_width = atlas_w * divide_by;
r_height = atlas_h * divide_by;
}