virtualx-engine/editor/io_plugins/editor_atlas.cpp
2017-04-08 00:11:42 +02:00

153 lines
4.8 KiB
C++

/*************************************************************************/
/* editor_atlas.cpp */
/*************************************************************************/
/* This file is part of: */
/* GODOT ENGINE */
/* http://www.godotengine.org */
/*************************************************************************/
/* Copyright (c) 2007-2017 Juan Linietsky, Ariel Manzur. */
/* Copyright (c) 2014-2017 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.h"
#include "print_string.h"
struct _EditorAtlasWorkRect {
Size2i s;
Point2i p;
int idx;
_FORCE_INLINE_ bool operator<(const _EditorAtlasWorkRect &p_r) const { return s.width > p_r.s.width; };
};
struct _EditorAtlasWorkRectResult {
Vector<_EditorAtlasWorkRect> result;
int max_w;
int max_h;
};
void EditorAtlas::fit(const Vector<Size2i> &p_rects, Vector<Point2i> &r_result, Size2i &r_size) {
//super simple, almost brute force scanline stacking fitter
//it's pretty basic for now, but it tries to make sure that the aspect ratio of the
//resulting atlas is somehow square. This is necessary because video cards have limits
//on texture size (usually 2048 or 4096), so the more square a texture, the more chances
//it will work in every hardware.
// for example, it will prioritize a 1024x1024 atlas (works everywhere) instead of a
// 256x8192 atlas (won't work anywhere).
ERR_FAIL_COND(p_rects.size() == 0);
Vector<_EditorAtlasWorkRect> wrects;
wrects.resize(p_rects.size());
for (int i = 0; i < p_rects.size(); i++) {
wrects[i].s = p_rects[i];
wrects[i].idx = i;
}
wrects.sort();
int widest = wrects[0].s.width;
Vector<_EditorAtlasWorkRectResult> results;
for (int i = 0; i <= 12; i++) {
int w = 1 << i;
int max_h = 0;
int max_w = 0;
if (w < widest)
continue;
Vector<int> hmax;
hmax.resize(w);
for (int j = 0; j < w; j++)
hmax[j] = 0;
//place them
int ofs = 0;
for (int j = 0; j < wrects.size(); j++) {
if (ofs + wrects[j].s.width > w) {
ofs = 0;
}
int from_y = 0;
for (int k = 0; k < wrects[j].s.width; k++) {
if (hmax[ofs + k] > from_y)
from_y = hmax[ofs + k];
}
wrects[j].p.x = ofs;
wrects[j].p.y = from_y;
int end_h = from_y + wrects[j].s.height;
int end_w = ofs + wrects[j].s.width;
for (int k = 0; k < wrects[j].s.width; k++) {
hmax[ofs + k] = end_h;
}
if (end_h > max_h)
max_h = end_h;
if (end_w > max_w)
max_w = end_w;
ofs += wrects[j].s.width;
}
_EditorAtlasWorkRectResult result;
result.result = wrects;
result.max_h = max_h;
result.max_w = max_w;
results.push_back(result);
}
//find the result with the best aspect ratio
int best = -1;
float best_aspect = 1e20;
for (int i = 0; i < results.size(); i++) {
float h = results[i].max_h;
float w = results[i].max_w;
float aspect = h > w ? h / w : w / h;
if (aspect < best_aspect) {
best = i;
best_aspect = aspect;
}
}
r_result.resize(p_rects.size());
for (int i = 0; i < p_rects.size(); i++) {
r_result[results[best].result[i].idx] = results[best].result[i].p;
}
r_size = Size2(results[best].max_w, results[best].max_h);
}