godot/core/math/rect2.cpp

276 lines
7.3 KiB
C++

/*************************************************************************/
/* rect2.cpp */
/*************************************************************************/
/* This file is part of: */
/* GODOT ENGINE */
/* https://godotengine.org */
/*************************************************************************/
/* Copyright (c) 2007-2021 Juan Linietsky, Ariel Manzur. */
/* Copyright (c) 2014-2021 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 "core/math/transform_2d.h" // Includes rect2.h but Rect2 needs Transform2D
bool Rect2::is_equal_approx(const Rect2 &p_rect) const {
return position.is_equal_approx(p_rect.position) && size.is_equal_approx(p_rect.size);
}
bool Rect2::intersects_segment(const Point2 &p_from, const Point2 &p_to, Point2 *r_pos, Point2 *r_normal) const {
#ifdef MATH_CHECKS
if (unlikely(size.x < 0 || size.y < 0)) {
ERR_PRINT("Rect2 size is negative, this is not supported. Use Rect2.abs() to get a Rect2 with a positive size.");
}
#endif
real_t min = 0, max = 1;
int axis = 0;
real_t sign = 0;
for (int i = 0; i < 2; i++) {
real_t seg_from = p_from[i];
real_t seg_to = p_to[i];
real_t box_begin = position[i];
real_t box_end = box_begin + size[i];
real_t cmin, cmax;
real_t csign;
if (seg_from < seg_to) {
if (seg_from > box_end || seg_to < box_begin) {
return false;
}
real_t length = seg_to - seg_from;
cmin = (seg_from < box_begin) ? ((box_begin - seg_from) / length) : 0;
cmax = (seg_to > box_end) ? ((box_end - seg_from) / length) : 1;
csign = -1.0;
} else {
if (seg_to > box_end || seg_from < box_begin) {
return false;
}
real_t length = seg_to - seg_from;
cmin = (seg_from > box_end) ? (box_end - seg_from) / length : 0;
cmax = (seg_to < box_begin) ? (box_begin - seg_from) / length : 1;
csign = 1.0;
}
if (cmin > min) {
min = cmin;
axis = i;
sign = csign;
}
if (cmax < max) {
max = cmax;
}
if (max < min) {
return false;
}
}
Vector2 rel = p_to - p_from;
if (r_normal) {
Vector2 normal;
normal[axis] = sign;
*r_normal = normal;
}
if (r_pos) {
*r_pos = p_from + rel * min;
}
return true;
}
bool Rect2::intersects_transformed(const Transform2D &p_xform, const Rect2 &p_rect) const {
#ifdef MATH_CHECKS
if (unlikely(size.x < 0 || size.y < 0 || p_rect.size.x < 0 || p_rect.size.y < 0)) {
ERR_PRINT("Rect2 size is negative, this is not supported. Use Rect2.abs() to get a Rect2 with a positive size.");
}
#endif
//SAT intersection between local and transformed rect2
Vector2 xf_points[4] = {
p_xform.xform(p_rect.position),
p_xform.xform(Vector2(p_rect.position.x + p_rect.size.x, p_rect.position.y)),
p_xform.xform(Vector2(p_rect.position.x, p_rect.position.y + p_rect.size.y)),
p_xform.xform(Vector2(p_rect.position.x + p_rect.size.x, p_rect.position.y + p_rect.size.y)),
};
real_t low_limit;
//base rect2 first (faster)
if (xf_points[0].y > position.y) {
goto next1;
}
if (xf_points[1].y > position.y) {
goto next1;
}
if (xf_points[2].y > position.y) {
goto next1;
}
if (xf_points[3].y > position.y) {
goto next1;
}
return false;
next1:
low_limit = position.y + size.y;
if (xf_points[0].y < low_limit) {
goto next2;
}
if (xf_points[1].y < low_limit) {
goto next2;
}
if (xf_points[2].y < low_limit) {
goto next2;
}
if (xf_points[3].y < low_limit) {
goto next2;
}
return false;
next2:
if (xf_points[0].x > position.x) {
goto next3;
}
if (xf_points[1].x > position.x) {
goto next3;
}
if (xf_points[2].x > position.x) {
goto next3;
}
if (xf_points[3].x > position.x) {
goto next3;
}
return false;
next3:
low_limit = position.x + size.x;
if (xf_points[0].x < low_limit) {
goto next4;
}
if (xf_points[1].x < low_limit) {
goto next4;
}
if (xf_points[2].x < low_limit) {
goto next4;
}
if (xf_points[3].x < low_limit) {
goto next4;
}
return false;
next4:
Vector2 xf_points2[4] = {
position,
Vector2(position.x + size.x, position.y),
Vector2(position.x, position.y + size.y),
Vector2(position.x + size.x, position.y + size.y),
};
real_t maxa = p_xform.elements[0].dot(xf_points2[0]);
real_t mina = maxa;
real_t dp = p_xform.elements[0].dot(xf_points2[1]);
maxa = MAX(dp, maxa);
mina = MIN(dp, mina);
dp = p_xform.elements[0].dot(xf_points2[2]);
maxa = MAX(dp, maxa);
mina = MIN(dp, mina);
dp = p_xform.elements[0].dot(xf_points2[3]);
maxa = MAX(dp, maxa);
mina = MIN(dp, mina);
real_t maxb = p_xform.elements[0].dot(xf_points[0]);
real_t minb = maxb;
dp = p_xform.elements[0].dot(xf_points[1]);
maxb = MAX(dp, maxb);
minb = MIN(dp, minb);
dp = p_xform.elements[0].dot(xf_points[2]);
maxb = MAX(dp, maxb);
minb = MIN(dp, minb);
dp = p_xform.elements[0].dot(xf_points[3]);
maxb = MAX(dp, maxb);
minb = MIN(dp, minb);
if (mina > maxb) {
return false;
}
if (minb > maxa) {
return false;
}
maxa = p_xform.elements[1].dot(xf_points2[0]);
mina = maxa;
dp = p_xform.elements[1].dot(xf_points2[1]);
maxa = MAX(dp, maxa);
mina = MIN(dp, mina);
dp = p_xform.elements[1].dot(xf_points2[2]);
maxa = MAX(dp, maxa);
mina = MIN(dp, mina);
dp = p_xform.elements[1].dot(xf_points2[3]);
maxa = MAX(dp, maxa);
mina = MIN(dp, mina);
maxb = p_xform.elements[1].dot(xf_points[0]);
minb = maxb;
dp = p_xform.elements[1].dot(xf_points[1]);
maxb = MAX(dp, maxb);
minb = MIN(dp, minb);
dp = p_xform.elements[1].dot(xf_points[2]);
maxb = MAX(dp, maxb);
minb = MIN(dp, minb);
dp = p_xform.elements[1].dot(xf_points[3]);
maxb = MAX(dp, maxb);
minb = MIN(dp, minb);
if (mina > maxb) {
return false;
}
if (minb > maxa) {
return false;
}
return true;
}