diff --git a/core/math/projection.cpp b/core/math/projection.cpp index d0ca7c56849..4a0faef08f1 100644 --- a/core/math/projection.cpp +++ b/core/math/projection.cpp @@ -596,101 +596,229 @@ Projection Projection::inverse() const { } void Projection::invert() { - int i, j, k; - int pvt_i[4], pvt_j[4]; /* Locations of pivot matrix */ - real_t pvt_val; /* Value of current pivot element */ - real_t hold; /* Temporary storage */ - real_t determinant = 1.0f; - for (k = 0; k < 4; k++) { - /** Locate k'th pivot element **/ - pvt_val = columns[k][k]; /** Initialize for search **/ - pvt_i[k] = k; - pvt_j[k] = k; - for (i = k; i < 4; i++) { - for (j = k; j < 4; j++) { - if (Math::abs(columns[i][j]) > Math::abs(pvt_val)) { - pvt_i[k] = i; - pvt_j[k] = j; - pvt_val = columns[i][j]; - } - } - } + // Adapted from Mesa's `src/util/u_math.c` `util_invert_mat4x4`. + // MIT licensed. Copyright 2008 VMware, Inc. Authored by Jacques Leroy. + Projection temp; + real_t *out = (real_t *)temp.columns; + real_t *m = (real_t *)columns; - /** Product of pivots, gives determinant when finished **/ - determinant *= pvt_val; - if (Math::is_zero_approx(determinant)) { - return; /** Matrix is singular (zero determinant). **/ - } + real_t wtmp[4][8]; + real_t m0, m1, m2, m3, s; + real_t *r0, *r1, *r2, *r3; - /** "Interchange" rows (with sign change stuff) **/ - i = pvt_i[k]; - if (i != k) { /** If rows are different **/ - for (j = 0; j < 4; j++) { - hold = -columns[k][j]; - columns[k][j] = columns[i][j]; - columns[i][j] = hold; - } - } +#define MAT(m, r, c) (m)[(c) * 4 + (r)] - /** "Interchange" columns **/ - j = pvt_j[k]; - if (j != k) { /** If columns are different **/ - for (i = 0; i < 4; i++) { - hold = -columns[i][k]; - columns[i][k] = columns[i][j]; - columns[i][j] = hold; - } - } + r0 = wtmp[0]; + r1 = wtmp[1]; + r2 = wtmp[2]; + r3 = wtmp[3]; - /** Divide column by minus pivot value **/ - for (i = 0; i < 4; i++) { - if (i != k) { - columns[i][k] /= (-pvt_val); - } - } + r0[0] = MAT(m, 0, 0); + r0[1] = MAT(m, 0, 1); + r0[2] = MAT(m, 0, 2); + r0[3] = MAT(m, 0, 3); + r0[4] = 1.0; + r0[5] = 0.0; + r0[6] = 0.0; + r0[7] = 0.0; - /** Reduce the matrix **/ - for (i = 0; i < 4; i++) { - hold = columns[i][k]; - for (j = 0; j < 4; j++) { - if (i != k && j != k) { - columns[i][j] += hold * columns[k][j]; - } - } - } + r1[0] = MAT(m, 1, 0); + r1[1] = MAT(m, 1, 1); + r1[2] = MAT(m, 1, 2); + r1[3] = MAT(m, 1, 3); + r1[5] = 1.0; + r1[4] = 0.0; + r1[6] = 0.0; + r1[7] = 0.0; - /** Divide row by pivot **/ - for (j = 0; j < 4; j++) { - if (j != k) { - columns[k][j] /= pvt_val; - } - } + r2[0] = MAT(m, 2, 0); + r2[1] = MAT(m, 2, 1); + r2[2] = MAT(m, 2, 2); + r2[3] = MAT(m, 2, 3); + r2[6] = 1.0; + r2[4] = 0.0; + r2[5] = 0.0; + r2[7] = 0.0; - /** Replace pivot by reciprocal (at last we can touch it). **/ - columns[k][k] = 1.0 / pvt_val; + r3[0] = MAT(m, 3, 0); + r3[1] = MAT(m, 3, 1); + r3[2] = MAT(m, 3, 2); + r3[3] = MAT(m, 3, 3); + + r3[7] = 1.0; + r3[4] = 0.0; + r3[5] = 0.0; + r3[6] = 0.0; + + /* choose pivot - or die */ + if (Math::abs(r3[0]) > Math::abs(r2[0])) { + SWAP(r3, r2); + } + if (Math::abs(r2[0]) > Math::abs(r1[0])) { + SWAP(r2, r1); + } + if (Math::abs(r1[0]) > Math::abs(r0[0])) { + SWAP(r1, r0); + } + ERR_FAIL_COND(0.0 == r0[0]); + + /* eliminate first variable */ + m1 = r1[0] / r0[0]; + m2 = r2[0] / r0[0]; + m3 = r3[0] / r0[0]; + s = r0[1]; + r1[1] -= m1 * s; + r2[1] -= m2 * s; + r3[1] -= m3 * s; + s = r0[2]; + r1[2] -= m1 * s; + r2[2] -= m2 * s; + r3[2] -= m3 * s; + s = r0[3]; + r1[3] -= m1 * s; + r2[3] -= m2 * s; + r3[3] -= m3 * s; + s = r0[4]; + if (s != 0.0) { + r1[4] -= m1 * s; + r2[4] -= m2 * s; + r3[4] -= m3 * s; + } + s = r0[5]; + if (s != 0.0) { + r1[5] -= m1 * s; + r2[5] -= m2 * s; + r3[5] -= m3 * s; + } + s = r0[6]; + if (s != 0.0) { + r1[6] -= m1 * s; + r2[6] -= m2 * s; + r3[6] -= m3 * s; + } + s = r0[7]; + if (s != 0.0) { + r1[7] -= m1 * s; + r2[7] -= m2 * s; + r3[7] -= m3 * s; } - /* That was most of the work, one final pass of row/column interchange */ - /* to finish */ - for (k = 4 - 2; k >= 0; k--) { /* Don't need to work with 1 by 1 corner*/ - i = pvt_j[k]; /* Rows to swap correspond to pivot COLUMN */ - if (i != k) { /* If rows are different */ - for (j = 0; j < 4; j++) { - hold = columns[k][j]; - columns[k][j] = -columns[i][j]; - columns[i][j] = hold; - } - } - - j = pvt_i[k]; /* Columns to swap correspond to pivot ROW */ - if (j != k) { /* If columns are different */ - for (i = 0; i < 4; i++) { - hold = columns[i][k]; - columns[i][k] = -columns[i][j]; - columns[i][j] = hold; - } - } + /* choose pivot - or die */ + if (Math::abs(r3[1]) > Math::abs(r2[1])) { + SWAP(r3, r2); } + if (Math::abs(r2[1]) > Math::abs(r1[1])) { + SWAP(r2, r1); + } + ERR_FAIL_COND(0.0 == r1[1]); + + /* eliminate second variable */ + m2 = r2[1] / r1[1]; + m3 = r3[1] / r1[1]; + r2[2] -= m2 * r1[2]; + r3[2] -= m3 * r1[2]; + r2[3] -= m2 * r1[3]; + r3[3] -= m3 * r1[3]; + s = r1[4]; + if (0.0 != s) { + r2[4] -= m2 * s; + r3[4] -= m3 * s; + } + s = r1[5]; + if (0.0 != s) { + r2[5] -= m2 * s; + r3[5] -= m3 * s; + } + s = r1[6]; + if (0.0 != s) { + r2[6] -= m2 * s; + r3[6] -= m3 * s; + } + s = r1[7]; + if (0.0 != s) { + r2[7] -= m2 * s; + r3[7] -= m3 * s; + } + + /* choose pivot - or die */ + if (Math::abs(r3[2]) > Math::abs(r2[2])) { + SWAP(r3, r2); + } + ERR_FAIL_COND(0.0 == r2[2]); + + /* eliminate third variable */ + m3 = r3[2] / r2[2]; + r3[3] -= m3 * r2[3]; + r3[4] -= m3 * r2[4]; + r3[5] -= m3 * r2[5]; + r3[6] -= m3 * r2[6]; + r3[7] -= m3 * r2[7]; + + /* last check */ + ERR_FAIL_COND(0.0 == r3[3]); + + s = 1.0 / r3[3]; /* now back substitute row 3 */ + r3[4] *= s; + r3[5] *= s; + r3[6] *= s; + r3[7] *= s; + + m2 = r2[3]; /* now back substitute row 2 */ + s = 1.0 / r2[2]; + r2[4] = s * (r2[4] - r3[4] * m2); + r2[5] = s * (r2[5] - r3[5] * m2); + r2[6] = s * (r2[6] - r3[6] * m2); + r2[7] = s * (r2[7] - r3[7] * m2); + m1 = r1[3]; + r1[4] -= r3[4] * m1; + r1[5] -= r3[5] * m1; + r1[6] -= r3[6] * m1; + r1[7] -= r3[7] * m1; + m0 = r0[3]; + r0[4] -= r3[4] * m0; + r0[5] -= r3[5] * m0; + r0[6] -= r3[6] * m0; + r0[7] -= r3[7] * m0; + + m1 = r1[2]; /* now back substitute row 1 */ + s = 1.0 / r1[1]; + r1[4] = s * (r1[4] - r2[4] * m1); + r1[5] = s * (r1[5] - r2[5] * m1), + r1[6] = s * (r1[6] - r2[6] * m1); + r1[7] = s * (r1[7] - r2[7] * m1); + m0 = r0[2]; + r0[4] -= r2[4] * m0; + r0[5] -= r2[5] * m0; + r0[6] -= r2[6] * m0; + r0[7] -= r2[7] * m0; + + m0 = r0[1]; /* now back substitute row 0 */ + s = 1.0 / r0[0]; + r0[4] = s * (r0[4] - r1[4] * m0); + r0[5] = s * (r0[5] - r1[5] * m0), + r0[6] = s * (r0[6] - r1[6] * m0); + r0[7] = s * (r0[7] - r1[7] * m0); + + MAT(out, 0, 0) = r0[4]; + MAT(out, 0, 1) = r0[5]; + MAT(out, 0, 2) = r0[6]; + MAT(out, 0, 3) = r0[7]; + MAT(out, 1, 0) = r1[4]; + MAT(out, 1, 1) = r1[5]; + MAT(out, 1, 2) = r1[6]; + MAT(out, 1, 3) = r1[7]; + MAT(out, 2, 0) = r2[4]; + MAT(out, 2, 1) = r2[5]; + MAT(out, 2, 2) = r2[6]; + MAT(out, 2, 3) = r2[7]; + MAT(out, 3, 0) = r3[4]; + MAT(out, 3, 1) = r3[5]; + MAT(out, 3, 2) = r3[6]; + MAT(out, 3, 3) = r3[7]; + +#undef MAT + + *this = temp; } void Projection::flip_y() { diff --git a/tests/core/math/test_projection.h b/tests/core/math/test_projection.h new file mode 100644 index 00000000000..7f41aaee3e7 --- /dev/null +++ b/tests/core/math/test_projection.h @@ -0,0 +1,87 @@ +/**************************************************************************/ +/* test_projection.h */ +/**************************************************************************/ +/* 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. */ +/**************************************************************************/ + +#ifndef TEST_PROJECTION_H +#define TEST_PROJECTION_H + +#include "core/math/projection.h" + +#include "core/string/print_string.h" +#include "tests/test_macros.h" + +namespace TestProjection { + +TEST_CASE("[Projection] Default construct") { + Projection p; + CHECK(p.columns[0][0] == 1.0); + CHECK(p.columns[0][1] == 0.0); + CHECK(p.columns[0][2] == 0.0); + CHECK(p.columns[0][3] == 0.0); + + CHECK(p.columns[1][0] == 0.0); + CHECK(p.columns[1][1] == 1.0); + CHECK(p.columns[1][2] == 0.0); + CHECK(p.columns[1][3] == 0.0); + + CHECK(p.columns[2][0] == 0.0); + CHECK(p.columns[2][1] == 0.0); + CHECK(p.columns[2][2] == 1.0); + CHECK(p.columns[2][3] == 0.0); + + CHECK(p.columns[3][0] == 0.0); + CHECK(p.columns[3][1] == 0.0); + CHECK(p.columns[3][2] == 0.0); + CHECK(p.columns[3][3] == 1.0); +} + +bool projection_is_equal_approx(const Projection &p_a, const Projection &p_b) { + for (int i = 0; i < 4; i++) { + for (int j = 0; j < 4; j++) { + if (!Math::is_equal_approx(p_a.columns[i][j], p_b.columns[i][j])) { + return false; + } + } + } + return true; +} + +TEST_CASE("[Projection] Orthogonal projection matrix inversion") { + Projection p = Projection::create_orthogonal(-125.0f, 125.0f, -125.0f, 125.0f, 0.01f, 25.0f); + CHECK(projection_is_equal_approx(p.inverse() * p, Projection())); +} + +TEST_CASE("[Projection] Perspective projection matrix inversion") { + Projection p = Projection::create_perspective(90.0f, 1.77777f, 0.05f, 4000.0f); + CHECK(projection_is_equal_approx(p.inverse() * p, Projection())); +} + +} //namespace TestProjection + +#endif // TEST_PROJECTION_H diff --git a/tests/test_main.cpp b/tests/test_main.cpp index a431f698297..9acdc98b1d6 100644 --- a/tests/test_main.cpp +++ b/tests/test_main.cpp @@ -65,6 +65,7 @@ #include "tests/core/math/test_geometry_3d.h" #include "tests/core/math/test_math_funcs.h" #include "tests/core/math/test_plane.h" +#include "tests/core/math/test_projection.h" #include "tests/core/math/test_quaternion.h" #include "tests/core/math/test_random_number_generator.h" #include "tests/core/math/test_rect2.h"