| 1 | /*
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| 2 | * Copyright (c) 2011 Petr Koupy
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| 3 | * All rights reserved.
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| 4 | *
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| 5 | * Redistribution and use in source and binary forms, with or without
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| 6 | * modification, are permitted provided that the following conditions
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| 7 | * are met:
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| 8 | *
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| 9 | * - Redistributions of source code must retain the above copyright
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| 10 | * notice, this list of conditions and the following disclaimer.
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| 11 | * - Redistributions in binary form must reproduce the above copyright
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| 12 | * notice, this list of conditions and the following disclaimer in the
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| 13 | * documentation and/or other materials provided with the distribution.
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| 14 | * - The name of the author may not be used to endorse or promote products
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| 15 | * derived from this software without specific prior written permission.
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| 16 | *
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| 17 | * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
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| 18 | * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
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| 19 | * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
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| 20 | * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
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| 21 | * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
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| 22 | * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
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| 23 | * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
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| 24 | * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
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| 25 | * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
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| 26 | * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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| 27 | */
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| 28 |
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| 29 | /** @addtogroup softrend
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| 30 | * @{
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| 31 | */
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| 32 | /**
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| 33 | * @file
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| 34 | */
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| 35 |
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| 36 | #include "transform.h"
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| 37 |
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| 38 | void transform_multiply(transform_t *res, const transform_t *left, const transform_t *right)
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| 39 | {
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| 40 | for (int i = 0; i < 3; ++i) {
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| 41 | for (int j = 0; j < 3; ++j) {
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| 42 | double comb = 0;
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| 43 | for (int k = 0; k < 3; ++k) {
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| 44 | comb += left->m[i][k] * right->m[k][j];
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| 45 | }
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| 46 | res->m[i][j] = comb;
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| 47 | }
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| 48 | }
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| 49 | }
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| 50 |
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| 51 | void transform_invert(transform_t *t)
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| 52 | {
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| 53 | double a = t->m[1][1] * t->m[2][2] - t->m[1][2] * t->m[2][1];
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| 54 | double b = t->m[1][2] * t->m[2][0] - t->m[2][2] * t->m[1][0];
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| 55 | double c = t->m[1][0] * t->m[2][1] - t->m[1][1] * t->m[2][0];
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| 56 | double d = t->m[0][2] * t->m[2][1] - t->m[0][1] * t->m[2][2];
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| 57 | double e = t->m[0][0] * t->m[2][2] - t->m[0][2] * t->m[2][0];
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| 58 | double f = t->m[2][0] * t->m[0][1] - t->m[0][0] * t->m[2][1];
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| 59 | double g = t->m[0][1] * t->m[1][2] - t->m[0][2] * t->m[1][1];
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| 60 | double h = t->m[0][2] * t->m[1][0] - t->m[0][0] * t->m[1][2];
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| 61 | double k = t->m[0][0] * t->m[1][1] - t->m[0][1] * t->m[1][0];
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| 62 |
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| 63 | double det = t->m[0][0] * a + t->m[0][1] * b + t->m[0][2] * c;
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| 64 | det = 1 / det;
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| 65 |
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| 66 | t->m[0][0] = a * det; t->m[0][1] = d * det; t->m[0][2] = g * det;
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| 67 | t->m[1][0] = b * det; t->m[1][1] = e * det; t->m[1][2] = h * det;
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| 68 | t->m[2][0] = c * det; t->m[2][1] = f * det; t->m[2][2] = k * det;
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| 69 | }
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| 70 |
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| 71 | void transform_identity(transform_t *t)
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| 72 | {
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| 73 | t->m[0][0] = 1; t->m[0][1] = 0; t->m[0][2] = 0;
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| 74 | t->m[1][0] = 0; t->m[1][1] = 1; t->m[1][2] = 0;
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| 75 | t->m[2][0] = 0; t->m[2][1] = 0; t->m[2][2] = 1;
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| 76 | }
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| 77 |
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| 78 | void transform_translate(transform_t *t, double dx, double dy)
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| 79 | {
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| 80 | transform_t a;
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| 81 | a.m[0][0] = 1; a.m[0][1] = 0; a.m[0][2] = dx;
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| 82 | a.m[1][0] = 0; a.m[1][1] = 1; a.m[1][2] = dy;
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| 83 | a.m[2][0] = 0; a.m[2][1] = 0; a.m[2][2] = 1;
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| 84 |
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| 85 | transform_t r;
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| 86 | transform_multiply(&r, &a, t);
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| 87 | *t = r;
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| 88 | }
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| 89 |
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| 90 | void transform_scale(transform_t *t, double qx, double qy)
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| 91 | {
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| 92 | transform_t a;
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| 93 | a.m[0][0] = qx; a.m[0][1] = 0; a.m[0][2] = 0;
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| 94 | a.m[1][0] = 0; a.m[1][1] = qy; a.m[1][2] = 0;
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| 95 | a.m[2][0] = 0; a.m[2][1] = 0; a.m[2][2] = 1;
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| 96 |
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| 97 | transform_t r;
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| 98 | transform_multiply(&r, &a, t);
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| 99 | *t = r;
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| 100 | }
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| 101 |
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| 102 | void transform_rotate(transform_t *t, double rad)
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| 103 | {
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| 104 | double s, c;
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| 105 |
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| 106 | // FIXME: temporary solution until there are trigonometric functions in libc
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| 107 |
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| 108 | while (rad < 0) {
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| 109 | rad += (2 * PI);
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| 110 | }
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| 111 |
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| 112 | while (rad > (2 * PI)) {
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| 113 | rad -= (2 * PI);
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| 114 | }
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| 115 |
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| 116 | if (rad >= 0 && rad < (PI / 4)) {
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| 117 | s = 0; c = 1;
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| 118 | } else if (rad >= (PI / 4) && rad < (3 * PI / 4)) {
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| 119 | s = 1; c = 0;
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| 120 | } else if (rad >= (3 * PI / 4) && rad < (5 * PI / 4)) {
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| 121 | s = 0; c = -1;
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| 122 | } else if (rad >= (5 * PI / 4) && rad < (7 * PI / 4)) {
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| 123 | s = -1; c = 0;
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| 124 | } else {
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| 125 | s = 0; c = 1;
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| 126 | }
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| 127 |
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| 128 | transform_t a;
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| 129 | a.m[0][0] = c; a.m[0][1] = -s; a.m[0][2] = 0;
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| 130 | a.m[1][0] = s; a.m[1][1] = c; a.m[1][2] = 0;
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| 131 | a.m[2][0] = 0; a.m[2][1] = 0; a.m[2][2] = 1;
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| 132 |
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| 133 | transform_t r;
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| 134 | transform_multiply(&r, &a, t);
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| 135 | *t = r;
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| 136 | }
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| 137 |
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| 138 | void transform_apply_linear(const transform_t *t, double *x, double *y)
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| 139 | {
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| 140 | double x_ = *x;
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| 141 | double y_ = *y;
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| 142 | *x = x_ * t->m[0][0] + y_ * t->m[0][1];
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| 143 | *y = x_ * t->m[1][0] + y_ * t->m[1][1];
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| 144 | }
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| 145 |
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| 146 | void transform_apply_affine(const transform_t *t, double *x, double *y)
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| 147 | {
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| 148 | double x_ = *x;
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| 149 | double y_ = *y;
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| 150 | *x = x_ * t->m[0][0] + y_ * t->m[0][1] + t->m[0][2];
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| 151 | *y = x_ * t->m[1][0] + y_ * t->m[1][1] + t->m[1][2];
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| 152 | }
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| 153 |
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| 154 | /** @}
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| 155 | */
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