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comparison src/coord.c @ 1:b5c0162ccf69

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Coordination tranforming
author Thinker K.F. Li <thinker@branda.to>
date Wed, 23 Jul 2008 13:57:33 +0800
parents
children 31402929c587
comparison
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0:5aca939dbfbe 1:b5c0162ccf69
1 #include <stdio.h>
2 #include <string.h>
3
4 typedef struct coord {
5 int seq;
6 float matrix[6];
7 float aggr_matrix[6];
8 struct coord *parent;
9 struct coord *children, *sibling;
10 } coord_t;
11
12 static void mul_matrix(float *m1, float *m2, float *dst) {
13 dst[0] = m1[0] * m2[0] + m1[1] * m2[3];
14 dst[1] = m1[0] * m2[1] + m1[1] * m2[4];
15 dst[2] = m1[0] * m2[2] + m1[1] * m2[5] + m1[2];
16 dst[3] = m1[3] * m2[0] + m1[4] * m2[3];
17 dst[4] = m1[3] * m2[1] + m1[4] * m2[4];
18 dst[5] = m1[3] * m2[2] + m1[4] * m2[5] + m1[5];
19 }
20
21 static void compute_transform_function(coord_t *visit) {
22 if(visit->parent)
23 mul_matrix(visit->parent->aggr_matrix,
24 visit->matrix, visit->aggr_matrix);
25 else
26 memcpy(visit->aggr_matrix, visit->matrix, sizeof(visit->matrix));
27 }
28
29 /*! \brief Update aggregate matrices of elements under a sub-tree.
30 *
31 * A subtree is specified by the root of it. All elements in the subtree
32 * are effected by that changes of matrix of the subtree root.
33 */
34 void update_aggr_matrix(coord_t *start) {
35 coord_t *visit, *child, *next;
36
37 compute_transform_function(start);
38
39 visit = start;
40 while(visit) {
41 child = visit->children;
42 while(child) {
43 compute_transform_function(child);
44 child = child->sibling;
45 }
46
47 if(visit->children)
48 visit = visit->children;
49 else if(visit->sibling)
50 visit = visit->sibling;
51 else {
52 next = NULL;
53 while(visit->parent && visit->parent != start) {
54 visit = visit->parent;
55 if(visit->sibling) {
56 next = visit->sibling;
57 break;
58 }
59 }
60 visit = next;
61 }
62 }
63 }
64
65 void coord_init(coord_t *co, coord_t *parent) {
66 memset(co, 0, sizeof(coord_t));
67 if(parent) {
68 co->parent = parent;
69 co->sibling = parent->children;
70 parent->children = co;
71 }
72 co->matrix[0] = 1;
73 co->matrix[4] = 1;
74 }
75
76 #ifdef UNITTEST
77
78 #include <CUnit/Basic.h>
79
80 void test_update_aggr_matrix(void) {
81 coord_t elms[6];
82
83 coord_init(elms, NULL);
84 coord_init(elms + 1, elms);
85 coord_init(elms + 2, elms);
86 coord_init(elms + 3, elms + 1);
87 coord_init(elms + 4, elms + 1);
88 coord_init(elms + 5, elms + 2);
89
90 /* | 2 -1 0 |
91 * | 0 1 0 |
92 * | 0 0 1 |
93 */
94 elms[0].matrix[0] = 2;
95 elms[0].matrix[1] = -1;
96
97 /* | 1 3 0 |
98 * | 5 1 0 |
99 * | 0 0 1 |
100 */
101 elms[1].matrix[1] = 3;
102 elms[1].matrix[3] = 5;
103
104 update_aggr_matrix(elms);
105
106 /* | -3 5 0 |
107 * | 5 1 0 |
108 * | 0 0 1 |
109 */
110 CU_ASSERT(elms[3].aggr_matrix[0] == -3);
111 CU_ASSERT(elms[3].aggr_matrix[1] == 5);
112 CU_ASSERT(elms[3].aggr_matrix[2] == 0);
113 CU_ASSERT(elms[3].aggr_matrix[3] == 5);
114 CU_ASSERT(elms[3].aggr_matrix[4] == 1);
115 CU_ASSERT(elms[3].aggr_matrix[5] == 0);
116
117 CU_ASSERT(elms[4].aggr_matrix[0] == -3);
118 CU_ASSERT(elms[4].aggr_matrix[1] == 5);
119 CU_ASSERT(elms[4].aggr_matrix[2] == 0);
120 CU_ASSERT(elms[4].aggr_matrix[3] == 5);
121 CU_ASSERT(elms[4].aggr_matrix[4] == 1);
122 CU_ASSERT(elms[4].aggr_matrix[5] == 0);
123
124 CU_ASSERT(elms[5].aggr_matrix[0] == 2);
125 CU_ASSERT(elms[5].aggr_matrix[1] == -1);
126 CU_ASSERT(elms[5].aggr_matrix[2] == 0);
127 CU_ASSERT(elms[5].aggr_matrix[3] == 0);
128 CU_ASSERT(elms[5].aggr_matrix[4] == 1);
129 CU_ASSERT(elms[5].aggr_matrix[5] == 0);
130 }
131
132 CU_pSuite get_coord_suite(void) {
133 CU_pSuite suite;
134
135 suite = CU_add_suite("Suite_coord", NULL, NULL);
136 CU_ADD_TEST(suite, test_update_aggr_matrix);
137
138 return suite;
139 }
140
141 #endif