## Revision 1026

working ray-polygon collisions, but needs a lot of clean up

View differences:

world.c
7 7
``` **/
```
8 8

9 9
```#include <stdio.h>
```
10
```#include <stdlib.h>
```
11
```#include <math.h>
```
12
```#include <stdarg.h>
```
10 13
```#include "world.h"
```
11 14

12 15

13
```double collide_circle(ray_t *ray, object_t *obj){
```
16

17
```double (*collide_func[NUM_SHAPES])(ray_t *ray, object_t *obj) =
```
18
```    {
```
19
```    collide_poly
```
20
```    };
```
21
```int (*create_func[NUM_SHAPES])(object_t *obj, va_list ap) =
```
22
```{
```
23
```    create_poly
```
24
```};
```
25
```double collide_circle(ray_t *ray, object_t *obj)
```
26
```{
```
14 27
```    return -1;
```
15 28
```}
```
16
```double collide_rect(ray_t *ray, object_t *obj){
```
17
```    return -2;
```
29

30
```double collide_seg(ray_t *ray, point_t p3, point_t p4)
```
31
```{
```
32
```    double denom, nume_a, nume_b, ua, ub, xint, yint, dist;
```
33
```    point_t p1 = ray->p;
```
34
```    point_t p2 = {ray->p.x+cos(ray->d),ray->p.y+sin(ray->d)};
```
35

36
```   // printf("(%g,%g) --> (%g,%g) with (%g,%g) --> (%g,%g)\n",p1.x,p1.y,p2.x,p2.y,p3.x,p3.y,p4.x,p4.y);
```
37
```    denom = (p2.y-p1.y)*(p4.x-p3.x)-(p2.x-p1.x)*(p4.y-p3.y);
```
38
```    if (denom == 0) {
```
39
```	return RAY_MISS;
```
40
```    }
```
41
```    nume_a = (p2.x-p1.x)*(p3.y-p1.y)-(p2.y-p1.y)*(p3.x-p1.x);
```
42
```    nume_b = (p4.x-p3.x)*(p3.y-p1.y)-(p4.y-p3.y)*(p3.x-p1.x);
```
43

44
```    ua = nume_a/denom;
```
45
```    if (ua < 0 || ua > 1) {
```
46
```	return RAY_MISS;
```
47
```    }
```
48

49
```    ub = nume_b/denom;
```
50
```    if (ub < 0) {
```
51
```	return RAY_MISS;
```
52
```    }
```
53

54
```    xint = p3.x+ua*(p4.x-p3.x);
```
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```    yint = p3.y+ua*(p4.y-p3.y);
```
56
```    dist = sqrt((xint-p1.x)*(xint-p1.x)+(yint-p1.y)*(yint-p1.y));
```
57
```    return dist;
```
58

18 59
```}
```
60
```double collide_rect(ray_t *ray, object_t *obj) {}
```
61
```    /*
```
62
```{
```
63
```    seg_t s;
```
64
```    double min = RAY_MISS, x;
```
65
```    rect_t *rect = (rect_t *)obj->props;
```
19 66

20
```double collide(ray_t *ray, object_t *obj) {
```
67
```    s.p1 = s.p2 = rect->p1;
```
68
```    s.p2.y = rect->p2.y;
```
69
```    if ((x = collide_seg(ray, (seg_t *)&s)) < min)
```
70
```	min = x;
```
71

72
```    s.p1 = rect->p2;
```
73
```    if ((x = collide_seg(ray, (seg_t *)&s)) < min)
```
74
```	min = x;
```
75

76
```    s.p2 = rect->p1;
```
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```    s.p2.x = rect->p2.x;
```
78
```    if ((x = collide_seg(ray, (seg_t *)&s)) < min)
```
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```	min = x;
```
80

81
```    s.p1 = rect->p1;
```
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```    if ((x = collide_seg(ray, (seg_t *)&s)) < min)
```
83
```	min = x;
```
84

85
```    return min;
```
86
```}
```
87
```*/
```
88

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```double collide_poly(ray_t *ray, object_t *obj)
```
90
```{
```
91
```    int i;
```
92
```    double min = RAY_MISS;
```
93
```    double x;
```
94
```    poly_t *p = (poly_t *) obj->props;
```
95
```
```
96
```    if (obj->id != ID_POLY){
```
97
```	return -1;
```
98
```    }
```
99

100
```    for (i = 0; i < p->num_pts - 1; i++) {
```
101
```	if ((x = collide_seg(ray, p->pts[i], p->pts[i+1])) < min){
```
102
```	    min = x;
```
103
```	}
```
104
```    }
```
105
```    if (p->type == POLY_DISCONNECTED) {
```
106
```	if ((x = collide_seg(ray,p->pts[i],p->pts[0])) < min)
```
107
```	    min = x;
```
108
```    }
```
109
```    return min;
```
110
```}
```
111

112
```double collide(ray_t *ray, object_t *obj)
```
113
```{
```
21 114
```    if (ray == NULL || obj == NULL)
```
115
```    {
```
22 116
```	return -1;
```
117
```    }
```
23 118
```    return collide_func[obj->id](ray, obj);
```
24 119
```}
```
120

121

122

123
```object_t *create(int id, ...)
```
124
```{
```
125
```    object_t *obj;
```
126
```    va_list args;
```
127

128
```    obj = malloc(sizeof(object_t));
```
129
```    obj->id = id;
```
130
```    va_start(args, id);
```
131
```    if (create_func[id](obj, args) < 0) {
```
132
```	free(obj);
```
133
```	obj = NULL;
```
134
```    }
```
135
```    va_end(args);
```
136
```    return obj;
```
137
```}
```
138

139
```/**
```
140
``` *
```
141
``` **/
```
142
```int create_poly(object_t *obj, va_list ap)
```
143
```{
```
144
```    int i;
```
145
```    poly_t *p;
```
146

147
```    int argc =  va_arg(ap, int);
```
148
```    int poly_type = va_arg(ap, int);
```
149

150
```    p = malloc(sizeof(poly_t));
```
151

152

153
```    p->num_pts = argc;
```
154
```    p->pts = malloc((argc) * sizeof(point_t));
```
155
```    p->type = poly_type;
```
156

157
```    for(i=0;i < argc; i++) {
```
158
```	p->pts[i].x = va_arg(ap, double);
```
159
```	p->pts[i].y = va_arg(ap, double);
```
160
```    }
```
161
```    obj->id = ID_POLY;
```
162
```    obj->bbox = NULL;
```
163
```    obj->props = p;
```
164
```    return 1;
```
165
```}
```
166

167
```int create_rect(object_t *obj, va_list ap)
```
168
```{
```
169
```    int i;
```
170
```    poly_t *p;
```
171
```    int argc = va_arg(ap, int);
```
172
```}
```
173

174
```void destroy_poly (object_t *obj)
```
175
```{
```
176
```    poly_t *p;
```
177
```    int i;
```
178

179
```    if (obj == NULL)
```
180
```	return;
```
181
```    p =  (poly_t *)obj->props;
```
182
```    if (p != NULL) free(p->pts);
```
183
```    free(p);
```
184
```    free(obj);
```
185

186
```    for (i = 0; i < p->num_pts; i++)
```
187
```    {
```
188
```    }
```
189

190

191

192

193
```}
```
194

195
```void print_object(object_t *obj)
```
196
```{
```
197
```    if (obj == NULL) {
```
198
```	printf("No object\n");
```
199
```	return;
```
200
```    }
```
201
```    int i;
```
202
```    poly_t *p;
```
203
```    switch (obj->id) {
```
204
```	case ID_POLY:
```
205
```	    p = (poly_t *) obj->props;
```
206
```	    printf("POLYGON (%d points, %s) { ", p->num_pts, p->type?"connected" : "disconnected");
```
207
```	    for (i = 0; i < p->num_pts; i++){
```
208
```		printf("(%g, %g) ", p->pts[i].x, p->pts[i].y);
```
209
```	    }
```
210
```	    printf("}\n");
```
211
```	    break;
```
212
```	default:
```
213
```	    break;
```
214
```
```
215
```    }
```
216
```}
```
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