samples.Query source code

1 
2 // written in the D programming language
3 
4 module samples.Query;
5 
6 import dchip.all;
7 
8 import samples.ChipmunkDemo;
9 import gameApp;
10 
11 import std.math;
12 
13 static cpSpace *space;
14 
15 static cpShape *querySeg = null;
16 
17 
18 static void
19 update(int ticks)
20 {
21     //messageString[0] = '\0';
22 
23     cpVect start = cpvzero;
24     cpVect end = /*cpv(0, 85);//*/mousePos;
25     cpVect lineEnd = end;
26 
27     //{
28     //	char infoString[1024];
29     //	sprintf(infoString, "Query: Dist(%f) Point%s, ", cpvdist(start, end), cpvstr(end));
30     //	strcat(messageString, infoString);
31     //}
32 
33     cpSegmentQueryInfo info = {};
34     if(cpSpaceSegmentQueryFirst(space, start, end, CP_ALL_LAYERS, CP_NO_GROUP, &info)){
35         cpVect point = cpSegmentQueryHitPoint(start, end, info);
36         lineEnd = cpvadd(point, cpvzero);//cpvmult(info.n, 4.0f));
37 
38         //char infoString[1024];
39         //sprintf(infoString, "Segment Query: Dist(%f) Normal%s", cpSegmentQueryHitDist(start, end, info), cpvstr(info.n));
40         //strcat(messageString, infoString);
41     } else {
42         //strcat(messageString, "Segment Query (None)");
43     }
44 
45     cpSegmentShapeSetEndpoints(querySeg, start, lineEnd);
46     // force it to update it's collision detection data so it will draw
47     cpShapeUpdate(querySeg, cpvzero, cpv(1.0f, 0.0f));
48 
49     // normal other stuff.
50     int steps = 1;
51     cpFloat dt = 1.0f/60.0f/cast(cpFloat)steps;
52 
53     for(int i=0; i<steps; i++){
54         cpSpaceStep(space, dt);
55     }
56 }
57 
58 static cpSpace *
59 init()
60 {
61     cpResetShapeIdCounter();
62 
63     space = cpSpaceNew();
64     space.iterations = 5;
65 
66     cpBody *staticBody = space.staticBody;
67     cpShape *shape;
68 
69     // add a non-collidable segment as a quick and dirty way to draw the query line
70     shape = cpSpaceAddShape(space, cpSegmentShapeNew(staticBody, cpvzero, cpv(100.0f, 0.0f), 4.0f));
71     shape.layers = 0;
72     querySeg = shape;
73 
74     { // add a fat segment
75         cpFloat mass = 1.0f;
76         cpFloat length = 100.0f;
77         cpVect a = cpv(-length/2.0f, 0.0f), b = cpv(length/2.0f, 0.0f);
78 
79         cpBody *_body = cpSpaceAddBody(space, cpBodyNew(mass, cpMomentForSegment(mass, a, b)));
80         _body.p = cpv(0.0f, 100.0f);
81 
82         cpSpaceAddShape(space, cpSegmentShapeNew(_body, a, b, 20.0f));
83     }
84 
85     { // add a static segment
86         cpSpaceAddShape(space, cpSegmentShapeNew(staticBody, cpv(0, 300), cpv(300, 0), 0.0f));
87     }
88 
89     { // add a pentagon
90         cpFloat mass = 1.0f;
91         const int NUM_VERTS = 5;
92 
93         cpVect verts[NUM_VERTS];
94         for(int i=0; i<NUM_VERTS; i++){
95             cpFloat angle = -2*PI*i/(cast(cpFloat) NUM_VERTS);
96             verts[i] = cpv(30*cos(angle), 30*sin(angle));
97         }
98 
99         cpBody *_body = cpSpaceAddBody(space, cpBodyNew(mass, cpMomentForPoly(mass, NUM_VERTS, verts.ptr, cpvzero)));
100         _body.p = cpv(50.0f, 50.0f);
101 
102         cpSpaceAddShape(space, cpPolyShapeNew(_body, NUM_VERTS, verts.ptr, cpvzero));
103     }
104 
105     { // add a circle
106         cpFloat mass = 1.0f;
107         cpFloat r = 20.0f;
108 
109         cpBody *_body = cpSpaceAddBody(space, cpBodyNew(mass, cpMomentForCircle(mass, 0.0f, r, cpvzero)));
110         _body.p = cpv(100.0f, 100.0f);
111 
112         cpSpaceAddShape(space, cpCircleShapeNew(_body, r, cpvzero));
113     }
114 
115     return space;
116 }
117 
118 static void
119 destroy()
120 {
121     ChipmunkDemoFreeSpaceChildren(space);
122     cpSpaceFree(space);
123 }
124 
125 chipmunkDemo Query = {
126     "Segment Query",
127     null,
128     &init,
129     &update,
130     &destroy,
131 };