samples.Tumble source code

1 
2 // written in the D programming language
3 
4 module samples.Tumble;
5 
6 import dchip.all;
7 
8 import samples.ChipmunkDemo;
9 
10 static cpSpace *space;
11 static cpBody *staticBody;
12 
13 static void
14 update(int ticks)
15 {
16     enum int steps = 3;
17     enum cpFloat dt = 1.0f/60.0f/cast(cpFloat)steps;
18 
19     for(int i=0; i<steps; i++){
20         cpSpaceStep(space, dt);
21 
22         // Manually update the position of the static shape so that
23         // the box rotates.
24         cpBodyUpdatePosition(staticBody, dt);
25 
26         // Because the box was added as a static shape and we moved it
27         // we need to manually rehash the static spatial hash.
28         cpSpaceReindexStatic(space);
29     }
30 }
31 
32 static cpSpace *
33 init()
34 {
35     staticBody = cpBodyNew(INFINITY, INFINITY);
36 
37     cpResetShapeIdCounter();
38 
39     space = cpSpaceNew();
40     space.gravity = cpv(0, -600);
41 
42     cpBody *_body;
43     cpShape *shape;
44 
45     // Vertexes for the bricks
46     int num = 4;
47     cpVect verts[] = [
48         cpv(-30,-15),
49         cpv(-30, 15),
50         cpv( 30, 15),
51         cpv( 30,-15),
52     ];
53 
54     // Set up the static box.
55     cpVect a = cpv(-200, -200);
56     cpVect b = cpv(-200,  200);
57     cpVect c = cpv( 200,  200);
58     cpVect d = cpv( 200, -200);
59 
60     shape = cpSpaceAddShape(space, cpSegmentShapeNew(staticBody, a, b, 0.0f));
61     shape.e = 1.0f; shape.u = 1.0f;
62     shape.layers = NOT_GRABABLE_MASK;
63 
64     shape = cpSpaceAddShape(space, cpSegmentShapeNew(staticBody, b, c, 0.0f));
65     shape.e = 1.0f; shape.u = 1.0f;
66     shape.layers = NOT_GRABABLE_MASK;
67 
68     shape = cpSpaceAddShape(space, cpSegmentShapeNew(staticBody, c, d, 0.0f));
69     shape.e = 1.0f; shape.u = 1.0f;
70     shape.layers = NOT_GRABABLE_MASK;
71 
72     shape = cpSpaceAddShape(space, cpSegmentShapeNew(staticBody, d, a, 0.0f));
73     shape.e = 1.0f; shape.u = 1.0f;
74     shape.layers = NOT_GRABABLE_MASK;
75 
76     // Give the box a little spin.
77     // Because staticBody is never added to the space, we will need to
78     // update it ourselves. (see above).
79     // NOTE: Normally you would want to add the segments as normal and not static shapes.
80     // I'm just doing it to demonstrate the cpSpaceReindexStatic() function.
81     staticBody.w = 0.4f;
82 
83     // Add the bricks.
84     for(int i=0; i<3; i++){
85         for(int j=0; j<7; j++){
86             _body = cpSpaceAddBody(space, cpBodyNew(1.0f, cpMomentForPoly(1.0f, num, verts.ptr, cpvzero)));
87             _body.p = cpv(i*60 - 150, j*30 - 150);
88 
89             shape = cpSpaceAddShape(space, cpPolyShapeNew(_body, num, verts.ptr, cpvzero));
90             shape.e = 0.0f; shape.u = 0.7f;
91         }
92     }
93 
94     return space;
95 }
96 
97 static void
98 destroy()
99 {
100     cpBodyFree(staticBody);
101     ChipmunkDemoFreeSpaceChildren(space);
102     cpSpaceFree(space);
103 }
104 
105 chipmunkDemo Tumble = {
106     "Tumble",
107     null,
108     &init,
109     &update,
110     &destroy,
111 };