File: Tank.c

package info (click to toggle)
chipmunk 5.3.4-1
  • links: PTS
  • area: main
  • in suites: wheezy
  • size: 6,552 kB
  • sloc: ansic: 10,469; objc: 1,845; ruby: 279; perl: 108; makefile: 62; sh: 20
file content (152 lines) | stat: -rw-r--r-- 4,960 bytes parent folder | download
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
/* Copyright (c) 2007 Scott Lembcke
 * 
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 * 
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 * 
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 * SOFTWARE.
 */
 
#include <stdlib.h>
#include <math.h>

#include "chipmunk.h"
#include "drawSpace.h"
#include "ChipmunkDemo.h"

extern cpVect mousePoint;

static cpSpace *space;

static cpBody *tankBody, *tankControlBody;

static void
update(int ticks)
{
	int steps = 1;
	cpFloat dt = 1.0f/60.0f/(cpFloat)steps;
	
	for(int i=0; i<steps; i++){
		// turn the control body based on the angle relative to the actual body
		cpVect mouseDelta = cpvsub(mousePoint, tankBody->p);
		cpFloat turn = cpvtoangle(cpvunrotate(tankBody->rot, mouseDelta));
		cpBodySetAngle(tankControlBody, tankBody->a - turn);
		
		// drive the tank towards the mouse
		if(cpvnear(mousePoint, tankBody->p, 30.0)){
			tankControlBody->v = cpvzero; // stop
		} else {
			cpFloat direction = (cpvdot(mouseDelta, tankBody->rot) > 0.0 ? 1.0 : -1.0);
			tankControlBody->v = cpvrotate(tankBody->rot, cpv(30.0f*direction, 0.0f));
		}
		
		cpSpaceStep(space, dt);
	}
}

static cpBody *
add_box(cpFloat size, cpFloat mass)
{
	cpVect verts[] = {
		cpv(-size,-size),
		cpv(-size, size),
		cpv( size, size),
		cpv( size,-size),
	};
	
	cpFloat radius = cpvlength(cpv(size, size));

	cpBody *body = cpSpaceAddBody(space, cpBodyNew(mass, cpMomentForPoly(mass, 4, verts, cpvzero)));
	body->p = cpv(frand()*(640 - 2*radius) - (320 - radius), frand()*(480 - 2*radius) - (240 - radius));
	
	cpShape *shape = cpSpaceAddShape(space, cpPolyShapeNew(body, 4, verts, cpvzero));
	shape->e = 0.0f; shape->u = 0.7f;
	
	return body;
}

static cpSpace *
init(void)
{
	cpResetShapeIdCounter();
	
	space = cpSpaceNew();
	cpSpaceResizeActiveHash(space, 30.0f, 1000);
	space->iterations = 10;
	space->sleepTimeThreshold = 0.5f;
	
	cpBody *staticBody = &space->staticBody;
	cpShape *shape;
		
	// Create segments around the edge of the screen.
	shape = cpSpaceAddShape(space, cpSegmentShapeNew(staticBody, cpv(-320,-240), cpv(-320,240), 0.0f));
	shape->e = 1.0f; shape->u = 1.0f;
	shape->layers = NOT_GRABABLE_MASK;

	shape = cpSpaceAddShape(space, cpSegmentShapeNew(staticBody, cpv(320,-240), cpv(320,240), 0.0f));
	shape->e = 1.0f; shape->u = 1.0f;
	shape->layers = NOT_GRABABLE_MASK;

	shape = cpSpaceAddShape(space, cpSegmentShapeNew(staticBody, cpv(-320,-240), cpv(320,-240), 0.0f));
	shape->e = 1.0f; shape->u = 1.0f;
	shape->layers = NOT_GRABABLE_MASK;

	shape = cpSpaceAddShape(space, cpSegmentShapeNew(staticBody, cpv(-320,240), cpv(320,240), 0.0f));
	shape->e = 1.0f; shape->u = 1.0f;
	shape->layers = NOT_GRABABLE_MASK;
	
	for(int i=0; i<50; i++){
		cpBody *body = add_box(10.0, 1.0);
		
		cpConstraint *pivot = cpSpaceAddConstraint(space, cpPivotJointNew2(staticBody, body, cpvzero, cpvzero));
		pivot->biasCoef = 0.0f; // disable joint correction
		pivot->maxForce = 1000.0f; // emulate linear friction
		
		cpConstraint *gear = cpSpaceAddConstraint(space, cpGearJointNew(staticBody, body, 0.0f, 1.0f));
		gear->biasCoef = 0.0f; // disable joint correction
		gear->maxForce = 5000.0f; // emulate angular friction
	}
	
	// We joint the tank to the control body and control the tank indirectly by modifying the control body.
	tankControlBody = cpBodyNew(INFINITY, INFINITY);
	tankBody = add_box(15.0, 10.0);
	
	cpConstraint *pivot = cpSpaceAddConstraint(space, cpPivotJointNew2(tankControlBody, tankBody, cpvzero, cpvzero));
	pivot->biasCoef = 0.0f; // disable joint correction
	pivot->maxForce = 10000.0f; // emulate linear friction
	
	cpConstraint *gear = cpSpaceAddConstraint(space, cpGearJointNew(tankControlBody, tankBody, 0.0f, 1.0f));
	gear->biasCoef = 1.0f; // limit angular correction rate
	gear->maxBias = 1.0f; // limit angular correction rate
	gear->maxForce = 500000.0f; // emulate angular friction
		
	return space;
}

static void
destroy(void)
{
	cpBodyFree(tankControlBody);
	cpSpaceFreeChildren(space);
	cpSpaceFree(space);
}

chipmunkDemo Tank = {
	"Tank",
	NULL,
	init,
	update,
	destroy,
};