1 2 // written in the D programming language 3 4 module samples.Springies; 5 6 import dchip.all; 7 8 import samples.ChipmunkDemo; 9 10 static cpSpace *space; 11 12 static cpFloat 13 springForce(cpConstraint *spring, cpFloat dist) 14 { 15 cpFloat clamp = 20.0f; 16 return cpfclamp(cpDampedSpringGetRestLength(spring) - dist, -clamp, clamp)*cpDampedSpringGetStiffness(spring); 17 } 18 19 static cpConstraint * 20 new_spring(cpBody *a, cpBody *b, cpVect anchr1, cpVect anchr2, cpFloat restLength, cpFloat stiff, cpFloat damp) 21 { 22 cpConstraint *spring = cpDampedSpringNew(a, b, anchr1, anchr2, restLength, stiff, damp); 23 cpDampedSpringSetSpringForceFunc(spring, &springForce); 24 25 return spring; 26 } 27 28 static void 29 update(int ticks) 30 { 31 enum int steps = 1; 32 enum cpFloat dt = 1.0f/60.0f/cast(cpFloat)steps; 33 34 for(int i=0; i<steps; i++){ 35 cpSpaceStep(space, dt); 36 } 37 } 38 39 static cpBody * 40 add_bar(cpVect a, cpVect b, int group) 41 { 42 cpVect center = cpvmult(cpvadd(a, b), 1.0f/2.0f); 43 cpFloat length = cpvlength(cpvsub(b, a)); 44 cpFloat mass = length/160.0f; 45 46 cpBody *_body = cpSpaceAddBody(space, cpBodyNew(mass, mass*length*length/12.0f)); 47 _body.p = center; 48 49 cpShape *shape = cpSpaceAddShape(space, cpSegmentShapeNew(_body, cpvsub(a, center), cpvsub(b, center), 10.0f)); 50 shape.group = group; 51 52 return _body; 53 } 54 55 static cpSpace * 56 init() 57 { 58 space = cpSpaceNew(); 59 cpBody *staticBody = space.staticBody; 60 61 cpBody *body1 = add_bar(cpv(-240, 160), cpv(-160, 80), 1); 62 cpBody *body2 = add_bar(cpv(-160, 80), cpv( -80, 160), 1); 63 cpBody *body3 = add_bar(cpv( 0, 160), cpv( 80, 0), 0); 64 cpBody *body4 = add_bar(cpv( 160, 160), cpv( 240, 160), 0); 65 cpBody *body5 = add_bar(cpv(-240, 0), cpv(-160, -80), 2); 66 cpBody *body6 = add_bar(cpv(-160, -80), cpv( -80, 0), 2); 67 cpBody *body7 = add_bar(cpv( -80, 0), cpv( 0, 0), 2); 68 cpBody *body8 = add_bar(cpv( 0, -80), cpv( 80, -80), 0); 69 cpBody *body9 = add_bar(cpv( 240, 80), cpv( 160, 0), 3); 70 cpBody *body10 = add_bar(cpv( 160, 0), cpv( 240, -80), 3); 71 cpBody *body11 = add_bar(cpv(-240, -80), cpv(-160, -160), 4); 72 cpBody *body12 = add_bar(cpv(-160, -160), cpv( -80, -160), 0); 73 cpBody *body13 = add_bar(cpv( 0, -160), cpv( 80, -160), 0); 74 cpBody *body14 = add_bar(cpv( 160, -160), cpv( 240, -160), 0); 75 76 cpSpaceAddConstraint(space, cpPivotJointNew2( body1, body2, cpv( 40,-40), cpv(-40,-40))); 77 cpSpaceAddConstraint(space, cpPivotJointNew2( body5, body6, cpv( 40,-40), cpv(-40,-40))); 78 cpSpaceAddConstraint(space, cpPivotJointNew2( body6, body7, cpv( 40, 40), cpv(-40, 0))); 79 cpSpaceAddConstraint(space, cpPivotJointNew2( body9, body10, cpv(-40,-40), cpv(-40, 40))); 80 cpSpaceAddConstraint(space, cpPivotJointNew2(body11, body12, cpv( 40,-40), cpv(-40, 0))); 81 82 cpFloat stiff = 100.0f; 83 cpFloat damp = 0.5f; 84 cpSpaceAddConstraint(space, new_spring(staticBody, body1, cpv(-320, 240), cpv(-40, 40), 0.0f, stiff, damp)); 85 cpSpaceAddConstraint(space, new_spring(staticBody, body1, cpv(-320, 80), cpv(-40, 40), 0.0f, stiff, damp)); 86 cpSpaceAddConstraint(space, new_spring(staticBody, body1, cpv(-160, 240), cpv(-40, 40), 0.0f, stiff, damp)); 87 88 cpSpaceAddConstraint(space, new_spring(staticBody, body2, cpv(-160, 240), cpv( 40, 40), 0.0f, stiff, damp)); 89 cpSpaceAddConstraint(space, new_spring(staticBody, body2, cpv( 0, 240), cpv( 40, 40), 0.0f, stiff, damp)); 90 91 cpSpaceAddConstraint(space, new_spring(staticBody, body3, cpv( 80, 240), cpv(-40, 80), 0.0f, stiff, damp)); 92 93 cpSpaceAddConstraint(space, new_spring(staticBody, body4, cpv( 80, 240), cpv(-40, 0), 0.0f, stiff, damp)); 94 cpSpaceAddConstraint(space, new_spring(staticBody, body4, cpv( 320, 240), cpv( 40, 0), 0.0f, stiff, damp)); 95 96 cpSpaceAddConstraint(space, new_spring(staticBody, body5, cpv(-320, 80), cpv(-40, 40), 0.0f, stiff, damp)); 97 98 cpSpaceAddConstraint(space, new_spring(staticBody, body9, cpv( 320, 80), cpv( 40, 40), 0.0f, stiff, damp)); 99 100 cpSpaceAddConstraint(space, new_spring(staticBody, body10, cpv( 320, 0), cpv( 40,-40), 0.0f, stiff, damp)); 101 cpSpaceAddConstraint(space, new_spring(staticBody, body10, cpv( 320,-160), cpv( 40,-40), 0.0f, stiff, damp)); 102 103 cpSpaceAddConstraint(space, new_spring(staticBody, body11, cpv(-320,-160), cpv(-40, 40), 0.0f, stiff, damp)); 104 105 cpSpaceAddConstraint(space, new_spring(staticBody, body12, cpv(-240,-240), cpv(-40, 0), 0.0f, stiff, damp)); 106 cpSpaceAddConstraint(space, new_spring(staticBody, body12, cpv( 0,-240), cpv( 40, 0), 0.0f, stiff, damp)); 107 108 cpSpaceAddConstraint(space, new_spring(staticBody, body13, cpv( 0,-240), cpv(-40, 0), 0.0f, stiff, damp)); 109 cpSpaceAddConstraint(space, new_spring(staticBody, body13, cpv( 80,-240), cpv( 40, 0), 0.0f, stiff, damp)); 110 111 cpSpaceAddConstraint(space, new_spring(staticBody, body14, cpv( 80,-240), cpv(-40, 0), 0.0f, stiff, damp)); 112 cpSpaceAddConstraint(space, new_spring(staticBody, body14, cpv( 240,-240), cpv( 40, 0), 0.0f, stiff, damp)); 113 cpSpaceAddConstraint(space, new_spring(staticBody, body14, cpv( 320,-160), cpv( 40, 0), 0.0f, stiff, damp)); 114 115 cpSpaceAddConstraint(space, new_spring( body1, body5, cpv( 40,-40), cpv(-40, 40), 0.0f, stiff, damp)); 116 cpSpaceAddConstraint(space, new_spring( body1, body6, cpv( 40,-40), cpv( 40, 40), 0.0f, stiff, damp)); 117 cpSpaceAddConstraint(space, new_spring( body2, body3, cpv( 40, 40), cpv(-40, 80), 0.0f, stiff, damp)); 118 cpSpaceAddConstraint(space, new_spring( body3, body4, cpv(-40, 80), cpv(-40, 0), 0.0f, stiff, damp)); 119 cpSpaceAddConstraint(space, new_spring( body3, body4, cpv( 40,-80), cpv(-40, 0), 0.0f, stiff, damp)); 120 cpSpaceAddConstraint(space, new_spring( body3, body7, cpv( 40,-80), cpv( 40, 0), 0.0f, stiff, damp)); 121 cpSpaceAddConstraint(space, new_spring( body3, body7, cpv(-40, 80), cpv(-40, 0), 0.0f, stiff, damp)); 122 cpSpaceAddConstraint(space, new_spring( body3, body8, cpv( 40,-80), cpv( 40, 0), 0.0f, stiff, damp)); 123 cpSpaceAddConstraint(space, new_spring( body3, body9, cpv( 40,-80), cpv(-40,-40), 0.0f, stiff, damp)); 124 cpSpaceAddConstraint(space, new_spring( body4, body9, cpv( 40, 0), cpv( 40, 40), 0.0f, stiff, damp)); 125 cpSpaceAddConstraint(space, new_spring( body5, body11, cpv(-40, 40), cpv(-40, 40), 0.0f, stiff, damp)); 126 cpSpaceAddConstraint(space, new_spring( body5, body11, cpv( 40,-40), cpv( 40,-40), 0.0f, stiff, damp)); 127 cpSpaceAddConstraint(space, new_spring( body7, body8, cpv( 40, 0), cpv(-40, 0), 0.0f, stiff, damp)); 128 cpSpaceAddConstraint(space, new_spring( body8, body12, cpv(-40, 0), cpv( 40, 0), 0.0f, stiff, damp)); 129 cpSpaceAddConstraint(space, new_spring( body8, body13, cpv(-40, 0), cpv(-40, 0), 0.0f, stiff, damp)); 130 cpSpaceAddConstraint(space, new_spring( body8, body13, cpv( 40, 0), cpv( 40, 0), 0.0f, stiff, damp)); 131 cpSpaceAddConstraint(space, new_spring( body8, body14, cpv( 40, 0), cpv(-40, 0), 0.0f, stiff, damp)); 132 cpSpaceAddConstraint(space, new_spring(body10, body14, cpv( 40,-40), cpv(-40, 0), 0.0f, stiff, damp)); 133 cpSpaceAddConstraint(space, new_spring(body10, body14, cpv( 40,-40), cpv(-40, 0), 0.0f, stiff, damp)); 134 135 return space; 136 } 137 138 static void 139 destroy() 140 { 141 ChipmunkDemoFreeSpaceChildren(space); 142 cpSpaceFree(space); 143 } 144 145 chipmunkDemo Springies = { 146 "Springies", 147 null, 148 &init, 149 &update, 150 &destroy, 151 };