void RCPBody::applyImpulse(RVector const & impulse)
{
if (mBody) {
cpBodyApplyImpulseAtWorldPoint(mBody, cpv(impulse.x(), impulse.y()), cpBodyLocalToWorld(mBody, cpBodyGetCenterOfGravity(mBody)));
}
}
void Slice::ClipPoly(cpSpace *space, cpShape *shape, cpVect n, cpFloat dist)
{
cpBody *body = cpShapeGetBody(shape);
int count = cpPolyShapeGetCount(shape);
int clippedCount = 0;
cpVect *clipped = (cpVect *)alloca((count + 1)*sizeof(cpVect));
for(int i=0, j=count-1; i<count; j=i, i++){
cpVect a = cpBodyLocalToWorld(body, cpPolyShapeGetVert(shape, j));
cpFloat a_dist = cpvdot(a, n) - dist;
if(a_dist < 0.0){
clipped[clippedCount] = a;
clippedCount++;
}
cpVect b = cpBodyLocalToWorld(body, cpPolyShapeGetVert(shape, i));
cpFloat b_dist = cpvdot(b, n) - dist;
if(a_dist*b_dist < 0.0f){
cpFloat t = cpfabs(a_dist)/(cpfabs(a_dist) + cpfabs(b_dist));
clipped[clippedCount] = cpvlerp(a, b, t);
clippedCount++;
}
}
cpVect centroid = cpCentroidForPoly(clippedCount, clipped);
cpFloat mass = cpAreaForPoly(clippedCount, clipped, 0.0f)*DENSITY;
cpFloat moment = cpMomentForPoly(mass, clippedCount, clipped, cpvneg(centroid), 0.0f);
cpBody *new_body = cpSpaceAddBody(space, cpBodyNew(mass, moment));
cpBodySetPosition(new_body, centroid);
cpBodySetVelocity(new_body, cpBodyGetVelocityAtWorldPoint(body, centroid));
cpBodySetAngularVelocity(new_body, cpBodyGetAngularVelocity(body));
cpTransform transform = cpTransformTranslate(cpvneg(centroid));
cpShape *new_shape = cpSpaceAddShape(space, cpPolyShapeNew(new_body, clippedCount, clipped, transform, 0.0));
// Copy whatever properties you have set on the original shape that are important
cpShapeSetFriction(new_shape, cpShapeGetFriction(shape));
}
int applykeys(Ship* s, bool* keylist)
{
if (keylist[0])
cpBodyApplyForceAtLocalPoint(s->body, cpv(0, 1e7), cpv(0.5, 0));
if (keylist[1])
cpBodyApplyForceAtLocalPoint(s->body, cpv(0, -1e6), cpv(0.5, 3));
if (keylist[2])
{
cpBodyApplyForceAtLocalPoint(s->body, cpv(1e6, 0), cpv(0, 0));
cpBodyApplyForceAtLocalPoint(s->body, cpv(-1e6, 0), cpv(1, 3));
}
if (keylist[3])
{
cpBodyApplyForceAtLocalPoint(s->body, cpv(1e6, 0), cpv(0, 3));
cpBodyApplyForceAtLocalPoint(s->body, cpv(-1e6, 0), cpv(1, 0));
}
if (keylist[4])
{
cpBodyApplyForceAtLocalPoint(s->body, cpv(-1e6, 0), cpv(1, 3));
cpBodyApplyForceAtLocalPoint(s->body, cpv(-1e6, 0), cpv(1, 0));
}
if (keylist[5])
{
cpBodyApplyForceAtLocalPoint(s->body, cpv(1e6, 0), cpv(0, 3));
cpBodyApplyForceAtLocalPoint(s->body, cpv(1e6, 0), cpv(0, 0));
}
if (keylist[6] && last_time_updated - s->last_fired > 1)
{
cpVect tip = cpBodyLocalToWorld(s->body, nosev + cpv(0, 0.1));
cpVect base = cpBodyLocalToWorld(s->body, cpv(0.5, 0));
cpVect newvel = cpvnormalize(tip - base) * shell_muzzle_vel + cpBodyGetVelocityAtLocalPoint(s->body, nosev);
Shell* newshell = addshell(tip, newvel, cpBodyGetAngle(s->body));
cpBodyApplyImpulseAtLocalPoint(s->body, cpv(0, -1)*cpBodyGetMass(newshell->body)*shell_muzzle_vel, cpv(0.5, 3));
s->last_fired = last_time_updated;
}
return 0;
}
Vector2f RigidBody2D::GetCenterOfGravity(CoordSys coordSys) const
{
cpVect cog = cpBodyGetCenterOfGravity(m_handle);
switch (coordSys)
{
case CoordSys_Global:
cog = cpBodyLocalToWorld(m_handle, cog);
break;
case CoordSys_Local:
break; // Nothing to do
}
return Vector2f(static_cast<float>(cog.x), static_cast<float>(cog.y));
}
Vec2 PhysicsBody::local2World(const Vec2& point)
{
return PhysicsHelper::cpv2point(cpBodyLocalToWorld(_cpBody, PhysicsHelper::point2cpv(point)));
}
struct gun instantiate_gun(struct obj *owner, const char *gunType,
const char *bulletType)
{
// fprintf(stderr, "\n\n\n%s\n\n\n", bulletType);
struct gun ret = {.bulletType = strdup(bulletType), .owner = owner, .cooldown = owner->room->ticks};
ret.fire = guntbl_find(&fires, gunType);
return ret;
}
void machinegun_fire(struct gun *self)
{
if (self->owner->room->ticks - self->cooldown > 1) {
struct obj *bullet = instantiate_object(self->bulletType,
self->owner->objectVect,
self->owner->room);
cpBodySetPosition(bullet->body,
cpBodyLocalToWorld(self->owner->body,
cpv(0, -self->owner->radius - bullet->radius - 2)));
cpBodySetMoment(bullet->body,
cpMomentForCircle(10000.0, 0.0,
bullet->radius*2, cpvzero));
cpBodySetAngle(bullet->body, cpBodyGetAngle(self->owner->body) + M_PI);
((struct bullet_extra*)bullet->extra)->speed = 20.0;
((struct bullet_extra*)bullet->extra)->owner = self->owner;
cpBodyApplyImpulseAtLocalPoint(self->owner->body,
cpv(0, 50.0),
cpv(0, -(self->owner->radius * 2)));
self->cooldown = self->owner->room->ticks;
}
}
struct gunpair {
const char *name;
const gunmethod method;
};
void register_guns(void)
{
struct gunpair pairs[] = {{"machine gun", machinegun_fire}};
for (size_t i = 0; i < ARRAY_LENGTH(pairs); i++) {
char *currentName = pairs[i].name;
gunmethod currentMethod = pairs[i].method;
if ((!currentName && currentMethod) || (currentName && !currentMethod)) {
CROAK("Unevenly sized methodpair array");
}
guntbl_insert(&fires, currentName, currentMethod);
}
}
void guntbl_insert(struct guntbl *table, const char *key, gunmethod method)
{
int offset = hash(key) % 32;
if (table->keys[offset]) {
if (strcmp(table->keys[offset], key) == 0 ) {
table->methods[offset] = method;
} else {
if (!table->next)
{
table->next = malloc(sizeof(struct guntbl));
*table->next = (struct guntbl){.next = NULL};
}
guntbl_insert(table->next, key, method);
}
} else {
cpBool Buoyancy::WaterPreSolve(cpArbiter *arb, cpSpace *space, void *ptr)
{
CP_ARBITER_GET_SHAPES(arb, water, poly);
cpBody *body = cpShapeGetBody(poly);
// Get the top of the water sensor bounding box to use as the water level.
cpFloat level = cpShapeGetBB(water).t;
// Clip the polygon against the water level
int count = cpPolyShapeGetCount(poly);
int clippedCount = 0;
#ifdef _MSC_VER
// MSVC is pretty much the only compiler in existence that doesn't support variable sized arrays.
cpVect clipped[10];
#else
cpVect clipped[count + 1];
#endif
for(int i=0, j=count-1; i<count; j=i, i++){
cpVect a = cpBodyLocalToWorld(body, cpPolyShapeGetVert(poly, j));
cpVect b = cpBodyLocalToWorld(body, cpPolyShapeGetVert(poly, i));
if(a.y < level){
clipped[clippedCount] = a;
clippedCount++;
}
cpFloat a_level = a.y - level;
cpFloat b_level = b.y - level;
if(a_level*b_level < 0.0f){
cpFloat t = cpfabs(a_level)/(cpfabs(a_level) + cpfabs(b_level));
clipped[clippedCount] = cpvlerp(a, b, t);
clippedCount++;
}
}
// Calculate buoyancy from the clipped polygon area
cpFloat clippedArea = cpAreaForPoly(clippedCount, clipped, 0.0f);
cpFloat displacedMass = clippedArea*FLUID_DENSITY;
cpVect centroid = cpCentroidForPoly(clippedCount, clipped);
cpDataPointer data = ptr;
DrawPolygon(clippedCount, clipped, 0.0f, RGBAColor(0, 0, 1, 1), RGBAColor(0, 0, 1, 0.1f), data);
DrawDot(5, centroid, RGBAColor(0, 0, 1, 1), data);
cpFloat dt = cpSpaceGetCurrentTimeStep(space);
cpVect g = cpSpaceGetGravity(space);
// Apply the buoyancy force as an impulse.
cpBodyApplyImpulseAtWorldPoint(body, cpvmult(g, -displacedMass*dt), centroid);
// Apply linear damping for the fluid drag.
cpVect v_centroid = cpBodyGetVelocityAtWorldPoint(body, centroid);
cpFloat k = k_scalar_body(body, centroid, cpvnormalize(v_centroid));
cpFloat damping = clippedArea*FLUID_DRAG*FLUID_DENSITY;
cpFloat v_coef = cpfexp(-damping*dt*k); // linear drag
// cpFloat v_coef = 1.0/(1.0 + damping*dt*cpvlength(v_centroid)*k); // quadratic drag
cpBodyApplyImpulseAtWorldPoint(body, cpvmult(cpvsub(cpvmult(v_centroid, v_coef), v_centroid), 1.0/k), centroid);
// Apply angular damping for the fluid drag.
cpVect cog = cpBodyLocalToWorld(body, cpBodyGetCenterOfGravity(body));
cpFloat w_damping = cpMomentForPoly(FLUID_DRAG*FLUID_DENSITY*clippedArea, clippedCount, clipped, cpvneg(cog), 0.0f);
cpBodySetAngularVelocity(body, cpBodyGetAngularVelocity(body)*cpfexp(-w_damping*dt/cpBodyGetMoment(body)));
return cpTrue;
}
