void CCClipOut::update(float time) {
CCClippingNode* clipper = (CCClippingNode*)getTarget();
CCDrawNode* stencil = (CCDrawNode*)clipper->getStencil();
// clear
stencil->clear();
// build polygon
float distance = m_distance * (1 - time);
if(distance < FLT_EPSILON) {
CCPoint v[] = {
CCPointZero,
CCPointZero,
CCPointZero,
CCPointZero
};
stencil->drawPolygon(v, 4, cc4fGREEN, 0, cc4fTRANSPARENT);
} else {
CCPoint v[] = {
m_p1,
m_p2,
ccp(m_p2.x + distance * m_cos,
m_p2.y + distance * m_sin),
ccp(m_p1.x + distance * m_cos,
m_p1.y + distance * m_sin)
};
stencil->drawPolygon(v, 4, cc4fGREEN, 0, cc4fTRANSPARENT);
}
}
void CCClipOut::startWithTarget(CCNode *pTarget) {
CCAssert(dynamic_cast<CCClippingNode*>(pTarget) != NULL, "CCClipOut target must be a CCClippingNode instance");
CCActionInterval::startWithTarget(pTarget);
// ensure the stencil of clipper is CCDrawNode
CCClippingNode* clipper = (CCClippingNode*)pTarget;
CCNode* stencil = clipper->getStencil();
if(dynamic_cast<CCDrawNode*>(stencil) == NULL) {
clipper->setStencil(CCDrawNode::create());
}
// direction radian
// treat is like a clip in
float r = ccpToAngle(ccp(-m_direction.x, -m_direction.y));
m_cos = cosf(r);
m_sin = sinf(r);
// max distance along direction
const CCSize& size = pTarget->getContentSize();
m_distance = size.width * fabsf(m_cos) + size.height * fabsf(m_sin);
// calculate fixed edge endpoints
if(r > M_PI_2) {
float p1Len = size.width * cosf(r - M_PI_2);
m_p1.x = size.width - p1Len * cosf(r - M_PI_2);
m_p1.y = -p1Len * sinf(r - M_PI_2);
float p2Len = size.height * sinf(r - M_PI_2);
m_p2.x = size.width + p2Len * cosf(r - M_PI_2);
m_p2.y = p2Len * sinf(r - M_PI_2);
} else if(r >= 0) {
float p1Len = size.height * m_cos;
m_p1.x = p1Len * cosf(r + M_PI_2);
m_p1.y = p1Len * sinf(r + M_PI_2);
float p2Len = size.width * m_sin;
m_p2.x = p2Len * cosf(r - M_PI_2);
m_p2.y = p2Len * sinf(r - M_PI_2);
} else if(r < -M_PI_2) {
float p1Len = size.height * sinf(-r - M_PI_2);
m_p1.x = size.width + p1Len * cosf(-r - M_PI_2);
m_p1.y = size.height - p1Len * sinf(-r - M_PI_2);
float p2Len = size.width * cosf(-r - M_PI_2);
m_p2.x = size.width - p2Len * cosf(-r - M_PI_2);
m_p2.y = size.height + p2Len * sinf(-r - M_PI_2);
} else {
float p1Len = size.width * sinf(-r);
m_p1.x = p1Len * cosf(r + M_PI_2);
m_p1.y = size.height + p1Len * sinf(r + M_PI_2);
float p2Len = size.height * cosf(-r);
m_p2.x = -p2Len * cosf(r + M_PI_2);
m_p2.y = size.height - p2Len * sinf(r + M_PI_2);
}
}
void CCClipIn::update(float time) {
CCClippingNode* clipper = (CCClippingNode*)getTarget();
CCDrawNode* stencil = (CCDrawNode*)clipper->getStencil();
// clear
stencil->clear();
// build polygon
float distance = m_distance * time;
CCPoint v[] = {
m_p1,
m_p2,
ccp(m_p2.x + distance * m_cos,
m_p2.y + distance * m_sin),
ccp(m_p1.x + distance * m_cos,
m_p1.y + distance * m_sin)
};
stencil->drawPolygon(v, 4, cc4fGREEN, 0, cc4fTRANSPARENT);
}
