//------------------------------------------------------------------
void seraParticle::update(){
ofPoint attractPt(mahoPos[1].x, mahoPos[1].y);
frc = attractPt-pos;
frc.normalize();
vel *= drag;
vel += frc * seraParticleKasokuAmt;
pos += vel;
}
void demoParticle::choca( )
{
ofPoint attractPt(ofGetMouseX(), ofGetMouseY());
frc = attractPt-pos;
//obtiene la distancia
float dist = frc.length();
frc.normalize();
// se repelen los puntos serca del mouse
if( dist < 90 ){
pos += -frc * 0.1;
}
}
//------------------------------------------------------------------
void demoParticle::update(){
// 1 - APPLY THE FORCES BASED ON WHICH MODE WE ARE IN
// 1 - 加载的力取决于我们选择何种模式
if( mode == PARTICLE_MODE_ATTRACT ){
ofPoint attractPt(ofGetMouseX(), ofGetMouseY());
frc = attractPt-pos; // we get the attraction force/vector by looking at the mouse pos relative to our pos
// 粒子获得的引力是通过计算鼠标位置和粒子位置的关系得到的
frc.normalize(); // by normalizing we disregard how close the particle is to the attraction point
// 通过初始化力，我们忽略了粒子和吸引点之间的距离。
vel *= drag; // apply drag
// 用拖拽
vel += frc * 0.6; // apply force
// 用力
}
else if( mode == PARTICLE_MODE_REPEL ){
ofPoint attractPt(ofGetMouseX(), ofGetMouseY());
frc = attractPt-pos;
// let get the distance and only repel points close to the mouse
// 击退离鼠标够近的粒子
float dist = frc.length();
frc.normalize();
vel *= drag;
if( dist < 150 ){
vel += -frc * 0.6; // notice the frc is negative
// 注意，力是相反的
}else{
//if the particles are not close to us, lets add a little bit of random movement using noise. this is where uniqueVal comes in handy.
//如果粒子不够靠近，我们可以用噪点制造一些随机移动。这就是为什么我们前面创建了一个随机数字,它让每个粒子的移动略微不同。
frc.x = ofSignedNoise(uniqueVal, pos.y * 0.01, ofGetElapsedTimef()*0.2);
frc.y = ofSignedNoise(uniqueVal, pos.x * 0.01, ofGetElapsedTimef()*0.2);
vel += frc * 0.04;
}
}
else if( mode == PARTICLE_MODE_NOISE ){
/* lets simulate falling snow
the fake wind is meant to add a shift to the particles based on where in x they are
we add pos.y as an arg so to prevent obvious vertical banding around x values - try removing the pos.y * 0.006 to see the banding
下面，我们会用粒子模拟下雪的效果
为了模拟风对雪的影响，我们会在x轴上加入一个移动效果
提供y坐标为了不给x坐标过多的影响力
*/
float fakeWindX = ofSignedNoise(pos.x * 0.003, pos.y * 0.006, ofGetElapsedTimef() * 0.6);
frc.x = fakeWindX * 0.25 + ofSignedNoise(uniqueVal, pos.y * 0.04) * 0.6;
frc.y = ofSignedNoise(uniqueVal, pos.x * 0.006, ofGetElapsedTimef()*0.2) * 0.09 + 0.18;
vel *= drag;
vel += frc * 0.4;
// we do this so as to skip the bounds check for the bottom and make the particles go back to the top of the screen
// 如果往下移动时发现跨过边界，就屏幕下消失然后从上面出现
if( pos.y + vel.y > ofGetHeight() ){
pos.y -= ofGetHeight();
}
}
else if( mode == PARTICLE_MODE_NEAREST_POINTS ){
if( attractPoints ){
// 1 - find closest attractPoint
// 1 - 寻找周围最接近的粒子
ofPoint closestPt;
int closest = -1;
float closestDist = 9999999;
for(unsigned int i = 0; i < attractPoints->size(); i++){
float lenSq = ( attractPoints->at(i)-pos ).lengthSquared();
if( lenSq < closestDist ){
closestDist = lenSq;
closest = i;
}
}
// 2 - if we have a closest point - lets calcuate the force towards it
// 2 - 计算力对closetPt产生的力量
if( closest != -1 ){
closestPt = attractPoints->at(closest);
float dist = sqrt(closestDist);
// in this case we don't normalize as we want to have the force proportional to distance
// 不要规范为0至1，力量必须相对一距离
frc = closestPt - pos;
// 别忘了乘以拖拽
vel *= drag;
// lets also limit our attraction to a certain distance and don't apply if 'f' key is pressed
// 设置吸引力的底线，如果按下'f'就放弃
if( dist < 300 && dist > 40 && !ofGetKeyPressed('f') ){
vel += frc * 0.003;
}else{
// if the particles are not close to us, lets add a little bit of random movement using noise. this is where uniqueVal comes in handy.
// 距离够远的话可以考虑添加一点随机行为
frc.x = ofSignedNoise(uniqueVal, pos.y * 0.01, ofGetElapsedTimef()*0.2);
frc.y = ofSignedNoise(uniqueVal, pos.x * 0.01, ofGetElapsedTimef()*0.2);
vel += frc * 0.4;
}
}
}
}
// 2 - UPDATE OUR POSITION
// 2 - 更新位置
pos += vel;
// 3 - (optional) LIMIT THE PARTICLES TO STAY ON SCREEN
// we could also pass in bounds to check - or alternatively do this at the ofApp level
// 防止粒子走出屏幕，碰到边界时就立刻改变方向
if( pos.x > ofGetWidth() ){
pos.x = ofGetWidth();
vel.x *= -1.0;
}else if( pos.x < 0 ){
pos.x = 0;
vel.x *= -1.0;
}
if( pos.y > ofGetHeight() ){
pos.y = ofGetHeight();
vel.y *= -1.0;
}
else if( pos.y < 0 ){
pos.y = 0;
vel.y *= -1.0;
}
}
//------------------------------------------------------------------
void demoParticle::update(ofPoint extraAttractor){
//1 - APPLY THE FORCES BASED ON WHICH MODE WE ARE IN
if( mode == PARTICLE_MODE_ATTRACT ){
/*
ofVec2f attractPt(ofGetMouseX(), ofGetMouseY());
frc = attractPt-pos; // we get the attraction force/vector by looking at the mouse pos relative to our pos
frc.normalize(); //by normalizing we disregard how close the particle is to the attraction point
vel *= drag; //apply drag
vel += frc * 0.6; //apply force
*/
ofPoint attractPt = extraAttractor;
frc = attractPt-pos; // we get the attraction force/vector by looking at the mouse pos relative to our pos
frc.normalize(); //by normalizing we disregard how close the particle is to the attraction point
vel *= drag; //apply drag
vel += frc * 0.6; //apply force
}
else if( mode == PARTICLE_MODE_REPEL ){
ofVec2f attractPt(ofGetMouseX(), ofGetMouseY());
frc = attractPt-pos;
//let get the distance and only repel points close to the mouse
float dist = frc.length();
frc.normalize();
vel *= drag;
if( dist < 150 ){
vel += -frc * 0.6; //notice the frc is negative
}else{
//if the particles are not close to us, lets add a little bit of random movement using noise. this is where uniqueVal comes in handy.
frc.x = ofSignedNoise(uniqueVal, pos.y * 0.01, ofGetElapsedTimef()*0.2);
frc.y = ofSignedNoise(uniqueVal, pos.x * 0.01, ofGetElapsedTimef()*0.2);
vel += frc * 0.04;
}
}
else if( mode == PARTICLE_MODE_NOISE ){
//lets simulate falling snow
//the fake wind is meant to add a shift to the particles based on where in x they are
//we add pos.y as an arg so to prevent obvious vertical banding around x values - try removing the pos.y * 0.006 to see the banding
float fakeWindX = ofSignedNoise(pos.x * 0.003, pos.y * 0.006, ofGetElapsedTimef() * 0.6);
frc.x = fakeWindX * 0.25 + ofSignedNoise(uniqueVal, pos.y * 0.04) * 0.6;
frc.y = ofSignedNoise(uniqueVal, pos.x * 0.006, ofGetElapsedTimef()*0.2) * 0.09 + 0.18;
vel *= drag;
vel += frc * 0.4;
//we do this so as to skip the bounds check for the bottom and make the particles go back to the top of the screen
if( pos.y + vel.y > ofGetHeight() ){
pos.y -= ofGetHeight();
}
}
else if( mode == PARTICLE_MODE_NEAREST_POINTS ){
if( attractPoints ){
//1 - find closest attractPoint
ofVec2f closestPt;
int closest = -1;
float closestDist = 9999999;
for(unsigned int i = 0; i < attractPoints->size(); i++){
float lenSq = ( attractPoints->at(i)-pos ).lengthSquared();
if( lenSq < closestDist ){
closestDist = lenSq;
closest = i;
}
}
//2 - if we have a closest point - lets calcuate the force towards it
if( closest != -1 ){
closestPt = attractPoints->at(closest);
float dist = sqrt(closestDist);
//in this case we don't normalize as we want to have the force proportional to distance
frc = closestPt - pos;
vel *= drag;
//lets also limit our attraction to a certain distance and don't apply if 'f' key is pressed
if( dist < 300 && dist > 40 && !ofGetKeyPressed('f') ){
vel += frc * 0.003;
}else{
//if the particles are not close to us, lets add a little bit of random movement using noise. this is where uniqueVal comes in handy.
frc.x = ofSignedNoise(uniqueVal, pos.y * 0.01, ofGetElapsedTimef()*0.2);
frc.y = ofSignedNoise(uniqueVal, pos.x * 0.01, ofGetElapsedTimef()*0.2);
vel += frc * 0.4;
}
}
}
}
//2 - UPDATE OUR POSITION
pos += vel;
//3 - (optional) LIMIT THE PARTICLES TO STAY ON SCREEN
//we could also pass in bounds to check - or alternatively do this at the ofApp level
if( pos.x > ofGetWidth() ){
pos.x = ofGetWidth();
vel.x *= -1.0;
}else if( pos.x < 0 ){
pos.x = 0;
vel.x *= -1.0;
}
if( pos.y > ofGetHeight() ){
pos.y = ofGetHeight();
vel.y *= -1.0;
}
else if( pos.y < 0 ){
pos.y = 0;
vel.y *= -1.0;
}
}
