[work 29] Flow Field – A school of square –

Movie

Source code

about

• Flow Field上に四角を配置する（正規分布）
• Flowに従って四角を回転、拡縮させる

file

• 上部にあるファイル名が表示されているボタンを押すと、表示されるファイルが切り替わります
• 別ウィンドウ表示したい時や行番号などが無いRawMode表示したい時は、コード内右上のボタンを押してください（ボタンはマウスオーバーすると表示されます）

#include "ofMain.h"
#include "ofApp.h"

//================================
int main( ){

    // 4K:4096x2160
    // 2K:2048x1080
    // FullHD:1920x1080
    // HD:1440x1080
    // HD720p:1280x720
    // DVD:720x480
    // setup the GL context
	ofSetupOpenGL(1280,720, OF_WINDOW);

	// this kicks off the running of my app
	// can be OF_WINDOW or OF_FULLSCREEN
	// pass in width and height too:
	ofRunApp( new ofApp());

}

#pragma once

#include "ofMain.h"
#include <random>

#include "FlowField.hpp"
#include "Square.hpp"


class ofApp : public ofBaseApp{
	public:
    ofApp();
    ~ofApp();
    
		void setup();
		void update();
		void draw();
		
		void keyPressed(int key);
		void keyReleased(int key);
		void mouseMoved(int x, int y);
		void mouseDragged(int x, int y, int button);
		void mousePressed(int x, int y, int button);
		void mouseReleased(int x, int y, int button);
		void mouseEntered(int x, int y);
		void mouseExited(int x, int y);
		void windowResized(int w, int h);
		void dragEvent(ofDragInfo dragInfo);
		void gotMessage(ofMessage msg);
    
private:
    unique_ptr<FlowField> ff;
    int resolution;
    
    std::vector<unique_ptr<Square>> square;
};

#include "ofApp.h"


ofApp::ofApp(){
    
}

ofApp::~ofApp(){
    
}

//--------------------------------------------------------------
void ofApp::setup(){
    double fps = 30;
    
    ofSetFrameRate(fps);
    ofBackground(0);
    ofSetBackgroundAuto(true);
    
    resolution = 20;
    ff = make_unique<FlowField>(resolution);
    ff->setup();
}

//--------------------------------------------------------------
void ofApp::update(){
    ofVec2f point;
    std::random_device seed_gen;
    std::default_random_engine engine(seed_gen());
    std::normal_distribution<> dist(0.0, 1.0);
    for (int i = 0; i < 5; i++) {
        point.x = ofMap(dist(engine), -5, 5, 0, ofGetWidth(), true);
        point.y = ofMap(dist(engine), -5, 5, 0, ofGetHeight(), true);
        
        square.push_back(make_unique<Square>(point, resolution, resolution));
    }
    
    ff->update();
    
    for (unique_ptr<Square> &s: square) {
        s->follow(ff);
    }
}

//--------------------------------------------------------------
void ofApp::draw(){
    for (unique_ptr<Square> &s: square) {
        s->display();
    }
}

#ifndef FlowField_hpp
#define FlowField_hpp

#include <stdio.h>
#include "ofMain.h"


class FlowField {
public:
    FlowField(int r);
    ~FlowField();
    void setup();
    void update();
    void display();
    ofVec2f lookup(ofVec2f pos);
private:
    int cols, rows;
    int resolution;
    float xoff, yoff, zoff;
    std::vector<std::vector<ofVec2f>> field;
};
#endif /* FlowField_hpp */

#include "FlowField.hpp"


FlowField::FlowField(int r)
{
    resolution = r;
    cols = ofGetWidth() / resolution;
    rows = ofGetHeight() / resolution;
    field.assign(cols, std::vector<ofVec2f>(rows, ofVec2f(0, 0)));
}


FlowField::~FlowField()
{
    
}


void FlowField::setup()
{
    zoff = 0;
}


void FlowField::update()
{
    xoff = 0;
    for (int x = 0; x < cols; x++) {
        yoff = 0;
        for (int y = 0; y < rows; y++) {
            float theta = ofMap(ofNoise(xoff, yoff, zoff), 0, 1, 0, TWO_PI);
            ofVec2f dir = ofVec2f(std::cos(theta), std::sin(theta));
            field[x][y] = dir.normalize();
            yoff += 0.05;
        }
        xoff += 0.05;
    }
    zoff += 0.01;
}


void FlowField::display()
{
    for (int x = 0; x < cols; x++) {
        for (int y = 0; y < rows; y++) {
            ofPushMatrix();
            ofTranslate(x * resolution, y * resolution);
            ofNoFill();
            ofSetColor(255);
            ofDrawRectangle(0, 0, resolution, resolution);
            
            ofVec2f c = ofVec2f(resolution / 2, resolution / 2);
            int len = resolution * 3 / 4;
            ofVec2f t0 = c - (field[x][y] * len / 2);
            ofVec2f t1 = c + (field[x][y] * len / 2);
            ofSetColor(255, 255, 0);
            ofDrawLine(t0.x, t0.y, t1.x, t1.y);
            ofPopMatrix();
        }
    }
}


ofVec2f FlowField::lookup(ofVec2f pos)
{
    int col = (int)ofClamp(pos.x / resolution, 0, cols - 1);
    int row = (int)ofClamp(pos.y / resolution, 0, rows - 1);
    return field[col][row];
}

#ifndef Square_hpp
#define Square_hpp

#include <stdio.h>
#include "ofMain.h"
#include "FlowField.hpp"

class Square {
public:
    Square(ofVec2f pos, float w, float h);
    ~Square();
    void display();
    void follow(unique_ptr<FlowField> &flow);
    
private:
    ofColor color;
    ofVec2f location;
    float angle;
    float width;
    float height;
};
#endif /* Square_hpp */

#include "Square.hpp"



Square::Square(ofVec2f pos, float w, float h)
{
    color = ofColor(ofRandom(255), ofRandom(255), ofRandom(255));
    location = pos;
    width = w * 2;
    height = h;
}


Square::~Square()
{
    
}


void Square::display()
{
    ofSetColor(color);
    ofPushMatrix();
    ofTranslate(location.x, location.y);
    ofRotateDeg(angle);
    float shrink = (180 - std::abs(angle)) / 180;
    ofSetRectMode(OF_RECTMODE_CENTER);
    ofDrawRectangle(0, 0, width * shrink, height * shrink);
    ofPopMatrix();
}


void Square::follow(unique_ptr<FlowField> &flow)
{
    ofVec2f dir = flow->lookup(location);
    ofVec2f org = ofVec2f(1, 0);
    angle = org.angle(dir);
}

Link to the reference page

ソースコードで使用したAPIの中から要点になりそうなものをいくつか選んでリストアップしました。

Development environment

• openframeworks 0.10.1
• c++
• macOS
• Xcode