#include <GL/glut.h>
#include <iostream>
#include <vector>
#include <cmath>
using namespace std;
const GLfloat wh=600;
struct point {
float x;
float y;
};
vector<point>V;
vector<point> V1, V2; int model = 0; bool dragging = false;
vector<point>& de_Casteljau(int n) {
V1.resize(V.size()); V2.resize(0);
for (float t = 0; t <= 1;t=t+0.02) {
for (int j = 1; j < n; j++) {
for (int k = 0; k < n - j;k++) {
if (j == 1) {
V1[k].x = (1 - t) * V[k].x + t * V[k + 1].x;
V1[k].y = (1 - t) * V[k].y + t * V[k + 1].y;
}
else {
V1[k].x = (1 - t) * V1[k].x + t * V1[k + 1].x;
V1[k].y = (1 - t) * V1[k].y + t * V1[k + 1].y;
}
}
}
cout << V1[0].x << " " << V1[0].y << endl;
V2.push_back(V1[0]);
}
return V2;
}
int findnearest(float x,float y ) {
float min = 1000000; int re=0;
for (int i = 0; i < V.size(); i++) {
float d = (V[i].x - x) * (V[i].x - x) + (V[i].y - y) * (V[i].y - y);
if (d < min) {
re = i; min = d;
}
}
return re;
}
void draw() {
glClear(GL_COLOR_BUFFER_BIT);
glBegin(GL_LINE_STRIP);
for (int i = 0; i < V.size(); i++) {
point p = V[i];
glVertex2f(p.x, p.y);
}
glEnd();
glFlush();
vector<point>re = de_Casteljau(V.size()); re.push_back(V.back());
glBegin(GL_LINE_STRIP);
for (int i = 0; i < re.size(); i++) {
point p = re[i];
glVertex2f(p.x, p.y);
}
glEnd();
glFlush();
}
int id = 0;
void mymouse(int button, int state, int x, int y) {
y = wh - y;
if (button == GLUT_LEFT_BUTTON && state == GLUT_DOWN) {
if (model == 0) {
point p; p.x = x; p.y = y;
V.push_back(p);
glBegin(GL_POINTS);
glVertex2f(p.x, p.y);
glEnd();
glFlush();
}
else if (model == 1) {
id= findnearest(x, y);
V.erase(V.begin() + id);
if (V.size() > 1)draw();
else { cout << "点数必须>=2" << endl; }
}
else if (model == 2) {
id = findnearest(x, y);
cout << "点号" << id << endl;
dragging = true;
}
else if (model == 3) {
point p; p.x = x; p.y = y;
V.push_back(p);
glBegin(GL_POINTS);
glVertex2f(p.x, p.y);
glEnd();
glFlush();
draw();
}
}
if (button == GLUT_LEFT_BUTTON && state == GLUT_UP) {
if (dragging==true) {
dragging = false;
V[id].x = x; V[id].y = y;
if (V.size() > 1)draw();
return;
}
}
}
void keyboard(unsigned char key,int x,int y) {
if (key == 32) {
draw();
}
}
void Mymenu(int m) {
model = m;
if (model == 4) {
exit(0);
}
}
int main(int argc, char* argv[])
{
glutInit(&argc, argv);
glutInitDisplayMode(GLUT_SINGLE | GLUT_RED);
glutInitWindowPosition(50, 50);
glutInitWindowSize(800, 600);
glutCreateWindow("Bezier");
cout << "。。。。" << endl;
glMatrixMode(GL_PROJECTION);
glLoadIdentity();
gluOrtho2D(0, 800, 0, 600);
glClearColor(1, 1, 1, 1);
glClear(GL_COLOR_BUFFER_BIT);
glColor3f(160.0/255.0,82.0/255.0,45.0/255.0);
glLineWidth(2.0f); glPointSize(5);
glutMouseFunc(&mymouse);
glutKeyboardFunc(&keyboard);
glutCreateMenu(Mymenu);
glutAddMenuEntry("Delete", 1);
glutAddMenuEntry("Move", 2);
glutAddMenuEntry("Insert", 3);
glutAddMenuEntry("Exit", 4);
glutAttachMenu(GLUT_RIGHT_BUTTON);
glutMainLoop();
return 0;
}
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