Qpainter实时绘制图形动画效果

#include "mainwindow.h" #include <QApplication> #include"qpainter.h" #include <math.h> void MainWindow::paintEvent(QPaintEvent *ev) { // int aa[10]={10,20,30,40,50,60,70,80,90,100}; QPainter p(this); QPen pen; // int i=counter; for(int i=0;i<counter;i++) { if(i<=400) { pen.setColor(Qt::blue); pen.setWidth(3); p.setPen(pen); if(i<=200) { int a = i; int b = sqrt(10000-(a-100)*(a-100))+100; p.drawPoint(a+100, b+100); } else { int a = 400-i; int b = 100-sqrt(10000-(a-100)*(a-100)); p.drawPoint(a+100, b+100); } } /////////////////400-800////////////////////// else if(i>400&&i<=800) { pen.setColor(Qt::black); pen.setWidth(3); p.setPen(pen); if(i<=600) { int a = i-400; int b = sqrt(10000-(a-100)*(a-100))+100; p.drawPoint(a+250, b+100); } else { int a = 800-i; int b = 100-sqrt(10000-(a-100)*(a-100)); p.drawPoint(a+250, b+100); } } /////////////////////800-1200/////////////////////// else if(i>800&&i<=1200) { pen.setColor(Qt::red); pen.setWidth(3); p.setPen(pen); if(i<=1000) { int a = i-800; int b = sqrt(10000-(a-100)*(a-100))+100; p.drawPoint(a+400, b+100); } else { int a = 1200-i; int b = 100-sqrt(10000-(a-100)*(a-100)); p.drawPoint(a+400, b+100); } } ////////////////////1200-1600////////////////////// else if(i>1200&&i<=1600) { pen.setColor(Qt::yellow); pen.setWidth(3); p.setPen(pen); if(i<=1400) { int a = i-1200; int b = sqrt(10000-(a-100)*(a-100))+100; p.drawPoint(a+175, b+250); } else { int a = 1600-i; int b = 100-sqrt(10000-(a-100)*(a-100)); p.drawPoint(a+175, b+250); } } ///////////////////1600-2000///////////////////// else if(i>1600&&i<=2000) { pen.setColor(Qt::green); pen.setWidth(3); p.setPen(pen); if(i<=1800) { int a = i-1600; int b = sqrt(10000-(a-100)*(a-100))+100; p.drawPoint(a+325, b+250); } else { int a = 2000-i; int b = 100-sqrt(10000-(a-100)*(a-100)); p.drawPoint(a+325, b+250); } } ///////////////////////////////////////////////////////// } update(); } int main(int argc, char *argv[]) { QApplication a(argc, argv); MainWindow w; w.show(); return a.exec(); }