本文實例為大家分享了OpenGL繪制Bezier曲線的具體代碼，供大家參考，具體內(nèi)容如下
最近在看Francis S Hill ,Jr 和 Stephen M Kelley合著的《計算機圖形學》(OpenGL版)(第三版)書中有繪制三個控制點的Bezier曲線的代碼。自己重新敲了一遍代碼。發(fā)現(xiàn)了其中的一點小錯誤，修正過來了。并做了一點小小的改動。
源碼見下
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#include <windows.h>#include <math.h>#include <gl/GL.h>#include <gl/glut.h>int SCREEN_HEIGHT = 480;int NUMPOINTS = 0;class Point{public: float x, y; void setxy(float x2, float y2) { x = x2; y = y2; } Point operator&(const Point & rPoint) { x = rPoint.x; y = rPoint.y; return * this; }};Point abc[3];void myInit(){ glClearColor(0.0,0.0,0.0,0.0); glColor3f(1.0f, 0.0, 0.0); glPointSize(4.0); glMatrixMode(GL_PROJECTION); glLoadIdentity(); gluOrtho2D(0.0, 640, 0.0, 480.0);}void drawDot(Point pt) { glBegin(GL_POINTS); glVertex2f(pt.x, pt.y); glEnd(); glFlush();}void drawLine(Point p1, Point p2){ glBegin(GL_LINES); glVertex2f(p1.x, p1.y); glVertex2f(p2.x, p2.y); glEnd(); glFlush();}//三個控制點的貝塞爾曲線Point drawBezier(Point A, Point B, Point C, double t) { Point P; P.x = pow((1-t), 2) * A.x + 2*t*(1-t)*B.x + pow(t, 2)*C.x; P.y = pow((1-t), 2) * A.y + 2*t*(1-t)*B.y + pow(t, 2)*C.y; return P;}void myMouse(int button, int state, int x, int y){ if(button == GLUT_LEFT_BUTTON && state == GLUT_DOWN) { abc[NUMPOINTS].setxy((float)x, (float)(SCREEN_HEIGHT - y)); NUMPOINTS++; if (NUMPOINTS == 3) { glColor3f(1.0, 0.0, 1.0); drawDot(abc[0]); drawDot(abc[1]); drawDot(abc[2]); glColor3f(1.0, 1.0, 0.0); drawLine(abc[0], abc[1]); drawLine(abc[1], abc[2]); glColor3f(0.0, 1.0, 1.0); Point POld = abc[0]; for (double t = 0.0; t<=1.0;t+=0.1) { Point P = drawBezier(abc[0], abc[1], abc[2], t); drawLine(POld, P); POld = P; } glColor3f(1.0, 0.0, 0.0); NUMPOINTS = 0; } }}void myDisplay(){ glClear(GL_COLOR_BUFFER_BIT); glFlush();}int main(int argc, char * agrv[]){ glutInit(&argc, agrv); glutInitDisplayMode(GLUT_SINGLE | GLUT_RGB); glutInitWindowSize(640, 480); glutInitWindowPosition(100, 150); glutCreateWindow("Bezier Curve"); glutMouseFunc(myMouse); glutDisplayFunc(myDisplay); myInit(); glutMainLoop(); return 0;} |
以上就是本文的全部內(nèi)容，希望對大家的學習有所幫助，也希望大家多多支持服務器之家。
原文鏈接：https://blog.csdn.net/dreamcs/article/details/5907734
