aa.rar_光栅化

#include <GL/glut.h> #include <stdlib.h> #include <iostream.h> #include <algorithm> int x0=0,y0=0,x1=0,y1=0,x2=0,y2=0; float a=0.0f,b=0.0f,c=0.0f; //用于存储到三条边的系数 float k1=0.0f,k2=0.0f,k0=0.0f; //用于均一化 int minx=0,maxx=0,miny=0,maxy=0; void m(){ //求范围 minx=x0; maxx=x0; miny=y0; maxy=y0; if(x1<minx)minx=x1; if(x1>maxx)maxx=x1; if(x2<minx)minx=x2; if(x2>maxx)maxx=x2; if(y1<miny)miny=y1; if(y1>maxy)maxy=y1; if(y2<miny)miny=y2; if(y2>maxy)maxy=y2; } void uni(){ k0=1/(float)((y0-y1)*x2+(x1-x0)*y2+x0*y1-x1*y0); k1=1/(float)((y1-y2)*x0+(x2-x1)*y0+x1*y2-x2*y1); k2=1/(float)((y2-y0)*x1+(x0-x2)*y1+x2*y0-x0*y2); } int compute(int i,int j){ //用于计算三个系数并均一化 c=((y0-y1)*i+(x1-x0)*j+x0*y1-x1*y0)*k0; a=((y1-y2)*i+(x2-x1)*j+x1*y2-x2*y1)*k1; b=((y2-y0)*i+(x0-x2)*j+x2*y0-x0*y2)*k2; if(a>0&&b>0&&c>0){ return 1; } else return 0; } void display(void) { glClear (GL_COLOR_BUFFER_BIT); int i,j; m(); //glColor3f (1.0f, 1.0f, 1.0f); glBegin(GL_POINTS); uni(); for(i=minx;i<maxx;i++) for(j=miny;j<maxy;j++){ if(compute(i,j)==1){ glColor3f(a,b,c); glVertex2f(i,j); } } glEnd(); /* don't wait! * start processing buffered OpenGL routines */ glFlush (); } void init (void) { /* select clearing color */ glClearColor (0.0, 0.0, 0.0, 0.0); /* initialize viewing values */ glMatrixMode(GL_PROJECTION); glLoadIdentity(); gluOrtho2D(0, 500, 0, 500); } /* * Declare initial window size, position, and display mode * (single buffer and RGBA). Open window with "hello" * in its title bar. Call initialization routines. * Register callback function to display graphics. * Enter main loop and process events. */ int main(int argc, char** argv) { glutInit(&argc, argv); glutInitDisplayMode (GLUT_SINGLE | GLUT_RGB); //设置窗口大小，以像素为单位 glutInitWindowSize (500, 500); glutInitWindowPosition (100, 100); glutCreateWindow ("triangle"); init (); do{ cout<<"Enter the first Point:"; cin>>x0>>y0; if(x0>=0&&y0>=0&&x0<=500&&y0<=500) break; else cout<<"Worng data !!!Enter the number between 0 and 500\n"; }while(1); do{ cout<<"Enter the second Point:"; cin>>x1>>y1; if(x1>=0&&y1>=0&&x1<=500&&y1<=500) break; else cout<<"Worng data !!!Enter the number between 0 and 500\n"; }while(1); do{ cout<<"Enter the third Point:"; cin>>x2>>y2; if(x2>=0&&y2>=0&&x2<=500&&y2<=500) break; else cout<<"Worng data !!!Enter the number between 0 and 500\n"; }while(1); // m(); // cout<<minx<<" "<<miny<<" "<<maxx<<" "<<maxy; // uni(); // if(compute(15,15)==1)cout<<a<<" "<<b<<" "<<c; glutDisplayFunc(display); glutMainLoop(); return 0; /* ANSI C requires main to return int. */ }