dda.rar_直线剪裁

#include <GL/glut.h> #include <math.h> #include <stdio.h> #include <windows.h> int xf,xl,yf,yl; void init(void) { glClearColor(1.0,1.0,1.0,0.0); //Set display-window color to white. glMatrixMode(GL_PROJECTION); //Set projection parameters. gluOrtho2D(0.0,200.0,0.0,150.0); //Define the display window. } int abs(int x) { if(x>=0) return x; else return -x; } int round(double x) { return int(x+0.5); } void setPixel(GLint xCoord,GLint yCoord) { int vertex1[]={xCoord-1,yCoord-1}; int vertex2[]={xCoord+1,yCoord+1}; DWORD iTime=GetCurrentTime(); glRectiv(vertex1,vertex2); // while(GetCurrentTime()<iTime+20); glFlush(); } void DDAline(int x0,int y0,int x1,int y1) { int step,x,y,i; double dx,dy,xcurent=double(x0),ycurent=double(y0); x=abs(x1-x0); y=abs(y1-y0); step=x>y?x:y; dx=double(x1-x0)/step; dy=double(y1-y0)/step; for(i=0;i<step;i++) { setPixel(round(xcurent),round(ycurent)); xcurent+=dx; ycurent+=dy; } } void lineSegment(void) { glClear(GL_COLOR_BUFFER_BIT); //Clear display window. glColor3f(0.0,1.0,1.0); //Set line segment color to red. DDAline(xf,yf,xl,yl); //Specify line-segment geometry. glFlush(); //Process all OpenGL routines as quickly as possible. } void main(int argc,char **argv) { glutInit(&argc,argv); //Initialize GLUT. glutInitDisplayMode(GLUT_SINGLE | GLUT_RGB); //Set display mode; glutInitWindowPosition(50,100); //Set top-left display-window position. glutInitWindowSize(300,400); //Set display-window width and height. glutCreateWindow("An Example OpenGL Program"); //Create display widow. printf("please input the first point(x0,y0) of the line: "); scanf("%d%d",&xf,&yf); printf("please input the last point(x1,y1) of the line: "); scanf("%d%d",&xl,&yl); init(); //Execute initialization procedure. glutDisplayFunc(lineSegment); //Send graphics to display window. glutMainLoop(); //Display everything and wait. } #include <GL/glut.h> #include <math.h> #include <stdio.h> #include <windows.h> int xf,xl,yf,yl; void init(void) { glClearColor(1.0,1.0,1.0,0.0); //Set display-window color to white. glMatrixMode(GL_PROJECTION); //Set projection parameters. gluOrtho2D(0.0,200.0,0.0,150.0); //Define the display window. } int abs(int x) { if(x>=0) return x; else return -x; } int round(double x) { return int(x+0.5); } void setPixel(GLint xCoord,GLint yCoord) { int vertex1[]={xCoord-1,yCoord-1}; int vertex2[]={xCoord+1,yCoord+1}; DWORD iTime=GetCurrentTime(); glRectiv(vertex1,vertex2); // while(GetCurrentTime()<iTime+20); glFlush(); } void DDAline(int x0,int y0,int x1,int y1) { int step,x,y,i; double dx,dy,xcurent=double(x0),ycurent=double(y0); x=abs(x1-x0); y=abs(y1-y0); step=x>y?x:y; dx=double(x1-x0)/step; dy=double(y1-y0)/step; for(i=0;i<step;i++) { setPixel(round(xcurent),round(ycurent)); xcurent+=dx; ycurent+=dy; } } void lineSegment(void) { glClear(GL_COLOR_BUFFER_BIT); //Clear display window. glColor3f(0.0,1.0,1.0); //Set line segment color to red. DDAline(xf,yf,xl,yl); //Specify line-segment geometry. glFlush(); //Process all OpenGL routines as quickly as possible. } void main(int argc,char **argv) { glutInit(&argc,argv); //Initialize GLUT. glutInitDisplayMode(GLUT_SINGLE | GLUT_RGB); //Set display mode; glutInitWindowPosition(50,100); //Set top-left display-window position. glutInitWindowSize(300,400); //Set display-window width and height. glutCreateWindow("An Example OpenGL Program"); //Create display widow. printf("please input the first point(x0,y0) of the line: "); scanf("%d%d",&xf,&yf); printf("please input the last point(x1,y1) of the line: "); scanf("%d%d",&xl,&yl); init(); //Execute initialization procedure. glutDisplayFunc(lineSegment); //Send graphics to display window. glutMainLoop(); //Display everything and wait. }