【文件属性】：
文件名称：Bresenham画线算法
文件大小：2KB
文件格式：TXT
更新时间：2013-12-30 15:32:57
Bresenham
Bresenham画线算法
#include
#include
#define BLACK 0
void draw_pixel(int ix,int iy,int value)
{
glBegin(GL_POINTS);
glVertex2i(ix,iy);
glEnd();
}
bres(int x1,int y1,int x2,int y2)
{
int dx,dy,i,e;
int incx,incy,inc1,inc2;
int x,y;
dx=x2-x1;
dy=y2-y1;
if(dx<0) dx=-dx;
if(dy<0) dy=-dy;
incx=1;
if(x2dy)
{
draw_pixel(x,y,BLACK);
e=2*dy-dx;
inc1 = 2*(dy-dx);
inc2 = 2*dy;
for(i=0;i=0)
{
y+=incy;
e+=inc1;
}
else
e+=inc2;
x+=incx;
draw_pixel(x,y,BLACK);
}
}
else
{
draw_pixel(x,y,BLACK);
e=2*dx-dy;
inc1=2*(dx-dy);
inc2=2*dx;
for(i=0;i=0)
{
x+=incx;
e+=inc1;
}
else
e+=inc2;
y+=incy;
draw_pixel(x,y,BLACK);
}
}
}
void display()
{
glClear(GL_COLOR_BUFFER_BIT);
bres(200,200,100,50);
glFlush();
}
void myinit()
{
glClearColor(1.0,1.0,1.0,1.0);
glColor3f(1.0,0.0,0.0);
glPointSize(1.0);
glMatrixMode(GL_PROJECTION);
glLoadIdentity();
gluOrtho2D(0.0,499.0,0.0,499.0);
}
void main(int argc,char **argv)
{
/* standard GLUT initialization */
glutInit(&argc, argv);
glutInitDisplayMode(GLUT_SINGLE | GLUT_RGB );/*default,not needed*/
glutInitWindowSize(500,500); /* 500×500 pixel window */
glutInitWindowPosition(0,0);/* place window top left on display */
glutCreateWindow("Bresenham's algorithm ");/* window title */
glutDisplayFunc(display); /* display callback invoked when window opened
*/
myinit(); /*set attributes */
glutMainLoop(); /* enter event loop */
}
