#include <stdio.h>
#include <math.h>
#include <process.h>
/* she ru */
int Round(float a)
{
return (int)(a + 0.5);
}
/* DDA */
void LineWithDDA(int xStart,int yStart,int xEnd,int yEnd)
{
int dx =xEnd - xStart,dy =yEnd - yStart,steps,k;
float xIn, yIn, x = xStart, y = yStart;
if(fabs(dx) > fabs(dy))
{
steps = fabs(dx);
}
else
{
steps = fabs(dy);
}
xIn = (float)dx / (float)steps;
yIn = (float)dy / (float)steps;
putpixel(Round(x),Round(y),2);
for(k=0;k<steps;k++)
{
x+=xIn;
y+=yIn;
putpixel(Round(x),Round(y),2);
}
getch();
}
/* |k|<1 */
void LineWithBresenham_One(int xStart,int yStart,int xEnd,int yEnd)
{
int dx = fabs(xEnd -xStart), dy = fabs(yEnd - yStart);
int currentP = 2 * dy - dx;
int twoDy = 2 * dy, twoDySubTwoDx = 2 * (dy - dx);
int x, y;
if(xStart == xEnd)
{
line(xStart,yStart,xEnd,yEnd);
return ;
}
if(yStart == yEnd)
{
line(xStart,yStart,xEnd,yEnd);
return;
}
if(xStart > xEnd)
{
x = xEnd;
y = yEnd;
xEnd = xStart;
}
else
{
x = xStart;
y = yStart;
}
putpixel(x,y,2);
while(x < xEnd)
{
x++;
if(currentP < 0)
{
currentP += twoDy;
}
else
{
y++;
currentP += twoDySubTwoDx;
}
putpixel(x,y,2);
}
getch();
}
/* |k|>1 */
void LineWithBresenham_Two(int xStart,int yStart,int xEnd,int yEnd)
{
int dx = fabs(xEnd -xStart), dy = fabs(yEnd - yStart);
int currentP = 2 * dy - dx;
int twoDx = 2 * dx, twoDxSubTwoDy = 2 * (dx - dy);
int x, y;
if(xStart == xEnd)
{
line(xStart,yStart,xEnd,yEnd);
return ;
}
if(yStart == yEnd)
{
line(xStart,yStart,xEnd,yEnd);
return;
}
if(yStart > yEnd)
{
x = xEnd;
y = yEnd;
yEnd = yStart;
}
else
{
x = xStart;
y = yStart;
}
putpixel(x,y,2);
while(y < yEnd)
{
y++;
if(currentP < 0)
{
currentP += twoDx;
}
else
{
x++;
currentP += twoDxSubTwoDy;
}
putpixel(x,y,2);
}
getch();
}
void InitScreen()
{
clrscr();
printf("\n\n\n\n\n ***********************************************************\n");
printf(" * *\n");
printf(" * This is a graphics system,you can use it to graphics. *\n");
printf(" * *\n");
printf(" ***********************************************************\n");
printf("\n\n\n\n 1 Line a line with Bresenham while |k|<1. \n\n");
printf(" 2 Line a line with Bresenham while |k|>1. \n\n");
printf(" 3 Line a Line with DDA including x>y and x<y in xOy\n\n");
printf(" 0 Exit system.\n\n\n");
printf(" Please select a number:");
}
int main()
{
/* request autodetection */
int gdriver = DETECT, gmode, errorcode;
int xStart, yStart, xEnd, yEnd;
int number;
InitScreen();
flag:scanf("%d",&number);
if(number == 1)
{
printf(" Please input four numbers:");
scanf("%d%d%d%d",&xStart,&yStart,&xEnd,&yEnd);
/* initialize graphics and local variables */
initgraph(&gdriver, &gmode, "");
/* read result of initialization */
errorcode = graphresult();
if (errorcode != grOk)
{
printf("Graphics error: %s\n", grapherrormsg(errorcode));
printf("Press any key to halt:");
getch();
exit(1); /* terminate with an error code */
}
LineWithBresenham_One(fabs(xStart),fabs(yStart),fabs(xEnd),fabs(yEnd)) ;
closegraph();
InitScreen();
goto flag;
}
else if(number == 2)
{
printf(" Please input four numbers:");
scanf("%d%d%d%d",&xStart,&yStart,&xEnd,&yEnd);
initgraph(&gdriver, &gmode, "");
/* read result of initialization */
errorcode = graphresult();
if (errorcode != grOk)
{
printf("Graphics error: %s\n", grapherrormsg(errorcode));
printf("Press any key to halt:");
getch();
exit(1); /* terminate with an error code */
}
LineWithBresenham_Two(fabs(xStart),fabs(yStart),fabs(xEnd),fabs(yEnd)) ;
closegraph();
InitScreen();
goto flag;
}
else if(number == 3)
{
printf(" Please input four numbers:");
scanf("%d%d%d%d",&xStart,&yStart,&xEnd,&yEnd);
initgraph(&gdriver, &gmode, "");
/* read result of initialization */
errorcode = graphresult();
if (errorcode != grOk)
{
printf("Graphics error: %s\n", grapherrormsg(errorcode));
printf("Press any key to halt:");
getch();
exit(1); /* terminate with an error code */
}
LineWithDDA(fabs(xStart),fabs(yStart),fabs(xEnd),fabs(yEnd)) ;
closegraph();
InitScreen();
goto flag;
}
else if(number == 0)
{
/* abort(); */
exit(0);
}
/* clean up */
/* getch();
closegraph();
return 0; */
}
本文转自terryli51CTO博客，原文链接： http://blog.51cto.com/terryli/520654，如需转载请自行联系原作者