wto的非歧视原则包括:求助C语言的有关图形处理的函数知识

函数名: line
功 能: 在指定两点间画一直线
用 法: void far line(int x0, int y0, int x1, int y1);
程序例:

#include <graphics.h>
#include <stdlib.h>
#include <stdio.h>
#include <conio.h>

int main(void)
{
/* request auto detection */
int gdriver = DETECT, gmode, errorcode;
int xmax, ymax;

/* initialize graphics and local variables */
initgraph(&gdriver, &gmode, "");

/* read result of initialization */
errorcode = graphresult();
/* an error occurred */
if (errorcode != grOk)
{
printf("Graphics error: %s\n",
grapherrormsg(errorcode));
printf("Press any key to halt:");
getch();
exit(1);
}

setcolor(getmaxcolor());
xmax = getmaxx();
ymax = getmaxy();

/* draw a diagonal line */
line(0, 0, xmax, ymax);

/* clean up */
getch();
closegraph();
return 0;
}

函数名: linerel
功 能: 从当前位置点(CP)到与CP有一给定相对距离的点画一直线
用 法: void far linerel(int dx, int dy);
程序例:

#include <graphics.h>
#include <stdlib.h>
#include <stdio.h>
#include <conio.h>

int main(void)
{
/* request auto detection */
int gdriver = DETECT, gmode, errorcode;
char msg[80];

/* 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);
}

/* move the C.P. to location (20, 30) */
moveto(20, 30);

/* create and output a
message at (20, 30) */
sprintf(msg, " (%d, %d)", getx(), gety());
outtextxy(20, 30, msg);

/* draw a line to a point a relative
distance away from the current
value of C.P. */
linerel(100, 100);

/* create and output a message at C.P. */
sprintf(msg, " (%d, %d)", getx(), gety());
outtext(msg);

/* clean up */
getch();
closegraph();
return 0;
}

函数名: circle
功 能: 在给定半径以(x, y)为圆心画圆
用 法: void far circle(int x, int y, int radius);
程序例:

#include <graphics.h>
#include <stdlib.h>
#include <stdio.h>
#include <conio.h>

int main(void)
{
/* request auto detection */
int gdriver = DETECT, gmode, errorcode;
int midx, midy;
int radius = 100;

/* initialize graphics and local variables */
initgraph(&gdriver, &gmode, "");

/* read result of initialization */
errorcode = graphresult();
if (errorcode != grOk) /* an error occurred */
{
printf("Graphics error: %s\n", grapherrormsg(errorcode));
printf("Press any key to halt:");
getch();
exit(1); /* terminate with an error code */
}

midx = getmaxx() / 2;
midy = getmaxy() / 2;
setcolor(getmaxcolor());

/* draw the circle */
circle(midx, midy, radius);

/* clean up */
getch();
closegraph();
return 0;
}

函数名: cleardevice
功 能: 清除图形屏幕
用 法: void far cleardevice(void);
程序例:

#include <graphics.h>
#include <stdlib.h>
#include <stdio.h>
#include <conio.h>

int main(void)
{
/* request auto detection */
int gdriver = DETECT, gmode, errorcode;
int midx, midy;

/* initialize graphics and local variables */
initgraph(&gdriver, &gmode, "");

/* read result of initialization */
errorcode = graphresult();
if (errorcode != grOk) /* an error occurred */
{
printf("Graphics error: %s\n", grapherrormsg(errorcode));
printf("Press any key to halt:");
getch();
exit(1); /* terminate with an error code */
}

midx = getmaxx() / 2;
midy = getmaxy() / 2;
setcolor(getmaxcolor());

/* for centering screen messages */
settextjustify(CENTER_TEXT, CENTER_TEXT);

/* output a message to the screen */
outtextxy(midx, midy, "press any key to clear the screen:");

/* wait for a key */
getch();

/* clear the screen */
cleardevice();

/* output another message */
outtextxy(midx, midy, "press any key to quit:");

/* clean up */
getch();
closegraph();
return 0;
}