[编程资料]C语言库函数大全及应用实例六

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/* the names of the line styles supported */
char *lname[] = { "SOLID_LINE",
"DOTTED_LINE",
"CENTER_LINE",
"DASHED_LINE",
"USERBIT_LINE"
};

int main(void)
{
/* request auto detection */
int gdriver = DETECT, gmode, errorcode;
struct linesettingstype lineinfo;
int midx, midy;
char lstyle[80], lpattern[80], lwidth[80];

/* 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;

/* get information about current line settings */
getlinesettings(&lineinfo);

/* convert line information into strings */
sprintf(lstyle, "%s is the line style.",
lname[lineinfo.linestyle]);
sprintf(lpattern, "0x%X is the user-defined line pattern.",
lineinfo.upattern);
sprintf(lwidth, "%d is the line thickness.",
lineinfo.thickness);

/* display the information */
settextjustify(CENTER_TEXT, CENTER_TEXT);
outtextxy(midx, midy, lstyle);
outtextxy(midx, midy+2*textheight("W"), lpattern);
outtextxy(midx, midy+4*textheight("W"), lwidth);

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

函数名: getmaxcolor
功 能: 返回可以传给函数setcolor的最大颜色值
用 法: int far getmaxcolor(void);
程序例:

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

/* 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;

/* grab the color info. and convert it to a string */
sprintf(colstr, "This mode supports colors 0..%d", getmaxcolor());

/* display the information */
settextjustify(CENTER_TEXT, CENTER_TEXT);
outtextxy(midx, midy, colstr);

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

函数名: getmaxx
功 能: 返回屏幕的最大x坐标
用 法: int far getmaxx(void);
程序例:

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

/* 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;

/* convert max resolution values into strings */
sprintf(xrange, "X values range from 0..%d", getmaxx());
sprintf(yrange, "Y values range from 0..%d", getmaxy());

/* display the information */
settextjustify(CENTER_TEXT, CENTER_TEXT);
outtextxy(midx, midy, xrange);
outtextxy(midx, midy+textheight("W"), yrange);

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

函数名: getmaxy
功 能: 返回屏幕的最大y坐标
用 法: int far getmaxy(void);
程序例:

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

/* 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;

/* convert max resolution values into strings */
sprintf(xrange, "X values range from 0..%d", getmaxx());
sprintf(yrange, "Y values range from 0..%d", getmaxy());

/* display the information */
settextjustify(CENTER_TEXT, CENTER_TEXT);
outtextxy(midx, midy, xrange);
outtextxy(midx, midy+textheight("W"), yrange);

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

函数名: getmodename
功 能: 返回含有指定图形模式名的字符串指针
用 法: char *far getmodename(int mode_name);
程序例:

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int main(void)
{
/* request autodetection */
int gdriver = DETECT, gmode, errorcode;
int midx, midy, mode;
char numname[80], modename[80];

/* 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;

/* get mode number and name strings */
mode = getgraphmode();
sprintf(numname, "%d is the current mode number.", mode);
sprintf(modename, "%s is the current graphics mode.", getmodename(mode));

/* display the information */
settextjustify(CENTER_TEXT, CENTER_TEXT);
outtextxy(midx, midy, numname);
outtextxy(midx, midy+2*textheight("W"), modename);

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

函数名: getmoderange
功 能: 取给定图形驱动程序的模式范围
用 法: void far getmoderange(int graphdriver, int far *lomode,
int far *himode);
程序例:

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int main(void)
{
/* request auto detection */
int gdriver = DETECT, gmode, errorcode;
int midx, midy;
int low, high;
char mrange[80];

/* 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;

/* get the mode range for this driver */
getmoderange(gdriver, &low, &high);

/* convert mode range info. into strings */
sprintf(mrange, "This driver supports modes %d..%d", low, high);

/* display the information */
settextjustify(CENTER_TEXT, CENTER_TEXT);
outtextxy(midx, midy, mrange);

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

函数名: getpalette
功 能: 返回有关当前调色板的信息
用 法: void far getpalette(struct palettetype far *palette);
程序例:

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int main(void)
{
/* request auto detection */
int gdriver = DETECT, gmode, errorcode;
struct palettetype pal;
char psize[80], pval[20];
int i, ht;
int y = 10;

/* 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();
/* terminate with an error code */
exit(1);
}

/* grab a copy of the palette */
getpalette(&pal);

/* convert palette info. into strings */
sprintf(psize, "The palette has %d \
modifiable entries.", pal.size);

/* display the information */
outtextxy(0, y, psize);
if (pal.size != 0)
{
ht = textheight("W");
y += 2*ht;
outtextxy(0, y, "Here are the current \
values:");
y += 2*ht;
for (i=0; i
{
sprintf(pval,
"palette[%02d]: 0x%02X", i,
pal.colors[i]);
outtextxy(0, y, pval);
}
}

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

函数名: getpass
功 能: 读一个口令
用 法: char *getpass(char *prompt);
程序例:

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int main(void)
{
char *password;

password = getpass("Input a password:");
cprintf("The password is: %s\r\n",
password);
return 0;
}

函数名: getpixel
功 能: 取得指定像素的颜色
用 法: int far getpixel(int x, int y);
程序例:

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#define PIXEL_COUNT 1000
#define DELAY_TIME 100 /* in milliseconds */

int main(void)
{
/* request auto detection */
int gdriver = DETECT, gmode, errorcode;
int i, x, y, color, maxx, maxy,
maxcolor, seed;

/* 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();
/* terminate with an error code */
exit(1);
}

maxx = getmaxx() + 1;
maxy = getmaxy() + 1;
maxcolor = getmaxcolor() + 1;

while (!kbhit())
{
/* seed the random number generator */
seed = random(32767);
srand(seed);
for (i=0; i
{
x = random(maxx);
y = random(maxy);
color = random(maxcolor);
putpixel(x, y, color);
}

delay(DELAY_TIME);
srand(seed);
for (i=0; i
{
x = random(maxx);
y = random(maxy);
color = random(maxcolor);
if (color == getpixel)