imagesize

imagesize是一種函式名，功能是返回保存點陣圖像所需的位元組數。

基本介紹

• 中文名：imagesize
• 外文名： imagesize
• 功 能：返回保存點陣圖像所需的位元組數

基本信息

用 法: unsigned far imagesize(int left, int top, int right, int bottom);

頭檔案: conio.h

程式舉例

#include <stdio.h>

#include <conio.h>

#include <dos.h>

#include <graphics.h>

#define ARROW_SIZE 10

void draw_arrow(int x,int y);

int main(void)

{

int gdriver,gmode,errorcode;

int x,y,maxx;

int *arrow;

unsigned size;

/* initialize graphics and local variables */ //初始化圖形和局部變數

gdriver=DETECT;

initgraph(&gdriver,&gmode,"");

/* read the result of initialization */ //讀取初始化的結果

errorcode=graphresult();

if(errorcode!=grOk) /* an error occurred */

{

printf("Graphics error: %s\n",grapherrormsg(errorcode));

getch();

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

}

maxx=getmaxx();

x=0;

y=getmaxy()/2;

/* calculate the size of the image */ //計算圖像的大小

size=imagesize(x,y-ARROW_SIZE,x+2*ARROW_SIZE,y+ARROW_SIZE);

/* allocate memory to hold the image */ //重複直到一個鍵被按下

arrow=(int*)malloc(size);

/* grab the image */ //獲取圖像

getimage(x,y-ARROW_SIZE,x+2*ARROW_SIZE,y+ARROW_SIZE,arrow);

/* repeat until a key is pressed */

while(!kbhit())

{

/* plot new image */ //重新列印的圖像

draw_arrow(x,y);

delay(400); /* delay time */ //延遲時間

/* erase old image */ //刪除舊圖片

putimage(x,y-ARROW_SIZE,arrow,AND_PUT);

x+=2*ARROW_SIZE;

if(maxx-x<2*ARROW_SIZE) x=0;

}

/* clean up */ //清理

free(arrow);

closegraph();

return 0;

}

/* draw an arrow on the screen */ //在螢幕上畫一個箭頭

void draw_arrow(int x,int y)

{

moveto(x,y);

linerel(0,-1*ARROW_SIZE);

linerel(2*ARROW_SIZE,ARROW_SIZE);

linerel(-2*ARROW_SIZE,ARROW_SIZE);

linerel(0,-1*ARROW_SIZE);

}