第十一章 C语言 图形库函数.doc

1. 初始化图形系统? 函数名: initgraph 功? 能: 初始化图形系统 用? 法: void far initgraph(int far *graphdriver, int far *graphmode, ??? char far *pathtodriver); 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; ?? /* initialize graphics mode */ ?? 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);???????????? /* return with error code */ ?? } ?? /* draw a line */ ?? line(0, 0, getmaxx(), getmaxy()); ?? /* clean up */ ?? getch(); ?? closegraph(); ?? return 0; } ? ? 2. ? 函数名: drawpoly 功? 能: 画多边形 用? 法: void far drawpoly(int numpoints, int far *polypoints); 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 maxx, maxy; ?? /* our polygon array */ ?? int poly[10]; ?? /* 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(); ?? /* terminate with an error code */ ????? exit(1); ?? } ?? maxx = getmaxx(); ?? maxy = getmaxy(); ?? poly[0] = 20;??????? /* 1st vertext */ ?? poly[1] = maxy / 2; ?? poly[2] = maxx - 20; /* 2nd */ ?? poly[3] = 20; ?? poly[4] = maxx - 50; /* 3rd */ ?? poly[5] = maxy - 20; ?? poly[6] = maxx / 2;? /* 4th */ ?? poly[7] = maxy / 2; /* ?? drawpoly doesnt automatically close ?? the polygon, so we close it. */ ?? poly[8] = poly[0]; ?? poly[9] = poly[1]; ?? /* draw