lafore_robert_objectoriented_programming_in_c

Console Graphics Lite

idea was to create the minimum routines that would do the job. You can examine the source files at the end of this appendix if you’re curious.

Microsoft Compilers

The Microsoft compilers no longer include their own console graphics routines as they did several years ago. However, Windows itself provides a set of routines for simple console graphics operations, such as positioning the cursor and changing the text color. For the Microsoft compilers, the Console Graphics Lite functions access these built-in Windows console functions. (Thanks to André LaMothe for suggesting this solution. His excellent game book is listed in Appendix H, “Bibliography.”)

To use the console graphics functions you should use a project of type “Win32 Console Application,” as described in Appendix C.

The Windows console functions won’t work unless you initialize the console graphics system, so calling the init_graphics() function is essential if you’re using the Microsoft compiler.

Borland Compilers

Borland C++ still has built-in graphics functions, both for console-mode graphics and for pixel graphics. If you use the BORLACON.CPP file, the Console Graphics Lite functions are translated into Borland console functions, which they closely resemble.

You might wonder why you can’t use the Borland compiler to access the console functions built into Windows. The problem is that to create a console-mode program in Borland C++, you must use either an EasyWin or a DOS target, both of which are 16-bit systems. The Windows console functions are 32-bit functions, and so can’t be used in Borland’s console mode.

When you use Borland C++, the iostream approach to I/O (cout <<) doesn’t produce different colors. Thus some of the example programs, like HORSE.CPP, use console-mode functions such as cputs() and putch(), found in the CONIO.H file.

Source Code Listings

Here are the listings for the four files used in Console Graphics Lite: MSOFTCON.H and MSOFTCON.CPP for Microsoft, and BORLACON.H and BORLACON.CPP for C++Builder. Normally there won’t be any reason for you to worry about the internals of these files. They are shown here for reference.

885

E

GRAPHICS C

L ONSOLE

ITE

Console Graphics Lite

SetConsoleCursorPosition(hConsole, cursor_pos);

}

//--------------------------------------------------------------

void clear_screen()

{

set_cursor_pos(1, 25); for(int j=0; j<25; j++)

putch(‘\n’); set_cursor_pos(1, 1);

}

887

E

GRAPHICS C

L ONSOLE

ITE

Console Graphics Lite

}//end for

}

//--------------------------------------------------------------

void draw_line(int x1, int y1, int x2, int y2)

{

int w, z, t, w1, w2, z1, z2;

double xDelta=x1-x2, yDelta=y1-y2, slope; bool isMoreHoriz;

if( fabs(xDelta) > fabs(yDelta) ) //more horizontal

set_cursor_pos(w, z); else

set_cursor_pos(z, w); putch(fill_char);

}

}

}

//--------------------------------------------------------------

void draw_pyramid(int x1, int y1, int height)

{

int x, y;

for(y=y1; y<y1+height; y++)

{

889

E

GRAPHICS C

L ONSOLE

ITE

Console Graphics Lite

void clear_screen();

void wait(int milliseconds); void clear_line();

void draw_rectangle(int left, int top, int right, int bottom); void draw_circle(int x, int y, int rad);

void draw_line(int x1, int y1, int x2, int y2); void draw_pyramid(int x1, int y1, int height); void set_fill_style(fstyle);

#endif // _INC_WCONSOLE

Listing for BORLACON.CPP

//borlacon.cpp

//provides drawing routines for Borland console functions #include “borlaCon.h”

Sleep(milliseconds);

}

//--------------------------------------------------------------

891

E

GRAPHICS C

L ONSOLE

ITE

{

int w, z, t, w1, w2, z1, z2;

double xDelta=x1-x2, yDelta=y1-y2, slope; bool isMoreHoriz;

if( fabs(xDelta) > fabs(yDelta) ) //more horizontal

}

}

Console Graphics Lite

893

E

GRAPHICS C

L ONSOLE

ITE