Computer Graphics Course Notes

First Section: Basics of Drawing in C++

• When programming, you need to call the standard library. This is done by including the header file. For graphics, you need graphics.h.

• The screen is typically a DOS screen. However, for drawing, you need to set the graphics mode.

  • This is done using the initgraph() function.

initgraph() function

• Used to initialize the graphics system.

• Prototype: void initgraph(int far *graphdriver, int far *graphmode, char far *pathtodriver);

  • graphdriver: pointer to the graphics driver.

  • graphmode: pointer to the graphics mode.

  • pathtodriver: path to the BGI files.

• Must be called before any other graphics function.

detectgraph() function

• Detects the graphics adapter and sets the graphics mode.

• Prototype: void detectgraph(int far *graphdriver, int far *graphmode);

• Example:

  • c++ detectgraph(&grd,&grm);

getgraphmode() function

• Gets the current graphics mode.

• Prototype: int getgraphmode(void);

• Example:

  • ```c++
    int gm;
    gm = getgraphmode();
    printf(