Programming and Graphics

8.1 Glut 265

The graphics display is shown in Figure 8.1.2(a). In this code, we have intro-
duced theglRasterPos2ifunction to move the pen to a specified position, and
theglutBitmapCharacterfunction to draw a character on the screen using a
specified font.

The following function also contained in the filetheend.ccprints a char-
acter array using a different method:

void write1()

{

glClear(GLCOLORBUFFERBIT);

char * ps = "The End";

int x = 35, y=50;

while(*ps)

{

glRasterPos2i(x,y);

glutBitmapCharacter(GLUTBITMAP 8 BY13,*ps);

x=x+4;

ps = ps+1;

}

glFlush();

}

The graphics display is shown in Figure 8.1.2(b). In the second method, the
individual characters of the array are identified by the pointerpswhose value is
sequentially increased by one unit until the end of the array has been reached.

Available fonts include the following:

GLUT_BITMAP_8_BY_13

GLUT_BITMAP_9_BY_15

GLUT_BITMAP_HELVETICA_10

GLUT_BITMAP_HELVETICA_12

GLUT_BITMAP_HELVETICA_18

GLUT_BITMAP_TIMES_ROMAN_10

GLUT_BITMAP_HELVETICA_18

GLUT_BITMAP_TIMES_ROMAN_24

Spectacular designs

OpenGL allows us to manipulate the color with spectacular results seen
in professional designs. The following function generates the design shown in
Figure 8.1.3:

void spectacular()

{