Stroke Fonts

A stroke font is a font built with lines. As opposed to bitmap fonts, stroke fonts behave like any 3D object, i.e. the characters can be rotated, scaled, and translated.

In this section we’ll present the GLUT functions to put some stroke text on the screen. Basically, you just need one function: glutStrokeCharacter. The syntax is as follows:

void glutStrokeCharacter(void *font, int character)

Parameters:

• font – the name of the font to use (see bellow for a list of what’s available
• character – what to render, a letter, symbol, number, etc…

The font options available are:

• GLUT_STROKE_ROMAN
• GLUT_STROKE_MONO_ROMAN (fixed width font: 104.76 units wide).

The following line of text exemplifies a call to the glutStrokeCharacter function to output a single character at the current local coordinates:

glutStrokeCharacter(GLUT_STROKE_ROMAN,'3');

As opposed to bitmap fonts, the render location for stroke fonts is specified in the same way as for any graphical primitive, i.e. using translations, rotations and scales.

The following function renders a string starting at the specified position in local world coordinates:

void renderStrokeFontString(
		float x,
		float y,
		float z,
		void *font,
		char *string) {

	char *c;
	glPushMatrix();
	glTranslatef(x, y,z);

	for (c=string; *c != '\0'; c++) {
		glutStrokeCharacter(font, *c);
	}

	glPopMatrix();
}

Note: GLUT uses lines to draw stroke fonts, therefore we can specify the width of the line with the function glLineWidth. This function takes a float specifying the width as the only parameter.

As for bitmap fonts, GLUT provides a function that returns the width of a character. The function is glutStrokeWidth and the syntax is as follows:

int glutStrokeWidth(void *font, int character);

Parameters:

• font – one of the pre defined fonts in GLUT, see above.
• character – the character which we want to know the width