CSCI441::FontUtils Namespace Reference

Utility class to render text overlays on screen

Usage:
(1) During setup, call loadFont() to load a ttf font file
(2) Immediately prior to rendering, call bindFont() to load font context
(3) Subsequently call renderText() for every string to be rendered to screen
(4) During cleanup, call releaseFont() to deallocate font memory

To make placement of text within window easier, such that the (x, y) coordinate corresponds to the pixel location, call setWindowSize() after loading the font (and anytime the window size changes).. More...

Functions
bool	loadFont (const char *filename)
	registers a TrueTypeFont file with a shader program to render text to screen
void	releaseFont ()
	deallocates CPU and GPU memory related to text rendering
void	bindFont ()
	sets all necessary font contexts
void	setColor (glm::vec3 color)
	specify the color to render the text
void	setColor (glm::vec4 color)
	specify the color to render the text
void	setWindowSize (GLint width, GLint height)
	store the size of the window
void	setWindowSize (GLfloat width, GLfloat height)
	store the size of the window
void	setFontSize (GLfloat scaleX, GLfloat scaleY)
	set the amount to scale font when drawing
void	renderText (const char *str, GLfloat x, GLfloat y)
	draws the given text starting at the top left (x, y) coordinate specified

Detailed Description

Utility class to render text overlays on screen

Usage:
(1) During setup, call loadFont() to load a ttf font file
(2) Immediately prior to rendering, call bindFont() to load font context
(3) Subsequently call renderText() for every string to be rendered to screen
(4) During cleanup, call releaseFont() to deallocate font memory

To make placement of text within window easier, such that the (x, y) coordinate corresponds to the pixel location, call setWindowSize() after loading the font (and anytime the window size changes)..

Function Documentation

bindFont()

void CSCI441::FontUtils::bindFont ( )

inline

sets all necessary font contexts

Note

binds VertexArray and GL_ARRAY_BUFFER

binds GL_TEXTURE_2D to GL_TEXTURE0

uses shader program

Precondition

MUST call CSCI441::FontUtility::loadFont(const char*) prior to this call

loadFont()

bool CSCI441::FontUtils::loadFont ( const char *  filename )

inline

registers a TrueTypeFont file with a shader program to render text to screen

Parameters

filename

ttf font file to load

Returns

true if font file was successfully loaded AND internal font shader program successfully compiled

renderText()

void CSCI441::FontUtils::renderText ( const char *  str, GLfloat  x, GLfloat  y  )

inline

draws the given text starting at the top left (x, y) coordinate specified

Parameters

str	text to render to screen
x	x coordinate in screen space to place text within window (corresponds to left edge of text)
y	y coordinate in screen space to place text within window (corresponds to top edge of text)

Precondition

MUST call CSCI441::FontUtility::bindFont() prior to this call

Note

see CSCI441::FontUtils::setWindowSize() for help in specifying the (x, y) coordinate

see CSCI441::FontUtility::setColor() to change the displayed color

setColor() [1/2]

void CSCI441::FontUtils::setColor ( glm::vec3  color )

inline

specify the color to render the text

Parameters

color

text color

Note

sets alpha channel to 1.0

setColor() [2/2]

void CSCI441::FontUtils::setColor ( glm::vec4  color )

inline

specify the color to render the text

Parameters

color

text color

setFontSize()

void CSCI441::FontUtils::setFontSize ( GLfloat  scaleX, GLfloat  scaleY  )

inline

set the amount to scale font when drawing

Parameters

scaleX	amount to scale font horizontally
scaleY	amount to scale font vertically

Note

values typically refer to inverse screen size, e.g. the size of each pixel

setWindowSize() [1/2]

void CSCI441::FontUtils::setWindowSize ( GLfloat  width, GLfloat  height  )

inline

store the size of the window

Parameters

width	window width
height	window height

Note

this allows CSCI441::FontUtils::renderText() to specify the (x, y) coordinate in screen space. The (x, y) coordinate then corresponds to the top left pixel to begin drawing at.

setWindowSize() [2/2]

void CSCI441::FontUtils::setWindowSize ( GLint  width, GLint  height  )

inline

store the size of the window

Parameters

width	window width
height	window height

Note

this allows CSCI441::FontUtils::renderText() to specify the (x, y) coordinate in screen space. The (x, y) coordinate then corresponds to the top left pixel to begin drawing at.