Skybox::Text Class Reference

Functions for drawing text in OpenGL ES. More...

#include <Text.h>

Public Member Functions
	Text (const char *resourceDirectory, int windowWidth, int windowHeight)
	Constructor for Text. More...
	Text (void)
	Overloaded default constructor. More...
	~Text (void)
	Overloaded default destructor. More...
void	clear (void)
	Removes the current string from the class. More...
void	addString (int xPosition, int yPosition, const char *string, int red, int green, int blue, int alpha)
	Add a std::string to be drawn to the screen. More...
void	draw (void)
	Draw the text to the screen. More...

Static Public Attributes
static const int	textureCharacterWidth = 8
	The width (in pixels) of the characters in the text texture. More...
static const int	textureCharacterHeight = 16
	The height (in pixels) of the characters in the text texture. More...

Private Attributes
Matrix	projectionMatrix
int	numberOfCharacters
float *	textVertex
float *	textTextureCoordinates
float *	color
GLshort *	textIndex
int	m_iLocPosition
int	m_iLocProjection
int	m_iLocTextColor
int	m_iLocTexCoord
int	m_iLocTexture
GLuint	vertexShaderID
GLuint	fragmentShaderID
GLuint	programID
GLuint	textureID

Static Private Attributes
static const char	textureFilename [] = "font.raw"
static const char	vertexShaderFilename []
static const char	fragmentShaderFilename []
static const float	scale = 1.0f
	Scaling factor to use when rendering the text. More...

Detailed Description

Functions for drawing text in OpenGL ES.

Uses a texture with images of alphanumeric and punctuation symbols. The class converts strings into texture coordinates in order to render the correct symbol from the texture for each character of the string.

Definition at line 107 of file Text.h.

Constructor & Destructor Documentation

Skybox::Text::Text	(	const char *	resourceDirectory,
		int	windowWidth,
		int	windowHeight
	)

Constructor for Text.

Parameters

[in]	resourceDirectory	Path to the resources. Where the textures and shaders are located.
[in]	windowWidth	The width of the window (in pixles) that the text is being used in.
[in]	windowHeight	The height of the window (in pixles) that the text is being used in.

Definition at line 101 of file Text.cpp.

Skybox::Text::Text

(

void

)

Overloaded default constructor.

Definition at line 338 of file Text.cpp.

Skybox::Text::~Text

(

void

)

Overloaded default destructor.

Definition at line 353 of file Text.cpp.

Member Function Documentation

void Skybox::Text::addString	(	int	xPosition,
		int	yPosition,
		const char *	string,
		int	red,
		int	green,
		int	blue,
		int	alpha
	)

Add a std::string to be drawn to the screen.

Parameters

[in]	xPosition	The X position (in pixels) to start drawing the text. Measured from the left of the screen.
[in]	yPosition	The Y position (in pixels) to start drawing the text. Measured from the bottom of the screen.
[in]	string	The string to be rendered on the screen.
[in]	red	The red component of the text colour (accepts values 0-255).
[in]	green	The green component of the text colour (accepts values 0-255).
[in]	blue	The blue component of the text colour (accepts values 0-255).
[in]	alpha	The alpha component of the text colour (accepts values 0-255). Affects the transparency of the text.

Definition at line 181 of file Text.cpp.

void Skybox::Text::clear

(

void

)

Removes the current string from the class.

Should be called before adding a new string to render using addString().

Definition at line 170 of file Text.cpp.

void Skybox::Text::draw

(

void

)

Draw the text to the screen.

Should be called each time through the render loop so that the text is drawn every frame.

Definition at line 285 of file Text.cpp.

Member Data Documentation

float* Skybox::Text::color

private

Definition at line 126 of file Text.h.

const char Skybox::Text::fragmentShaderFilename[]

staticprivate

Definition at line 112 of file Text.h.

GLuint Skybox::Text::fragmentShaderID

private

Definition at line 134 of file Text.h.

int Skybox::Text::m_iLocPosition

private

Definition at line 128 of file Text.h.

int Skybox::Text::m_iLocProjection

private

Definition at line 129 of file Text.h.

int Skybox::Text::m_iLocTexCoord

private

Definition at line 131 of file Text.h.

int Skybox::Text::m_iLocTextColor

private

Definition at line 130 of file Text.h.

int Skybox::Text::m_iLocTexture

private

Definition at line 132 of file Text.h.

int Skybox::Text::numberOfCharacters

private

Definition at line 123 of file Text.h.

GLuint Skybox::Text::programID

private

Definition at line 135 of file Text.h.

Matrix Skybox::Text::projectionMatrix

private

Definition at line 122 of file Text.h.

const float Skybox::Text::scale = 1.0f

staticprivate

Scaling factor to use when rendering the text.

Warning

Experimental: allows drawing characters bigger than the texture was. Range 0.75-3.0 seems to work reasonably.

Definition at line 120 of file Text.h.

GLshort* Skybox::Text::textIndex

private

Definition at line 127 of file Text.h.

float* Skybox::Text::textTextureCoordinates

private

Definition at line 125 of file Text.h.

const int Skybox::Text::textureCharacterHeight = 16

static

The height (in pixels) of the characters in the text texture.

Warning

Change only if the text texture is changed and the height of the characters is different.

Definition at line 149 of file Text.h.

const int Skybox::Text::textureCharacterWidth = 8

static

The width (in pixels) of the characters in the text texture.

Warning

Change only if the text texture is changed and the width of the characters is different.

Definition at line 143 of file Text.h.

const char Skybox::Text::textureFilename = "font.raw"

staticprivate

Definition at line 110 of file Text.h.

GLuint Skybox::Text::textureID

private

Definition at line 136 of file Text.h.

float* Skybox::Text::textVertex

private

Definition at line 124 of file Text.h.

const char Skybox::Text::vertexShaderFilename[]

staticprivate

Definition at line 111 of file Text.h.

GLuint Skybox::Text::vertexShaderID

private

Definition at line 133 of file Text.h.

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The documentation for this class was generated from the following files:

• /mnt/d/working/gitlab/opengles-sdk-android/samples/advanced_samples/Skybox/jni/Text.h
• /mnt/d/working/gitlab/opengles-sdk-android/samples/advanced_samples/Skybox/jni/Text.cpp