#include <CUTexture.h>

Inheritance diagram for cugl::Texture:

Public Types
enum	PixelFormat : GLenum { PixelFormat::RGBA = GL_RGBA, PixelFormat::RGB = GL_RGBA, PixelFormat::RED = GL_RED, PixelFormat::ALPHA = GL_ALPHA, PixelFormat::UNDEFINED = GL_RG }

Public Member Functions
	Texture ()

	~Texture ()

void	dispose ()

bool	init (int width, int height, PixelFormat format=PixelFormat::RGBA)

bool	initWithData (const void *data, int width, int height, PixelFormat format=PixelFormat::RGBA)

bool	initWithFile (const std::string &filename)

const Texture &	operator= (const void *data)

const Texture &	set (const void *data)

bool	isReady () const

bool	isActive () const

bool	hasMipMaps () const

void	buildMipMaps ()

GLuint	getBuffer ()

void	setName (std::string name)

const std::string &	getName () const

unsigned int	getWidth () const

unsigned int	getHeight () const

Size	getSize ()

PixelFormat	getFormat () const

GLuint	getMinFilter () const

GLuint	getMagFilter () const

void	setMinFilter (GLuint minFilter)

void	setMagFilter (GLuint magFilter)

GLuint	getWrapS () const

GLuint	getWrapT () const

void	setWrapS (GLuint wrap)

void	setWrapT (GLuint wrap)

const std::shared_ptr< Texture > &	getParent () const

std::shared_ptr< Texture >	getParent ()

std::shared_ptr< Texture >	getSubTexture (GLfloat minS, GLfloat maxS, GLfloat minT, GLfloat maxT)

bool	isSubTexture () const

GLfloat	getMinS () const

GLfloat	getMinT () const

GLfloat	getMaxS () const

GLfloat	getMaxT () const

void	bind ()

void	unbind ()

std::string	toString (bool verbose=false) const

	operator std::string () const

Static Public Member Functions
static std::shared_ptr< Texture >	alloc (int width, int height, PixelFormat format=PixelFormat::RGBA)

static std::shared_ptr< Texture >	allocWithData (const void *data, int width, int height, PixelFormat format=PixelFormat::RGBA)

static std::shared_ptr< Texture >	allocWithFile (const std::string &filename)

Detailed Description

This is a class representing an OpenGL texture.

We enforce that all textures must be a power-of-two along each dimension (though they need not be square). This is still required by some mobile devices and so it is easiest to require it across the board.

This class also provides support for texture atlases. Any non-repeating texture can produce a subtexture. A subtexture wraps the same texture data (and so does not require a context switch in the rendering pipeline), but has different start and end boundaries, as defined by minS, maxS, minT and maxT. See getSubtexture() for more information.

Member Enumeration Documentation

enum cugl::Texture::PixelFormat : GLenum

strong

This enum lists the possible texture pixel formats.

Because of cross-platform issues (we must support both OpenGL and OpenGLES), our textures only support a small subset of formats. No other formats are supported.

Enumerator
RGBA	The default type; RGB with alpha transparency
RGB	RGB with no alpha (all blending assumes alpha is 1.0)
RED	A single color channel of red (all blending assumes alpha is 1.0)
ALPHA	An alpha-only channel
UNDEFINED	The image is not yet defined

Constructor & Destructor Documentation

cugl::Texture::Texture ( )

Creates a new empty texture with no size.

This method performs no allocations. You must call init to generate a proper OpenGL texture.

cugl::Texture::~Texture ( )

inline

Deletes this texture, disposing all resources

Member Function Documentation

static std::shared_ptr<Texture> cugl::Texture::alloc	(	int	width,
		int	height,
		PixelFormat	format = `PixelFormat::RGBA`
	)

inlinestatic

Returns a new empty texture with the given dimensions.

When initialization is done, the texture is no longer bound. However, any other texture that was bound during initialization is also no longer bound.

You must use the set() method to load data into the texture.

Parameters

width	The texture width in pixels
height	The texture height in pixels
format	The texture data format

Returns: a new empty texture with the given dimensions.

static std::shared_ptr<Texture> cugl::Texture::allocWithData	(	const void *	data,
		int	width,
		int	height,
		PixelFormat	format = `PixelFormat::RGBA`
	)

inlinestatic

Returns a new texture with the given data.

When initialization is done, the texture is no longer bound. However, any other texture that was bound during initialization is also no longer bound.

The data format must match the one given.

Parameters

data	The texture data (size widthheightformat)
width	The texture width in pixels
height	The texture height in pixels
format	The texture data format

Returns: a new texture with the given data.

static std::shared_ptr<Texture> cugl::Texture::allocWithFile ( const std::string & filename )

inlinestatic

Returns a new texture with the data from the given file.

When initialization is done, the texture is no longer bound. However, any other texture that was bound during initialization is also no longer bound.

This method can load any file format supported by SDL_Image. This includes (but is not limited to) PNG, JPEG, GIF, TIFF, BMP and PCX.

The texture will be stored in RGBA format, even if it is a file format that does not support transparency (e.g. JPEG).

Parameters

filename The file supporting the texture file.

Returns: a new texture with the given data

void cugl::Texture::bind ( )

Binds this texture, making it active.

Once bound, any OpenGL calls will then use this texture.

void cugl::Texture::buildMipMaps ( )

Builds mipmaps for the current texture.

This method will fail if this texture is a subtexture. Only the parent texture can have mipmaps. In addition, mipmaps can only be built if the texture size is a power of two.

void cugl::Texture::dispose ( )

Deletes the OpenGL texture and resets all attributes.

You must reinitialize the texture to use it.

GLuint cugl::Texture::getBuffer ( )

inline

Returns the OpenGL buffer for this texture.

This method will return 0 if the texture is not initialized.

Returns: the OpenGL buffer for this texture.

PixelFormat cugl::Texture::getFormat ( ) const

inline

Returns the data format of this texture.

The data format determines what type of data can be assigned to this texture.

Returns: the data format of this texture.

unsigned int cugl::Texture::getHeight ( ) const

inline

Returns the height of this texture in pixels.

Returns: the height of this texture in pixels.

GLuint cugl::Texture::getMagFilter ( ) const

inline

Returns the mag filter of this texture.

The mag filter is the algorithm hint that OpenGL uses to make an image larger. The default is GL_LINEAR.

Returns: the mag filter of this texture.

GLfloat cugl::Texture::getMaxS ( ) const

inline

Returns the maximum S texture coordinate for this texture.

When rescaling texture coordinates for a subtexture, this value is used in place of 0.

Returns: the maximum S texture coordinate for this texture.

GLfloat cugl::Texture::getMaxT ( ) const

inline

Returns the maximum T texture coordinate for this texture.

When rescaling texture coordinates for a subtexture, this value is used in place of 0.

Returns: the maximum T texture coordinate for this texture.

GLuint cugl::Texture::getMinFilter ( ) const

inline

Returns the min filter of this texture.

The min filter is the algorithm hint that OpenGL uses to make an image smaller. The default is GL_NEAREST.

Returns: the min filter of this texture.

GLfloat cugl::Texture::getMinS ( ) const

inline

Returns the minimum S texture coordinate for this texture.

When rescaling texture coordinates for a subtexture, this value is used in place of 0.

Returns: the minimum S texture coordinate for this texture.

GLfloat cugl::Texture::getMinT ( ) const

inline

Returns the minimum T texture coordinate for this texture.

When rescaling texture coordinates for a subtexture, this value is used in place of 0.

Returns: the minimum T texture coordinate for this texture.

const std::string& cugl::Texture::getName ( ) const

inline

Returns the name of this texture.

A name is a user-defined way of identifying a texture. Subtextures are permitted to have different names than their parents.

Returns: the name of this texture.

const std::shared_ptr<Texture>& cugl::Texture::getParent ( ) const

inline

Returns the parent texture of this subtexture.

This method will return nullptr is this is not a subtexture.

Returns the parent texture of this subtexture.

std::shared_ptr<Texture> cugl::Texture::getParent ( )

inline

Returns the parent texture of this subtexture.

This method will return nullptr is this is not a subtexture.

Returns the parent texture of this subtexture.

Size cugl::Texture::getSize ( )

inline

Returns the size of this texture in pixels.

Returns: the size of this texture in pixels.

std::shared_ptr<Texture> cugl::Texture::getSubTexture	(	GLfloat	minS,
		GLfloat	maxS,
		GLfloat	minT,
		GLfloat	maxT
	)

Returns a subtexture with the given dimensions.

The values must be 0 <= minS <= maxS <= 1 and 0 <= minT <= maxT <= 1. They specify the region of the texture to extract the subtexture.

It is the responsibility of the user to rescale the texture coordinates when using subtexture. Otherwise, the OpenGL pipeline will just use the original texture instead. See the method SpriteBatch#prepare() for an example of how to scale texture coordinates.

It is possible to make a subtexture of a subtexture. However, in that case, the minS, maxS, minT and maxT values are all with respect to the original root texture. Furthermore, the parent of the new subtexture will be the original root texture. So no tree of subtextures is more than one level deep.

Returns a subtexture with the given dimensions.

unsigned int cugl::Texture::getWidth ( ) const

inline

Returns the width of this texture in pixels.

Returns: the width of this texture in pixels.

GLuint cugl::Texture::getWrapS ( ) const

inline

Returns the horizontal wrap of this texture.

The default is GL_CLAMP_TO_EDGE.

Returns: the horizontal wrap of this texture.

GLuint cugl::Texture::getWrapT ( ) const

inline

Returns the vertical wrap of this texture.

The default is GL_CLAMP_TO_EDGE.

Returns: the vertical wrap of this texture.

bool cugl::Texture::hasMipMaps ( ) const

inline

Returns whether this texture has generated mipmaps.

If this texture is a subtexture of texture with mipmaps, this method will also return true (and vice versa)

Returns: whether this texture has generated mipmaps.

bool cugl::Texture::init	(	int	width,
		int	height,
		PixelFormat	format = `PixelFormat::RGBA`
	)

Initializes an empty texture with the given dimensions.

When initialization is done, the texture is no longer bound. However, any other texture that was bound during initialization is also no longer bound.

You must use the set() method to load data into the texture.

Parameters

width	The texture width in pixels
height	The texture height in pixels
format	The texture data format

Returns: true if initialization was successful.

bool cugl::Texture::initWithData	(	const void *	data,
		int	width,
		int	height,
		PixelFormat	format = `PixelFormat::RGBA`
	)

Initializes an texture with the given data.

When initialization is done, the texture is no longer bound. However, any other texture that was bound during initialization is also no longer bound.

The data format must match the one given.

Parameters

data	The texture data (size widthheightformat)
width	The texture width in pixels
height	The texture height in pixels
format	The texture data format

Returns: true if initialization was successful.

bool cugl::Texture::initWithFile ( const std::string & filename )

Initializes an texture with the data from the given file.

When initialization is done, the texture is no longer bound. However, any other texture that was bound during initialization is also no longer bound.

This method can load any file format supported by SDL_Image. This includes (but is not limited to) PNG, JPEG, GIF, TIFF, BMP and PCX.

The texture will be stored in RGBA format, even if it is a file format that does not support transparency (e.g. JPEG).

Parameters

filename The file supporting the texture file.

Returns: true if initialization was successful.

bool cugl::Texture::isActive ( ) const

inline

Returns whether this texture is actively in use.

If this texture is a subtexture of texture in use, this method will also return true (and vice versa)

If this texture is the parent of a subtexture in use, this method will return true.

Returns: whether this texture is actively in use.

bool cugl::Texture::isReady ( ) const

inline

Returns true if this shader has been compiled and is ready for use.

Returns: true if this shader has been compiled and is ready for use.

bool cugl::Texture::isSubTexture ( ) const

inline

Returns true if this texture is a subtexture.

This is the same as checking if the parent is not nullptr.

Returns: true if this texture is a subtexture.

cugl::Texture::operator std::string ( ) const

inline

Cast from Texture to a string.

const Texture& cugl::Texture::operator= ( const void * data )

inline

Sets this texture to have the contents of the given buffer.

The buffer must have the correct data format. In addition, the buffer must be size width*height*format.

This method binds the texture if it is not currently active.

Parameters

data	The buffer to read into the texture

Returns: a reference to this (modified) texture for chaining.

const Texture& cugl::Texture::set ( const void * data )

Sets this texture to have the contents of the given buffer.

The buffer must have the correct data format. In addition, the buffer must be size width*height*format.

This method binds the texture if it is not currently active.

Parameters

data	The buffer to read into the texture

Returns: a reference to this (modified) texture for chaining.

void cugl::Texture::setMagFilter ( GLuint magFilter )

Sets the mag filter of this texture.

The mag filter is the algorithm hint that OpenGL uses to make an image larger. The default is GL_LINEAR.

Parameters

magFilter The mag filter of this texture.

void cugl::Texture::setMinFilter ( GLuint minFilter )

Sets the min filter of this texture.

The min filter is the algorithm hint that OpenGL uses to make an image smaller. The default is GL_NEAREST.

Parameters

minFilter The min filter of this texture.

void cugl::Texture::setName ( std::string name )

inline

Sets the name of this texture.

A name is a user-defined way of identifying a texture. Subtextures are permitted to have different names than their parents.

Parameters

name	The name of this texture.

void cugl::Texture::setWrapS ( GLuint wrap )

Sets the horizontal wrap of this texture.

The default is GL_CLAMP_TO_EDGE.

void cugl::Texture::setWrapT ( GLuint wrap )

Sets the vertical wrap of this texture.

The default is GL_CLAMP_TO_EDGE.

std::string cugl::Texture::toString ( bool verbose = false ) const

Returns a string representation of this texture for debugging purposes.

If verbose is true, the string will include class information. This allows us to unambiguously identify the class.

Parameters

verbose Whether to include class information

Returns: a string representation of this texture for debugging purposes.

void cugl::Texture::unbind ( )

Uninds this texture, making it no longer active.

Once unbound, OpenGL calls will no longer use this texture.

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

renderer/CUTexture.h

Public Types

Public Member Functions

Static Public Member Functions

Detailed Description

Member Enumeration Documentation

Constructor & Destructor Documentation

Member Function Documentation