gfx::Texture Class Reference

OpenGL 2D texture. More...

#include <gfx_opengl_texture2.hh>

Inheritance diagram for gfx::Texture:

List of all members.

Public Types
enum	eForceAlpha { eForceAlpha_FALSE, eForceAlpha_TRUE }
enum	{ MAX_TEXTURE_WIDTH_BITS = 12 }
enum	{ MAX_TEXTURE_WIDTH = 1 << (MAX_TEXTURE_WIDTH_BITS-1) }
enum	{ MAX_TEXTURE_BYTES = MAX_TEXTURE_WIDTH * MAX_TEXTURE_WIDTH * 4 }
Public Member Functions
	Texture (void)
	Texture (const uint width, const uint height, const eTexelType externalTexelType, const eTexelType internalTexelType)
	Texture (const Targa &targa, const eMipmap mipmap=eMipmap_OFF, const eForceAlpha forceAlpha=eForceAlpha_FALSE)
	~Texture ()
void	Bind (void) const
CLASS_METHOD void	Map (const TexCoord2 &tc)
CLASS_METHOD void	Map (fp tx, fp ty)
bool	IfValid (void) const
uint	GetWidth (void) const
uint	GetHeight (void) const
uint	DimCnt (void) const
uint	GetTexelCnt (void) const
uint	GetExternalByteCnt (void) const
CLASS_METHOD uint	GetTotalMemoryUsed (void)
void	SetTextureImage (const Array< Texel32 > &texels, const eMipmap mipmap=eMipmap_OFF)
void	SetTextureImage (const Texel32 *texels, const uint texelCnt, const eMipmap mipmap=eMipmap_OFF)
void	SetTextureImage (const uint8 *texels, const uint externalByteCnt, const eMipmap mipmap=eMipmap_OFF)
void	SetMinFilter (eMinFilter filter)
void	SetMagFilter (eMagFilter filter)
void	SetFastestFilters (void)
void	SetWrap (eWrap wrap, uint dim)
void	SetWrap (eWrap wrap)
void	SetFunc (eFunc func)
Private Member Functions
void	Init (const uint width, const uint height, const eTexelType externalTexelType, const eTexelType internalTexelType)
uint	TexelCntToExternalByteCnt (const uint texelCnt) const
uint	TexelCntToInternalByteCnt (const uint texelCnt) const
uint	GetInternalTexelCnt (void) const
uint	GetInternalByteCnt (void) const
uint	GetByteCnt_ (const bool hasAlpha) const
uint	GetTexelCnt_ (const bool hasAlpha) const
uint	TexelCntToByteCnt_ (const uint texelCnt, const uint texelLen) const
uint	EstimateInternalByteCnt (const eMipmap mipmap) const
Private Attributes
Bits	mBits
eTexelType	mExternalTexelType
	GL_GBRA8, GL_RGBA8, etc.
eTexelType	mInternalTexelType
	not BGR/BGRA
GLuint	mId
	OpenGL texture object ID.
eFunc	mTexFunc
	passed to glTexEnv() by Texture::Begin()
CLASS_VAR int	msTotalMemoryUsed
	total memory used by all textures
Friends
bool	operator< (Texture &a, Texture &b)
Classes
struct	Bits

---

Detailed Description

OpenGL 2D texture.

///
/// Texture is a mixin class for 2D textures.
///
/// - Clients are the source of texture images.
///   Clients can procedurally-generate or load texture images from files
///   and pass them to Texture::SetTextureImage().
/// - Interface for setting texture modes (filters, blend functions, etc).
/// - Abstracts texel types (BGRA8, RGBA8).
/// - Tracks texture memory usage.
///
/// Invalid textures are useful:
/// ----------------------------
/// The default Texture ctor creates an inexpensive-but-invalid Texture.
/// Invalid Textures are a substitute for NULL pointers.
/// Any client that does construct invalid Textures is responsible
/// for checking Texture::IfValid() before calling a Texture method
/// (else results are UNDEFINED).
///
/// Example of procedural textures:
/// -------------------------------
/// // Creates a Texture object.  It has no image yet.
/// shptr<Texture> tex = new Texture( TEXEL_BGRA8, width, height );
///
/// // Generate texture image.
/// // Client allocates and fills the texture image.
/// // Texel32 is a typedef that abstracts BGRA8 or RGBA8 format.
/// const uint texelCnt = tex->GetTexelCnt();
/// Array<Texture::Texel32> texels( texelCnt );
/// for ( uint i = 0; i < texelCnt; i += Texture::TEXEL32_LEN )
/// {
///     // Whether Texel32 is in RGBA8 or BGRA8 order
///     // is abstracted by these #defines.
///     ASSERT( i < texelCnt );
///     Texture::Texel32 texel = (b << Texture::TEXEL32_BB_BIT_SHIFT)
///                            | (g << Texture::TEXEL32_GG_BIT_SHIFT)
///                            | (r << Texture::TEXEL32_RR_BIT_SHIFT)
///                            | (a << Texture::TEXEL32_AA_BIT_SHIFT);
///     texels[i] = texel;
/// }
/// tex->SetTextureImage( texels );
///
/// 

---

Member Enumeration Documentation

enum gfx::Texture::eForceAlpha

Enumerator:

eForceAlpha_FALSE
eForceAlpha_TRUE

anonymous enum

Enumerator:

MAX_TEXTURE_WIDTH_BITS

anonymous enum

Enumerator:

MAX_TEXTURE_WIDTH

anonymous enum

Enumerator:

MAX_TEXTURE_BYTES

---

Constructor & Destructor Documentation

gfx::Texture::Texture

(

void

)

Construct an invalid Texture (substitutes for NULL pointer).

gfx::Texture::Texture	(	const uint	width,
		const uint	height,
		const eTexelType	externalTexelType,
		const eTexelType	internalTexelType
	)

gfx::Texture::Texture	(	const Targa &	targa,
		const eMipmap	mipmap = eMipmap_OFF,
		const eForceAlpha	forceAlpha = eForceAlpha_FALSE
	)

Construct Texture object from a Targa graphics file.

Parameters:

	targa
	mimap
	forceAlpha	Treat the Targa object has having an Alpha channel even if, according to the Targa file's format (header), it doesn't. Forcing is possible since the old Targa C code converts to full RGBA.

gfx::Texture::~Texture

(

)

---

Member Function Documentation

void gfx::Texture::Bind

(

void

)

const [inline]

Bind texture.

Precondition:

Texture is valid.

Caller has enabled texturing using GFX::EnableTexture2(true). BTW, to disable texturing, call GFX::EnableTexture2(false).

CLASS_METHOD void gfx::Texture::Map

(

const TexCoord2 &

tc

)

[inline]

Send 2D texture coordinates to map texture to a polygon. Map are class methods since, being unassociated with a texture object, simplifies code that switches between texture objects.

CLASS_METHOD void gfx::Texture::Map	(	fp	tx,
		fp	ty
	)			[inline]

bool gfx::Texture::IfValid

(

void

)

const [inline]

Texture info.

uint gfx::Texture::GetWidth

(

void

)

const [inline]

uint gfx::Texture::GetHeight

(

void

)

const [inline]

uint gfx::Texture::DimCnt

(

void

)

const [inline]

uint gfx::Texture::GetTexelCnt

(

void

)

const

Returns:

Amount of texels in texture image. Whether loaded or not, or internal or external. Ignoring mipmaps.

uint gfx::Texture::GetExternalByteCnt

(

void

)

const

Returns:

Amount of bytes a texture image has or will have (whether loaded or not). Excluding mipmaps (if mipmapped, only returns the size of the largest mipmap).

CLASS_METHOD uint gfx::Texture::GetTotalMemoryUsed

(

void

)

[inline]

void gfx::Texture::SetTextureImage	(	const Array< Texel32 > &	texels,
		const eMipmap	mipmap = eMipmap_OFF
	)

Texture image. GetTextureImage() omitted.

void gfx::Texture::SetTextureImage	(	const Texel32 *	texels,
		const uint	texelCnt,
		const eMipmap	mipmap = eMipmap_OFF
	)

void gfx::Texture::SetTextureImage	(	const uint8 *	texels,
		const uint	externalByteCnt,
		const eMipmap	mipmap = eMipmap_OFF
	)

Load texture image into OpenGL (from raw byte array).

Parameters:

	texels	This class checks that caller used the right count.
	externalByteCnt	Count of BYTES in source texture image (external from gfxsys).
	mipmap

void gfx::Texture::SetMinFilter

(

eMinFilter

filter

)

Texture mode.

Texture modes.

Some OpenGL texture functions affect all texture objects, some affect only the bound one. Thus, since glTexEnv() doesn't affect the bound texture object, Texture::Bind() must call it every time.

http://www.opengl.org/resources/faq/technical/texture.htm The following functions affect the state of a texture object: glTexImage*(), glTexSubImage*(), glCopyTexImage*(), glCopyTexSubImage*(), glTexParameter*(), and glPrioritizeTextures(). Since the GLU routines for building mipmap pyramids ultimately call glTexImage*(), they also affect texture objects. Absent from this list are: glTexEnv*() and glTexGen*() which don't affect a particular texture object.

void gfx::Texture::SetMagFilter

(

eMagFilter

filter

)

void gfx::Texture::SetFastestFilters

(

void

)

void gfx::Texture::SetWrap	(	eWrap	wrap,
		uint	dim
	)

void gfx::Texture::SetWrap

(

eWrap

wrap

)

void gfx::Texture::SetFunc

(

eFunc

func

)

void gfx::Texture::Init	(	const uint	width,
		const uint	height,
		const eTexelType	externalTexelType,
		const eTexelType	internalTexelType
	)			[private]

Misc private methods.

uint gfx::Texture::TexelCntToExternalByteCnt

(

const uint

texelCnt

)

const [private]

Returns:

Convert texel count to byte count.

uint gfx::Texture::TexelCntToInternalByteCnt

(

const uint

texelCnt

)

const [private]

uint gfx::Texture::GetInternalTexelCnt

(

void

)

const [private]

uint gfx::Texture::GetInternalByteCnt

(

void

)

const [private]

uint gfx::Texture::GetByteCnt_

(

const bool

hasAlpha

)

const [private]

uint gfx::Texture::GetTexelCnt_

(

const bool

hasAlpha

)

const [private]

uint gfx::Texture::TexelCntToByteCnt_	(	const uint	texelCnt,
		const uint	texelLen
	)			const [private]

uint gfx::Texture::EstimateInternalByteCnt

(

const eMipmap

mipmap

)

const [private]

Estimate the amount of memory a texture is ACTIVELY consuming, including mipmaps.

---

Friends And Related Function Documentation

bool operator<	(	Texture &	a,
		Texture &	b
	)			[friend]

For STL containers.

---

Member Data Documentation

Bits gfx::Texture::mBits [private]

eTexelType gfx::Texture::mExternalTexelType [private]

GL_GBRA8, GL_RGBA8, etc.

eTexelType gfx::Texture::mInternalTexelType [private]

not BGR/BGRA

GLuint gfx::Texture::mId [private]

OpenGL texture object ID.

eFunc gfx::Texture::mTexFunc [private]

passed to glTexEnv() by Texture::Begin()

int gfx::Texture::msTotalMemoryUsed [private]

total memory used by all textures

---

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

• gfx_opengl_texture2.hh
• gfx_opengl_texture2.cc

Palomino 3D Engine documents generated by doxygen 1.5.3 on Fri Nov 23 11:26:28 2007