com.sun.opengl.util.texture

## Class TextureIO

- java.lang.Object
- - com.sun.opengl.util.texture.TextureIO

    public class TextureIO
    extends Object

Provides input and output facilities for both loading OpenGL textures from disk and streams as well as writing textures already in memory back to disk.

The TextureIO class supports an arbitrary number of plug-in readers and writers via TextureProviders and TextureWriters. TextureProviders know how to produce TextureData objects from files, InputStreams and URLs. TextureWriters know how to write TextureData objects to disk in various file formats. The TextureData class represents the raw data of the texture before it has been converted to an OpenGL texture object. The Texture class represents the OpenGL texture object and provides easy facilities for using the texture.

There are several built-in TextureProviders and TextureWriters supplied with the TextureIO implementation. The most basic provider uses the platform's Image I/O facilities to read in a BufferedImage and convert it to a texture. This is the baseline provider and is registered so that it is the last one consulted. All others are asked first to open a given file.

There are three other providers registered by default as of the time of this writing. One handles SGI RGB (".sgi", ".rgb") images from both files and streams. One handles DirectDraw Surface (".dds") images read from files, though can not read these images from streams. One handles Targa (".tga") images read from both files and streams. These providers are executed in an arbitrary order. Some of these providers require the file's suffix to either be specified via the newTextureData methods or for the file to be named with the appropriate suffix. In general a file suffix should be provided to the newTexture and newTextureData methods if at all possible.

Note that additional TextureProviders, if reading images from InputStreams, must use the mark()/reset() methods on InputStream when probing for e.g. magic numbers at the head of the file to make sure not to disturb the state of the InputStream for downstream TextureProviders.

There are analogous TextureWriters provided for writing textures back to disk if desired. As of this writing, there are four TextureWriters registered by default: one for Targa files, one for SGI RGB files, one for DirectDraw surface (.dds) files, and one for ImageIO-supplied formats such as .jpg and .png. Some of these writers have certain limitations such as only being able to write out textures stored in GL_RGB or GL_RGBA format. The DDS writer supports fetching and writing to disk of texture data in DXTn compressed format. Whether this will occur is dependent on whether the texture's internal format is one of the DXTn compressed formats and whether the target file is .dds format.

### Field Summary

Fields
`static String` `DDS` Constant which can be used as a file suffix to indicate a DirectDraw Surface file.
`static String` `GIF` Constant which can be used as a file suffix to indicate a GIF file.
`static String` `JPG` Constant which can be used as a file suffix to indicate a JPEG file.
`static String` `PNG` Constant which can be used as a file suffix to indicate a PNG file.
`static String` `SGI` Constant which can be used as a file suffix to indicate an SGI RGB file.
`static String` `SGI_RGB` Constant which can be used as a file suffix to indicate an SGI RGB file.
`static String` `TGA` Constant which can be used as a file suffix to indicate a Targa file.
`static String` `TIFF` Constant which can be used as a file suffix to indicate a TIFF file.

### Constructor Summary

Constructors
Constructor and Description
`TextureIO()`

### Method Summary

Methods
`static void` `addTextureProvider(TextureProvider provider)` Adds a TextureProvider to support reading of a new file format.
`static void` `addTextureWriter(TextureWriter writer)` Adds a TextureWriter to support writing of a new file format.
`static boolean` `isTexRectEnabled()` Indicates whether the GL_ARB_texture_rectangle extension is allowed to be used for non-power-of-two textures; see `setTexRectEnabled`.
`static Texture` `newTexture(BufferedImage image, boolean mipmap)` Creates an OpenGL texture object from the specified BufferedImage using the current OpenGL context.
`static Texture` `newTexture(File file, boolean mipmap)` Creates an OpenGL texture object from the specified file using the current OpenGL context.
`static Texture` `newTexture(InputStream stream, boolean mipmap, String fileSuffix)` Creates an OpenGL texture object from the specified stream using the current OpenGL context.
`static Texture` `newTexture(int target)` Creates an OpenGL texture object associated with the given OpenGL texture target using the current OpenGL context.
`static Texture` `newTexture(TextureData data)` Creates an OpenGL texture object from the specified TextureData using the current OpenGL context.
`static Texture` `newTexture(URL url, boolean mipmap, String fileSuffix)` Creates an OpenGL texture object from the specified URL using the current OpenGL context.
`static TextureData` `newTextureData(BufferedImage image, boolean mipmap)` Creates a TextureData from the given BufferedImage.
`static TextureData` `newTextureData(BufferedImage image, int internalFormat, int pixelFormat, boolean mipmap)` Creates a TextureData from the given BufferedImage, using the specified OpenGL internal format and pixel format for the texture which will eventually result.
`static TextureData` `newTextureData(File file, boolean mipmap, String fileSuffix)` Creates a TextureData from the given file.
`static TextureData` `newTextureData(File file, int internalFormat, int pixelFormat, boolean mipmap, String fileSuffix)` Creates a TextureData from the given file, using the specified OpenGL internal format and pixel format for the texture which will eventually result.
`static TextureData` `newTextureData(InputStream stream, boolean mipmap, String fileSuffix)` Creates a TextureData from the given stream.
`static TextureData` `newTextureData(InputStream stream, int internalFormat, int pixelFormat, boolean mipmap, String fileSuffix)` Creates a TextureData from the given stream, using the specified OpenGL internal format and pixel format for the texture which will eventually result.
`static TextureData` `newTextureData(URL url, boolean mipmap, String fileSuffix)` Creates a TextureData from the given URL.
`static TextureData` `newTextureData(URL url, int internalFormat, int pixelFormat, boolean mipmap, String fileSuffix)` Creates a TextureData from the given URL, using the specified OpenGL internal format and pixel format for the texture which will eventually result.
`static void` `setTexRectEnabled(boolean enabled)` Toggles the use of the GL_ARB_texture_rectangle extension by the TextureIO classes.
`static void` `write(Texture texture, File file)` Writes the given texture to a file.

### Methods inherited from class java.lang.Object

`clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait`

### Field Detail

#### DDS

    public static final String DDS

Constant which can be used as a file suffix to indicate a DirectDraw Surface file.

See Also:
  Constant Field Values

#### SGI

    public static final String SGI

Constant which can be used as a file suffix to indicate an SGI RGB file.

See Also:
  Constant Field Values

#### SGI_RGB

    public static final String SGI_RGB

Constant which can be used as a file suffix to indicate an SGI RGB file.

See Also:
  Constant Field Values

#### GIF

    public static final String GIF

Constant which can be used as a file suffix to indicate a GIF file.

See Also:
  Constant Field Values

#### JPG

    public static final String JPG

Constant which can be used as a file suffix to indicate a JPEG file.

See Also:
  Constant Field Values

#### PNG

    public static final String PNG

Constant which can be used as a file suffix to indicate a PNG file.

See Also:
  Constant Field Values

#### TGA

    public static final String TGA

Constant which can be used as a file suffix to indicate a Targa file.

See Also:
  Constant Field Values

#### TIFF

    public static final String TIFF

Constant which can be used as a file suffix to indicate a TIFF file.

See Also:
  Constant Field Values

### Constructor Detail

#### TextureIO

    public TextureIO()

### Method Detail

#### newTextureData

    public static TextureData newTextureData(File file,
                             boolean mipmap,
                             String fileSuffix)
                                      throws IOException

Creates a TextureData from the given file. Does no OpenGL work.

Parameters:
  `file` - the file from which to read the texture data
  `mipmap` - whether mipmaps should be produced for this texture either by autogenerating them or reading them from the file. Some file formats support multiple mipmaps in a single file in which case those mipmaps will be used rather than generating them.
  `fileSuffix` - the suffix of the file name to be used as a hint of the file format to the underlying texture provider, or null if none and should be auto-detected (some texture providers do not support this)
Returns:
  the texture data from the file, or null if none of the registered texture providers could read the file
Throws:
  `IOException` - if an error occurred while reading the file

#### newTextureData

    public static TextureData newTextureData(InputStream stream,
                             boolean mipmap,
                             String fileSuffix)
                                      throws IOException

Creates a TextureData from the given stream. Does no OpenGL work.

Parameters:
  `stream` - the stream from which to read the texture data
  `mipmap` - whether mipmaps should be produced for this texture either by autogenerating them or reading them from the file. Some file formats support multiple mipmaps in a single file in which case those mipmaps will be used rather than generating them.
  `fileSuffix` - the suffix of the file name to be used as a hint of the file format to the underlying texture provider, or null if none and should be auto-detected (some texture providers do not support this)
Returns:
  the texture data from the stream, or null if none of the registered texture providers could read the stream
Throws:
  `IOException` - if an error occurred while reading the stream

#### newTextureData

    public static TextureData newTextureData(URL url,
                             boolean mipmap,
                             String fileSuffix)
                                      throws IOException

Creates a TextureData from the given URL. Does no OpenGL work.

Parameters:
  `url` - the URL from which to read the texture data
  `mipmap` - whether mipmaps should be produced for this texture either by autogenerating them or reading them from the file. Some file formats support multiple mipmaps in a single file in which case those mipmaps will be used rather than generating them.
  `fileSuffix` - the suffix of the file name to be used as a hint of the file format to the underlying texture provider, or null if none and should be auto-detected (some texture providers do not support this)
Returns:
  the texture data from the URL, or null if none of the registered texture providers could read the URL
Throws:
  `IOException` - if an error occurred while reading the URL

#### newTextureData

    public static TextureData newTextureData(BufferedImage image,
                             boolean mipmap)

Creates a TextureData from the given BufferedImage. Does no OpenGL work.

Parameters:
  `image` - the BufferedImage containing the texture data
  `mipmap` - whether mipmaps should be produced for this texture by autogenerating them
Returns:
  the texture data from the image

#### newTextureData

    public static TextureData newTextureData(File file,
                             int internalFormat,
                             int pixelFormat,
                             boolean mipmap,
                             String fileSuffix)
                                      throws IOException,
                                             IllegalArgumentException

Creates a TextureData from the given file, using the specified OpenGL internal format and pixel format for the texture which will eventually result. The internalFormat and pixelFormat must be specified and may not be zero; to use default values, use the variant of this method which does not take these arguments. Does no OpenGL work.

Parameters:
  `file` - the file from which to read the texture data
  `internalFormat` - the OpenGL internal format of the texture which will eventually result from the TextureData
  `pixelFormat` - the OpenGL pixel format of the texture which will eventually result from the TextureData
  `mipmap` - whether mipmaps should be produced for this texture either by autogenerating them or reading them from the file. Some file formats support multiple mipmaps in a single file in which case those mipmaps will be used rather than generating them.
  `fileSuffix` - the suffix of the file name to be used as a hint of the file format to the underlying texture provider, or null if none and should be auto-detected (some texture providers do not support this)
Returns:
  the texture data from the file, or null if none of the registered texture providers could read the file
Throws:
  `IllegalArgumentException` - if either internalFormat or pixelFormat was 0
  `IOException` - if an error occurred while reading the file

#### newTextureData

    public static TextureData newTextureData(InputStream stream,
                             int internalFormat,
                             int pixelFormat,
                             boolean mipmap,
                             String fileSuffix)
                                      throws IOException,
                                             IllegalArgumentException

Creates a TextureData from the given stream, using the specified OpenGL internal format and pixel format for the texture which will eventually result. The internalFormat and pixelFormat must be specified and may not be zero; to use default values, use the variant of this method which does not take these arguments. Does no OpenGL work.

Parameters:
  `stream` - the stream from which to read the texture data
  `internalFormat` - the OpenGL internal format of the texture which will eventually result from the TextureData
  `pixelFormat` - the OpenGL pixel format of the texture which will eventually result from the TextureData
  `mipmap` - whether mipmaps should be produced for this texture either by autogenerating them or reading them from the file. Some file formats support multiple mipmaps in a single file in which case those mipmaps will be used rather than generating them.
  `fileSuffix` - the suffix of the file name to be used as a hint of the file format to the underlying texture provider, or null if none and should be auto-detected (some texture providers do not support this)
Returns:
  the texture data from the stream, or null if none of the registered texture providers could read the stream
Throws:
  `IllegalArgumentException` - if either internalFormat or pixelFormat was 0
  `IOException` - if an error occurred while reading the stream

#### newTextureData

    public static TextureData newTextureData(URL url,
                             int internalFormat,
                             int pixelFormat,
                             boolean mipmap,
                             String fileSuffix)
                                      throws IOException,
                                             IllegalArgumentException

Creates a TextureData from the given URL, using the specified OpenGL internal format and pixel format for the texture which will eventually result. The internalFormat and pixelFormat must be specified and may not be zero; to use default values, use the variant of this method which does not take these arguments. Does no OpenGL work.

Parameters:
  `url` - the URL from which to read the texture data
  `internalFormat` - the OpenGL internal format of the texture which will eventually result from the TextureData
  `pixelFormat` - the OpenGL pixel format of the texture which will eventually result from the TextureData
  `mipmap` - whether mipmaps should be produced for this texture either by autogenerating them or reading them from the file. Some file formats support multiple mipmaps in a single file in which case those mipmaps will be used rather than generating them.
  `fileSuffix` - the suffix of the file name to be used as a hint of the file format to the underlying texture provider, or null if none and should be auto-detected (some texture providers do not support this)
Returns:
  the texture data from the URL, or null if none of the registered texture providers could read the URL
Throws:
  `IllegalArgumentException` - if either internalFormat or pixelFormat was 0
  `IOException` - if an error occurred while reading the URL

#### newTextureData

    public static TextureData newTextureData(BufferedImage image,
                             int internalFormat,
                             int pixelFormat,
                             boolean mipmap)
                                      throws IllegalArgumentException

Creates a TextureData from the given BufferedImage, using the specified OpenGL internal format and pixel format for the texture which will eventually result. The internalFormat and pixelFormat must be specified and may not be zero; to use default values, use the variant of this method which does not take these arguments. Does no OpenGL work.

Parameters:
  `image` - the BufferedImage containing the texture data
  `internalFormat` - the OpenGL internal format of the texture which will eventually result from the TextureData
  `pixelFormat` - the OpenGL pixel format of the texture which will eventually result from the TextureData
  `mipmap` - whether mipmaps should be produced for this texture either by autogenerating them or reading them from the file. Some file formats support multiple mipmaps in a single file in which case those mipmaps will be used rather than generating them.
Returns:
  the texture data from the image
Throws:
  `IllegalArgumentException` - if either internalFormat or pixelFormat was 0

#### newTexture

    public static Texture newTexture(TextureData data)
                              throws GLException,
                                     IllegalArgumentException

Creates an OpenGL texture object from the specified TextureData using the current OpenGL context.

Parameters:
  `data` - the texture data to turn into an OpenGL texture
Throws:
  `GLException` - if no OpenGL context is current or if an OpenGL error occurred
  `IllegalArgumentException` - if the passed TextureData was null

#### newTexture

    public static Texture newTexture(File file,
                     boolean mipmap)
                              throws IOException,
                                     GLException

Creates an OpenGL texture object from the specified file using the current OpenGL context.

Parameters:
  `file` - the file from which to read the texture data
  `mipmap` - whether mipmaps should be produced for this texture either by autogenerating them or reading them from the file. Some file formats support multiple mipmaps in a single file in which case those mipmaps will be used rather than generating them.
Throws:
  `IOException` - if an error occurred while reading the file
  `GLException` - if no OpenGL context is current or if an OpenGL error occurred

#### newTexture

    public static Texture newTexture(InputStream stream,
                     boolean mipmap,
                     String fileSuffix)
                              throws IOException,
                                     GLException

Creates an OpenGL texture object from the specified stream using the current OpenGL context.

Parameters:
  `stream` - the stream from which to read the texture data
  `mipmap` - whether mipmaps should be produced for this texture either by autogenerating them or reading them from the file. Some file formats support multiple mipmaps in a single file in which case those mipmaps will be used rather than generating them.
  `fileSuffix` - the suffix of the file name to be used as a hint of the file format to the underlying texture provider, or null if none and should be auto-detected (some texture providers do not support this)
Throws:
  `IOException` - if an error occurred while reading the stream
  `GLException` - if no OpenGL context is current or if an OpenGL error occurred

#### newTexture

    public static Texture newTexture(URL url,
                     boolean mipmap,
                     String fileSuffix)
                              throws IOException,
                                     GLException

Creates an OpenGL texture object from the specified URL using the current OpenGL context.

Parameters:
  `url` - the URL from which to read the texture data
  `mipmap` - whether mipmaps should be produced for this texture either by autogenerating them or reading them from the file. Some file formats support multiple mipmaps in a single file in which case those mipmaps will be used rather than generating them.
  `fileSuffix` - the suffix of the file name to be used as a hint of the file format to the underlying texture provider, or null if none and should be auto-detected (some texture providers do not support this)
Throws:
  `IOException` - if an error occurred while reading the URL
  `GLException` - if no OpenGL context is current or if an OpenGL error occurred

#### newTexture

    public static Texture newTexture(BufferedImage image,
                     boolean mipmap)
                              throws GLException

Creates an OpenGL texture object from the specified BufferedImage using the current OpenGL context.

Parameters:
  `image` - the BufferedImage from which to read the texture data
  `mipmap` - whether mipmaps should be produced for this texture by autogenerating them
Throws:
  `GLException` - if no OpenGL context is current or if an OpenGL error occurred

#### newTexture

    public static Texture newTexture(int target)
                              throws GLException

Creates an OpenGL texture object associated with the given OpenGL texture target using the current OpenGL context. The texture has no initial data. This is used, for example, to construct cube maps out of multiple TextureData objects.

Parameters:
  `target` - the OpenGL target type, eg GL.GL_TEXTURE_2D, GL.GL_TEXTURE_RECTANGLE_ARB
Throws:
  `GLException` - if no OpenGL context is current or if an OpenGL error occurred

#### write

    public static void write(Texture texture,
             File file)
                      throws IOException,
                             GLException

Writes the given texture to a file. The type of the file is inferred from its suffix. An OpenGL context must be current in order to fetch the texture data back from the OpenGL pipeline. This method causes the specified Texture to be bound to the GL_TEXTURE_2D state. If no suitable writer for the requested file format was found, throws an IOException.

Reasonable attempts are made to produce good results in the resulting images. The Targa, SGI and ImageIO writers produce results in the correct vertical orientation for those file formats. The DDS writer performs no vertical flip of the data, even in uncompressed mode. (It is impossible to perform such a vertical flip with compressed data.) Applications should keep this in mind when using this routine to save textures to disk for later re-loading.

Any mipmaps for the specified texture are currently discarded when it is written to disk, regardless of whether the underlying file format supports multiple mipmaps in a given file.

Throws:
  `IOException` - if an error occurred during writing or no suitable writer was found
  `GLException` - if no OpenGL context was current or an OpenGL-related error occurred

#### addTextureProvider

    public static void addTextureProvider(TextureProvider provider)

Adds a TextureProvider to support reading of a new file format.

#### addTextureWriter

    public static void addTextureWriter(TextureWriter writer)

Adds a TextureWriter to support writing of a new file format.

#### setTexRectEnabled

    public static void setTexRectEnabled(boolean enabled)

Toggles the use of the GL_ARB_texture_rectangle extension by the TextureIO classes. By default, on hardware supporting this extension, the TextureIO classes may use the GL_ARB_texture_rectangle extension for non-power-of-two textures. (If the hardware supports the GL_ARB_texture_non_power_of_two extension, that one is preferred.) In some situations, for example when writing shaders, it is advantageous to force the texture target to always be GL_TEXTURE_2D in order to have one version of the shader, even at the expense of texture memory in the case where NPOT textures are not supported. This method allows the use of the GL_ARB_texture_rectangle extension to be turned off globally for this purpose. The default is that the use of the extension is enabled.

#### isTexRectEnabled

    public static boolean isTexRectEnabled()

Indicates whether the GL_ARB_texture_rectangle extension is allowed to be used for non-power-of-two textures; see `setTexRectEnabled`.