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. */ public class TextureIO { /** Constant which can be used as a file suffix to indicate a DirectDraw Surface file. */ public static final String DDS = "dds"; /** Constant which can be used as a file suffix to indicate an SGI RGB file. */ public static final String SGI = "sgi"; /** Constant which can be used as a file suffix to indicate an SGI RGB file. */ public static final String SGI_RGB = "rgb"; /** Constant which can be used as a file suffix to indicate a GIF file. */ public static final String GIF = "gif"; /** Constant which can be used as a file suffix to indicate a JPEG file. */ public static final String JPG = "jpg"; /** Constant which can be used as a file suffix to indicate a PNG file. */ public static final String PNG = "png"; /** Constant which can be used as a file suffix to indicate a Targa file. */ public static final String TGA = "tga"; /** Constant which can be used as a file suffix to indicate a TIFF file. */ public static final String TIFF = "tiff"; //---------------------------------------------------------------------- // methods that *do not* require a current context // These methods assume RGB or RGBA textures. // Some texture providers may not recognize the file format unless // the fileSuffix is specified, so it is strongly recommended to // specify it wherever it is known. // Some texture providers may also only support one kind of input, // i.e., reading from a file as opposed to a stream. /** * Creates a TextureData from the given file. Does no OpenGL work. * * @param file the file from which to read the texture data * @param 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. * @param 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) * @return 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 */ public static TextureData newTextureData(File file, boolean mipmap, String fileSuffix) throws IOException { return newTextureDataImpl(file, 0, 0, mipmap, fileSuffix); } /** * Creates a TextureData from the given stream. Does no OpenGL work. * * @param stream the stream from which to read the texture data * @param 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. * @param 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) * @return 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 */ public static TextureData newTextureData(InputStream stream, boolean mipmap, String fileSuffix) throws IOException { return newTextureDataImpl(stream, 0, 0, mipmap, fileSuffix); } /** * Creates a TextureData from the given URL. Does no OpenGL work. * * @param url the URL from which to read the texture data * @param 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. * @param 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) * @return 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 */ public static TextureData newTextureData(URL url, boolean mipmap, String fileSuffix) throws IOException { return newTextureDataImpl(url, 0, 0, mipmap, fileSuffix); } /** * Creates a TextureData from the given BufferedImage. Does no * OpenGL work. * * @param image the BufferedImage containing the texture data * @param mipmap whether mipmaps should be produced for this * texture by autogenerating them * @return the texture data from the image */ public static TextureData newTextureData(BufferedImage image, boolean mipmap) { return newTextureDataImpl(image, 0, 0, mipmap); } //---------------------------------------------------------------------- // These methods make no assumption about the OpenGL internal format // or pixel format of the texture; they must be specified by the // user. It is not allowed to supply 0 (indicating no preference) // for either the internalFormat or the pixelFormat; // IllegalArgumentException will be thrown in this case. /** * 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. * * @param file the file from which to read the texture data * @param internalFormat the OpenGL internal format of the texture * which will eventually result from the TextureData * @param pixelFormat the OpenGL pixel format of the texture * which will eventually result from the TextureData * @param 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. * @param 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) * @return 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 * @throws IOException if an error occurred while reading the file */ public static TextureData newTextureData(File file, int internalFormat, int pixelFormat, boolean mipmap, String fileSuffix) throws IOException, IllegalArgumentException { if ((internalFormat == 0) || (pixelFormat == 0)) { throw new IllegalArgumentException("internalFormat and pixelFormat must be non-zero"); } return newTextureDataImpl(file, internalFormat, pixelFormat, mipmap, fileSuffix); } /** * 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. * * @param stream the stream from which to read the texture data * @param internalFormat the OpenGL internal format of the texture * which will eventually result from the TextureData * @param pixelFormat the OpenGL pixel format of the texture * which will eventually result from the TextureData * @param 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. * @param 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) * @return 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 * @throws IOException if an error occurred while reading the stream */ public static TextureData newTextureData(InputStream stream, int internalFormat, int pixelFormat, boolean mipmap, String fileSuffix) throws IOException, IllegalArgumentException { if ((internalFormat == 0) || (pixelFormat == 0)) { throw new IllegalArgumentException("internalFormat and pixelFormat must be non-zero"); } return newTextureDataImpl(stream, internalFormat, pixelFormat, mipmap, fileSuffix); } /** * 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. * * @param url the URL from which to read the texture data * @param internalFormat the OpenGL internal format of the texture * which will eventually result from the TextureData * @param pixelFormat the OpenGL pixel format of the texture * which will eventually result from the TextureData * @param 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. * @param 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) * @return 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 * @throws IOException if an error occurred while reading the URL */ public static TextureData newTextureData(URL url, int internalFormat, int pixelFormat, boolean mipmap, String fileSuffix) throws IOException, IllegalArgumentException { if ((internalFormat == 0) || (pixelFormat == 0)) { throw new IllegalArgumentException("internalFormat and pixelFormat must be non-zero"); } return newTextureDataImpl(url, internalFormat, pixelFormat, mipmap, fileSuffix); } /** * 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. * * @param image the BufferedImage containing the texture data * @param internalFormat the OpenGL internal format of the texture * which will eventually result from the TextureData * @param pixelFormat the OpenGL pixel format of the texture * which will eventually result from the TextureData * @param 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. * @return the texture data from the image * @throws IllegalArgumentException if either internalFormat or * pixelFormat was 0 */ public static TextureData newTextureData(BufferedImage image, int internalFormat, int pixelFormat, boolean mipmap) throws IllegalArgumentException { if ((internalFormat == 0) || (pixelFormat == 0)) { throw new IllegalArgumentException("internalFormat and pixelFormat must be non-zero"); } return newTextureDataImpl(image, internalFormat, pixelFormat, mipmap); } //---------------------------------------------------------------------- // methods that *do* require a current context // /** * Creates an OpenGL texture object from the specified TextureData * using the current OpenGL context. Does not automatically generate * mipmaps for the resulting texture. * * @param data the texture data to turn into an OpenGL texture * @throws GLException if no OpenGL context is current or if an * OpenGL error occurred * @throws IllegalArgumentException if the passed TextureData was null */ public static Texture newTexture(TextureData data) throws GLException, IllegalArgumentException { if (data == null) { throw new IllegalArgumentException("Null TextureData"); } return new Texture(data); } /** * Creates an OpenGL texture object from the specified file using * the current OpenGL context. Does not automatically generate * mipmaps for the resulting texture. * * @param file the file from which to read the texture data * @param 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 * @throws GLException if no OpenGL context is current or if an * OpenGL error occurred */ public static Texture newTexture(File file, boolean mipmap) throws IOException, GLException { TextureData data = newTextureData(file, mipmap, getFileSuffix(file)); Texture texture = newTexture(data); data.flush(); return texture; } /** * Creates an OpenGL texture object from the specified stream using * the current OpenGL context. Does not automatically generate * mipmaps for the resulting texture. * * @param stream the stream from which to read the texture data * @param 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. * @param 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 * @throws GLException if no OpenGL context is current or if an * OpenGL error occurred */ public static Texture newTexture(InputStream stream, boolean mipmap, String fileSuffix) throws IOException, GLException { TextureData data = newTextureData(stream, mipmap, fileSuffix); Texture texture = newTexture(data); data.flush(); return texture; } /** * Creates an OpenGL texture object from the specified URL using the * current OpenGL context. Does not automatically generate mipmaps * for the resulting texture. * * @param url the URL from which to read the texture data * @param 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. * @param 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 * @throws GLException if no OpenGL context is current or if an * OpenGL error occurred */ public static Texture newTexture(URL url, boolean mipmap, String fileSuffix) throws IOException, GLException { TextureData data = newTextureData(url, mipmap, fileSuffix); Texture texture = newTexture(data); data.flush(); return texture; } /** * Creates an OpenGL texture object from the specified BufferedImage * using the current OpenGL context. * * @param image the BufferedImage from which to read the texture data * @param 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 */ public static Texture newTexture(BufferedImage image, boolean mipmap) throws GLException { TextureData data = newTextureData(image, mipmap); Texture texture = newTexture(data); data.flush(); return texture; } /** * 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. * * @throws GLException if no OpenGL context is current or if an * OpenGL error occurred */ public static Texture newTexture(int target) throws GLException { return new Texture(target); } /** * 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
* @throws GLException if no OpenGL context was current or an
* OpenGL-related error occurred
*/
public static void write(Texture texture, File file) throws IOException, GLException {
if (texture.getTarget() != GL.GL_TEXTURE_2D) {
throw new GLException("Only GL_TEXTURE_2D textures are supported");
}
// First fetch the texture data
GL gl = GLU.getCurrentGL();
texture.bind();
int internalFormat = glGetTexLevelParameteri(GL.GL_TEXTURE_2D, 0, GL.GL_TEXTURE_INTERNAL_FORMAT);
int width = glGetTexLevelParameteri(GL.GL_TEXTURE_2D, 0, GL.GL_TEXTURE_WIDTH);
int height = glGetTexLevelParameteri(GL.GL_TEXTURE_2D, 0, GL.GL_TEXTURE_HEIGHT);
int border = glGetTexLevelParameteri(GL.GL_TEXTURE_2D, 0, GL.GL_TEXTURE_BORDER);
TextureData data = null;
if (internalFormat == GL.GL_COMPRESSED_RGB_S3TC_DXT1_EXT ||
internalFormat == GL.GL_COMPRESSED_RGBA_S3TC_DXT1_EXT ||
internalFormat == GL.GL_COMPRESSED_RGBA_S3TC_DXT3_EXT ||
internalFormat == GL.GL_COMPRESSED_RGBA_S3TC_DXT5_EXT) {
// Fetch using glGetCompressedTexImage
int size = glGetTexLevelParameteri(GL.GL_TEXTURE_2D, 0, GL.GL_TEXTURE_COMPRESSED_IMAGE_SIZE);
ByteBuffer res = ByteBuffer.allocate(size);
gl.glGetCompressedTexImage(GL.GL_TEXTURE_2D, 0, res);
data = new TextureData(internalFormat, width, height, border, internalFormat, GL.GL_UNSIGNED_BYTE,
false, true, true, res, null);
} else {
int bytesPerPixel = 0;
int fetchedFormat = 0;
switch (internalFormat) {
case GL.GL_RGB:
case GL.GL_BGR:
case GL.GL_RGB8:
bytesPerPixel = 3;
fetchedFormat = GL.GL_RGB;
break;
case GL.GL_RGBA:
case GL.GL_BGRA:
case GL.GL_ABGR_EXT:
case GL.GL_RGBA8:
bytesPerPixel = 4;
fetchedFormat = GL.GL_RGBA;
break;
default:
throw new IOException("Unsupported texture internal format 0x" + Integer.toHexString(internalFormat));
}
// Fetch using glGetTexImage
int packAlignment = glGetInteger(GL.GL_PACK_ALIGNMENT);
int packRowLength = glGetInteger(GL.GL_PACK_ROW_LENGTH);
int packSkipRows = glGetInteger(GL.GL_PACK_SKIP_ROWS);
int packSkipPixels = glGetInteger(GL.GL_PACK_SKIP_PIXELS);
int packSwapBytes = glGetInteger(GL.GL_PACK_SWAP_BYTES);
gl.glPixelStorei(GL.GL_PACK_ALIGNMENT, 1);
gl.glPixelStorei(GL.GL_PACK_ROW_LENGTH, 0);
gl.glPixelStorei(GL.GL_PACK_SKIP_ROWS, 0);
gl.glPixelStorei(GL.GL_PACK_SKIP_PIXELS, 0);
gl.glPixelStorei(GL.GL_PACK_SWAP_BYTES, 0);
ByteBuffer res = ByteBuffer.allocate((width + (2 * border)) *
(height + (2 * border)) *
bytesPerPixel);
System.err.println("Allocated buffer of size " + res.remaining() + " for fetched image (" +
((fetchedFormat == GL.GL_RGB) ? "GL_RGB" : "GL_RGBA") + ")");
gl.glGetTexImage(GL.GL_TEXTURE_2D, 0, fetchedFormat, GL.GL_UNSIGNED_BYTE, res);
gl.glPixelStorei(GL.GL_PACK_ALIGNMENT, packAlignment);
gl.glPixelStorei(GL.GL_PACK_ROW_LENGTH, packRowLength);
gl.glPixelStorei(GL.GL_PACK_SKIP_ROWS, packSkipRows);
gl.glPixelStorei(GL.GL_PACK_SKIP_PIXELS, packSkipPixels);
gl.glPixelStorei(GL.GL_PACK_SWAP_BYTES, packSwapBytes);
data = new TextureData(internalFormat, width, height, border, fetchedFormat, GL.GL_UNSIGNED_BYTE,
false, false, false, res, null);
System.out.println("data.getPixelFormat() = " +
((data.getPixelFormat() == GL.GL_RGB) ? "GL_RGB" : "GL_RGBA"));
}
for (Iterator iter = textureWriters.iterator(); iter.hasNext(); ) {
TextureWriter writer = (TextureWriter) iter.next();
if (writer.write(file, data)) {
return;
}
}
throw new IOException("No suitable texture writer found");
}
//----------------------------------------------------------------------
// Helper function for above TextureProviders
/**
* Returns the suffix of the given file name for identifying the
* file to the configured TextureProviders.
*
* @param file name of the file
*/
public static String getFileSuffix(File file) {
return getFileSuffix(file.getName());
}
/**
* Returns the suffix of the given file name for identifying the
* file to the configured TextureProviders.
*
* @param filename name of the file
*/
public static String getFileSuffix(String filename) {
int lastDot = filename.lastIndexOf('.');
if (lastDot < 0) {
return null;
}
return toLowerCase(filename.substring(lastDot + 1));
}
//----------------------------------------------------------------------
// Helper function which may be more generally useful
//
/** Flips the supplied BufferedImage vertically. This is often a
necessary conversion step to display a Java2D image correctly
with OpenGL and vice versa. */
public static void flipImageVertically(BufferedImage image) {
WritableRaster raster = image.getRaster();
Object scanline1 = null;
Object scanline2 = null;
for (int i = 0; i < image.getHeight() / 2; i++) {
scanline1 = raster.getDataElements(0, i, image.getWidth(), 1, scanline1);
scanline2 = raster.getDataElements(0, image.getHeight() - i - 1, image.getWidth(), 1, scanline2);
raster.setDataElements(0, i, image.getWidth(), 1, scanline2);
raster.setDataElements(0, image.getHeight() - i - 1, image.getWidth(), 1, scanline1);
}
}
//----------------------------------------------------------------------
// SPI support
//
/** Adds a TextureProvider to support reading of a new file
format. */
public static void addTextureProvider(TextureProvider provider) {
// Must always add at the front so the ImageIO provider is last,
// so we don't accidentally use it instead of a user's possibly
// more optimal provider
textureProviders.add(0, provider);
}
/** Adds a TextureWriter to support writing of a new file
format. */
public static void addTextureWriter(TextureWriter writer) {
// Must always add at the front so the ImageIO writer is last,
// so we don't accidentally use it instead of a user's possibly
// more optimal writer
textureWriters.add(0, writer);
}
//----------------------------------------------------------------------
// Internals only below this point
//
private static List/*