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 AWTTextureWriter { private static final boolean DEBUG = Debug.debug("TextureReader"); //---------------------------------------------------------------------- // 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. /** * 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();
if(!_gl.isGL2()) {
throw new GLException("Only GL2 supports fetching compressed images, GL: "+_gl);
}
GL2 gl = _gl.getGL2();
texture.bind();
int internalFormat = glGetTexLevelParameteri(gl, GL.GL_TEXTURE_2D, 0, GL2.GL_TEXTURE_INTERNAL_FORMAT);
int width = glGetTexLevelParameteri(gl, GL.GL_TEXTURE_2D, 0, GL2.GL_TEXTURE_WIDTH);
int height = glGetTexLevelParameteri(gl, GL.GL_TEXTURE_2D, 0, GL2.GL_TEXTURE_HEIGHT);
int border = glGetTexLevelParameteri(gl, GL.GL_TEXTURE_2D, 0, GL2.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.GL_TEXTURE_2D, 0, GL2.GL_TEXTURE_COMPRESSED_IMAGE_SIZE);
ByteBuffer res = ByteBuffer.allocate(size);
gl.glGetCompressedTexImage(GL.GL_TEXTURE_2D, 0, res);
data = new AWTTextureData(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 GL2.GL_BGR:
case GL.GL_RGB8:
bytesPerPixel = 3;
fetchedFormat = GL.GL_RGB;
break;
case GL.GL_RGBA:
case GL2.GL_BGRA:
case GL2.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(GL2.GL_PACK_ROW_LENGTH);
int packSkipRows = glGetInteger(GL2.GL_PACK_SKIP_ROWS);
int packSkipPixels = glGetInteger(GL2.GL_PACK_SKIP_PIXELS);
int packSwapBytes = glGetInteger(GL2.GL_PACK_SWAP_BYTES);
gl.glPixelStorei(GL.GL_PACK_ALIGNMENT, 1);
gl.glPixelStorei(GL2.GL_PACK_ROW_LENGTH, 0);
gl.glPixelStorei(GL2.GL_PACK_SKIP_ROWS, 0);
gl.glPixelStorei(GL2.GL_PACK_SKIP_PIXELS, 0);
gl.glPixelStorei(GL2.GL_PACK_SWAP_BYTES, 0);
ByteBuffer res = ByteBuffer.allocate((width + (2 * border)) *
(height + (2 * border)) *
bytesPerPixel);
if (DEBUG) {
System.out.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(GL2.GL_PACK_ROW_LENGTH, packRowLength);
gl.glPixelStorei(GL2.GL_PACK_SKIP_ROWS, packSkipRows);
gl.glPixelStorei(GL2.GL_PACK_SKIP_PIXELS, packSkipPixels);
gl.glPixelStorei(GL2.GL_PACK_SWAP_BYTES, packSwapBytes);
data = new AWTTextureData(internalFormat, width, height, border, fetchedFormat, GL.GL_UNSIGNED_BYTE,
false, false, false, res, null);
if (DEBUG) {
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");
}
//----------------------------------------------------------------------
// SPI support
//
/** 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);
}
//---------------------------------------------------------------------------
// Global disabling of texture rectangle extension
//
//----------------------------------------------------------------------
// Internals only below this point
//
private static List/*