diff options
| -rwxr-xr-x | src/classes/com/sun/opengl/util/Screenshot.java | 136 |
1 files changed, 124 insertions, 12 deletions
diff --git a/src/classes/com/sun/opengl/util/Screenshot.java b/src/classes/com/sun/opengl/util/Screenshot.java index dfbc44b02..d91e7f8f5 100755 --- a/src/classes/com/sun/opengl/util/Screenshot.java +++ b/src/classes/com/sun/opengl/util/Screenshot.java @@ -57,7 +57,9 @@ public class Screenshot { * file. Requires the OpenGL context for the desired drawable to be * current. This is the fastest mechanism for taking a screenshot of * an application. Contributed by Carsten Weisse of Bytonic Software - * (http://bytonic.de/). + * (http://bytonic.de/). <p> + * + * No alpha channel is written with this variant. * * @param file the file to write containing the screenshot * @param width the width of the current drawable @@ -71,9 +73,41 @@ public class Screenshot { public static void writeToTargaFile(File file, int width, int height) throws GLException, IOException { + writeToTargaFile(file, width, height, false); + } + + /** + * Takes a fast screenshot of the current OpenGL drawable to a Targa + * file. Requires the OpenGL context for the desired drawable to be + * current. This is the fastest mechanism for taking a screenshot of + * an application. Contributed by Carsten Weisse of Bytonic Software + * (http://bytonic.de/). + * + * @param file the file to write containing the screenshot + * @param width the width of the current drawable + * @param height the height of the current drawable + * @param alpha whether the alpha channel should be saved. If true, + * requires GL_EXT_abgr extension to be present. + * + * @throws GLException if an OpenGL context was not current or + * another OpenGL-related error occurred + * @throws IOException if an I/O error occurred while writing the + * file + */ + public static void writeToTargaFile(File file, + int width, + int height, + boolean alpha) throws GLException, IOException { RandomAccessFile out = new RandomAccessFile(file, "rw"); FileChannel ch = out.getChannel(); - int fileLength = TARGA_HEADER_SIZE + width * height * 3; + int pixelSize = (alpha ? 32 : 24); + int numChannels = (alpha ? 4 : 3); + int readbackType = (alpha ? GL.GL_ABGR_EXT : GL.GL_BGR); + if (alpha) { + checkExtABGR(); + } + + int fileLength = TARGA_HEADER_SIZE + width * height * numChannels; out.setLength(fileLength); MappedByteBuffer image = ch.map(FileChannel.MapMode.READ_WRITE, 0, fileLength); @@ -84,7 +118,7 @@ public class Screenshot { image.put(13, (byte) (width >> 8)); // width image.put(14, (byte) (height & 0xFF)); // height image.put(15, (byte) (height >> 8)); // height - image.put(16, (byte) 24); // pixel size + image.put(16, (byte) pixelSize); // pixel size // go to image data position image.position(TARGA_HEADER_SIZE); @@ -98,7 +132,7 @@ public class Screenshot { psm.save(gl); // read the BGR values into the image buffer - gl.glReadPixels(0, 0, width, height, GL.GL_BGR, + gl.glReadPixels(0, 0, width, height, readbackType, GL.GL_UNSIGNED_BYTE, bgr); // Restore pixel storage modes @@ -114,7 +148,9 @@ public class Screenshot { * drawable to be current. Note that the scanlines of the resulting * image are flipped vertically in order to correctly match the * OpenGL contents, which takes time and is therefore not as fast as - * the Targa screenshot function. + * the Targa screenshot function. <P> + * + * No alpha channel is read back with this variant. * * @param width the width of the current drawable * @param height the height of the current drawable @@ -124,8 +160,37 @@ public class Screenshot { */ public static BufferedImage readToBufferedImage(int width, int height) throws GLException { + return readToBufferedImage(width, height, false); + } + + /** + * Takes a screenshot of the current OpenGL drawable to a + * BufferedImage. Requires the OpenGL context for the desired + * drawable to be current. Note that the scanlines of the resulting + * image are flipped vertically in order to correctly match the + * OpenGL contents, which takes time and is therefore not as fast as + * the Targa screenshot function. + * + * @param width the width of the current drawable + * @param height the height of the current drawable + * @param alpha whether the alpha channel should be read back. If + * true, requires GL_EXT_abgr extension to be present. + * + * @throws GLException if an OpenGL context was not current or + * another OpenGL-related error occurred + */ + public static BufferedImage readToBufferedImage(int width, + int height, + boolean alpha) throws GLException { + int bufImgType = (alpha ? BufferedImage.TYPE_4BYTE_ABGR : BufferedImage.TYPE_3BYTE_BGR); + int readbackType = (alpha ? GL.GL_ABGR_EXT : GL.GL_BGR); + + if (alpha) { + checkExtABGR(); + } + // Allocate necessary storage - BufferedImage image = new BufferedImage(width, height, BufferedImage.TYPE_3BYTE_BGR); + BufferedImage image = new BufferedImage(width, height, bufImgType); GL gl = GLU.getCurrentGL(); @@ -134,7 +199,7 @@ public class Screenshot { psm.save(gl); // read the BGR values into the image - gl.glReadPixels(0, 0, width, height, GL.GL_BGR, + gl.glReadPixels(0, 0, width, height, readbackType, GL.GL_UNSIGNED_BYTE, ByteBuffer.wrap(((DataBufferByte) image.getRaster().getDataBuffer()).getData())); @@ -153,7 +218,9 @@ public class Screenshot { * not the fastest mechanism for taking a screenshot but may be more * convenient than others for getting images for consumption by * other packages. The file format is inferred from the suffix of - * the given file. + * the given file. <P> + * + * No alpha channel is saved with this variant. * * @throws GLException if an OpenGL context was not current or * another OpenGL-related error occurred @@ -165,10 +232,48 @@ public class Screenshot { public static void writeToFile(File file, int width, int height) throws IOException, GLException { - BufferedImage image = readToBufferedImage(width, height); - if (!ImageIO.write(image, FileUtil.getFileSuffix(file), file)) { - throw new IOException("Unsupported file format " + - FileUtil.getFileSuffix(file)); + writeToFile(file, width, height, false); + } + + /** + * Takes a screenshot of the current OpenGL drawable to the + * specified file on disk using the ImageIO package. Requires the + * OpenGL context for the desired drawable to be current. This is + * not the fastest mechanism for taking a screenshot but may be more + * convenient than others for getting images for consumption by + * other packages. The file format is inferred from the suffix of + * the given file. <P> + * + * Note that some file formats, in particular JPEG, can not handle + * an alpha channel properly. If the "alpha" argument is specified + * as true for such a file format it will be silently ignored. + * + * @param file the file name to which to save the image + * @param file width the width of the image to read back and save + * @param file height the width of the image to read back and save + * @param alpha whether an alpha channel should be saved. If true, + * requires GL_EXT_abgr extension to be present. + * + * @throws GLException if an OpenGL context was not current or + * another OpenGL-related error occurred + * + * @throws IOException if an I/O error occurred or if the file could + * not be written to disk due to the requested file format being + * unsupported by ImageIO + */ + public static void writeToFile(File file, + int width, + int height, + boolean alpha) throws IOException, GLException { + String fileSuffix = FileUtil.getFileSuffix(file); + if (alpha && (fileSuffix.equals("jpg") || fileSuffix.equals("jpeg"))) { + // JPEGs can't deal properly with alpha channels + alpha = false; + } + + BufferedImage image = readToBufferedImage(width, height, alpha); + if (!ImageIO.write(image, fileSuffix, file)) { + throw new IOException("Unsupported file format " + fileSuffix); } } @@ -177,6 +282,13 @@ public class Screenshot { return tmp[0]; } + private static void checkExtABGR() { + GL gl = GLU.getCurrentGL(); + if (!gl.isExtensionAvailable("GL_EXT_abgr")) { + throw new IllegalArgumentException("Saving alpha channel requires GL_EXT_abgr"); + } + } + static class PixelStorageModes { int packAlignment; int packRowLength; |