1 files changed, 107 insertions, 0 deletions
diff --git a/src/jogl/classes/jogamp/opengl/util/pngj/ImageLines.java b/src/jogl/classes/jogamp/opengl/util/pngj/ImageLines.java
new file mode 100644
index 000000000..fb2cf5910
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+++ b/src/jogl/classes/jogamp/opengl/util/pngj/ImageLines.java
@@ -0,0 +1,107 @@
+package jogamp.opengl.util.pngj;
+
+import jogamp.opengl.util.pngj.ImageLine.SampleType;
+
+/**
+ * Wraps in a matrix a set of image rows, not necessarily contiguous - but
+ * equispaced.
+ *
+ * The fields mirrors those of {@link ImageLine}, and you can access each row as
+ * a ImageLine backed by the matrix row, see
+ * {@link #getImageLineAtMatrixRow(int)}
+ */
+public class ImageLines {
+
+	public final ImageInfo imgInfo;
+	public final int channels;
+	public final int bitDepth;
+	public final SampleType sampleType;
+	public final boolean samplesUnpacked;
+	public final int elementsPerRow;
+	public final int rowOffset;
+	public final int nRows;
+	public final int rowStep;
+	public final int[][] scanlines;
+	public final byte[][] scanlinesb;
+
+	/**
+	 * Allocates a matrix to store {@code nRows} image rows. See
+	 * {@link ImageLine} and {@link PngReader#readRowsInt()}
+	 * {@link PngReader#readRowsByte()}
+	 *
+	 * @param imgInfo
+	 * @param stype
+	 * @param unpackedMode
+	 * @param rowOffset
+	 * @param nRows
+	 * @param rowStep
+	 */
+	public ImageLines(ImageInfo imgInfo, SampleType stype, boolean unpackedMode, int rowOffset, int nRows, int rowStep) {
+		this.imgInfo = imgInfo;
+		channels = imgInfo.channels;
+		bitDepth = imgInfo.bitDepth;
+		this.sampleType = stype;
+		this.samplesUnpacked = unpackedMode || !imgInfo.packed;
+		elementsPerRow = unpackedMode ? imgInfo.samplesPerRow : imgInfo.samplesPerRowPacked;
+		this.rowOffset = rowOffset;
+		this.nRows = nRows;
+		this.rowStep = rowStep;
+		if (stype == SampleType.INT) {
+			scanlines = new int[nRows][elementsPerRow];
+			scanlinesb = null;
+		} else if (stype == SampleType.BYTE) {
+			scanlinesb = new byte[nRows][elementsPerRow];
+			scanlines = null;
+		} else
+			throw new PngjExceptionInternal("bad ImageLine initialization");
+	}
+
+	/**
+	 * Warning: this always returns a valid matrix row (clamping on 0 : nrows-1,
+	 * and rounding down) Eg: rowOffset=4,rowStep=2 imageRowToMatrixRow(17)
+	 * returns 6 , imageRowToMatrixRow(1) returns 0
+	 */
+	public int imageRowToMatrixRow(int imrow) {
+		int r = (imrow - rowOffset) / rowStep;
+		return r < 0 ? 0 : (r < nRows ? r : nRows - 1);
+	}
+
+	/**
+	 * Same as imageRowToMatrixRow, but returns negative if invalid
+	 */
+	public int imageRowToMatrixRowStrict(int imrow) {
+		imrow -= rowOffset;
+		int mrow = imrow >= 0 && imrow % rowStep == 0 ? imrow / rowStep : -1;
+		return mrow < nRows ? mrow : -1;
+	}
+
+	/**
+	 * Converts from matrix row number (0 : nRows-1) to image row number
+	 *
+	 * @param mrow
+	 *            Matrix row number
+	 * @return Image row number. Invalid only if mrow is invalid
+	 */
+	public int matrixRowToImageRow(int mrow) {
+		return mrow * rowStep + rowOffset;
+	}
+
+	/**
+	 * Returns a ImageLine is backed by the matrix, no allocation done
+	 *
+	 * @param mrow
+	 *            Matrix row, from 0 to nRows This is not necessarily the image
+	 *            row, see {@link #imageRowToMatrixRow(int)} and
+	 *            {@link #matrixRowToImageRow(int)}
+	 * @return A new ImageLine, backed by the matrix, with the correct ('real')
+	 *         rownumber
+	 */
+	public ImageLine getImageLineAtMatrixRow(int mrow) {
+		if (mrow < 0 || mrow > nRows)
+			throw new PngjException("Bad row " + mrow + ". Should be positive and less than " + nRows);
+		ImageLine imline = sampleType == SampleType.INT ? new ImageLine(imgInfo, sampleType, samplesUnpacked,
+				scanlines[mrow], null) : new ImageLine(imgInfo, sampleType, samplesUnpacked, null, scanlinesb[mrow]);
+		imline.setRown(matrixRowToImageRow(mrow));
+		return imline;
+	}
+}