Bug 576334 - Image is loaded with wrong colors from 32-bit BMP

Change-Id: I91fe91c6f29f949bcac349c3cc2c5925b0d7b03e
Signed-off-by: Alexandr Miloslavskiy <alexandr.miloslavskiy@syntevo.com>
Reviewed-on: https://git.eclipse.org/r/c/platform/eclipse.platform.swt/+/185958
Tested-by: Platform Bot <platform-bot@eclipse.org>
Tested-by: Niraj Modi <niraj.modi@in.ibm.com>
Reviewed-by: Niraj Modi <niraj.modi@in.ibm.com>

Author: SyntevoAlex

bundles/org.eclipse.swt/Eclipse SWT/common/org/eclipse/swt/internal/image/WinBMPFileFormat.java

@@ -21,6 +21,12 @@
 public final class WinBMPFileFormat extends FileFormat {
 	static final int BMPFileHeaderSize = 14;
 	static final int BMPHeaderFixedSize = 40;
+
+	static final int BI_RGB       = 0;
+	static final int BI_RLE8      = 1;
+	static final int BI_RLE4      = 2;
+	static final int BI_BITFIELDS = 3;
+
 	int importantColors;
 	Point pelsPerMeter = new Point(0, 0);
 
@@ -31,10 +37,10 @@ public final class WinBMPFileFormat extends FileFormat {
  * Answer the size of the compressed data.
  */
 int compress(int comp, byte[] src, int srcOffset, int numBytes, byte[] dest, boolean last) {
-	if (comp == 1) { // BMP_RLE8_COMPRESSION
+	if (comp == BI_RLE8) {
 		return compressRLE8Data(src, srcOffset, numBytes, dest, last);
 	}
-	if (comp == 2) { // BMP_RLE4_COMPRESSION
+	if (comp == BI_RLE4) {
 		return compressRLE4Data(src, srcOffset, numBytes, dest, last);
 	}
 	SWT.error(SWT.ERROR_INVALID_IMAGE);
@@ -271,12 +277,12 @@ void convertPixelsToBGR(ImageData image, byte[] dest) {
 	}
 }
 void decompressData(byte[] src, byte[] dest, int stride, int cmp) {
-	if (cmp == 1) { // BMP_RLE8_COMPRESSION
+	if (cmp == BI_RLE8) {
 		if (decompressRLE8Data(src, src.length, stride, dest, dest.length) <= 0)
 			SWT.error(SWT.ERROR_INVALID_IMAGE);
 		return;
 	}
-	if (cmp == 2) { // BMP_RLE4_COMPRESSION
+	if (cmp == BI_RLE4) {
 		if (decompressRLE4Data(src, src.length, stride, dest, dest.length) <= 0)
 			SWT.error(SWT.ERROR_INVALID_IMAGE);
 		return;
@@ -452,7 +458,7 @@ byte[] loadData(byte[] infoHeader, int stride) {
 	int dataSize = height * stride;
 	byte[] data = new byte[dataSize];
 	int cmp = (infoHeader[16] & 0xFF) | ((infoHeader[17] & 0xFF) << 8) | ((infoHeader[18] & 0xFF) << 16) | ((infoHeader[19] & 0xFF) << 24);
-	if (cmp == 0 || cmp == 3) { // BMP_NO_COMPRESSION
+	if (cmp == BI_RGB || cmp == BI_BITFIELDS) {
 		try {
 			if (inputStream.read(data) != dataSize)
 				SWT.error(SWT.ERROR_INVALID_IMAGE);
@@ -556,7 +562,7 @@ PaletteData loadPalette(byte[] infoHeader) {
 		return paletteFromBytes(buf, numColors);
 	}
 	if (depth == 16) {
-		if (this.compression == 3) {
+		if (this.compression == BI_BITFIELDS) {
 			try {
 				return new PaletteData(inputStream.readInt(), inputStream.readInt(), inputStream.readInt());
 			} catch (IOException e) {
@@ -566,9 +572,18 @@ PaletteData loadPalette(byte[] infoHeader) {
 		return new PaletteData(0x7C00, 0x3E0, 0x1F);
 	}
 	if (depth == 24) return new PaletteData(0xFF, 0xFF00, 0xFF0000);
-	if (this.compression == 3) {
+	if (this.compression == BI_BITFIELDS) {
 		try {
-			return new PaletteData(inputStream.readInt(), inputStream.readInt(), inputStream.readInt());
+			/*
+			 * ImageData is expected to be in big-endian format when
+			 * (bpp != 16); see 'ImageData.getByteOrder()'. At the same
+			 * time, 'inputStream' is a 'LEDataInputStream', that is,
+			 * low-endian. Therefore, masks need to be converted.
+			 */
+			final int maskR = Integer.reverseBytes(inputStream.readInt());
+			final int maskG = Integer.reverseBytes(inputStream.readInt());
+			final int maskB = Integer.reverseBytes(inputStream.readInt());
+			return new PaletteData(maskR, maskG, maskB);
 		} catch (IOException e) {
 			SWT.error(SWT.ERROR_IO, e);
 		}

tests/org.eclipse.swt.tests/ManualTests/org/eclipse/swt/tests/manual/Bug576334_32bpp_BMP_Colors.java

@@ -0,0 +1,47 @@
+/*******************************************************************************
+ * Copyright (c) 2021 Syntevo and others.
+ *
+ * This program and the accompanying materials
+ * are made available under the terms of the Eclipse Public License 2.0
+ * which accompanies this distribution, and is available at
+ * https://www.eclipse.org/legal/epl-2.0/
+ *
+ * SPDX-License-Identifier: EPL-2.0
+ *
+ * Contributors:
+ *     Syntevo - initial API and implementation
+ *******************************************************************************/
+
+package org.eclipse.swt.tests.manual;
+
+import org.eclipse.swt.graphics.*;
+import org.eclipse.swt.layout.GridLayout;
+import org.eclipse.swt.widgets.*;
+
+import java.io.InputStream;
+
+public class Bug576334_32bpp_BMP_Colors {
+	public static void main (String[] args) {
+		final Display display = new Display ();
+		final Shell shell = new Shell (display);
+		shell.setLayout (new GridLayout ());
+
+		Label hint = new Label (shell, 0);
+		hint.setText ("The image below shall be orange; not green");
+
+		InputStream imageStream = Bug576334_32bpp_BMP_Colors.class.getResourceAsStream ("/Bug576334_32bpp_BMP_Colors.bmp");
+		ImageData imageData = new ImageData (imageStream);
+		Image image = new Image (display, imageData);
+
+		Label imageLabel = new Label (shell, 0);
+		imageLabel.setImage (image);
+
+		shell.pack ();
+		shell.open ();
+		while (!shell.isDisposed ()) {
+			if (!display.readAndDispatch ())
+				display.sleep ();
+		}
+		display.dispose ();
+	}
+}