Merge branch 'bug-623' into release/1.43.0

[simantics/platform.git] / bundles / org.eclipse.swt.win32.win32.x86_64 / src / org / eclipse / swt / internal / image / PngTrnsChunk.java

diff --git a/bundles/org.eclipse.swt.win32.win32.x86_64/src/org/eclipse/swt/internal/image/PngTrnsChunk.java b/bundles/org.eclipse.swt.win32.win32.x86_64/src/org/eclipse/swt/internal/image/PngTrnsChunk.java
new file mode 100644 (file)
index 0000000..9df7d9d
--- /dev/null
+++ b/bundles/org.eclipse.swt.win32.win32.x86_64/src/org/eclipse/swt/internal/image/PngTrnsChunk.java
@@ -0,0 +1,158 @@
+/*******************************************************************************
+ * Copyright (c) 2000, 2011 IBM Corporation 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:
+ *     IBM Corporation - initial API and implementation
+ *******************************************************************************/
+package org.eclipse.swt.internal.image;
+
+
+import org.eclipse.swt.*;
+import org.eclipse.swt.graphics.*;
+
+public class PngTrnsChunk extends PngChunk {
+       static final int TRANSPARENCY_TYPE_PIXEL = 0;
+       static final int TRANSPARENCY_TYPE_ALPHAS = 1;
+       static final int RGB_DATA_LENGTH = 6;
+
+PngTrnsChunk(RGB rgb) {
+       super(RGB_DATA_LENGTH);
+       setType(TYPE_tRNS);
+       setInt16(DATA_OFFSET, rgb.red);
+       setInt16(DATA_OFFSET + 2, rgb.green);
+       setInt16(DATA_OFFSET + 4, rgb.blue);
+       setCRC(computeCRC());
+}
+
+PngTrnsChunk(byte[] reference){
+       super(reference);
+}
+
+@Override
+int getChunkType() {
+       return CHUNK_tRNS;
+}
+
+void validateLength(PngIhdrChunk header, PngPlteChunk paletteChunk) {
+       boolean valid;
+       switch (header.getColorType()) {
+               case PngIhdrChunk.COLOR_TYPE_RGB:
+                       // Three 2-byte values (RGB)
+                       valid = getLength() == 6;
+                       break;
+               case PngIhdrChunk.COLOR_TYPE_PALETTE:
+                       // Three 2-byte values (RGB)
+                       valid = getLength() <= paletteChunk.getLength();
+                       break;
+               case PngIhdrChunk.COLOR_TYPE_GRAYSCALE:
+                       // One 2-byte value
+                       valid = getLength() == 2;
+                       break;
+               // Cannot use both Alpha and tRNS
+               case PngIhdrChunk.COLOR_TYPE_RGB_WITH_ALPHA:
+               case PngIhdrChunk.COLOR_TYPE_GRAYSCALE_WITH_ALPHA:
+               default:
+                       valid = false;
+       }
+       if (!valid) {
+               SWT.error(SWT.ERROR_INVALID_IMAGE);
+       }
+}
+
+/**
+ * Answer whether the chunk is a valid tRNS chunk.
+ */
+void validate(PngFileReadState readState, PngIhdrChunk headerChunk, PngPlteChunk paletteChunk) {
+       if (!readState.readIHDR
+               || (headerChunk.getMustHavePalette() && !readState.readPLTE)
+               || readState.readIDAT
+               || readState.readIEND)
+       {
+               SWT.error(SWT.ERROR_INVALID_IMAGE);
+       } else {
+               readState.readTRNS = true;
+       }
+
+       validateLength(headerChunk, paletteChunk);
+
+       super.validate(readState, headerChunk);
+}
+
+
+int getTransparencyType(PngIhdrChunk header) {
+       if (header.getColorType() == PngIhdrChunk.COLOR_TYPE_PALETTE) {
+               return TRANSPARENCY_TYPE_ALPHAS;
+       }
+       return TRANSPARENCY_TYPE_PIXEL;
+}
+
+/**
+ * Answer the transparent pixel RGB value.
+ * This is not valid for palette color types.
+ * This is not valid for alpha color types.
+ * This will convert a grayscale value into
+ * a palette index.
+ * It will compress a 6 byte RGB into a 3 byte
+ * RGB.
+ */
+int getSwtTransparentPixel(PngIhdrChunk header) {
+       switch (header.getColorType()) {
+               case PngIhdrChunk.COLOR_TYPE_GRAYSCALE:
+                       int gray = ((reference[DATA_OFFSET] & 0xFF) << 8)
+                               + (reference[DATA_OFFSET + 1] & 0xFF);
+                       if (header.getBitDepth() > 8) {
+                               return PNGFileFormat.compress16BitDepthTo8BitDepth(gray);
+                       }
+                       return gray & 0xFF;
+               case PngIhdrChunk.COLOR_TYPE_RGB:
+                       int red = ((reference[DATA_OFFSET] & 0xFF) << 8)
+                               | (reference[DATA_OFFSET + 1] & 0xFF);
+                       int green = ((reference[DATA_OFFSET + 2] & 0xFF) << 8)
+                               | (reference[DATA_OFFSET + 3] & 0xFF);
+                       int blue = ((reference[DATA_OFFSET + 4] & 0xFF) << 8)
+                               | (reference[DATA_OFFSET + 5] & 0xFF);
+                       if (header.getBitDepth() > 8) {
+                               red = PNGFileFormat.compress16BitDepthTo8BitDepth(red);
+                               green = PNGFileFormat.compress16BitDepthTo8BitDepth(green);
+                               blue = PNGFileFormat.compress16BitDepthTo8BitDepth(blue);
+                       }
+                       return (red << 16) | (green << 8) | blue;
+               default:
+                       SWT.error(SWT.ERROR_INVALID_IMAGE);
+                       return -1;
+       }
+}
+
+/**
+ * Answer an array of Alpha values that correspond to the
+ * colors in the palette.
+ * This is only valid for the COLOR_TYPE_PALETTE color type.
+ */
+byte[] getAlphaValues(PngIhdrChunk header, PngPlteChunk paletteChunk) {
+       if (header.getColorType() != PngIhdrChunk.COLOR_TYPE_PALETTE) {
+               SWT.error(SWT.ERROR_INVALID_IMAGE);
+       }
+       byte[] alphas = new byte[paletteChunk.getPaletteSize()];
+       int dataLength = getLength();
+       int i = 0;
+       for (i = 0; i < dataLength; i++) {
+               alphas[i] = reference[DATA_OFFSET + i];
+       }
+       /**
+        * Any palette entries which do not have a corresponding
+        * alpha value in the tRNS chunk are spec'd to have an
+        * alpha of 255.
+        */
+       for (int j = i; j < alphas.length; j++) {
+               alphas[j] = (byte) 255;
+       }
+       return alphas;
+}
+}