Add minimal metadata + minor clean-up

imageio/imageio-dds/src/main/java/com/twelvemonkeys/imageio/plugins/dds/DDS.java

@@ -30,10 +30,12 @@
 
 package com.twelvemonkeys.imageio.plugins.dds;
 
+@SuppressWarnings("unused")
 interface DDS {
     byte[] MAGIC = new byte[]{'D', 'D', 'S', ' '};
     int HEADER_SIZE = 124;
 
+    // Header Flags
     int FLAG_CAPS = 0x1;              // Required in every .dds file.
     int FLAG_HEIGHT = 0x2;            // Required in every .dds file.
     int FLAG_WIDTH = 0x4;             // Required in every .dds file.
@@ -42,4 +44,8 @@ interface DDS {
     int FLAG_MIPMAPCOUNT = 0x20000;   // Required in a mipmapped texture.
     int FLAG_LINEARSIZE = 0x80000;    // Required when pitch is provided for a compressed texture.
     int FLAG_DEPTH = 0x800000;        // Required in a depth texture.
+
+    // Pixel Format Flags
+    int PIXEL_FORMAT_FLAG_FOURCC = 0x04;
+    int PIXEL_FORMAT_FLAG_RGB = 0x40;
 }

imageio/imageio-dds/src/main/java/com/twelvemonkeys/imageio/plugins/dds/DDSHeader.java

@@ -53,6 +53,7 @@ final class DDSHeader {
     private int blueMask;
     private int alphaMask;
 
+    @SuppressWarnings("unused")
     static DDSHeader read(final ImageInputStream imageInput) throws IOException {
         DDSHeader header = new DDSHeader();
 

imageio/imageio-dds/src/main/java/com/twelvemonkeys/imageio/plugins/dds/DDSImageReader.java

@@ -38,6 +38,7 @@ import com.twelvemonkeys.imageio.util.ImageTypeSpecifiers;
 import javax.imageio.ImageIO;
 import javax.imageio.ImageReadParam;
 import javax.imageio.ImageTypeSpecifier;
+import javax.imageio.metadata.IIOMetadata;
 import javax.imageio.spi.ImageReaderSpi;
 
 import java.awt.*;
@@ -90,6 +91,7 @@ public final class DDSImageReader extends ImageReaderBase {
         checkBounds(imageIndex);
         readHeader();
 
+        // TODO: Implement for the specific formats...
         return ImageTypeSpecifiers.createFromBufferedImageType(BufferedImage.TYPE_INT_ARGB);
     }
 
@@ -141,6 +143,13 @@ public final class DDSImageReader extends ImageReaderBase {
         return destination;
     }
 
+    @Override
+    public IIOMetadata getImageMetadata(int imageIndex) throws IOException {
+        ImageTypeSpecifier imageType = getRawImageType(imageIndex);
+
+        return new DDSMetadata(imageType, header);
+    }
+
     private void readHeader() throws IOException {
         if (header == null) {
             imageInput.setByteOrder(ByteOrder.LITTLE_ENDIAN);

imageio/imageio-dds/src/main/java/com/twelvemonkeys/imageio/plugins/dds/DDSImageReaderSpi.java

@@ -65,7 +65,7 @@ public final class DDSImageReaderSpi extends ImageReaderSpiBase {
     }
 
     @Override
-    public ImageReader createReaderInstance(Object extension) throws IOException {
+    public ImageReader createReaderInstance(Object extension) {
         return new DDSImageReader(this);
     }
 

imageio/imageio-dds/src/main/java/com/twelvemonkeys/imageio/plugins/dds/DDSMetadata.java

@@ -0,0 +1,58 @@
+/*
+ * Copyright (c) 2024, Harald Kuhr
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * * Redistributions of source code must retain the above copyright notice, this
+ *   list of conditions and the following disclaimer.
+ *
+ * * Redistributions in binary form must reproduce the above copyright notice,
+ *   this list of conditions and the following disclaimer in the documentation
+ *   and/or other materials provided with the distribution.
+ *
+ * * Neither the name of the copyright holder nor the names of its
+ *   contributors may be used to endorse or promote products derived from
+ *   this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+ * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
+ * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+ * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+package com.twelvemonkeys.imageio.plugins.dds;
+
+import javax.imageio.ImageTypeSpecifier;
+
+import com.twelvemonkeys.imageio.StandardImageMetadataSupport;
+
+final class DDSMetadata extends StandardImageMetadataSupport {
+    DDSMetadata(ImageTypeSpecifier type, DDSHeader header) {
+        super(builder(type)
+                      .withCompressionTypeName(compressionName(header))
+                      .withFormatVersion("1.0")
+        );
+    }
+
+    private static String compressionName(DDSHeader header) {
+        // If the fourCC is valid, compression is one of the DXTn versions, otherwise None
+        int flags = header.getPixelFormatFlags();
+
+        if ((flags & DDS.PIXEL_FORMAT_FLAG_FOURCC) != 0) {
+            // DXTn
+            DDSType type = DDSType.valueOf(header.getFourCC());
+
+            return type.name();
+        }
+
+        return "None";
+    }
+}

imageio/imageio-dds/src/main/java/com/twelvemonkeys/imageio/plugins/dds/DDSReader.java

@@ -134,11 +134,12 @@ final class DDSReader {
     private DDSType getType() throws IIOException {
         int flags = header.getPixelFormatFlags();
 
-        if ((flags & 0x04) != 0) {
+        if ((flags & DDS.PIXEL_FORMAT_FLAG_FOURCC) != 0) {
             // DXT
             int type = header.getFourCC();
             return DDSType.valueOf(type);
-        } else if ((flags & 0x40) != 0) {
+
+        } else if ((flags & DDS.PIXEL_FORMAT_FLAG_RGB) != 0) {
             // RGB
             int bitCount = header.getBitCount();
             int redMask = header.getRedMask();
@@ -240,7 +241,7 @@ final class DDSReader {
                     int t1 = (buffer[index] & 0x0C) >> 2;
                     int t2 = (buffer[index] & 0x30) >> 4;
                     int t3 = (buffer[index++] & 0xC0) >> 6;
-                    pixels[4 * width * i + 4 * j + width * k + 0] = getDXTColor(c0, c1, 0xFF, t0);
+                    pixels[4 * width * i + 4 * j + width * k    ] = getDXTColor(c0, c1, 0xFF, t0);
                     if (4 * j + 1 >= width) continue;
                     pixels[4 * width * i + 4 * j + width * k + 1] = getDXTColor(c0, c1, 0xFF, t1);
                     if (4 * j + 2 >= width) continue;
@@ -270,7 +271,7 @@ final class DDSReader {
                     int a0 = (buffer[index++] & 0xFF);
                     int a1 = (buffer[index++] & 0xFF);
                     // 4bit alpha to 8bit alpha
-                    alphaTable[4 * k + 0] = 17 * ((a0 & 0xF0) >> 4);
+                    alphaTable[4 * k    ] = 17 * ((a0 & 0xF0) >> 4);
                     alphaTable[4 * k + 1] = 17 * (a0 & 0x0F);
                     alphaTable[4 * k + 2] = 17 * ((a1 & 0xF0) >> 4);
                     alphaTable[4 * k + 3] = 17 * (a1 & 0x0F);
@@ -285,7 +286,7 @@ final class DDSReader {
                     int t1 = (buffer[index] & 0x0C) >> 2;
                     int t2 = (buffer[index] & 0x30) >> 4;
                     int t3 = (buffer[index++] & 0xC0) >> 6;
-                    pixels[4 * width * i + 4 * j + width * k + 0] = getDXTColor(c0, c1, alphaTable[4 * k + 0], t0);
+                    pixels[4 * width * i + 4 * j + width * k    ] = getDXTColor(c0, c1, alphaTable[4 * k    ], t0);
                     if (4 * j + 1 >= width) continue;
                     pixels[4 * width * i + 4 * j + width * k + 1] = getDXTColor(c0, c1, alphaTable[4 * k + 1], t1);
                     if (4 * j + 2 >= width) continue;
@@ -343,7 +344,7 @@ final class DDSReader {
                     int t1 = (buffer[index] & 0x0C) >> 2;
                     int t2 = (buffer[index] & 0x30) >> 4;
                     int t3 = (buffer[index++] & 0xC0) >> 6;
-                    pixels[4 * width * i + 4 * j + width * k + 0] = getDXTColor(c0, c1, getDXT5Alpha(a0, a1, alphaTable[4 * k + 0]), t0);
+                    pixels[4 * width * i + 4 * j + width * k    ] = getDXTColor(c0, c1, getDXT5Alpha(a0, a1, alphaTable[4 * k    ]), t0);
                     if (4 * j + 1 >= width) continue;
                     pixels[4 * width * i + 4 * j + width * k + 1] = getDXTColor(c0, c1, getDXT5Alpha(a0, a1, alphaTable[4 * k + 1]), t1);
                     if (4 * j + 2 >= width) continue;