Add tests for local color tables in gif parser.

third_party/gif_decoder/src/androidTest/java/com/bumptech/glide/gifdecoder/GifHeaderParserTest.java

@@ -13,6 +13,7 @@ import java.nio.ByteOrder;
 import static org.junit.Assert.assertEquals;
 import static org.junit.Assert.assertFalse;
 import static org.junit.Assert.assertNotNull;
+import static org.junit.Assert.assertNull;
 
 /**
  * Tests for {@link com.bumptech.glide.gifdecoder.GifHeaderParser}.
@@ -62,10 +63,58 @@ public class GifHeaderParserTest {
 
     @Test
     public void testCanReadImageDescriptorWithoutGraphicalExtension() {
-        ByteBuffer buffer = ByteBuffer.allocate(GifBytesTestUtil.HEADER_LENGTH
-                + GifBytesTestUtil.IMAGE_DESCRIPTOR_LENGTH + 4).order(ByteOrder.LITTLE_ENDIAN);
+        final int lzwMinCodeSize = 2;
+        ByteBuffer buffer = ByteBuffer.allocate(
+                GifBytesTestUtil.HEADER_LENGTH
+                + GifBytesTestUtil.IMAGE_DESCRIPTOR_LENGTH
+                + GifBytesTestUtil.getImageDataSize(lzwMinCodeSize)
+        ).order(ByteOrder.LITTLE_ENDIAN);
         GifBytesTestUtil.writeHeaderAndLsd(buffer, 1, 1, false, 0);
-        GifBytesTestUtil.writeImageDescriptor(buffer, 0, 0, 1, 1);
+        GifBytesTestUtil.writeImageDescriptor(buffer, 0, 0, 1, 1, false /*hasLct*/, 0);
+        GifBytesTestUtil.writeFakeImageData(buffer, lzwMinCodeSize);
+
+        parser.setData(buffer.array());
+        GifHeader header = parser.parseHeader();
+        assertEquals(1, header.width);
+        assertEquals(1, header.height);
+        assertEquals(1, header.frameCount);
+        assertNotNull(header.frames.get(0));
+    }
+
+    @Test
+    public void testSetsFrameLocalColorTableToNullIfNoColorTable() {
+        final int lzwMinCodeSize = 2;
+        ByteBuffer buffer = ByteBuffer.allocate(
+                GifBytesTestUtil.HEADER_LENGTH
+                + GifBytesTestUtil.IMAGE_DESCRIPTOR_LENGTH
+                + GifBytesTestUtil.getImageDataSize(lzwMinCodeSize)
+        ).order(ByteOrder.LITTLE_ENDIAN);
+        GifBytesTestUtil.writeHeaderAndLsd(buffer, 1, 1, false, 0);
+        GifBytesTestUtil.writeImageDescriptor(buffer, 0, 0, 1, 1, false /*hasLct*/, 0);
+        GifBytesTestUtil.writeFakeImageData(buffer, lzwMinCodeSize);
+
+        parser.setData(buffer.array());
+        GifHeader header = parser.parseHeader();
+        assertEquals(1, header.width);
+        assertEquals(1, header.height);
+        assertEquals(1, header.frameCount);
+        assertNotNull(header.frames.get(0));
+        assertNull(header.frames.get(0).lct);
+    }
+
+    @Test
+    public void testSetsFrameLocalColorTableIfHasColorTable() {
+        final int lzwMinCodeSize = 2;
+        final int numColors = 4;
+        ByteBuffer buffer = ByteBuffer.allocate(
+                GifBytesTestUtil.HEADER_LENGTH
+                + GifBytesTestUtil.IMAGE_DESCRIPTOR_LENGTH
+                + GifBytesTestUtil.getImageDataSize(lzwMinCodeSize)
+                + GifBytesTestUtil.getColorTableLength(numColors)
+        ).order(ByteOrder.LITTLE_ENDIAN);
+        GifBytesTestUtil.writeHeaderAndLsd(buffer, 1, 1, false, 0);
+        GifBytesTestUtil.writeImageDescriptor(buffer, 0, 0, 1, 1, true /*hasLct*/, numColors);
+        GifBytesTestUtil.writeColorTable(buffer, numColors);
         GifBytesTestUtil.writeFakeImageData(buffer, 2);
 
         parser.setData(buffer.array());
@@ -74,6 +123,32 @@ public class GifHeaderParserTest {
         assertEquals(1, header.height);
         assertEquals(1, header.frameCount);
         assertNotNull(header.frames.get(0));
+
+        GifFrame frame = header.frames.get(0);
+        assertNotNull(frame.lct);
+    }
+
+    @Test
+    public void testCanParseMultipleFrames() {
+        final int lzwMinCodeSize = 2;
+        final int expectedFrames = 3;
+
+        final int frameSize = GifBytesTestUtil.IMAGE_DESCRIPTOR_LENGTH
+                + GifBytesTestUtil.getImageDataSize(lzwMinCodeSize);
+        ByteBuffer buffer = ByteBuffer.allocate(
+                GifBytesTestUtil.HEADER_LENGTH + expectedFrames * frameSize
+        ).order(ByteOrder.LITTLE_ENDIAN);
+
+        GifBytesTestUtil.writeHeaderAndLsd(buffer, 1, 1, false, 0);
+        for (int i = 0; i < expectedFrames; i++) {
+            GifBytesTestUtil.writeImageDescriptor(buffer, 0, 0, 1, 1, false /*hasLct*/, 0 /*numColors*/);
+            GifBytesTestUtil.writeFakeImageData(buffer, 2);
+        }
+
+        parser.setData(buffer.array());
+        GifHeader header = parser.parseHeader();
+        assertEquals(expectedFrames, header.frameCount);
+        assertEquals(expectedFrames, header.frames.size());
     }
 
     private InputStream openResource(String imageName) throws IOException {

third_party/gif_decoder/src/androidTest/java/com/bumptech/glide/gifdecoder/test/GifBytesTestUtil.java

@@ -11,6 +11,15 @@ public class GifBytesTestUtil {
     // Length in bytes.
     public static final int IMAGE_DESCRIPTOR_LENGTH = 10;
 
+    public static int getColorTableLength(int numColors) {
+        return 3 * numColors;
+    }
+
+    public static int getImageDataSize(int lzwMinCodeSize) {
+        // TODO: fill this out.
+        return 4;
+    }
+
     public static void writeFakeImageData(ByteBuffer out, int lzwMinCodeSize) {
         // 1 for lzwMinCodeSize, 1 for length, 1 for min content, 1 for block terminator.
         verifyRemaining(out, 4);
@@ -25,16 +34,40 @@ public class GifBytesTestUtil {
         out.put((byte) 0x00);
     }
 
+    public static void writeColorTable(ByteBuffer out, int numColors) {
+        verifyRemaining(out, getColorTableLength(numColors));
+        for (int i = 0; i < numColors; i++) {
+            out.put((byte) (0xFF0000 & i));
+            out.put((byte) (0x00FF00 & i));
+            out.put((byte) (0x0000FF & i));
+        }
+    }
+
     public static void writeImageDescriptor(ByteBuffer out, int imageLeft, int imageTop, int imageWidth,
-            int imageHeight) {
+            int imageHeight, boolean hasLct, int numColors) {
         verifyRemaining(out, IMAGE_DESCRIPTOR_LENGTH);
         verifyShortValues(imageLeft, imageTop, imageWidth, imageHeight);
 
+        final byte packed;
+        if (hasLct) {
+            int size = log2(numColors) - 1;
+            packed = (byte) (0x80 | size);
+        } else {
+            packed = 0x00;
+        }
+
         // Image separator
         out.put((byte) 0x2C);
+        out
+                .putShort((short) imageLeft)
+                .putShort((short) imageTop)
+                .putShort((short) imageWidth)
+                .putShort((short) imageHeight)
+                .put(packed);
+    }
 
-        out.putShort((short) imageLeft).putShort((short) imageTop).putShort((short) imageWidth)
-                .putShort((short) imageHeight);
+    private static int log2(int num) {
+        return (int) Math.round(Math.log(num) / Math.log(2));
     }
 
     public static void writeHeaderAndLsd(ByteBuffer out, int width, int height, boolean hasGct, int gctSize) {

third_party/gif_decoder/src/androidTest/java/com/bumptech/glide/gifdecoder/test/GifBytesTestUtilTest.java

@@ -3,6 +3,7 @@ package com.bumptech.glide.gifdecoder.test;
 import org.junit.Test;
 
 import java.nio.ByteBuffer;
+import java.util.Arrays;
 
 import static org.junit.Assert.assertArrayEquals;
 
@@ -33,15 +34,78 @@ public class GifBytesTestUtilTest {
     }
 
     @Test
-    public void testWriteImageDescriptor() {
+    public void testWriteImageDescriptorWithoutColorTable() {
         ByteBuffer buffer = ByteBuffer.allocate(GifBytesTestUtil.IMAGE_DESCRIPTOR_LENGTH);
-        GifBytesTestUtil.writeImageDescriptor(buffer, 10, 9, 8, 7);
+        GifBytesTestUtil.writeImageDescriptor(buffer, 10, 9, 8, 7, false, 0);
+
+        byte[] expected = new byte[] {
+                // Image separator.
+                0x2C,
+                // Image left.
+                0x00, 0x0A,
+                // Image right.
+                0x00, 0X09,
+                // Image width.
+                0x00, 0x08,
+                // Image height.
+                0x00, 0x07,
+                // Packed field.
+                0x00
+        };
 
-        byte[] expected = new byte[] { 0x2C, 0x00, 0x0A, 0x00, 0X09, 0x00, 0x08, 0x000, 0x07, 0x00 };
+        assertArrayEquals(expected, buffer.array());
+    }
+
+    @Test
+    public void testWriteImageDescriptorWithColorTable() {
+        ByteBuffer buffer = ByteBuffer.allocate(GifBytesTestUtil.IMAGE_DESCRIPTOR_LENGTH);
+        GifBytesTestUtil.writeImageDescriptor(buffer, 10, 9, 8, 7, true, 4);
+
+        byte packedField =
+                // Set LCT flag
+                (byte) 0x80
+                // Size of color table (2^(N + 1) == 4)
+                | 0x01;
+
+        byte[] expected = new byte[] {
+                // Image separator.
+                0x2C,
+                // Image left.
+                0x00, 0x0A,
+                // Image right.
+                0x00, 0X09,
+                // Image width.
+                0x00, 0x08,
+                // Image height.
+                0x00, 0x07,
+                packedField
+        };
 
         assertArrayEquals(expected, buffer.array());
     }
 
+    @Test
+    public void testWriteColorTable() {
+        final int numColors = 4;
+        ByteBuffer buffer = ByteBuffer.allocate(GifBytesTestUtil.getColorTableLength(numColors));
+        GifBytesTestUtil.writeColorTable(buffer, numColors);
+
+        byte[] expected = new byte[] {
+                // First color.
+                0x00, 0x00, 0x00,
+                // Second color.
+                0x00, 0x00, 0x01,
+                // Third color.
+                0x00, 0x00, 0x02,
+                // Fourth color.
+                0x00, 0x00, 0x03,
+        };
+
+
+        assertArrayEquals("expected=" + Arrays.toString(expected) + " received=" + Arrays.toString(buffer.array()),
+                expected, buffer.array());
+    }
+
     @Test
     public void testWriteFakeImageData() {
         ByteBuffer buffer = ByteBuffer.allocate(4);