101 lines
3.2 KiB
Java
101 lines
3.2 KiB
Java
package ar.com.hjg.pngj.chunks;
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import ar.com.hjg.pngj.ImageInfo;
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import ar.com.hjg.pngj.PngReader;
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import ar.com.hjg.pngj.PngWriter;
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/**
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* Chunk copy policy to apply when copyng from a {@link PngReader} to a
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* {@link PngWriter}.
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* <p>
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* The constants are bit-masks, they can be OR-ed
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* <p>
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* Reference:
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* <a href="http://www.w3.org/TR/PNG/#14">http://www.w3.org/TR/PNG/#14</a> <br>
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*/
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public class ChunkCopyBehaviour {
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/** Don't copy anything */
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public static final int COPY_NONE = 0;
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/** copy the palette */
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public static final int COPY_PALETTE = 1;
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/** copy all 'safe to copy' chunks */
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public static final int COPY_ALL_SAFE = 1 << 2;
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/**
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* copy all, including palette
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*/
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public static final int COPY_ALL = 1 << 3; // includes palette!
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/**
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* Copy PHYS chunk (physical resolution)
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*/
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public static final int COPY_PHYS = 1 << 4; // dpi
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/**
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* Copy al textual chunks.
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*/
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public static final int COPY_TEXTUAL = 1 << 5; // all textual types
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/**
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* Copy TRNS chunk
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*/
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public static final int COPY_TRANSPARENCY = 1 << 6; //
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/**
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* Copy unknown chunks (unknown by our factory)
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*/
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public static final int COPY_UNKNOWN = 1 << 7; // all unknown (by the factory!)
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/**
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* Copy almost all: excepts only HIST (histogram) TIME and TEXTUAL chunks
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*/
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public static final int COPY_ALMOSTALL = 1 << 8;
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private static boolean maskMatch(int v, int mask) {
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return (v & mask) != 0;
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}
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/**
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* Creates a predicate equivalent to the copy mask
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* <p>
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* Given a copy mask (see static fields) and the ImageInfo of the target
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* PNG, returns a predicate that tells if a
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* chunk should be copied.
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* <p>
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* This is a handy helper method, you can also create and set your own
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* predicate
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*/
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public static ChunkPredicate createPredicate(final int copyFromMask, final ImageInfo imgInfo) {
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return new ChunkPredicate() {
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public boolean match(PngChunk chunk) {
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if (chunk.crit) {
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if (chunk.id.equals(ChunkHelper.PLTE)) {
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if (imgInfo.indexed && maskMatch(copyFromMask, ChunkCopyBehaviour.COPY_PALETTE))
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return true;
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if (!imgInfo.greyscale && maskMatch(copyFromMask, ChunkCopyBehaviour.COPY_ALL))
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return true;
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}
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} else { // ancillary
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boolean text = (chunk instanceof PngChunkTextVar);
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boolean safe = chunk.safe;
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// notice that these if are not exclusive
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if (maskMatch(copyFromMask, ChunkCopyBehaviour.COPY_ALL))
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return true;
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if (safe && maskMatch(copyFromMask, ChunkCopyBehaviour.COPY_ALL_SAFE))
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return true;
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if (chunk.id.equals(ChunkHelper.tRNS) && maskMatch(copyFromMask, ChunkCopyBehaviour.COPY_TRANSPARENCY))
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return true;
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if (chunk.id.equals(ChunkHelper.pHYs) && maskMatch(copyFromMask, ChunkCopyBehaviour.COPY_PHYS))
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return true;
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if (text && maskMatch(copyFromMask, ChunkCopyBehaviour.COPY_TEXTUAL))
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return true;
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if (maskMatch(copyFromMask, ChunkCopyBehaviour.COPY_ALMOSTALL) && !(ChunkHelper.isUnknown(chunk) || text || chunk.id.equals(ChunkHelper.hIST) || chunk.id.equals(ChunkHelper.tIME)))
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return true;
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if (maskMatch(copyFromMask, ChunkCopyBehaviour.COPY_UNKNOWN) && ChunkHelper.isUnknown(chunk))
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return true;
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}
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return false;
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}
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};
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}
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}
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