diff options
Diffstat (limited to 'src/jogl/classes/jogamp/opengl/util/pngj/PngHelper.java')
| -rw-r--r-- | src/jogl/classes/jogamp/opengl/util/pngj/PngHelper.java | 213 |
1 files changed, 213 insertions, 0 deletions
diff --git a/src/jogl/classes/jogamp/opengl/util/pngj/PngHelper.java b/src/jogl/classes/jogamp/opengl/util/pngj/PngHelper.java new file mode 100644 index 000000000..1016b1b64 --- /dev/null +++ b/src/jogl/classes/jogamp/opengl/util/pngj/PngHelper.java @@ -0,0 +1,213 @@ +package jogamp.opengl.util.pngj;
+
+import java.io.IOException;
+import java.io.InputStream;
+import java.io.OutputStream;
+import java.nio.charset.Charset;
+import java.util.HashSet;
+import java.util.Set;
+import java.util.zip.CRC32;
+
+/**
+ * Some utility static methods.
+ * <p>
+ * See also <code>FileHelper</code> (if not sandboxed).
+ * <p>
+ * Client code should rarely need these methods.
+ */
+public class PngHelper {
+ /**
+ * Default charset, used internally by PNG for several things
+ */
+ public static Charset charsetLatin1 = Charset.forName("ISO-8859-1");
+ public static Charset charsetUTF8 = Charset.forName("UTF-8"); // only for some chunks
+
+ static boolean DEBUG = false;
+
+ public static int readByte(InputStream is) {
+ try {
+ return is.read();
+ } catch (IOException e) {
+ throw new PngjOutputException(e);
+ }
+ }
+
+ /**
+ * -1 if eof
+ *
+ * PNG uses "network byte order"
+ */
+ public static int readInt2(InputStream is) {
+ try {
+ int b1 = is.read();
+ int b2 = is.read();
+ if (b1 == -1 || b2 == -1)
+ return -1;
+ return (b1 << 8) + b2;
+ } catch (IOException e) {
+ throw new PngjInputException("error reading readInt2", e);
+ }
+ }
+
+ /**
+ * -1 if eof
+ */
+ public static int readInt4(InputStream is) {
+ try {
+ int b1 = is.read();
+ int b2 = is.read();
+ int b3 = is.read();
+ int b4 = is.read();
+ if (b1 == -1 || b2 == -1 || b3 == -1 || b4 == -1)
+ return -1;
+ return (b1 << 24) + (b2 << 16) + (b3 << 8) + b4;
+ } catch (IOException e) {
+ throw new PngjInputException("error reading readInt4", e);
+ }
+ }
+
+ public static int readInt1fromByte(byte[] b, int offset) {
+ return (b[offset] & 0xff);
+ }
+
+ public static int readInt2fromBytes(byte[] b, int offset) {
+ return ((b[offset] & 0xff) << 16) | ((b[offset + 1] & 0xff));
+ }
+
+ public static int readInt4fromBytes(byte[] b, int offset) {
+ return ((b[offset] & 0xff) << 24) | ((b[offset + 1] & 0xff) << 16) | ((b[offset + 2] & 0xff) << 8)
+ | (b[offset + 3] & 0xff);
+ }
+
+ public static void writeByte(OutputStream os, byte b) {
+ try {
+ os.write(b);
+ } catch (IOException e) {
+ throw new PngjOutputException(e);
+ }
+ }
+
+ public static void writeInt2(OutputStream os, int n) {
+ byte[] temp = { (byte) ((n >> 8) & 0xff), (byte) (n & 0xff) };
+ writeBytes(os, temp);
+ }
+
+ public static void writeInt4(OutputStream os, int n) {
+ byte[] temp = new byte[4];
+ writeInt4tobytes(n, temp, 0);
+ writeBytes(os, temp);
+ }
+
+ public static void writeInt2tobytes(int n, byte[] b, int offset) {
+ b[offset] = (byte) ((n >> 8) & 0xff);
+ b[offset + 1] = (byte) (n & 0xff);
+ }
+
+ public static void writeInt4tobytes(int n, byte[] b, int offset) {
+ b[offset] = (byte) ((n >> 24) & 0xff);
+ b[offset + 1] = (byte) ((n >> 16) & 0xff);
+ b[offset + 2] = (byte) ((n >> 8) & 0xff);
+ b[offset + 3] = (byte) (n & 0xff);
+ }
+
+ /**
+ * guaranteed to read exactly len bytes. throws error if it cant
+ */
+ public static void readBytes(InputStream is, byte[] b, int offset, int len) {
+ if (len == 0)
+ return;
+ try {
+ int read = 0;
+ while (read < len) {
+ int n = is.read(b, offset + read, len - read);
+ if (n < 1)
+ throw new RuntimeException("error reading bytes, " + n + " !=" + len);
+ read += n;
+ }
+ } catch (IOException e) {
+ throw new PngjInputException("error reading", e);
+ }
+ }
+
+ public static void writeBytes(OutputStream os, byte[] b) {
+ try {
+ os.write(b);
+ } catch (IOException e) {
+ throw new PngjOutputException(e);
+ }
+ }
+
+ public static void writeBytes(OutputStream os, byte[] b, int offset, int n) {
+ try {
+ os.write(b, offset, n);
+ } catch (IOException e) {
+ throw new PngjOutputException(e);
+ }
+ }
+
+ public static void logdebug(String msg) {
+ if (DEBUG)
+ System.out.println(msg);
+ }
+
+ public static Set<String> asSet(String... values) {
+ return new HashSet<String>(java.util.Arrays.asList(values));
+ }
+
+ public static Set<String> unionSets(Set<String> set1, Set<String> set2) {
+ Set<String> s = new HashSet<String>();
+ s.addAll(set1);
+ s.addAll(set2);
+ return s;
+ }
+
+ public static Set<String> unionSets(Set<String> set1, Set<String> set2, Set<String> set3) {
+ Set<String> s = new HashSet<String>();
+ s.addAll(set1);
+ s.addAll(set2);
+ s.addAll(set3);
+ return s;
+ }
+
+ private static final ThreadLocal<CRC32> crcProvider = new ThreadLocal<CRC32>() {
+ protected CRC32 initialValue() {
+ return new CRC32();
+ }
+ };
+
+ /** thread-singleton crc engine */
+ public static CRC32 getCRC() {
+ return crcProvider.get();
+ }
+
+ static final byte[] pngIdBytes = { -119, 80, 78, 71, 13, 10, 26, 10 }; // png magic
+
+ public static double resMetersToDpi(long res) {
+ return (double) res * 0.0254;
+ }
+
+ public static long resDpiToMeters(double dpi) {
+ return (long) (dpi / 0.0254 + 0.5);
+ }
+
+ public static int doubleToInt100000(double d) {
+ return (int) (d * 100000.0 + 0.5);
+ }
+
+ public static double intToDouble100000(int i) {
+ return i / 100000.0;
+ }
+
+ public static int clampTo_0_255(int i) {
+ return i > 255 ? 255 : (i < 0 ? 0 : i);
+ }
+
+ public static int clampTo_0_65535(int i) {
+ return i > 65535 ? 65535 : (i < 0 ? 0 : i);
+ }
+
+ public static int clampTo_128_127(int x) {
+ return x > 127 ? 127 : (x < -128 ? -128 : x);
+ }
+
+}
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