2003/08/10 06:03:02

[org.ibex.core.git] / src / org / xwt / PNG.java

diff --git a/src/org/xwt/PNG.java b/src/org/xwt/PNG.java
index f0d9b7e..4f5640a 100644 (file)
--- a/src/org/xwt/PNG.java
+++ b/src/org/xwt/PNG.java
@@ -21,7 +21,7 @@ import java.util.Enumeration;
 import java.util.zip.*;
 
 /** Converts an InputStream carrying a PNG image into an ARGB int[] */
-public class PNG implements ImageDecoder {
+public class PNG extends ImageDecoder {
 
     // Public Methods ///////////////////////////////////////////////////////////////////////////////
 
@@ -54,7 +54,7 @@ public class PNG implements ImageDecoder {
         // consume the header
         if ((inputStream.read() != 137) || (inputStream.read() != 80) || (inputStream.read() != 78) || (inputStream.read() != 71) ||
             (inputStream.read() != 13) || (inputStream.read() != 10) || (inputStream.read() != 26) || (inputStream.read() != 10)) {
-            System.out.println("PNG: error: input file " + name + " is not a PNG file");
+            Log.log(this, "PNG: error: input file " + name + " is not a PNG file");
             data = new int[] { };
             width = height = 0;
             return;
@@ -159,8 +159,12 @@ public class PNG implements ImageDecoder {
     /** handle transparency chunk; modifies palette */
     private void handletRNS() throws IOException {
         int chunkLen = chunkLength;
-               if (palette == null) throw new IOException("tRNS chunk encountered before pLTE");
-               int len = palette.length;
+        if (palette == null) {
+            if (Log.on) Log.log(this, "warning: tRNS chunk encountered before pLTE; ignoring alpha channel");
+            inputStream.skip(chunkLength);
+            return;
+        }
+        int len = palette.length;
         if (colorType == 3) {
             transparency = true;
 
@@ -255,9 +259,9 @@ public class PNG implements ImageDecoder {
                 } else {
                     data[i] =
                         0xFF000000 |
-                        ((palette[3 * pix[i] + 0] & 0xff) << 16) |
-                        ((palette[3 * pix[i] + 1] & 0xff) << 8) |
-                        (palette[3 * pix[i] + 2] & 0xff);
+                        ((palette[3 * (pix[i] & 0xff) + 0] & 0xff) << 16) |
+                        ((palette[3 * (pix[i] & 0xff) + 1] & 0xff) << 8) |
+                        (palette[3 * (pix[i] & 0xff) + 2] & 0xff);
                 }
             }