[Swingme-svn] SF.net SVN: swingme:[2971] iOSME/src/javax/microedition/lcdui/Image.java

[<yu...@us...>]

Revision: 2971
          http://sourceforge.net/p/swingme/code/2971
Author:   yuranet
Date:     2025-12-13 13:50:49 +0000 (Sat, 13 Dec 2025)
Log Message:
-----------
fix creating image with alpha from int[]

Modified Paths:
--------------
    iOSME/src/javax/microedition/lcdui/Image.java

Modified: iOSME/src/javax/microedition/lcdui/Image.java
===================================================================
--- iOSME/src/javax/microedition/lcdui/Image.java	2025-12-13 12:22:31 UTC (rev 2970)
+++ iOSME/src/javax/microedition/lcdui/Image.java	2025-12-13 13:50:49 UTC (rev 2971)
@@ -230,7 +230,7 @@
         int size = Math.max(available, 8 * 1024);
         BufferedInputStream buffInput = new BufferedInputStream(stream, size);
 
-        //byte[] bytes = stream.readAllBytes?(); // added in java 9
+        //byte[] bytes = stream.readAllBytes(); // added in java 9
         byte[] bytes = Streams.readFullyNoClose(buffInput);
 
         return createImage(bytes, 0, bytes.length);
@@ -495,12 +495,25 @@
 
     public void setRGB(int[] rgbData, int offset, int srcScanLength, int width, int height, boolean processAlpha) {
         Graphics g = getGraphics();
+        CGContextRef context = g.getContext();
+
         int distScanLength = getIntsPerRow();
 
-        IntPtr intPtr = CoreGraphics.CGBitmapContextGetData(g.getContext()).getIntPtr();
+        int info = CoreGraphics.CGBitmapContextGetBitmapInfo(context);
+        //int order = info & CGBitmapInfo.ByteOrderMask; // CGBitmapInfo.ByteOrder32Little
+        int alpha = info & CGBitmapInfo.AlphaInfoMask; // CGImageAlphaInfo.PremultipliedFirst
+
+        IntPtr intPtr = CoreGraphics.CGBitmapContextGetData(context).getIntPtr();
         for (int y = 0; y < height; y++) {
             if (processAlpha) {
-                intPtr.copyFrom(rgbData, offset+ y * srcScanLength, y * distScanLength, width);
+                if (alpha == CGImageAlphaInfo.PremultipliedFirst || alpha == CGImageAlphaInfo.PremultipliedLast) {
+                    for (int x = 0; x < width; x++) {
+                        intPtr.setValue(y * distScanLength + x, premultiplyAlpha(rgbData[offset + y * srcScanLength + x]));
+                    }
+                }
+                else {
+                    intPtr.copyFrom(rgbData, offset + y * srcScanLength, y * distScanLength, width);
+                }
             }
             else {
                 // TODO this could be better
@@ -511,6 +524,19 @@
         }
     }
 
+    private static int premultiplyAlpha(int argb) {
+        int a = argb >>> 24;
+        if (a == 255) return argb;
+        int r = (argb >> 16) & 0xFF;
+        int g = (argb >> 8)  & 0xFF;
+        int b = argb & 0xFF;
+        // + 127 is half of 255, and is added so we do not round down the result
+        r = (r * a + 127) / 255;
+        g = (g * a + 127) / 255;
+        b = (b * a + 127) / 255;
+        return (a << 24) | (r << 16) | (g << 8) | b;
+    }
+
     public void setRGB(int x, int y, int color) {
         Graphics g = getGraphics();
         int srcScanLenght = getIntsPerRow();

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