Support for transparency in 32bit bitmaps on color targets.

This uses the alpha blending capabilities introduced with anti-aliased fonts
to draw bitmaps with transparency information. The bmp loader is extended to read
this information (pass FORMAT_TRANSPARENT in format). The alpha information will
be used when drawing the bitmap.

git-svn-id: svn://svn.rockbox.org/rockbox/trunk@30937 a1c6a512-1295-4272-9138-f99709370657

1 files changed, 3 insertions, 0 deletions

diff --git a/firmware/export/lcd.h b/firmware/export/lcd.h
index 47ea94bca9..ad579820ad 100644
--- a/firmware/export/lcd.h
+++ b/firmware/export/lcd.h
@@ -468,6 +468,9 @@ struct bitmap {
     int format;
     unsigned char *maskdata;
 #endif
+#ifdef HAVE_LCD_COLOR
+    int alpha_offset; /* byte-offset of alpha channel in data */
+#endif
     unsigned char *data;
 };