PSP: fixed cursor disappearance bug in 16-bit games

The 5650 16-bit format doesn't include alpha bits and is treated as having alpha by the PSP hardware. Other formats such as 5551 don't have their alpha bit set in the cursor buffer. Instead of adding it, we just turn on the 'reverse alpha' feature for these bits. The problem was not making an exception for 5650.

1 files changed, 14 insertions, 2 deletions

diff --git a/backends/platform/psp/cursor.cpp b/backends/platform/psp/cursor.cpp
index cf879e095a..420b0398c3 100644
--- a/backends/platform/psp/cursor.cpp
+++ b/backends/platform/psp/cursor.cpp
@@ -327,8 +327,20 @@ inline void Cursor::setRendererModePalettized(bool palettized) {
 		_renderer.setAlphaReverse(false);
 		_renderer.setColorTest(false);
 	} else {			// 16 bits, no palette
+		// Color test is an easy way for the hardware to make our keycolor 
+		// transparent.
+		_renderer.setColorTest(true);	
+		
+		// Alpha blending is not strictly required, but makes the cursor look
+		// much better
 		_renderer.setAlphaBlending(true);
-		_renderer.setAlphaReverse(true); // We can't change all alpha values, so just reverse
-		_renderer.setColorTest(true);	// Color test to make our key color transparent
+		
+		// Pixel formats without alpha (5650) are considered to have their alpha set.
+		// Since pixel formats with alpha don't have their alpha bits set, we reverse
+		// the alpha format for them so that 0 alpha is 1.
+		if (_buffer.getPixelFormat() != PSPPixelFormat::Type_5650) 
+			_renderer.setAlphaReverse(true);
+		else
+			_renderer.setAlphaReverse(false);
 	}
 }