Compatibility fix for GetDisplayMode

ayuanx · Aug 3, 2024 · 7bb3158 · 7bb3158
1 parent e10f1a3
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diff --git a/README.md b/README.md
@@ -48,6 +48,9 @@ Tip: If the game does not utilize DirectDraw at all, or if the game already supp
 
 # Revisions:
 
+v.2024.08.04
+- Compatibility fix for GetDisplayMode.
+
 v.2023.08.04
 - Export DirectDrawEnumerateExA.
 

diff --git a/dd.cpp b/dd.cpp
@@ -227,6 +227,16 @@ namespace dd
 	{
 		PROLOGUE;
 		HRESULT hResult = This->dd1->lpVtbl->GetDisplayMode( This->dd1, lpDDSurfaceDesc );
+		if (dx::enabled && (lpDDSurfaceDesc->dwFlags & DDSD_PIXELFORMAT)) {
+			lpDDSurfaceDesc->ddpfPixelFormat.dwSize = sizeof(DDPIXELFORMAT);
+			lpDDSurfaceDesc->ddpfPixelFormat.dwFlags = dx::bpp == 8 ? DDPF_RGB | DDPF_PALETTEINDEXED8 : DDPF_RGB;
+			lpDDSurfaceDesc->ddpfPixelFormat.dwRGBBitCount = dx::bpp;
+			lpDDSurfaceDesc->ddpfPixelFormat.dwRBitMask = dx::bpp == 8 ? 0 : (dx::bpp == 16 ? 0xF800 : 0xFF0000);
+			lpDDSurfaceDesc->ddpfPixelFormat.dwGBitMask = dx::bpp == 8 ? 0 : (dx::bpp == 16 ? 0x07E0 : 0x00FF00);
+			lpDDSurfaceDesc->ddpfPixelFormat.dwBBitMask = dx::bpp == 8 ? 0 : (dx::bpp == 16 ? 0x001F : 0x0000FF);
+			lpDDSurfaceDesc->ddpfPixelFormat.dwRGBAlphaBitMask = 0;
+		}
+		// TODO: May need to fix lPitch too.
 		INFO("GetDisplayMode %08X\n", This->dd1);
 		EPILOGUE( hResult );
 	}