eliminating exception use

stepmania/src/RageSurface_Save_BMP.cpp

@@ -5,25 +5,26 @@
 #include "RageUtil.h"
 #include "RageFile.h"
 
-struct FatalError: public RageException  { FatalError(const CString &str): RageException(str) { } };
+static void WriteBytes( RageFile &f, CString &sError, const void *buf, int size )
-
-static void WriteBytes( RageFile &f, const void *buf, int size )
 {
+	if( sError.size() != 0 )
+		return;
+
 	int ret = f.Write( buf, size );
 	if( ret == -1 )
-		throw FatalError( f.GetError() );
+		sError = f.GetError();
 }
 
-static void write_le16( RageFile &f, uint16_t val )
+static void write_le16( RageFile &f, CString &sError, uint16_t val )
 {
 	val = Swap16LE( val );
-	WriteBytes( f, &val, sizeof(uint16_t) );
+	WriteBytes( f, sError, &val, sizeof(uint16_t) );
 }
 
-static void write_le32( RageFile &f, uint32_t val )
+static void write_le32( RageFile &f, CString &sError, uint32_t val )
 {
 	val = Swap32LE( val );
-	WriteBytes( f, &val, sizeof(uint32_t) );
+	WriteBytes( f, sError, &val, sizeof(uint32_t) );
 }
 
 bool RageSurface_Save_BMP( RageSurface *surface, RageFile &f )
@@ -34,45 +35,45 @@ bool RageSurface_Save_BMP( RageSurface *surface, RageFile &f )
 		Swap24LE( 0xFF0000 ), Swap24LE( 0x00FF00 ), Swap24LE( 0x0000FF ), 0 );
 	RageSurfaceUtils::CopySurface( surface, converted_surface );
 
-try {
+	CString sError;
+
 	int iFilePitch = converted_surface->pitch;
 	iFilePitch = (iFilePitch+3) & ~3; // round up a multiple of 4
 
 	int iDataSize = converted_surface->h * iFilePitch;
 	const int iHeaderSize = 0x36;
 
-	WriteBytes( f, "BM", 2 );
+	WriteBytes( f, sError, "BM", 2 );
-	write_le32( f, iHeaderSize+iDataSize ); // size (offset 0x2)
+	write_le32( f, sError, iHeaderSize+iDataSize ); // size (offset 0x2)
-	write_le32( f, 0 ); // reserved (offset 0x6)
+	write_le32( f, sError, 0 ); // reserved (offset 0x6)
-	write_le32( f, iHeaderSize ); // bitmap offset (offset 0xA)
+	write_le32( f, sError, iHeaderSize ); // bitmap offset (offset 0xA)
-	write_le32( f, 0x28 ); // header size (offset 0xE)
+	write_le32( f, sError, 0x28 ); // header size (offset 0xE)
-	write_le32( f, surface->w ); // width (offset 0x14)
+	write_le32( f, sError, surface->w ); // width (offset 0x14)
-	write_le32( f, surface->h ); // height (offset 0x18)
+	write_le32( f, sError, surface->h ); // height (offset 0x18)
-	write_le16( f, 1 ); // planes (offset 0x1A)
+	write_le16( f, sError, 1 ); // planes (offset 0x1A)
-	write_le16( f, (uint16_t) converted_surface->fmt.BytesPerPixel*8 ); // bpp (offset 0x1C)
+	write_le16( f, sError, (uint16_t) converted_surface->fmt.BytesPerPixel*8 ); // bpp (offset 0x1C)
-	write_le32( f, 0 ); // compression (offset 0x1E)
+	write_le32( f, sError, 0 ); // compression (offset 0x1E)
-	write_le32( f, iDataSize ); // bitmap size (offset 0x22)
+	write_le32( f, sError, iDataSize ); // bitmap size (offset 0x22)
-	write_le32( f, 0 ); // horiz resolution (offset 0x26)
+	write_le32( f, sError, 0 ); // horiz resolution (offset 0x26)
-	write_le32( f, 0 ); // vert resolution (offset 0x2A)
+	write_le32( f, sError, 0 ); // vert resolution (offset 0x2A)
-	write_le32( f, 0 ); // colors (offset 0x2E)
+	write_le32( f, sError, 0 ); // colors (offset 0x2E)
-	write_le32( f, 0 ); // important colors (offset 0x32)
+	write_le32( f, sError, 0 ); // important colors (offset 0x32)
 
 	for( int y = converted_surface->h-1; y >= 0; --y )
 	{
 		const uint8_t *pRow = converted_surface->pixels + converted_surface->pitch*y;
-		WriteBytes( f, pRow, converted_surface->pitch );
+		WriteBytes( f, sError, pRow, converted_surface->pitch );
 
-		/* Pad */
+		/* Pad the row to the pitch. */
 		uint8_t padding[4] = { 0,0,0,0 };
-		WriteBytes( f, padding, iFilePitch-converted_surface->pitch );
+		WriteBytes( f, sError, padding, iFilePitch-converted_surface->pitch );
 	}
-} catch(...) {
-	delete converted_surface;
-	return false;
-}
 
 	delete converted_surface;
 
+	if( sError.size() != 0 )
+		return false;
+
 	if( f.Flush() == -1 )
 		return false;