From f6e4c0266cf1ae4b2a839cd083591134279d9cce Mon Sep 17 00:00:00 2001
From: twinaphex <libretro@gmail.com>
Date: Fri, 8 Nov 2013 06:45:33 +0100
Subject: [PATCH] Take out Silent_Blip_Buffer

---
 mednafen/include/blip/Blip_Buffer.h | 13 ---------
 mednafen/sound/Blip_Buffer.cpp      | 41 ++---------------------------
 2 files changed, 2 insertions(+), 52 deletions(-)

diff --git a/mednafen/include/blip/Blip_Buffer.h b/mednafen/include/blip/Blip_Buffer.h
index f021441..2b69645 100644
--- a/mednafen/include/blip/Blip_Buffer.h
+++ b/mednafen/include/blip/Blip_Buffer.h
@@ -256,19 +256,6 @@ private:
 
 int const blip_sample_bits = 30;
 
-// Dummy Blip_Buffer to direct sound output to, for easy muting without
-// having to stop sound code.
-class Silent_Blip_Buffer : public Blip_Buffer {
-	buf_t_ buf [blip_buffer_extra_ + 1];
-public:
-	// The following cannot be used (an assertion will fail if attempted):
-	blargg_err_t set_sample_rate( long samples_per_sec, int msec_length );
-	blip_time_t count_clocks( long count ) const;
-	void mix_samples( blip_sample_t const* buf, long count );
-	
-	Silent_Blip_Buffer();
-};
-
 #define BLIP_RESTRICT
 
 // Optimized reading from Blip_Buffer, for use in custom sample output
diff --git a/mednafen/sound/Blip_Buffer.cpp b/mednafen/sound/Blip_Buffer.cpp
index caba41c..4602c53 100644
--- a/mednafen/sound/Blip_Buffer.cpp
+++ b/mednafen/sound/Blip_Buffer.cpp
@@ -23,8 +23,6 @@ Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA */
 	#include BLARGG_ENABLE_OPTIMIZER
 #endif
 
-int const silent_buf_size = 1; // size used for Silent_Blip_Buffer
-
 Blip_Buffer::Blip_Buffer()
 {
 	factor_       = (blip_u64)ULLONG_MAX;
@@ -37,31 +35,12 @@ Blip_Buffer::Blip_Buffer()
 	clock_rate_   = 0;
 	bass_freq_    = 16;
 	length_       = 0;
-	
-	// assumptions code makes about implementation-defined features
-	#ifndef NDEBUG
-		// right shift of negative value preserves sign
-		buf_t_ i = -0x7FFFFFFE;
-		assert( (i >> 1) == -0x3FFFFFFF );
-		
-		// casting to short truncates to 16 bits and sign-extends
-		i = 0x18000;
-		assert( (short) i == -0x8000 );
-	#endif
 }
 
 Blip_Buffer::~Blip_Buffer()
 {
-	if ( buffer_size_ != silent_buf_size )
-		free( buffer_ );
-}
-
-Silent_Blip_Buffer::Silent_Blip_Buffer()
-{
-	factor_      = 0;
-	buffer_      = buf;
-	buffer_size_ = silent_buf_size;
-	memset( buf, 0, sizeof buf ); // in case machine takes exception for signed overflow
+   if (buffer_)
+      free( buffer_ );
 }
 
 void Blip_Buffer::clear( int entire_buffer )
@@ -78,12 +57,6 @@ void Blip_Buffer::clear( int entire_buffer )
 
 Blip_Buffer::blargg_err_t Blip_Buffer::set_sample_rate( long new_rate, int msec )
 {
-	if ( buffer_size_ == silent_buf_size )
-	{
-		assert( 0 );
-		return "Internal (tried to resize Silent_Blip_Buffer)";
-	}
-	
 	// start with maximum length that resampled time can represent
 	blip_s64 new_size = (ULLONG_MAX >> BLIP_BUFFER_ACCURACY) - blip_buffer_extra_ - 64;
 
@@ -106,14 +79,10 @@ Blip_Buffer::blargg_err_t Blip_Buffer::set_sample_rate( long new_rate, int msec
 		if ( !p )
 			return "Out of memory";
 
-		//if(new_size > buffer_size_)
-		//	memset(buffer_ + buffer_size_, 0, (new_size + blip_buffer_extra_) * sizeof *buffer_
-
 		buffer_ = (buf_t_*) p;
 	}
 	
 	buffer_size_ = new_size;
-	assert( buffer_size_ != silent_buf_size );
 	
 	// update things based on the sample rate
 	sample_rate_ = new_rate;
@@ -255,12 +224,6 @@ long Blip_Buffer::read_samples( blip_sample_t* BLIP_RESTRICT out, long max_sampl
 
 void Blip_Buffer::mix_samples( blip_sample_t const* in, long count )
 {
-	if ( buffer_size_ == silent_buf_size )
-	{
-		assert( 0 );
-		return;
-	}
-	
 	buf_t_* out = buffer_ + (offset_ >> BLIP_BUFFER_ACCURACY) + blip_widest_impulse_ / 2;
 	
 	int const sample_shift = blip_sample_bits - 16;