1 files changed, 123 insertions, 0 deletions
diff --git a/plugins/gme/game-music-emu-0.6pre/gme/Fir_Resampler.cpp b/plugins/gme/game-music-emu-0.6pre/gme/Fir_Resampler.cpp
new file mode 100644
index 00000000..b46ad922
--- /dev/null
+++ b/plugins/gme/game-music-emu-0.6pre/gme/Fir_Resampler.cpp
@@ -0,0 +1,123 @@
+// Game_Music_Emu 0.6-pre. http://www.slack.net/~ant/
+
+#include "Fir_Resampler.h"
+
+#include <math.h>
+
+/* Copyright (C) 2004-2008 Shay Green. This module is free software; you
+can redistribute it and/or modify it under the terms of the GNU Lesser
+General Public License as published by the Free Software Foundation; either
+version 2.1 of the License, or (at your option) any later version. This
+module is distributed in the hope that it will be useful, but WITHOUT ANY
+WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
+FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License for more
+details. You should have received a copy of the GNU Lesser General Public
+License along with this module; if not, write to the Free Software Foundation,
+Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA */
+
+#include "blargg_source.h"
+
+#undef PI
+#define PI 3.1415926535897932384626433832795029
+
+static void gen_sinc( double rolloff, int width, double offset, double spacing, double scale,
+		int count, short* out )
+{
+	double const maxh = 256;
+	double const step = PI / maxh * spacing;
+	double const to_w = maxh * 2 / width;
+	double const pow_a_n = pow( rolloff, maxh );
+	scale /= maxh * 2;
+	
+	double angle = (count / 2 - 1 + offset) * -step;
+	while ( count-- )
+	{
+		*out++ = 0;
+		double w = angle * to_w;
+		if ( fabs( w ) < PI )
+		{
+			double rolloff_cos_a = rolloff * cos( angle );
+			double num = 1 - rolloff_cos_a -
+					pow_a_n * cos( maxh * angle ) +
+					pow_a_n * rolloff * cos( (maxh - 1) * angle );
+			double den = 1 - rolloff_cos_a - rolloff_cos_a + rolloff * rolloff;
+			double sinc = scale * num / den - scale;
+			
+			out [-1] = (short) (cos( w ) * sinc + sinc);
+		}
+		angle += step;
+	}
+}
+
+Fir_Resampler_::Fir_Resampler_( int width, sample_t impulses_ [] ) :
+	width_( width ),
+	impulses( impulses_ )
+{
+	imp = NULL;
+}
+
+void Fir_Resampler_::clear_()
+{
+	imp = impulses;
+	Resampler::clear_();
+}
+
+blargg_err_t Fir_Resampler_::set_rate_( double new_factor )
+{
+	double const rolloff = 0.999;
+	double const gain = 1.0;
+	
+	// determine number of sub-phases that yield lowest error
+	double ratio_ = 0.0;
+	int res = -1;
+	{
+		double least_error = 2;
+		double pos = 0;
+		for ( int r = 1; r <= max_res; r++ )
+		{
+			pos += new_factor;
+			double nearest = floor( pos + 0.5 );
+			double error = fabs( pos - nearest );
+			if ( error < least_error )
+			{
+				res = r;
+				ratio_ = nearest / res;
+				least_error = error;
+			}
+		}
+	}
+	RETURN_ERR( Resampler::set_rate_( ratio_ ) );
+	
+	// how much of input is used for each output sample
+	int const step = stereo * (int) floor( ratio_ );
+	double fraction = fmod( ratio_, 1.0 );
+	
+	double const filter = (ratio_ < 1.0) ? 1.0 : 1.0 / ratio_;
+	double pos = 0.0;
+	//int input_per_cycle = 0;
+	sample_t* out = impulses;
+	for ( int n = res; --n >= 0; )
+	{
+		gen_sinc( rolloff, int (width_ * filter + 1) & ~1, pos, filter,
+				double (0x7FFF * gain * filter), (int) width_, out );
+		out += width_;
+		
+		int cur_step = step;
+		pos += fraction;
+		if ( pos >= 0.9999999 )
+		{
+			pos -= 1.0;
+			cur_step += stereo;
+		}
+		
+		*out++ = (cur_step - width_ * 2 + 4) * sizeof (sample_t);
+		*out++ = 4 * sizeof (sample_t);
+		//input_per_cycle += cur_step;
+	}
+	// last offset moves back to beginning of impulses
+	out [-1] -= (char*) out - (char*) impulses;
+	
+	imp = impulses;
+	
+	return blargg_ok;
+}