From 02cfbb7d322c6a683924ceb3b6277fca33c6b97e Mon Sep 17 00:00:00 2001
From: "Steinar H. Gunderson" <sgunderson@bigfoot.com>
Date: Fri, 3 May 2013 23:33:06 +0200
Subject: [PATCH] Split the synth part into a library, with a Makefile.

---
 Makefile       | 15 +++++++++++++++
 common.h       |  7 +++++++
 synth.cpp      | 41 +++++++----------------------------------
 synth.h        | 13 +++++++++++++
 synth_main.cpp | 42 ++++++++++++++++++++++++++++++++++++++++++
 5 files changed, 84 insertions(+), 34 deletions(-)
 create mode 100644 Makefile
 create mode 100644 common.h
 create mode 100644 synth.h
 create mode 100644 synth_main.cpp

diff --git a/Makefile b/Makefile
new file mode 100644
index 0000000..50610c3
--- /dev/null
+++ b/Makefile
@@ -0,0 +1,15 @@
+all: synth
+
+%.o: %.cpp
+	$(CXX) -MMD -MP $(CPPFLAGS) $(CXXFLAGS) -o $@ -c $<
+
+OBJS=synth.o synth_main.o
+
+DEPS=$(OBJS:.o=.d)
+-include $(DEPS)
+
+synth: synth.o synth_main.o
+	$(CXX) -o $@ $^ $(LDFLAGS)
+
+clean:
+	$(RM) synth $(OBJS) $(DEPS)
diff --git a/common.h b/common.h
new file mode 100644
index 0000000..32cc6b5
--- /dev/null
+++ b/common.h
@@ -0,0 +1,7 @@
+#ifndef _COMMON_H
+#define _COMMON_H 1
+
+#define WAVE_FREQ 44100
+#define C64_FREQ 985248
+
+#endif  // !defined(_COMMON_H)
diff --git a/synth.cpp b/synth.cpp
index 244b717..4c039c2 100644
--- a/synth.cpp
+++ b/synth.cpp
@@ -4,12 +4,12 @@
 #include <vector>
 #include <assert.h>
 
+#include "common.h"
+
 using namespace std;
 
 #define LANCZOS_RADIUS 10
 #define RESOLUTION 256
-#define WAVE_FREQ 44100
-#define C64_FREQ 985248
 
 // Cutoff frequency of low-pass filter (must be max. WAVE_FREQ / 2 or you
 // will get aliasing)
@@ -121,37 +121,13 @@ static float filter_update(float in)
 	return out;
 }
 
-int main(int argc, char **argv)
+vector<float> synth(const vector<pulse> &pulses)
 {
 	make_table();
 
-	FILE *fp = fopen(argv[1], "rb");
-	fseek(fp, 14, SEEK_SET);
-
-	int x = 0;
-
-	while (!feof(fp)) {
-		int len = getc(fp);
-		int cycles;
-		if (len == 0) {
-			int a = getc(fp);
-			int b = getc(fp);
-			int c = getc(fp);
-			cycles = a | (b << 8) | (c << 16);
-		} else {
-			cycles = len * 8;
-		}
-		pulse p;
-		p.start = float(x) * WAVE_FREQ / C64_FREQ;
-		p.end = (float(x) + cycles * 0.5) * WAVE_FREQ / C64_FREQ;
-		pulses.push_back(p);
-		x += cycles;
-	}
-
-	int len_cycles = x;
-	int len_samples = int(ceil(float(len_cycles) * WAVE_FREQ / C64_FREQ));
+	int len_samples = int(ceil(pulses.back().start + (pulses.back().end - pulses.back().start) * 2));
 	
-	fprintf(stderr, "%d pulses, total %.2f seconds (%d samples)\n", pulses.size(), len_cycles / float(C64_FREQ), len_samples);
+	fprintf(stderr, "%d pulses, total %.2f seconds (%d samples)\n", pulses.size(), len_samples / float(WAVE_FREQ), len_samples);
 
 	int pulse_begin = 0;
 
@@ -190,9 +166,6 @@ int main(int argc, char **argv)
 	for (int i = len_samples; i --> 0; ) {
 		refiltered_samples[i] = filter_update(filtered_samples[i]);
 	}
-	for (int i = 0; i < len_samples; ++i) {
-		//printf("%f %f\n", samples[i], refiltered_samples[i]);
-		short s = lrintf(refiltered_samples[i] * 16384.0f);
-		fwrite(&s, 2, 1, stdout);
-	}
+
+	return refiltered_samples;
 }
diff --git a/synth.h b/synth.h
new file mode 100644
index 0000000..3b71489
--- /dev/null
+++ b/synth.h
@@ -0,0 +1,13 @@
+#ifndef _SYNTH_H
+#define _SYNTH_H 1
+
+#include <vector>
+
+struct pulse {
+	// all values in samples
+	double start, end;
+};
+
+std::vector<float> synth(const std::vector<pulse> &pulses);
+
+#endif // !defined(_SYNTH_H)
diff --git a/synth_main.cpp b/synth_main.cpp
new file mode 100644
index 0000000..9f2ca96
--- /dev/null
+++ b/synth_main.cpp
@@ -0,0 +1,42 @@
+#include <stdio.h>
+#include <math.h>
+
+#include "common.h"
+#include "synth.h"
+
+using namespace std;
+
+int main(int argc, char **argv)
+{
+	FILE *fp = fopen(argv[1], "rb");
+	fseek(fp, 14, SEEK_SET);
+
+	int x = 0;
+	
+	vector<pulse> pulses;
+	while (!feof(fp)) {
+		int len = getc(fp);
+		int cycles;
+		if (len == 0) {
+			int a = getc(fp);
+			int b = getc(fp);
+			int c = getc(fp);
+			cycles = a | (b << 8) | (c << 16);
+		} else {
+			cycles = len * 8;
+		}
+		pulse p;
+		p.start = float(x) * WAVE_FREQ / C64_FREQ;
+		p.end = (float(x) + cycles * 0.5) * WAVE_FREQ / C64_FREQ;
+		pulses.push_back(p);
+		x += cycles;
+	}
+
+	vector<float> samples = synth(pulses);
+
+	for (int i = 0; i < samples.size(); ++i) {
+		//printf("%f %f\n", samples[i], refiltered_samples[i]);
+		short s = lrintf(samples[i] * 16384.0f);
+		fwrite(&s, 2, 1, stdout);
+	}
+}
-- 
2.39.2