added atodb table generators and fast cosine functions to math

spiricom committed 6 years ago

Commit 60e4c521 parent 5670f0b2 files · +66 −0Browse files

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2 files

leaf/Inc/leaf-math.h +9 −0
leaf/Src/leaf-math.c +57 −0

     float interpolate3max(float *buf, const int peakindex);
     float interpolate3phase(float *buf, const int peakindex);
+    float fastcosf(float fAngle);
+    float fastercosf(float fAngle);
     // alternative implementation for abs()
     // REQUIRES: 32 bit integers
     int fastabs_int(int in);
     //1000 gives a good curve from -1.0 to 0.0
     void LEAF_generate_exp(float* buffer, float base, float start, float end, float offset, int size);
+    void LEAF_generate_atodb(float* buffer, int size);
+    void LEAF_generate_atodbPositiveClipped(float* buffer, float lowerThreshold, float range, int size);
     float LEAF_poly_blep(float t, float dt);
     float LEAF_midiToFrequency(float f);

leaf/Src/leaf-math.c+57−0

@@ -64,6 +64,38 @@ float interpolate3phase(float *buf, const int peakindex) · 63 unmodified lines
64	return(fraction);	64	return(fraction);
65	}	65	}
66		66
		67
		68	// from http://www.wild-magic.com - found on music-dsp list
		69	float fastcosf(float fAngle)
		70	{
		71	float fASqr = fAngle*fAngle;
		72	float fResult = -2.605e-07f;
		73	fResult *= fASqr;
		74	fResult += 2.47609e-05f;
		75	fResult *= fASqr;
		76	fResult -= 1.3888397e-03f;
		77	fResult *= fASqr;
		78	fResult += 4.16666418e-02f;
		79	fResult *= fASqr;
		80	fResult -= 4.999999963e-01f;
		81	fResult *= fASqr;
		82	fResult += 1.0f;
		83	return fResult;
		84	}
		85
		86	float fastercosf(float fAngle)
		87	{
		88	float fASqr = fAngle*fAngle;
		89	float fResult = 3.705e-02f;
		90	fResult *= fASqr;
		91	fResult -= 4.967e-01f;
		92	fResult *= fASqr;
		93	fResult += 1.0f;
		94	return fResult;
		95	}
		96
		97
		98
67	// alternative implementation for abs()	99	// alternative implementation for abs()
68	// REQUIRES: 32 bit integers	100	// REQUIRES: 32 bit integers
69	int fastabs_int(int in){	101	int fastabs_int(int in){
@@ -444,6 +476,31 @@ void LEAF_generate_exp(float* buffer, float base, float start, float end, float · 374 unmodified lines
444	}	476	}
445	}	477	}
446		478
		479	void LEAF_generate_atodb(float* buffer, int size)
		480	{
		481	float increment = 1.0f / (float)size;
		482	float x = 0.0f;
		483	for (int i = 0; i < size; i++)
		484	{
		485	buffer[i] = atodb(x);
		486	x += increment;
		487	}
		488	}
		489
		490
		491	void LEAF_generate_atodbPositiveClipped(float* buffer, float lowerThreshold, float range, int size)
		492	{
		493	float increment = 1.0f / (float)size;
		494	float x = 0.0f;
		495	float scalar = range / fastabsf(lowerThreshold);
		496	for (int i = 0; i < size; i++)
		497	{
		498	float temp = atodb(x);
		499	temp = LEAF_clip(lowerThreshold, temp, 0.0f);
		500	buffer[i] = (temp-lowerThreshold) * scalar;
		501	x += increment;
		502	}
		503	}
447		504
448	// http://www.martin-finke.de/blog/articles/audio-plugins-018-polyblep-oscillator/	505	// http://www.martin-finke.de/blog/articles/audio-plugins-018-polyblep-oscillator/
449	// http://www.kvraudio.com/forum/viewtopic.php?t=375517	506	// http://www.kvraudio.com/forum/viewtopic.php?t=375517

added atodb table generators and fast cosine functions to math

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