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+/*----------------------------------------------------------------------------
+ *
+ * File: 
+ * eas_chorusdata.h
+ *
+ * Contents and purpose:
+ * Contains the prototypes for the Chorus effect.
+ *
+ *
+ * Copyright Sonic Network Inc. 2006
+
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ *----------------------------------------------------------------------------
+ * Revision Control:
+ *   $Revision: 309 $
+ *   $Date: 2006-09-12 18:52:45 -0700 (Tue, 12 Sep 2006) $
+ *----------------------------------------------------------------------------
+*/
+
+#ifndef _EAS_CHORUS_H
+#define _EAS_CHORUS_H
+
+#include "eas_types.h"
+#include "eas_audioconst.h"
+
+//defines for chorus
+
+#define EAS_CHORUS_BYPASS_DEFAULT	1
+#define EAS_CHORUS_PRESET_DEFAULT	0
+#define EAS_CHORUS_RATE_DEFAULT		30
+#define EAS_CHORUS_DEPTH_DEFAULT	39
+#define EAS_CHORUS_LEVEL_DEFAULT	32767
+
+#define EAS_CHORUS_LEVEL_MIN		0
+#define EAS_CHORUS_LEVEL_MAX		32767
+
+#define EAS_CHORUS_RATE_MIN			10
+#define EAS_CHORUS_RATE_MAX			50
+
+#define EAS_CHORUS_DEPTH_MIN		15
+#define EAS_CHORUS_DEPTH_MAX		60
+
+#define CHORUS_SIZE_MS 20
+#define CHORUS_L_SIZE ((CHORUS_SIZE_MS*_OUTPUT_SAMPLE_RATE)/1000)
+#define CHORUS_R_SIZE CHORUS_L_SIZE
+#define CHORUS_SHAPE_SIZE 128
+#define CHORUS_DELAY_MS 10
+
+#define CHORUS_MAX_TYPE			4	// any Chorus numbers larger than this are invalid
+
+typedef struct
+{
+	EAS_I16				m_nRate;
+	EAS_I16				m_nDepth;
+	EAS_I16				m_nLevel;
+
+} S_CHORUS_PRESET;
+
+typedef struct
+{
+	S_CHORUS_PRESET		m_sPreset[CHORUS_MAX_TYPE];	//array of presets
+
+} S_CHORUS_PRESET_BANK;
+
+/* parameters for each Chorus */
+typedef struct
+{
+	EAS_I32 lfoLPhase;
+	EAS_I32 lfoRPhase;
+	EAS_I16 chorusIndexL;
+	EAS_I16 chorusIndexR;
+	EAS_U16 chorusTapPosition;
+
+	EAS_I16 m_nRate;
+	EAS_I16 m_nDepth;
+	EAS_I16 m_nLevel;
+
+	//delay lines used by the chorus, longer would sound better
+	EAS_PCM chorusDelayL[CHORUS_L_SIZE];
+	EAS_PCM chorusDelayR[CHORUS_R_SIZE];
+
+	EAS_BOOL	bypass;
+	EAS_I8		preset;
+
+	EAS_I16		m_nCurrentChorus;			// preset number for current Chorus
+	EAS_I16		m_nNextChorus;				// preset number for next Chorus
+
+	S_CHORUS_PRESET			pPreset;
+
+	S_CHORUS_PRESET_BANK	m_sPreset;
+
+} S_CHORUS_OBJECT;
+
+
+/*----------------------------------------------------------------------------
+ * WeightedTap()
+ *----------------------------------------------------------------------------
+ * Purpose: Does fractional array look-up using linear interpolation
+ * 
+ * first convert indexDesired to actual desired index by taking into account indexReference
+ * then do linear interpolation between two actual samples using fractional part
+ *
+ * Inputs: 
+ * array: pointer to array of signed 16 bit values, typically either PCM data or control data
+ * indexReference: the circular buffer relative offset
+ * indexDesired: the fractional index we are looking up (16 bits index + 16 bits fraction)
+ * indexLimit: the total size of the array, used to compute buffer wrap
+ * 	
+ * Outputs:
+ * Value from the input array, linearly interpolated between two actual data values
+ *
+ *----------------------------------------------------------------------------
+*/
+static EAS_I16 WeightedTap(const EAS_I16 *array, EAS_I16 indexReference, EAS_I32 indexDesired, EAS_I16 indexLimit);
+
+/*----------------------------------------------------------------------------
+ * ChorusReadInPresets()
+ *----------------------------------------------------------------------------
+ * Purpose: sets global Chorus preset bank to defaults
+ * 
+ * Inputs: 
+ *			
+ * Outputs:
+ *
+ *----------------------------------------------------------------------------
+*/
+static EAS_RESULT ChorusReadInPresets(S_CHORUS_OBJECT *pChorusData);
+
+/*----------------------------------------------------------------------------
+ * ChorusUpdate
+ *----------------------------------------------------------------------------
+ * Purpose: 
+ * Update the Chorus preset parameters as required
+ *
+ * Inputs: 
+ *
+ * Outputs:
+ * 
+ * 
+ * Side Effects:
+ * - chorus paramters will be changed
+ * - m_nCurrentChorus := m_nNextChorus
+ *----------------------------------------------------------------------------
+*/
+static EAS_RESULT ChorusUpdate(S_CHORUS_OBJECT* pChorusData);
+
+#endif /* #ifndef _EAS_CHORUSDATA_H */
+
+