//the Pascal translation of libctru 1.0.0 headers files for the nintendo 3ds platform
//
// Copyright (c) 2016 Kenny D. Lee
// all rights reserved
//

  {*
   * @file channel.h
   * @brief Functions for interacting with DSP audio channels.
    }


{$ifdef 3dsintf}
  {/ Supported sample encodings. }
  type
     NDSP_Enc = (NDSP_ENCODING_PCM8 := 0,NDSP_ENCODING_PCM16 := 1, NDSP_ENCODING_ADPCM := 2);

   mixer= array[0..11] of double;
   coefficients=array[0..15] of u16;

    { Specifies the number of channels used in a sample. }
    function NDSP_CHANNELS(n : longint) : u32;    

    { Specifies the encoding used in a sample. }
    { was #define dname(params) para_def_expr }
    function NDSP_ENCODING(n : longint) : longint;    

    {/ Channel format flags for use with ndspChnSetFormat. }
const 
	NDSP_FORMAT_MONO_PCM8    = 1; //< Buffer contains Mono   PCM8.
	NDSP_FORMAT_MONO_PCM16   = 5; //< Buffer contains Mono   PCM16.
	NDSP_FORMAT_MONO_ADPCM   = 9; //< Buffer contains Mono   ADPCM.
	NDSP_FORMAT_STEREO_PCM8  = 2; //< Buffer contains Stereo PCM8.
	NDSP_FORMAT_STEREO_PCM16 = 6; //< Buffer contains Stereo PCM16.

    	NDSP_FORMAT_PCM8  = NDSP_FORMAT_MONO_PCM8;  //< (Alias) Buffer contains Mono PCM8. 
    	NDSP_FORMAT_PCM16 = NDSP_FORMAT_MONO_PCM16; //< (Alias) Buffer contains Mono PCM16. 
    	NDSP_FORMAT_ADPCM = NDSP_FORMAT_MONO_ADPCM; //< (Alias) Buffer contains Mono ADPCM. 

    { Flags }
    	NDSP_FRONT_BYPASS             = 1 shl 4; //< Front bypass. }
    	NDSP_3D_SURROUND_PREPROCESSED = 1 shl 6; //< (?) Unknown, under research }

    type

       ndspInterpType = (NDSP_INTERP_POLYPHASE := 0,NDSP_INTERP_LINEAR := 1, NDSP_INTERP_NONE := 2);
    {/@ }
    {/@name Basic channel operation }
    {/@ }
    {*
     * @brief Resets a channel.
     * @param id ID of the channel (0..23).
      }

    procedure ndspChnReset(id:cint);cdecl;external;

    {*
     * @brief Initializes the parameters of a channel.
     * @param id ID of the channel (0..23).
      }
    procedure ndspChnInitParams(id:cint);cdecl;external;

    {*
     * @brief Checks whether a channel is currently playing.
     * @param id ID of the channel (0..23).
     * @return Whether the channel is currently playing.
      }
    function ndspChnIsPlaying(id:cint):bool;cdecl;external;

    {*
     * @brief Gets the current sample position of a channel.
     * @param id ID of the channel (0..23).
     * @return The channel's sample position.
      }
    function ndspChnGetSamplePos(id:cint):u32;cdecl;external;

    {*
     * @brief Gets the sequence ID of the wave buffer that is currently playing in a channel.
     * @param id ID of the channel (0..23).
     * @return The sequence ID of the wave buffer.
      }
    function ndspChnGetWaveBufSeq(id:cint):u16;cdecl;external;

    {*
     * @brief Checks whether a channel is currently paused.
     * @param id ID of the channel (0..23).
     * @return Whether the channel is currently paused.
      }
    function ndspChnIsPaused(id:cint):bool;cdecl;external;

    {*
     * @brief Sets the pause status of a channel.
     * @param id ID of the channel (0..23).
     * @param paused Whether the channel is to be paused (true) or unpaused (false).
      }
    procedure ndspChnSetPaused(id:cint; paused:bool);cdecl;external;

    {/@ }
    {/@name Configuration }
    {/@ }
    {*
     * @brief Sets the format of a channel.
     * @param id ID of the channel (0..23).
     * @param format Format to use.
      }
    procedure ndspChnSetFormat(id:cint; format:u16);cdecl;external;

    {*
     * @brief Sets the interpolation type of a channel.
     * @param id ID of the channel (0..23).
     * @param type Interpolation type to use.
      }
    procedure ndspChnSetInterp(id:cint; _type:ndspInterpType);cdecl;external;

    {*
     * @brief Sets the sample rate of a channel.
     * @param id ID of the channel (0..23).
     * @param rate Sample rate to use.
      }
    procedure ndspChnSetRate(id:cint; rate:double);cdecl;external;

    {*
     * @brief Sets the mix parameters (volumes) of a channel.
     * @param id ID of the channel (0..23).
     * @param mix Mix parameters to use. Working hypothesis:
     *   - 0: Front left volume.
     *   - 1: Front right volume.
     *   - 2: Back left volume:
     *   - 3: Back right volume:
     *   - 4..7: Same as 0..3, but for auxiliary output 0.
     *   - 8..11: Same as 0..3, but for auxiliary output 1.}

    procedure ndspChnSetMix(id:cint; mix:mixer);cdecl;external;

    {*
     * @brief Sets the DSPADPCM coefficients of a channel.
     * @param id ID of the channel (0..23).
     * @param coefs DSPADPCM coefficients to use.
      }
    procedure ndspChnSetAdpcmCoefs(id:cint; coefs:coefficients);cdecl;external;

    {/@ }
    {/@name Wave buffers }
    {/@ }
    {*
     * @brief Clears the wave buffer queue of a channel and stops playback.
     * @param id ID of the channel (0..23).
      }
    procedure ndspChnWaveBufClear(id:cint);cdecl;external;

    {*
     * @brief Adds a wave buffer to the wave buffer queue of a channel.
     * @remark If the channel's wave buffer queue was empty before the use of this function, playback is started.
     * @param id ID of the channel (0..23).
     * @param buf Wave buffer to add.
      }
    procedure ndspChnWaveBufAdd(id:cint; buf:PndspWaveBuf);cdecl;external; // pointer

    {/@ }
    {/@name IIR filters }
    {/@ }
    {*
     * @brief Configures whether the IIR monopole filter of a channel is enabled.
     * @param id ID of the channel (0..23).
     * @param enable Whether to enable the IIR monopole filter.
      }
    procedure ndspChnIirMonoSetEnable(id:cint; enable:bool);cdecl;external;

    {*
     * @brief Manually sets up the parameters on monopole filter
     * @param id ID of the channel (0..23).
     * @param enable Whether to enable the IIR monopole filter.
      }
    function ndspChnIirMonoSetParamsCustomFilter(id:cint; a0:double; a1:double; b0:double):bool;cdecl;external;

    {*
     * @brief Sets the monopole to be a low pass filter. (Note: This is a lower-quality filter than the biquad one.)
     * @param id ID of the channel (0..23).
     * @param f0 Low pass cut-off frequency.
      }
    function ndspChnIirMonoSetParamsLowPassFilter(id:cint; f0:double):bool;cdecl;external;

    {*
     * @brief Sets the monopole to be a high pass filter. (Note: This is a lower-quality filter than the biquad one.)
     * @param id ID of the channel (0..23).
     * @param f0 High pass cut-off frequency.
      }
    function ndspChnIirMonoSetParamsHighPassFilter(id:cint; f0:double):bool;cdecl;external;

    {*
     * @brief Configures whether the IIR biquad filter of a channel is enabled.
     * @param id ID of the channel (0..23).
     * @param enable Whether to enable the IIR biquad filter.
      }
    procedure ndspChnIirBiquadSetEnable(id:cint; enable:bool);cdecl;external;

    {*
     * @brief Manually sets up the parameters of the biquad filter
     * @param id ID of the channel (0..23).
      }
    function ndspChnIirBiquadSetParamsCustomFilter(id:cint; a0:double; a1:double; a2:double; b0:double; 
               b1:double; b2:double):bool;cdecl;external;

    {*
     * @brief Sets the biquad to be a low pass filter.
     * @param id ID of the channel (0..23).
     * @param f0 Low pass cut-off frequency.
     * @param Q "Quality factor", typically should be sqrt(2)/2 (i.e. 0.7071).
      }
    function ndspChnIirBiquadSetParamsLowPassFilter(id:cint; f0:double; Q:double):bool;cdecl;external;

    {*
     * @brief Sets the biquad to be a high pass filter.
     * @param id ID of the channel (0..23).
     * @param f0 High pass cut-off frequency.
     * @param Q "Quality factor", typically should be sqrt(2)/2 (i.e. 0.7071).
      }
    function ndspChnIirBiquadSetParamsHighPassFilter(id:cint; f0:double; Q:double):bool;cdecl;external;

    {*
     * @brief Sets the biquad to be a band pass filter.
     * @param id ID of the channel (0..23).
     * @param f0 Mid-frequency.
     * @param Q "Quality factor", typically should be sqrt(2)/2 (i.e. 0.7071).
      }
    function ndspChnIirBiquadSetParamsBandPassFilter(id:cint; f0:double; Q:double):bool;cdecl;external;

    {*
     * @brief Sets the biquad to be a notch filter.
     * @param id ID of the channel (0..23).
     * @param f0 Notch frequency.
     * @param Q "Quality factor", typically should be sqrt(2)/2 (i.e. 0.7071).
      }
    function ndspChnIirBiquadSetParamsNotchFilter(id:cint; f0:double; Q:double):bool;cdecl;external;

    {*
     * @brief Sets the biquad to be a peaking equalizer.
     * @param id ID of the channel (0..23).
     * @param f0 Central frequency.
     * @param Q "Quality factor", typically should be sqrt(2)/2 (i.e. 0.7071).
     * @param gain Amount of gain (raw value = 10 ^ dB/40)
      }
    function ndspChnIirBiquadSetParamsPeakingEqualizer(id:cint; f0:double; Q:double; gain:double):bool;cdecl;external;
{$endif 3dsintf}

{$ifdef 3dsimpl}
    function NDSP_CHANNELS(n : longint) : u32;
      begin
         NDSP_CHANNELS:=u32(n and 3);
      end;

    function NDSP_ENCODING(n : longint) : longint;
      begin
         NDSP_ENCODING:=(u32 (n and 3) shl 2);
//         NDSP_ENCODING:=(u32(n(@(3)))) shl 2;
      end;
{$endif 3dsimpl}