vst.h

/*
 * Copyright 2020 Michael Fabian 'Xaymar' Dirks <info@xaymar.com>
 *
 * Redistribution and use in source and binary forms, with or without modification, are permitted provided that the following conditions are met:
 *
 * 1. Redistributions of source code must retain the above copyright notice, this list of conditions and the following disclaimer.
 *
 * 2. Redistributions in binary form must reproduce the above copyright notice, this list of conditions and the following disclaimer in the documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

/*
 * This was created from released VST2.x plugins, and is technically under the 2-clause BSD license. Depending on which country you are in, Steinberg can do fuck all about this. Notable countries for this are most members of the United States of America, the entirety of Europe, Japan, and Russia.
 *
 * Consult a lawyer if you don't know if clean room reverse engineering is allowed in your country.
 *
 * See README.md for all information.
 */

// Known additional information:
// - Function call standard seems to be stdcall.
// - Everything is aligned to 8 bytes.

// VST Versioning:
// - Base-10, thus can't store many version numbers.
// - Always four components, with the major one being able to store the most numbers.
// - Format is A...ABCD, so 1.2.3.4 would turn into 1234.

#pragma once
#ifndef VST2SDK_VST_H
#define VST2SDK_VST_H

#define VST_FUNCTION_INTERFACE __cdecl
#define VST_ALIGNMENT 8
#define VST_MAGICNUMBER 'VstP'

// Common VST buffer lengths:
// 8: OpCodes(GetLabel, GetName, GetValue)
#define VST_BUFFER_8 8
// 16:
#define VST_BUFFER_16 16
// 24: OpCodes?
#define VST_BUFFER_24 24
// 32: OpCodes(EffectName)
#define VST_BUFFER_32 32
#define VST_EFFECT_BUFFER_SIZE 32
// 64: OpCodes(ProductName, VendorName)
#define VST_BUFFER_64 64
#define VST_VENDOR_BUFFER_SIZE VST_BUFFER_64
#define VST_PRODUCT_BUFFER_SIZE VST_BUFFER_64
#define VST_NAME_BUFFER_SIZE VST_BUFFER_64
// 100:
#define VST_BUFFER_100 100

#define VST_MAX_CHANNELS 32 // Couldn't find any audio editing software which would attempt to add more channels.

#pragma pack(push, VST_ALIGNMENT)

#ifdef __cplusplus
#include <cinttypes>
extern "C" {
#else
#include <inttypes.h>
#endif

/*******************************************************************************
|* Enumeration
|*/
enum VST_VERSION {
	VST_VERSION_1       = 0, // Anything before 2.0, used by official plug-ins.
	VST_VERSION_1_0_0_0 = 1000, // 1.0, used by some third-party plug-ins.
	VST_VERSION_1_1_0_0 = 1100, // 1.1, used by some third-party plug-ins.
	VST_VERSION_2       = 2, // 2.0, used by official plug-ins.
	VST_VERSION_2_0_0_0 = 2000, // 2.0, used by some third-party plug-ins.
	VST_VERSION_2_1_0_0 = 2100, // 2.1
	VST_VERSION_2_2_0_0 = 2200, // 2.2
	VST_VERSION_2_3_0_0 = 2300, // 2.3
	VST_VERSION_2_4_0_0 = 2400, // 2.4

	// Pad to force 32-bit number.
	_VST_VERSION_PAD = 0xFFFFFFFFul,
};

enum VST_CATEGORY {
	VST_CATEGORY_UNCATEGORIZED = 0x00,
	VST_CATEGORY_01            = 0x01,
	VST_CATEGORY_02            = 0x02,
	VST_CATEGORY_03            = 0x03,
	VST_CATEGORY_04            = 0x04,
	VST_CATEGORY_05            = 0x05,
	VST_CATEGORY_06            = 0x06,
	VST_CATEGORY_07            = 0x07,
	VST_CATEGORY_RESTORATION   = 0x08, // Denoising and similar effects.
	VST_CATEGORY_09            = 0x09,
	VST_CATEGORY_CONTAINER     = 0x0A, // Plugin contains more than one Plugin.
	VST_CATEGORY_0B            = 0x0B,
	VST_CATEGORY_MAX, // Not part of specification, marks maximum category.

	// Pad to force 32-bit number.
	_VST_CATEGORY_PAD = 0xFFFFFFFFul,
};

enum VST_EFFECT_OPCODE {
	/* Create/Initialize the effect (if it has not been created already).
	 * 
	 * @return Always 0.
	 */
	VST_EFFECT_OPCODE_00         = 0x00,
	VST_EFFECT_OPCODE_CREATE     = 0x00,
	VST_EFFECT_OPCODE_INITIALIZE = 0x00,

	/* Destroy the effect (if there is any) and free its memory.
	 *
	 * This should destroy the actual object created by VST_ENTRYPOINT.
	 * 
	 * @return Always 0.
	 */
	VST_EFFECT_OPCODE_01      = 0x01,
	VST_EFFECT_OPCODE_DESTROY = 0x01,

	/* Set Program
	 *
	 *
	 */
	VST_EFFECT_OPCODE_02 = 0x02,

	/* Get Program
	 *
	 *
	 */
	VST_EFFECT_OPCODE_03 = 0x03,

	/* Set Program Name
	 *
	 *
	 */
	VST_EFFECT_OPCODE_04 = 0x04,

	/* Get Program Name
	 *
	 * "Returns 0. If ptr is valid, sets the first byte of ptr to 0 then returns 0."
	 */
	VST_EFFECT_OPCODE_05 = 0x05,

	/* Get the value? label for the parameter.
	 * 
	 * @param p_int1 Parameter index.
	 * @param p_ptr 'char[8]'
	 * @return 0 on success, 1 on failure.
	 */
	VST_EFFECT_OPCODE_06             = 0x06,
	VST_EFFECT_OPCODE_PARAM_GETLABEL = 0x06,

	/* Get the string value for the parameter.
	 * 
	 * @param p_int1 Parameter index.
	 * @param p_ptr 'char[8]'
	 * @return 0 on success, 1 on failure.
	 */
	VST_EFFECT_OPCODE_07             = 0x07,
	VST_EFFECT_OPCODE_PARAM_GETVALUE = 0x07,

	/* Get the name for the parameter.
	 * 
	 * @param p_int1 Parameter index.
	 * @param p_ptr 'char[8]'
	 * @return 0 on success, 1 on failure.
	 */
	VST_EFFECT_OPCODE_08            = 0x08,
	VST_EFFECT_OPCODE_PARAM_GETNAME = 0x08,

	/*
	 *
	 *
	 */
	VST_EFFECT_OPCODE_09 = 0x09,

	/* Set the new sample rate for the plugin to use.
	 * 
	 * @param p_float New sample rate as a float (double on 64-bit because register upgrades).
	 */
	VST_EFFECT_OPCODE_0A              = 0x0A,
	VST_EFFECT_OPCODE_SETSAMPLERATE   = 0x0A,
	VST_EFFECT_OPCODE_SET_SAMPLE_RATE = 0x0A,

	/* Sets the block size, which is the maximum number of samples passed into the effect via process calls.
	 *
	 * @param p_int2 The maximum number of samples to be passed in.
	 */
	VST_EFFECT_OPCODE_0B             = 0x0B,
	VST_EFFECT_OPCODE_SETBLOCKSIZE   = 0x0B,
	VST_EFFECT_OPCODE_SET_BLOCK_SIZE = 0x0B,

	/* Effect processing should be suspended/paused.
	 *
	 * Unclear if this is should result in a flush of buffers.
	 * 
	 * @param p_int2 0 if the effect should suspend processing, 1 if it should resume.
	 */
	VST_EFFECT_OPCODE_0C      = 0x0C,
	VST_EFFECT_OPCODE_SUSPEND = 0x0C,

	/* Retrieve the client rect size of the plugins window.
	 * If no window has been created, returns the default rect.
	 *
	 * @param p_ptr Pointer of type 'struct vst_rect*'.
	 * @return On success, returns 1 and updates p_ptr to the rect. On failure, returns 0.
	 */
	VST_EFFECT_OPCODE_0D             = 0x0D,
	VST_EFFECT_OPCODE_WINDOW_GETRECT = 0x0D,

	/* Create the window for the plugin.
	 * 
	 * @param p_ptr HWND of the parent window.
	 * @return 0 on failure, or HWND on success.
	 */
	VST_EFFECT_OPCODE_0E            = 0x0E,
	VST_EFFECT_OPCODE_WINDOW_CREATE = 0x0E,

	/* Destroy the plugins window.
	 * 
	 * @return Always 0.
	 */
	VST_EFFECT_OPCODE_0F             = 0x0F,
	VST_EFFECT_OPCODE_WINDOW_DESTROY = 0x0F,

	/*
	 *
	 *
	 */
	VST_EFFECT_OPCODE_10 = 0x10,

	/*
	 *
	 *
	 */
	VST_EFFECT_OPCODE_11 = 0x11,

	/*
	 *
	 *
	 */
	VST_EFFECT_OPCODE_12 = 0x12,

	/*
	 *
	 *
	 */
	VST_EFFECT_OPCODE_13 = 0x13,

	/*
	 *
	 *
	 */
	VST_EFFECT_OPCODE_14 = 0x14,

	/*
	 *
	 *
	 */
	VST_EFFECT_OPCODE_15 = 0x15,

	/* Always returns the FourCC 'NvEF' (0x4E764566).
	 */
	VST_EFFECT_OPCODE_16 = 0x16,

	/* Get Chunk
	 *
	 *
	 */
	VST_EFFECT_OPCODE_17 = 0x17,

	/* Set Chunk
	 *
	 *
	 */
	VST_EFFECT_OPCODE_18 = 0x18,

	// VST2.x starts here.

	/*
	 *
	 *
	 */
	VST_EFFECT_OPCODE_19 = 0x19,

	/* Can the parameter be automated?
	 *
	 * @param p_int1 Index of the parameter.
	 * @return 1 if the parameter can be automated, otherwise 0.
	 */
	VST_EFFECT_OPCODE_1A                  = 0x1A,
	VST_EFFECT_OPCODE_PARAM_ISAUTOMATABLE = 0x1A,

	/*
	 *
	 *
	 */
	VST_EFFECT_OPCODE_1B = 0x1B,

	/*
	 *
	 *
	 */
	VST_EFFECT_OPCODE_1C = 0x1C,

	/*
	 *
	 *
	 */
	VST_EFFECT_OPCODE_1D = 0x1D, // See VST_EFFECT_OPCODE_05

	/*
	 *
	 *
	 */
	VST_EFFECT_OPCODE_1E = 0x1E,

	/* Input connected.
	 *
	 *
	 */
	VST_EFFECT_OPCODE_1F = 0x1F,

	/* Input disconnected.
	 *
	 *
	 */
	VST_EFFECT_OPCODE_20 = 0x20,

	/* Retrieve the name of the input channel at the given index.
	 *
	 * @param p_int1 Index of the input to get the name for.
	 * @param p_ptr Pointer to a char* buffer able to hold at minimum 20 characters. Might need to be 32 even.
	 * @return 0 on failure, 1 on success.
	 */
	VST_EFFECT_OPCODE_21                   = 0x21,
	VST_EFFECT_OPCODE_INPUT_GETCHANNELNAME = 0x21,
	VST_EFFECT_OPCODE_INPUT_CHANNEL_NAME   = 0x21,

	/* Retrieve the name of the output channel at the given index.
	 *
	 * @param p_int1 Index of the output to get the name for.
	 * @param p_ptr Pointer to a char* buffer able to hold at minimum 20 characters. Might need to be 32 even.
	 * @return 0 on failure, 1 on success.
	 */
	VST_EFFECT_OPCODE_22                    = 0x22,
	VST_EFFECT_OPCODE_OUTPUT_GETCHANNELNAME = 0x22,
	VST_EFFECT_OPCODE_OUTPUT_CHANNEL_NAME   = 0x22,

	/* Retrieve category of this effect.
	 *
	 * @return The category that this effect is in, see VST_CATEGORY.
	 */
	VST_EFFECT_OPCODE_23              = 0x23,
	VST_EFFECT_OPCODE_EFFECT_CATEGORY = 0x23,

	/*
	 *
	 *
	 */
	VST_EFFECT_OPCODE_24 = 0x24,

	/*
	 *
	 *
	 */
	VST_EFFECT_OPCODE_25 = 0x25,

	/*
	 *
	 *
	 */
	VST_EFFECT_OPCODE_26 = 0x26,

	/*
	 *
	 *
	 */
	VST_EFFECT_OPCODE_27 = 0x27,

	/*
	 *
	 *
	 */
	VST_EFFECT_OPCODE_28 = 0x28,

	/*
	 *
	 *
	 */
	VST_EFFECT_OPCODE_29 = 0x29,

	/* Set the speaker arrangement 
	 *
	 * @param p_int2 (vst_speaker_arrangement*) Pointer to a pointer to the speaker arrangement for the input.
	 * @param p_ptr (vst_speaker_arrangement*) Pointer to a pointer to the speaker arrangement for the output.
	 */
	VST_EFFECT_OPCODE_2A                      = 0x2A,
	VST_EFFECT_OPCODE_SET_SPEAKER_ARRANGEMENT = 0x2A,

	/*
	 *
	 *
	 */
	VST_EFFECT_OPCODE_2B = 0x2B,

	/* Enable/Disable bypassing the effect.
	 *
	 * @param p_int2 Zero if bypassing the effect is disabled, otherwise 1.
	 */
	VST_EFFECT_OPCODE_2C     = 0x2C,
	VST_EFFECT_OPCODE_BYPASS = 0x2C,

	/* Retrieve the effect name into the ptr buffer.
	 *
	 * @param p_ptr char[64] Buffer containing a zero-terminated effect information string. May be shorter than 64 bytes on older hosts.
	 * @return Always 0, even on failure.
	 */
	VST_EFFECT_OPCODE_2D          = 0x2D,
	VST_EFFECT_OPCODE_GETNAME     = 0x2D,
	VST_EFFECT_OPCODE_EFFECT_NAME = 0x2D,

	/* Translate an error code to a string.
	 *
	 * @param p_ptr char[256] Buffer that should contain a zero-terminated error string.
	 */
	VST_EFFECT_OPCODE_2E              = 0x2E,
	VST_EFFECT_OPCODE_TRANSLATE_ERROR = 0x2E,

	/* Retrieve the vendor name into the ptr buffer.
	 *
	 * @param p_ptr char[64] Buffer containing a zero-terminated vendor information string. May be shorter than 64 bytes on older hosts.
	 * @return Always 0, even on failure.
	 */
	VST_EFFECT_OPCODE_2F          = 0x2F,
	VST_EFFECT_OPCODE_GETVENDOR   = 0x2F,
	VST_EFFECT_OPCODE_VENDOR_NAME = 0x2F,

	/* See VST_EFFECT_OPCODE_GETNAME
	 *
	 * Rarely used, if at all even supported. Not sure what the purpose of this is even.
	 */
	VST_EFFECT_OPCODE_30           = 0x30,
	VST_EFFECT_OPCODE_GETNAME2     = 0x30,
	VST_EFFECT_OPCODE_PRODUCT_NAME = 0x30,

	/* Retrieve the vendor version in return value.
	 *
	 * @return Version.
	 */
	VST_EFFECT_OPCODE_31               = 0x31,
	VST_EFFECT_OPCODE_GETVENDORVERSION = 0x31,
	VST_EFFECT_OPCODE_VENDOR_VERSION   = 0x31,

	/* User defined OP Code, for custom interaction.
	 * 
	 */
	VST_EFFECT_OPCODE_32     = 0x32,
	VST_EFFECT_OPCODE_CUSTOM = 0x32,

	/* Test for support of a specific named feature.
	 * 
	 * @param p_ptr Pointer to a zero-terminated buffer containing the feature name.
	 * @return Non-zero if the feature is supported, otherwise 0.
	 */
	VST_EFFECT_OPCODE_33       = 0x33,
	VST_EFFECT_OPCODE_SUPPORTS = 0x33,

	/* Number of samples that are at the tail at the end of playback.
	 * 
	 * @return 0 or 1 for no tail, > 1 for number of samples to tail.
	 */
	VST_EFFECT_OPCODE_34             = 0x34,
	VST_EFFECT_OPCODE_GETTAILSAMPLES = 0x34,
	VST_EFFECT_OPCODE_TAIL_SAMPLES   = 0x34,

	/*
	 *
	 *
	 */
	VST_EFFECT_OPCODE_35 = 0x35,

	/*
	 *
	 *
	 */
	VST_EFFECT_OPCODE_36 = 0x36,

	/*
	 *
	 *
	 */
	VST_EFFECT_OPCODE_37 = 0x37,

	/*
	 *
	 *
	 */
	VST_EFFECT_OPCODE_38 = 0x38,

	/* Parameter Properties
	 *
	 * @param p_ptr vst_parameter_properties*
	 * @return 1 if supported, otherwise 0.
	 */
	VST_EFFECT_OPCODE_39                       = 0x39,
	VST_EFFECT_OPCODE_GET_PARAMETER_PROPERTIES = VST_EFFECT_OPCODE_39,

	/* Retrieve the VST Version supported.
	 *
	 * @return Return 0 for <2.0, 2 for 2.0, 2100 for 2.1, 2200 for 2.2, 2300 for 2.3, etc.
	 */
	VST_EFFECT_OPCODE_3A          = 0x3A,
	VST_EFFECT_OPCODE_VST_VERSION = 0x3A,

	// VST 2.1 or later

	/*
	 *
	 *
	 */
	VST_EFFECT_OPCODE_3B = 0x3B,

	/*
	 *
	 *
	 */
	VST_EFFECT_OPCODE_3C = 0x3C,

	/*
	 *
	 *
	 */
	VST_EFFECT_OPCODE_3D = 0x3D,

	/*
	 *
	 *
	 */
	VST_EFFECT_OPCODE_3E = 0x3E,

	/*
	 *
	 *
	 */
	VST_EFFECT_OPCODE_3F = 0x3F,

	/*
	 *
	 *
	 */
	VST_EFFECT_OPCODE_40 = 0x40,

	/*
	 *
	 *
	 */
	VST_EFFECT_OPCODE_41 = 0x41,

	/*
	 *
	 *
	 */
	VST_EFFECT_OPCODE_42 = 0x42,

	/*
	 *
	 *
	 */
	VST_EFFECT_OPCODE_43 = 0x43,

	/*
	 *
	 *
	 */
	VST_EFFECT_OPCODE_44 = 0x44,

	// VST 2.3 or later

	/* Retrieve the speaker arrangement.
	 *
	 * @param p_int2 (vst_speaker_arrangement**) Pointer to a pointer to the speaker arrangement for the input.
	 * @param p_ptr (vst_speaker_arrangement**) Pointer to a pointer to the speaker arrangement for the output.
	 */
	VST_EFFECT_OPCODE_45                      = 0x45,
	VST_EFFECT_OPCODE_GET_SPEAKER_ARRANGEMENT = 0x45,

	/*
	 *
	 *
	 */
	VST_EFFECT_OPCODE_46 = 0x46,

	/* Begin processing of audio.
	 *
	 * 
	 * 
	 */
	VST_EFFECT_OPCODE_PROCESS_BEGIN = 0x47,

	/* End processing of audio.
	 *
	 * 
	 *
	 */
	VST_EFFECT_OPCODE_PROCESS_END = 0x48,

	/*
	 *
	 *
	 */
	VST_EFFECT_OPCODE_49 = 0x49,

	/*
	 *
	 *
	 */
	VST_EFFECT_OPCODE_4A = 0x4A,

	/*
	 *
	 *
	 */
	VST_EFFECT_OPCODE_4B = 0x4B,

	/*
	 *
	 *
	 */
	VST_EFFECT_OPCODE_4C = 0x4C,

	// VST 2.4 or later

	/*
	 *
	 *
	 */
	VST_EFFECT_OPCODE_4D = 0x4D,

	/*
	 *
	 *
	 */
	VST_EFFECT_OPCODE_4E = 0x4E,

	/*
	 *
	 *
	 */
	VST_EFFECT_OPCODE_4F = 0x4F,

	// Highest number of known OPCODE.
	VST_EFFECT_OPCODE_MAX,

	// Pad to force 32-bit number.
	_VST_EFFECT_OPCODE_PAD = 0xFFFFFFFFul,
};

enum VST_HOST_OPCODE {
	/*
	 * @param int1 -1 or Parameter Index
	 * @return Expected to return... something.
	 */
	VST_HOST_OPCODE_00 = 0x00, // cb(vst, 0x00, ?, 0, 0);
	VST_HOST_OPCODE_01 = 0x01,
	VST_HOST_OPCODE_02 = 0x02, // bool cb(0, 0x02, 0, 0, 0);
	VST_HOST_OPCODE_03 = 0x03,
	VST_HOST_OPCODE_04 = 0x04,
	VST_HOST_OPCODE_05 = 0x05,
	VST_HOST_OPCODE_06 = 0x06,
	VST_HOST_OPCODE_07 = 0x07,
	VST_HOST_OPCODE_08 = 0x08,
	VST_HOST_OPCODE_09 = 0x09,
	VST_HOST_OPCODE_0A = 0x0A,
	VST_HOST_OPCODE_0B = 0x0B,
	VST_HOST_OPCODE_0C = 0x0C,
	VST_HOST_OPCODE_0D = 0x0D,
	VST_HOST_OPCODE_0E = 0x0E,
	VST_HOST_OPCODE_0F = 0x0F,
	VST_HOST_OPCODE_10 = 0x10,
	VST_HOST_OPCODE_11 = 0x11,
	VST_HOST_OPCODE_12 = 0x12,
	VST_HOST_OPCODE_13 = 0x13,
	VST_HOST_OPCODE_14 = 0x14,
	VST_HOST_OPCODE_15 = 0x15,
	VST_HOST_OPCODE_16 = 0x16,
	VST_HOST_OPCODE_17 = 0x17,
	VST_HOST_OPCODE_18 = 0x18,
	VST_HOST_OPCODE_19 = 0x19,
	VST_HOST_OPCODE_1A = 0x1A,
	VST_HOST_OPCODE_1B = 0x1B,
	VST_HOST_OPCODE_1C = 0x1C,
	VST_HOST_OPCODE_1D = 0x1D,
	VST_HOST_OPCODE_1E = 0x1E,
	VST_HOST_OPCODE_1F = 0x1F,
	VST_HOST_OPCODE_20 = 0x20,
	VST_HOST_OPCODE_21 = 0x21,
	VST_HOST_OPCODE_22 = 0x22,
	VST_HOST_OPCODE_23 = 0x23,
	VST_HOST_OPCODE_24 = 0x24,
	VST_HOST_OPCODE_25 = 0x25,
	VST_HOST_OPCODE_26 = 0x26,
	VST_HOST_OPCODE_27 = 0x27,
	VST_HOST_OPCODE_28 = 0x28,
	VST_HOST_OPCODE_29 = 0x29,
	VST_HOST_OPCODE_2A = 0x2A,

	/* Parameter gained focus.
	 *
	 * @param int1 Parameter index.
	 */
	VST_HOST_OPCODE_2B = 0x2B,

	/* Parameter lost focus.
	 * 
	 * @param int1 Parameter index.
	 */
	VST_HOST_OPCODE_2C = 0x2C,

	VST_HOST_OPCODE_2D = 0x2D,
	VST_HOST_OPCODE_2E = 0x2E,
	VST_HOST_OPCODE_2F = 0x2F,

	// Highest number of known OPCODE.
	VST_HOST_OPCODE_MAX,

	// Pad to force 32-bit number.
	_VST_HOST_OPCODE_PAD = 0xFFFFFFFFul,
};

enum VST_ARRANGEMENT_TYPE {
	/* Custom speaker arrangement.
	 *
	 * Accidentally discovered through random testing.
	 */
	VST_ARRANGEMENT_TYPE_CUSTOM = -2,

	/* Unknown/Empty speaker layout.
	 *
	 */
	VST_ARRANGEMENT_TYPE_UNKNOWN = -1,

	/* Mono
	 */
	VST_ARRANGEMENT_TYPE_MONO = 0,

	/* Stereo
	 */
	VST_ARRANGEMENT_TYPE_STEREO = 1,

	/* 5.1
	 */
	VST_ARRANGEMENT_TYPE_5_1 = 0x0F,

	// Pad to force 32-bit number.
	_VST_ARRANGEMENT_TYPE_PAD = 0xFFFFFFFFul,
};

enum VST_SPEAKER_TYPE {
	VST_SPEAKER_TYPE_MONO       = 0,
	VST_SPEAKER_TYPE_LEFT       = 1,
	VST_SPEAKER_TYPE_RIGHT      = 2,
	VST_SPEAKER_TYPE_CENTER     = 3,
	VST_SPEAKER_TYPE_LFE        = 4,
	VST_SPEAKER_TYPE_LEFT_SIDE  = 5,
	VST_SPEAKER_TYPE_RIGHT_SIDE = 6,

	// Pad to force 32-bit number.
	_VST_SPEAKER_TYPE_PAD = 0xFFFFFFFFul,
};

enum VST_PARAMETER_FLAGS {
	/**
	 * Parameter is an on/off switch.
	 */
	VST_PARAMETER_FLAGS_SWITCH = 1,
	/**
	 * Limits defined by integers.
	 */
	VST_PARAMETER_FLAGS_INTEGER_LIMITS = 1 << 1,
	/**
	 * Uses float steps.
	 */
	VST_PARAMETER_FLAGS_STEP_FLOAT = 1 << 2,
	/**
	 * Uses integer steps.
	 */
	VST_PARAMETER_FLAGS_STEP_INT = 1 << 3,
	/**
	 * Respect index variable for display ordering.
	 */
	VST_PARAMETER_FLAGS_INDEX = 1 << 4,
	/**
	 * Respect category value and names.
	 */
	VST_PARAMETER_FLAGS_CATEGORY = 1 << 5,
	VST_PARAMETER_FLAGS_UNKNOWN6 = 1 << 6,
	_VST_PARAMETER_FLAGS_PAD     = 0xFFFFFFFFul,
};

/*******************************************************************************
|* Structures
|*/

struct vst_rect {
	int16_t left;
	int16_t top;
	int16_t right;
	int16_t bottom;
};

struct vst_effect {
	int32_t magic_number; // Should always be VST_MAGICNUMBER

	// 64-bit adds 4-byte padding here to align pointers.

	/* Control the VST through an opcode and up to four parameters.
	 * 
	 * @param this Pointer to the effect itself.
	 * @param opcode The opcode to run, see VST_EFFECT_OPCODES.
	 * @param p_int1 Parameter, see VST_EFFECT_OPCODES.
	 * @param p_int2 Parameter, see VST_EFFECT_OPCODES.
	 * @param p_ptr Parameter, see VST_EFFECT_OPCODES.
	 * @param p_float Parameter, see VST_EFFECT_OPCODES.
	 */
	intptr_t(VST_FUNCTION_INTERFACE* control)(vst_effect* pthis, VST_EFFECT_OPCODE opcode, int32_t p_int1, intptr_t p_int2, void* p_ptr, float p_float);

	/* Process the given number of samples in inputs and outputs.
	 *
	 * Different to process_float how? Never seen any difference.
	 * 
	 * @param pthis Pointer to the effect itself.
	 * @param inputs Pointer to an array of 'const float[samples]' with size numInputs.
	 * @param outputs Pointer to an array of 'float[samples]' with size numOutputs.
	 * @param samples Number of samples per channel in inputs.
	 */
	void(VST_FUNCTION_INTERFACE* process)(vst_effect* pthis, const float* const* inputs, float** outputs, int32_t samples);

	/* Updates the value for the parameter at the given index, or does nothing if out of bounds.
	 * 
	 * @param pthis Pointer to the effect itself.
	 * @param index Parameter index.
	 * @param value New value for the parameter.
	 */
	void(VST_FUNCTION_INTERFACE* set_parameter)(vst_effect* pthis, uint32_t index, float value);

	/* Returns the value stored for the parameter at index, or 0 if out of bounds.
	 * 
	 * @param pthis Pointer to the effect itself.
	 * @param index Parameter index.
	 * @return float Value of the parameter.
	 */
	float(VST_FUNCTION_INTERFACE* get_parameter)(vst_effect* pthis, uint32_t index);

	int32_t num_programs; // Number of possible programs.
	int32_t num_params; // Number of possible parameters.
	int32_t num_inputs; // Number of inputs.
	int32_t num_outputs; // Number of outputs.

	/* Bitflags
	 * 
	 * Bit		Description
	 * 1		Effect has "Editor"
	 * 2		Unknown (Found in: ReaDelay)
	 * 3		Unknown (Found in: ReaDelay)
	 * 4		Unknown (Found in: ReaDelay)
	 * 5		Has process_float (Found in: ReaDelay, ReaComp, ReaControlMIDI, ReaStream, ReaFir)
	 * 6		Unknown (Found in: ReaControlMIDI, ReaStream, ReaFir)
	 * 10		Unknown (Found in: ReaFir)
	 * 13		Has process_double (Found in: ReaControlMIDI)
	 */
	int32_t flags;

	// 64-bit adds 4-byte padding here to align pointers.

	void* _unknown_ptr_00[2];

	/* Initial delay before processing of samples can actually begin in Samples.
	 *
	 * Should be updated before or during handling the 0x47 control call. 
	 */
	int32_t delay;

	int32_t _unknown_int32_00[2]; // Unknown int32_t values.
	float   _unknown_float_00; // Seems to always be 1.0

	void* effect_internal; // Pointer to Plugin internal data
	void* host_internal; // Pointer to Host internal data.

	/* Id of the plugin.
	 *
	 * Due to this not being enough for uniqueness, it should not be used alone 
	 * for indexing. Ideally you want to index like this:
	 *     [unique_id][module_name][version][flags]
	 * If any of the checks after unique_id fail, you default to the first 
	 * possible choice.
	 */
	int32_t unique_id;

	/* Plugin version
	 * 
	 * Unrelated to the minimum VST Version, but often the same.
	 */
	int32_t version;

	// There is no padding here if everything went right.

	/* Process the given number of single samples in inputs and outputs.
	 *
	 * @param pthis Pointer to the effect itself.
	 * @param inputs Pointer to an array of 'const float[samples]' with size numInputs.
	 * @param outputs Pointer to an array of 'float[samples]' with size numOutputs.
	 * @param samples Number of samples per channel in inputs.
	 */
	void(VST_FUNCTION_INTERFACE* process_float)(vst_effect* pthis, const float* const* inputs, float** outputs, int32_t samples);

	/* Process the given number of double samples in inputs and outputs.
	 *
	 * Used only by 2.4 hosts and plugins, possibly restricted to said version.
	 * 
	 * @param pthis Pointer to the effect itself.
	 * @param inputs Pointer to an array of 'const double[samples]' with size numInputs.
	 * @param outputs Pointer to an array of 'double[samples]' with size numOutputs.
	 * @param samples Number of samples per channel in inputs.
	 */
	void(VST_FUNCTION_INTERFACE* process_double)(vst_effect* pthis, const double* const* inputs, double** outputs, int32_t samples);

	// Everything after this is unknown and was present in reacomp-standalone.dll.
	uint8_t _unknown[56]; // 56-bytes of something. Could also just be 52-bytes.
};

struct vst_parameter_properties {
	float step_f32;
	float step_small_f32;
	float step_large_f32;

	char name[VST_BUFFER_64];

	uint32_t flags;
	int32_t  min_value_i32;
	int32_t  max_value_i32;
	int32_t  step_i32;

	char label[VST_BUFFER_8];

	uint16_t index;

	uint16_t category;
	uint16_t num_parameters_in_category;
	uint16_t _unknown_00;

	char category_label[VST_BUFFER_24];

	char _unknown_01[VST_BUFFER_16];
};

struct vst_speaker_properties {
	float            _unknown_00; // 10.0 if LFE, otherwise random? Never exceeds -PI to PI range.
	float            _unknown_04; // 10.0 if LFE, otherwise random? Never exceeds -PI to PI range.
	float            _unknown_08; // 0.0 if LFE, otherwise 1.0.
	float            _unknown_0C;
	char             name[VST_BUFFER_64];
	VST_SPEAKER_TYPE type;

	uint8_t _unknown[28]; // Padding detected from testing.
};

struct vst_speaker_arrangement {
	VST_ARRANGEMENT_TYPE   type; // See VST_SPEAKER_ARRANGEMENT_TYPE
	int32_t                channels; // Number of channels in speakers.
	vst_speaker_properties speakers[VST_MAX_CHANNELS]; // Array of speaker properties, actual size defined by channels.
};

/* Callback used by the plugin to interface with the host.
 * 
 * @param opcode See VST_HOST_OPCODE
 * @param p_str Zero terminated string or null on call.
 * @return ?
 */
typedef intptr_t (*vst_host_callback)(vst_effect* plugin, VST_HOST_OPCODE opcode, int32_t p_int1, int64_t p_int2, const char* p_str, float p_float);

static const char* vst_host_string[] = {
	"GetResourcePath", // ReaControlMIDI
	"get_ini_file", // ReaControlMIDI
	"resolve_fn", // ReaControlMIDI
};

/* Entry point for VST2.x plugins.
 *
 * @return A new instance of the VST2.x effect.
 */
#define VST_ENTRYPOINT vst_effect* VSTPluginMain(vst_host_callback callback)
#define VST_ENTRYPOINT_WINDOWS                   \
	vst_effect* MAIN(vst_host_callback callback) \
	{                                            \
		return VSTPluginMain(callback);          \
	}
#define VST_ENTRYPOINT_MACOS                           \
	vst_effect* main_macho(vst_host_callback callback) \
	{                                                  \
		return VSTPluginMain(callback);                \
	}

#ifdef __cplusplus
}
#endif

// Variable size variant of vst_speaker_arrangement.
#ifdef __cplusplus
template<size_t T>
struct vst_speaker_arrangement_t {
	VST_ARRANGEMENT_TYPE   type; // See VST_SPEAKER_ARRANGEMENT_TYPE
	int32_t                channels; // Number of channels in speakers.
	vst_speaker_properties speakers[T]; // Array of speaker properties, actual size defined by channels.
};
#endif

#pragma pack(pop)

#endif