dolphin/Source/Core/InputCommon/Src/Configuration.cpp

//////////////////////////////////////////////////////////////////////////////////////////
// Project description
// ¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯
// Name: Input Configuration and Calibration
// Description: Common SDL Input Functions
//
// Author: Falcon4ever (nJoy@falcon4ever.com, www.multigesture.net), JPeterson etc
// Copyright (C) 2003-2008 Dolphin Project.
//
//////////////////////////////////////////////////////////////////////////////////////////
//
// Licensetype: GNU General Public License (GPL)
//
// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, version 2.0.
//
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU General Public License 2.0 for more details.
//
// A copy of the GPL 2.0 should have been included with the program.
// If not, see http://www.gnu.org/licenses/
//
// Official SVN repository and contact information can be found at
// http://code.google.com/p/dolphin-emu/
//
//////////////////////////////////////////////////////////////////////////////////////////



//////////////////////////////////////////////////////////////////////////////////////////
// Include
// ¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯
#include "SDL.h" // Local
////////////////////////////////////


namespace InputCommon
{


//////////////////////////////////////////////////////////////////////////////////////////
// Convert stick values
// ¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯

/* Convert stick values.

   The value returned by SDL_JoystickGetAxis is a signed integer s16
   (-32768 to 32767). The value used for the gamecube controller is an unsigned
   char u8 (0 to 255) with neutral at 0x80 (128), so that it's equivalent to a signed
   -128 to 127.
*/
// ¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯
int Pad_Convert(int _val)
{
	/* If the limits on PadState[].axis[] actually is a u16 then we don't need this
	   but if it's not actually limited to that we need to apply these limits */
	if(_val > 32767) _val = 32767; // upper limit
	if(_val < -32768) _val = -32768; // lower limit
		
	// Convert the range (-0x8000 to 0x7fff) to (0 to 0xffff)
	_val = 0x8000 +_val;

	// Convert the range (-32768 to 32767) to (-128 to 127)
	_val = _val >> 8;

	//Console::Print("0x%04x  %06i\n\n", _val, _val);

	return _val;
}

 
/* Convert the stick raidus from a circular to a square. I don't know what input values
   the actual GC controller produce for the GC, it may be a square, a circle or something
   in between. But one thing that is certain is that PC pads differ in their output (as
   shown in the list below), so it may be beneficiary to convert whatever radius they
   produce to the radius the GC games expect. This is the first implementation of this
   that convert a square radius to a circual radius. Use the advanced settings to enable
   and calibrate it.

   Observed diagonals:
   Perfect circle: 71% = sin(45)
   Logitech Dual Action: 100%
   Dual Shock 2 (Original) with Super Dual Box Pro: 90%
   XBox 360 Wireless: 85%
   GameCube Controller (Third Party) with EMS TrioLinker Plus II: 60%
*/
// ¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯
float SquareDistance(float deg)
{
	// See if we have to adjust the angle
	deg = abs(deg);
	if( (deg > 45 && deg < 135) ) deg = deg - 90;

	// Calculate radians from degrees
	float rad = deg * M_PI / 180;

	float val = abs(cos(rad));
	float dist = 1 / val; // Calculate distance from center

	//m_frame->m_pStatusBar2->SetLabel(wxString::Format("Deg:%f  Val:%f  Dist:%f", deg, val, dist));

	return dist;
}
std::vector<int> Pad_Square_to_Circle(int _x, int _y, int _pad, CONTROLLER_MAPPING _PadMapping)
{
	/* Do we need this? */
	if(_x > 32767) _x = 32767; if(_y > 32767) _y = 32767; // upper limit
	if(_x < -32768) _x = -32768; if(_y > 32767) _y = 32767; // lower limit

	// ====================================
	// Convert to circle
	// -----------
	int Tmp = atoi (_PadMapping.SDiagonal.substr(0, _PadMapping.SDiagonal.length() - 1).c_str());
	float Diagonal = Tmp / 100.0;

	// First make a perfect square in case we don't have one already
	float OrigDist = sqrt(  pow((float)_y, 2) + pow((float)_x, 2)  ); // Get current distance
	float rad = atan2((float)_y, (float)_x); // Get current angle
	float deg = rad * 180 / M_PI;

	// A diagonal of 85% means a distance of 1.20
	float corner_circle_dist = ( Diagonal / sin(45 * M_PI / 180) );
	float SquareDist = SquareDistance(deg);
	float adj_ratio1; // The original-to-square distance adjustment
	float adj_ratio2 = SquareDist; // The circle-to-square distance adjustment
	// float final_ratio; // The final adjustment to the current distance //TODO: This is not used
	float result_dist; // The resulting distance

	// Calculate the corner-to-square adjustment ratio
	if(corner_circle_dist < SquareDist) adj_ratio1 = SquareDist / corner_circle_dist;
		else adj_ratio1 = 1;

	// Calculate the resulting distance
	result_dist = OrigDist * adj_ratio1 / adj_ratio2;

	float x = result_dist * cos(rad); // calculate x
	float y = result_dist * sin(rad); // calculate y

	int int_x = (int)floor(x);
	int int_y = (int)floor(y);

	// Debugging
	//m_frame->m_pStatusBar2->SetLabel(wxString::Format("%f  %f  %i", corner_circle_dist, Diagonal, Tmp));

	std::vector<int> vec;
	vec.push_back(int_x);
	vec.push_back(int_y);
	return vec;
}
/////////////////////////////////////////////////////////////////////


}