source: rtems/c/src/lib/libbsp/arm/nds/touchscreen/reco.h @ 311dfa6

#ifndef RECO_H
#define RECO_H

#include <nds.h>

#define PA_RECOTESTS 40

#define PA_BACKSPACE 1    // On va dire que la touche backspace a pour valeur 1...
#define PA_ENTER     '\n'    // 3 pour Enter


typedef struct{
   u8 x, y;
} PA_StylusPosition;

typedef struct{
        u32 nvalues, oldn, veryold;
} PA_RecoValues;

typedef struct{
        u32 Length;
        u8 minX, minY, maxX, maxY; // Shape limits
        u8 startX, startY, endX, endY; // Start and end position
        s16 Angle;
        s32 Difference;
        u8 Shape;
} PA_RecoInfos;

typedef struct{
   char letter;
        char code[16];
} PA_FormType;

static inline u64 PA_Distance(s32 x1, s32 y1, s32 x2, s32 y2) {
   s64 h = x1 - x2;
   s64 v = y1 - y2;
   return(h*h + v*v);
}

#define PA_Cos(angle) PA_SIN[((angle) + 128)&511]
#define PA_Sin(angle) PA_SIN[((angle))&511]

static const s16 PA_SIN[512] = {
        0x0000,0x0003,0x0006,0x0009,0x000D,0x0010,0x0013,0x0016,        0x0019,0x001C,0x001F,0x0022,0x0026,0x0029,0x002C,0x002F,
        0x0032,0x0035,0x0038,0x003B,0x003E,0x0041,0x0044,0x0047,        0x004A,0x004D,0x0050,0x0053,0x0056,0x0059,0x005C,0x005F,
        0x0062,0x0065,0x0068,0x006B,0x006D,0x0070,0x0073,0x0076,        0x0079,0x007B,0x007E,0x0081,0x0084,0x0086,0x0089,0x008C,
        0x008E,0x0091,0x0093,0x0096,0x0098,0x009B,0x009D,0x00A0,        0x00A2,0x00A5,0x00A7,0x00AA,0x00AC,0x00AE,0x00B1,0x00B3,

        0x00B5,0x00B7,0x00B9,0x00BC,0x00BE,0x00C0,0x00C2,0x00C4,        0x00C6,0x00C8,0x00CA,0x00CC,0x00CE,0x00CF,0x00D1,0x00D3,
        0x00D5,0x00D7,0x00D8,0x00DA,0x00DC,0x00DD,0x00DF,0x00E0,        0x00E2,0x00E3,0x00E5,0x00E6,0x00E7,0x00E9,0x00EA,0x00EB,
        0x00ED,0x00EE,0x00EF,0x00F0,0x00F1,0x00F2,0x00F3,0x00F4,        0x00F5,0x00F6,0x00F7,0x00F8,0x00F8,0x00F9,0x00FA,0x00FA,
        0x00FB,0x00FC,0x00FC,0x00FD,0x00FD,0x00FE,0x00FE,0x00FE,        0x00FF,0x00FF,0x00FF,0x0100,0x0100,0x0100,0x0100,0x0100,

        0x0100,0x0100,0x0100,0x0100,0x0100,0x0100,0x00FF,0x00FF,        0x00FF,0x00FE,0x00FE,0x00FE,0x00FD,0x00FD,0x00FC,0x00FC,
        0x00FB,0x00FA,0x00FA,0x00F9,0x00F8,0x00F8,0x00F7,0x00F6,        0x00F5,0x00F4,0x00F3,0x00F2,0x00F1,0x00F0,0x00EF,0x00EE,
        0x00ED,0x00EB,0x00EA,0x00E9,0x00E7,0x00E6,0x00E5,0x00E3,        0x00E2,0x00E0,0x00DF,0x00DD,0x00DC,0x00DA,0x00D8,0x00D7,
        0x00D5,0x00D3,0x00D1,0x00CF,0x00CE,0x00CC,0x00CA,0x00C8,        0x00C6,0x00C4,0x00C2,0x00C0,0x00BE,0x00BC,0x00B9,0x00B7,

        0x00B5,0x00B3,0x00B1,0x00AE,0x00AC,0x00AA,0x00A7,0x00A5,        0x00A2,0x00A0,0x009D,0x009B,0x0098,0x0096,0x0093,0x0091,
        0x008E,0x008C,0x0089,0x0086,0x0084,0x0081,0x007E,0x007B,        0x0079,0x0076,0x0073,0x0070,0x006D,0x006B,0x0068,0x0065,
        0x0062,0x005F,0x005C,0x0059,0x0056,0x0053,0x0050,0x004D,        0x004A,0x0047,0x0044,0x0041,0x003E,0x003B,0x0038,0x0035,
        0x0032,0x002F,0x002C,0x0029,0x0026,0x0022,0x001F,0x001C,        0x0019,0x0016,0x0013,0x0010,0x000D,0x0009,0x0006,0x0003,

        0x0000,0xFFFD,0xFFFA,0xFFF7,0xFFF3,0xFFF0,0xFFED,0xFFEA,        0xFFE7,0xFFE4,0xFFE1,0xFFDE,0xFFDA,0xFFD7,0xFFD4,0xFFD1,
        0xFFCE,0xFFCB,0xFFC8,0xFFC5,0xFFC2,0xFFBF,0xFFBC,0xFFB9,        0xFFB6,0xFFB3,0xFFB0,0xFFAD,0xFFAA,0xFFA7,0xFFA4,0xFFA1,
        0xFF9E,0xFF9B,0xFF98,0xFF95,0xFF93,0xFF90,0xFF8D,0xFF8A,        0xFF87,0xFF85,0xFF82,0xFF7F,0xFF7C,0xFF7A,0xFF77,0xFF74,
        0xFF72,0xFF6F,0xFF6D,0xFF6A,0xFF68,0xFF65,0xFF63,0xFF60,        0xFF5E,0xFF5B,0xFF59,0xFF56,0xFF54,0xFF52,0xFF4F,0xFF4D,

        0xFF4B,0xFF49,0xFF47,0xFF44,0xFF42,0xFF40,0xFF3E,0xFF3C,        0xFF3A,0xFF38,0xFF36,0xFF34,0xFF32,0xFF31,0xFF2F,0xFF2D,
        0xFF2B,0xFF29,0xFF28,0xFF26,0xFF24,0xFF23,0xFF21,0xFF20,        0xFF1E,0xFF1D,0xFF1B,0xFF1A,0xFF19,0xFF17,0xFF16,0xFF15,
        0xFF13,0xFF12,0xFF11,0xFF10,0xFF0F,0xFF0E,0xFF0D,0xFF0C,        0xFF0B,0xFF0A,0xFF09,0xFF08,0xFF08,0xFF07,0xFF06,0xFF06,
        0xFF05,0xFF04,0xFF04,0xFF03,0xFF03,0xFF02,0xFF02,0xFF02,        0xFF01,0xFF01,0xFF01,0xFF00,0xFF00,0xFF00,0xFF00,0xFF00,

        0xFF00,0xFF00,0xFF00,0xFF00,0xFF00,0xFF00,0xFF01,0xFF01,        0xFF01,0xFF02,0xFF02,0xFF02,0xFF03,0xFF03,0xFF04,0xFF04,
        0xFF05,0xFF06,0xFF06,0xFF07,0xFF08,0xFF08,0xFF09,0xFF0A,        0xFF0B,0xFF0C,0xFF0D,0xFF0E,0xFF0F,0xFF10,0xFF11,0xFF12,
        0xFF13,0xFF15,0xFF16,0xFF17,0xFF19,0xFF1A,0xFF1B,0xFF1D,        0xFF1E,0xFF20,0xFF21,0xFF23,0xFF24,0xFF26,0xFF28,0xFF29,
        0xFF2B,0xFF2D,0xFF2F,0xFF31,0xFF32,0xFF34,0xFF36,0xFF38,        0xFF3A,0xFF3C,0xFF3E,0xFF40,0xFF42,0xFF44,0xFF47,0xFF49,

        0xFF4B,0xFF4D,0xFF4F,0xFF52,0xFF54,0xFF56,0xFF59,0xFF5B,        0xFF5E,0xFF60,0xFF63,0xFF65,0xFF68,0xFF6A,0xFF6D,0xFF6F,
        0xFF72,0xFF74,0xFF77,0xFF7A,0xFF7C,0xFF7F,0xFF82,0xFF85,        0xFF87,0xFF8A,0xFF8D,0xFF90,0xFF93,0xFF95,0xFF98,0xFF9B,
        0xFF9E,0xFFA1,0xFFA4,0xFFA7,0xFFAA,0xFFAD,0xFFB0,0xFFB3,        0xFFB6,0xFFB9,0xFFBC,0xFFBF,0xFFC2,0xFFC5,0xFFC8,0xFFCB,
        0xFFCE,0xFFD1,0xFFD4,0xFFD7,0xFFDA,0xFFDE,0xFFE1,0xFFE4,        0xFFE7,0xFFEA,0xFFED,0xFFF0,0xFFF3,0xFFF7,0xFFFA,0xFFFD};


static u16 PA_AdjustAngle(u16 angle, s16 anglerot, s32 startx, s32 starty, s32 targetx, s32 targety) {
u64 distances[3];

        startx = startx << 8; // Fixed point...
        starty = starty << 8; // Fixed point...
        targetx = targetx << 8; // Fixed point...
        targety = targety << 8; // Fixed point...

      u16 tempangle = (angle - anglerot) & 511;


      // Calcul des distances en fonction des angles
      distances[0] = PA_Distance(startx + PA_Cos(tempangle), starty - PA_Sin(tempangle), targetx, targety);
      tempangle += anglerot;
          tempangle &= 511;
      distances[1] = PA_Distance(startx + PA_Cos(tempangle), starty - PA_Sin(tempangle), targetx, targety);
      tempangle += anglerot;
          tempangle &= 511;
      distances[2] = PA_Distance(startx + PA_Cos(tempangle), starty - PA_Sin(tempangle), targetx, targety);



      // On regarde si l'angle est optimal. Si ce n'est pas le cas,
      // on fait tourner toujours dans le meme sens...
      if (distances[0] < distances[1])  angle -= anglerot;
      else if (distances[2] < distances[1])  angle += anglerot;

      return (angle&511);
}

static  inline u16 PA_GetAngle(s32 startx, s32 starty, s32 targetx, s32 targety) {
u16 angle = 0;
u16 anglerot = 180;


while(anglerot > 5) {
        angle = PA_AdjustAngle(angle, anglerot, startx, starty, targetx, targety);
        anglerot = (anglerot - ((3 * anglerot) >> 3)); // On diminue petit à petit la rotation...
}

// Ajustement encore plus précis...
anglerot = 4;
angle = PA_AdjustAngle(angle, anglerot, startx, starty, targetx, targety);
anglerot = 2;
angle = PA_AdjustAngle(angle, anglerot, startx, starty, targetx, targety);
anglerot = 1;
angle = PA_AdjustAngle(angle, anglerot, startx, starty, targetx, targety);

return angle;
}


#endif RECO_H