fish/surf/bezpt.c

   1 #include <aros/oldprograms.h>
   2 #include "mytypes.h"
   3 #include "scrnio.h"
   4 #include "control.h"
   5 #include "bezpt.h"
   6
   7 BezCoord Bezpt[MaxSegs+1];
   8
   9 int NumBezPts;
  10 int ActSeg;
  11 bool SegDrawn;
  12 int BezMesh = DefBezMeshVal;
  13 float BezStepSize = 1.0/DefBezMeshVal;
  14
  15 void DrawBox(int, int, int);
  16 void DrawSqr(int, int, int);
  17 void DrawPnt(int, int, int);
  18 void DrawLine(int, int, int, int, int);
  19 void ClrWindow(bool);
  20
  21 void SetBezMesh( value )
  22     int value;
  23 {
  24     BezMesh = value;
  25     BezStepSize = 1.0/value;
  26 }
  27
  28
  29 void ClearSegments()
  30 {
  31     NumBezPts = 0;
  32     ActSeg = 0;
  33 }
  34
  35
  36 static  float xa, xb, xc, xd;
  37 static  float ya, yb, yc, yd;
  38 /*
  39  * start up calculations that must be performed before calling
  40  * CalcBezPt on any given segment
  41  */
  42 void InitCalcBez()
  43 {
  44         xa = -StartPtX(ActSeg) + 3.0*( Cntrl1X(ActSeg) - Cntrl2X(ActSeg))
  45             + EndPtX(ActSeg);
  46         xb = 3.0 *( StartPtX(ActSeg) + Cntrl2X(ActSeg) - 2.0*Cntrl1X(ActSeg));
  47         xc = 3.0*( Cntrl1X(ActSeg) - StartPtX(ActSeg));
  48         xd = StartPtX(ActSeg);
  49
  50         ya = -StartPtY(ActSeg) + 3.0*( Cntrl1Y(ActSeg) - Cntrl2Y(ActSeg))
  51             + EndPtY(ActSeg);
  52         yb = 3.0 *( StartPtY(ActSeg) + Cntrl2Y(ActSeg) - 2.0*Cntrl1Y(ActSeg));
  53         yc = 3.0*( Cntrl1Y(ActSeg) - StartPtY(ActSeg));
  54         yd = StartPtY(ActSeg);
  55 }
  56
  57 /*
  58  * calculate a point on the bezier curve of a segment
  59  */
  60 void CalcBezPt( t, xvp, yvp)
  61     float t;
  62     float *xvp, *yvp;
  63 {
  64     *xvp = (( t*xa + xb) * t + xc) *t + xd;
  65
  66     *yvp = (( t*ya + yb) * t + yc) *t + yd;
  67 }
  68
  69
  70
  71 void XdrawBezSeg()
  72 {
  73     float t;
  74     float ftox, ftoy;
  75     int fromx, fromy, tox, toy;
  76
  77     InitCalcBez();
  78     for( fromx = StartPtX(ActSeg), fromy = StartPtY(ActSeg), t=BezStepSize;
  79         t < 1.0; fromx = tox, fromy = toy, t+= BezStepSize ) {
  80
  81         CalcBezPt( t, &ftox, &ftoy );
  82         tox = (int)ftox;
  83         toy = (int)ftoy;
  84         DrawLine( fromx, fromy, tox, toy, XOR );
  85         DrawPnt( tox, toy, XOR );
  86     }
  87     DrawLine( fromx, fromy, EndPtX(ActSeg), EndPtY(ActSeg),XOR);
  88 }
  89
  90
  91
  92 void XdrawAllBezSegs()
  93 {
  94     ResetActSeg();
  95     do {
  96         XdrawBezSeg();
  97         NextSeg();
  98     } while( ActSeg);
  99
 100     DrawStartPt();      /* Leonards changes */
 101     DrawEndPt();        /* Leonards changes */
 102     DrawControl0();
 103     DrawControl1();
 104 }
 105
 106
 107
 108 void ResetCurve()
 109 {
 110     if( NumBezPts > 0 && CurMode == FITBEZIER ) {
 111         int i;
 112
 113         ClrWindow(true);
 114         for( i = 0; i < NumBezPts; i++ ) {
 115             Bezpt[i].x.cur1 = Bezpt[i].x.prev2 = Bezpt[i].x.cur0;
 116             Bezpt[i].y.cur1 = Bezpt[i].y.prev2 = Bezpt[i].y.cur0;
 117         }
 118         ActSeg = 0;
 119
 120         XdrawAllBezSegs();
 121     }
 122 }
 123
 124
 125 /*
 126  * set the value of a bezpt element
 127  */
 128 static void SetBezPt( xval, yval )
 129     int xval, yval;
 130 {
 131     BezVal *i;
 132
 133     i = &Bezpt[NumBezPts-1].x;
 134     i->cur0 = i->prev2 = i->cur1 = xval;
 135     i = &Bezpt[NumBezPts-1].y;
 136     i->cur0 = i->prev2 = i->cur1 = yval;
 137 }
 138
 139
 140
 141
 142 void InitBezPt(xval,yval)
 143 int xval, yval;
 144 {
 145     int segno;
 146
 147     NumBezPts++;
 148     SetBezPt(xval,yval);
 149     segno = NumBezPts -2;
 150     if( segno >= 0) {
 151
 152         DrawLine( StartPtX( segno), StartPtY(segno),
 153                 EndPtX( segno), EndPtY(segno), XOR );
 154     }
 155 }
 156
 157
 158
 159
 160
 161 void EditBezPt(xval, yval)
 162         int xval, yval;
 163 {
 164     int segno = NumBezPts -2;
 165
 166     DrawLine( StartPtX(segno), StartPtY(segno),
 167           EndPtX( segno ), EndPtY(segno), XOR );
 168
 169     SetBezPt(xval, yval);
 170
 171     DrawLine( StartPtX( segno), StartPtY(segno),
 172           EndPtX( segno), EndPtY(segno), XOR );
 173 }
 174