#include "line.h"

void lineTranspose(Vertex *l, int cols) {

  int cnt = cols*LN_SEGS+1;

  for(int i = 0; i < cnt; ++i) {

    Vertex *v = &l[i];

    v->p = vtranspose(v->p);

    v->t = vtranspose(v->t);

  }

}

void lineGenH(Vertex *l, int cols, double y, double cellw, double cellh, double jitter, double depth) {

  if (cols <= 0) return;

  double kx = cellh < cellw ? cellh/cellw : 1.0;

  double ky = cellw < cellh ? cellw/cellh : 1.0;

  int cnt = cols*LN_SEGS+1;

  for(int i = 0; i < cnt; ++i)

    l[i] = (Vertex){ {i*cellw/LN_SEGS, y}, {}, 1 };

  if (jitter) for(int i = 1; i < cnt-1; ++i) {

    l[i].p.x += randTwo()*kx*jitter*cellw/2;

    l[i].p.y += randTwo()*ky*jitter*cellh;

    l[i].w   += randOne()*0.25;

  }

  for(int c = 0; c < cols; ++c) {

    double j = jitter ? randTwo()*(1-kx)/3 : 0;

    l[c*LN_SEGS+1].p.x += ( 0.3 - kx/6 + j)*cellw;

    l[c*LN_SEGS+2].p.x += ( 0.1 - kx/6 + j)*cellw;

    l[c*LN_SEGS+3].p.x += (-0.1 + kx/6 + j)*cellw;

    l[c*LN_SEGS+4].p.x += (-0.3 + kx/6 + j)*cellw;

    double d = randSign()*depth*ky*cellh;

    l[c*LN_SEGS+2].p.y += d;

    l[c*LN_SEGS+3].p.y += d;

  }

  Vec b = l[0].p, e = l[cnt-1].p;

  b.x -= 1/3.0; e.x += 1/3.0;

  for(int i = 0; i < cnt; ++i) {

    Vertex *v = &l[i];

    Vec p0 = i       ? (v-1)->p : b;

    Vec p1 = i+1<cnt ? (v+1)->p : e;

    v->t = vmul(vsub(p1, p0), v->w/2);

  }

}

void lineGenV(Vertex *l, int rows, double x, double cellw, double cellh, double jitter, double depth) {

  lineGenH(l, rows, x, cellh, cellw, jitter, depth);

  lineTranspose(l, rows);

}

void linePut(Vertex *l, int cells, int levels) {

  int cnt = cells*LN_SEGS;

  if (cnt > 0) {

    for(int i = 1; i <= cnt; ++i) {

      Vertex v0 = l[i-1];

      Vertex v1 = l[i];

      cubicto(

        v0.p.x, v0.p.y,

        v0.p.x + v0.t.x/3, v0.p.y + v0.t.y/3,

        v1.p.x - v1.t.x/3, v1.p.y - v1.t.y/3,

        v1.p.x, v1.p.y,

        levels );

    }

  } else {

    for(int i = -1; i >= cnt; --i) {

      Vertex v0 = l[i+1];

      Vertex v1 = l[i];

      cubicto(

        v0.p.x, v0.p.y,

        v0.p.x - v0.t.x/3, v0.p.y - v0.t.y/3,

        v1.p.x + v1.t.x/3, v1.p.y + v1.t.y/3,

        v1.p.x, v1.p.y,

        levels );

    }

  }

}

void lineDraw(Vertex *l, int cells, int levels) {

  if (!cells) return;

  moveTo(l->p.x, l->p.y);

  linePut(l, cells, levels);

  strokePath();

}