FillTriangle

void stdTriangle(Vertice v1, Vertice v2, Vertice v3) {
  Vertice t1 = new Vertice(0,0), t2 = new Vertice(0,0), t3 = new Vertice(0,0);
  if (v1.y < v2.y && v1.y < v3.y) { t1 = v1; t2 = (v2.y < v3.y ? v2 : v3); t3 = (v2.y < v3.y ? v3 : v2);}
  else if (v2.y < v3.y) { t1 = v2; t2 = (v1.y < v3.y ? v1 : v3); t3 = (v1.y < v3.y ? v3 : v1); }
  else { t1 = v3; t2 = (v1.y < v2.y ? v1 : v2); t3 = (v1.y < v2.y ? v2 : v1); }

  if (t2.y == t3.y) {
    stdTriangleFlatBottom(t1, t2, t3);
  }
  else if (t1.y == t2.y) {
    stdTriangleFlatTop(t1, t2, t3);
  }
  else {
    Vertice t4 = new Vertice((int)(t1.x + ((float)(t2.y-t1.y) / (float)(t3.y-t1.y)) * (t3.x-t1.x)), t2.y);
    stdTriangleFlatBottom(t1, t2, t4);
    stdTriangleFlatTop(t2, t4, t3);
  }
}

void stdTriangleFlatBottom(Vertice v1, Vertice v2, Vertice v3) {
  Vertice t1 = new Vertice(0,0), t2 = new Vertice(0,0), t3 = new Vertice(0,0);
  if (v1.y < v2.y) { if (v1.y < v3.y) { t1 = v1; t2 = (v2.x < v3.x ? v2 : v3); t3 = (v2.x < v3.x ? v3 : v2);}}
  else if (v2.y < v3.y) { t1 = v2; t2 = (v1.x < v3.x ? v1 : v3); t3 = (v1.x < v3.x ? v3 : v1); }
  else { t1 = v3; t2 = (v1.x < v2.x ? v1 : v2); t3 = (v1.x < v2.x ? v2 : v1); }

  float invslope1 = (float)(t2.x - t1.x) / (float)(t2.y - t1.y);
  float invslope2 = (float)(t3.x - t1.x) / (float)(t3.y - t1.y);

  float curx1 = t1.x;
  float curx2 = t1.x;

  for (int scanLineY = t1.y; scanLineY <= t2.y; scanLineY++) {
    HLine((int)curx1, (int)curx2, scanLineY);
    curx1 += invslope1;
    curx2 += invslope2;
  }
}

void stdTriangleFlatTop(Vertice v1, Vertice v2, Vertice v3) {
  Vertice t1 = new Vertice(0,0), t2 = new Vertice(0,0), t3 = new Vertice(0,0);
  if (v1.y > v2.y) { if (v1.y > v3.y) { t3 = v1; t1 = (v2.x < v3.x ? v2 : v3); t2 = (v2.x < v3.x ? v3 : v2);}}
  else if (v2.y > v3.y) { t3 = v2; t1 = (v1.x < v3.x ? v1 : v3); t2 = (v1.x < v3.x ? v3 : v1); }
  else { t3 = v3; t1 = (v1.x < v2.x ? v1 : v2); t2 = (v1.x < v2.x ? v2 : v1); }

  float invslope1 = (float)(t3.x - t1.x) / (float)(t3.y - t1.y);
  float invslope2 = (float)(t3.x - t2.x) / (float)(t3.y - t2.y);

  float curx1 = t3.x;
  float curx2 = t3.x;

  for (int scanLineY = t3.y; scanLineY > t1.y; scanLineY--) {
    HLine((int)curx1, (int)curx2, scanLineY);
    curx1 -= invslope1;
    curx2 -= invslope2;
  }
}

void HLine(int x0, int x1, int y) {
  int sx = x0 == x1 ? 0 : (x0<x1?1:-1);
  loadPixels();
  if (sx!=0)
  for (int i = x0; i != x1; i+=sx) {
    pixels[y*width+i] = g.fillColor;
  }
  pixels[y*width+x1] = g.fillColor;
  updatePixels();
}