public static void stbtt__fill_active_edges_new(float[] scanline, int scanline_fill, int len,
stbtt__active_edge e, float y_top)
{
var y_bottom = y_top + 1;
while (e != null)
{
if (e.fdx == 0)
{
var x0 = e.fx;
if (x0 < len)
{
if (x0 >= 0)
{
stbtt__handle_clipped_edge(scanline, 0, (int)x0, e, x0, y_top, x0, y_bottom);
stbtt__handle_clipped_edge(scanline, scanline_fill - 1, (int)x0 + 1, e, x0, y_top, x0, y_bottom);
}
else
{
stbtt__handle_clipped_edge(scanline, scanline_fill - 1, 0, e, x0, y_top, x0, y_bottom);
}
}
}
else
{
var x0 = e.fx;
var dx = e.fdx;
var xb = x0 + dx;
float x_top = 0;
float x_bottom = 0;
float sy0 = 0;
float sy1 = 0;
var dy = e.fdy;
if (e.sy > y_top)
{
x_top = x0 + dx * (e.sy - y_top);
sy0 = e.sy;
}
else
{
x_top = x0;
sy0 = y_top;
}
if (e.ey < y_bottom)
{
x_bottom = x0 + dx * (e.ey - y_top);
sy1 = e.ey;
}
else
{
x_bottom = xb;
sy1 = y_bottom;
}
if (x_top >= 0 && x_bottom >= 0 && x_top < len && x_bottom < len)
{
if ((int)x_top == (int)x_bottom)
{
float height = 0;
var x = (int)x_top;
height = sy1 - sy0;
scanline[x] += e.direction * (1 - (x_top - x + (x_bottom - x)) / 2) * height;
scanline[x + scanline_fill] += e.direction * height;
}
else
{
var x = 0;
var x1 = 0;
var x2 = 0;
float y_crossing = 0;
float step = 0;
float sign = 0;
float area = 0;
if (x_top > x_bottom)
{
float t = 0;
sy0 = y_bottom - (sy0 - y_top);
sy1 = y_bottom - (sy1 - y_top);
t = sy0;
sy0 = sy1;
sy1 = t;
t = x_bottom;
x_bottom = x_top;
x_top = t;
dx = -dx;
dy = -dy;
t = x0;
x0 = xb;
xb = t;
}
x1 = (int)x_top;
x2 = (int)x_bottom;
y_crossing = (x1 + 1 - x0) * dy + y_top;
sign = e.direction;
area = sign * (y_crossing - sy0);
scanline[x1] += area * (1 - (x_top - x1 + (x1 + 1 - x1)) / 2);
step = sign * dy;
for (x = x1 + 1; x < x2; ++x)
{
scanline[x] += area + step / 2;
area += step;
}
y_crossing += dy * (x2 - (x1 + 1));
scanline[x2] += area + sign * (1 - (x2 - x2 + (x_bottom - x2)) / 2) * (sy1 - y_crossing);
scanline[x2 + scanline_fill] += sign * (sy1 - sy0);
}
}
else
{
var x = 0;
for (x = 0; x < len; ++x)
{
var y0 = y_top;
var x1 = (float)x;
var x2 = (float)(x + 1);
var x3 = xb;
var y3 = y_bottom;
var y1 = (x - x0) / dx + y_top;
var y2 = (x + 1 - x0) / dx + y_top;
if (x0 < x1 && x3 > x2)
{
stbtt__handle_clipped_edge(scanline, 0, x, e, x0, y0, x1, y1);
stbtt__handle_clipped_edge(scanline, 0, x, e, x1, y1, x2, y2);
stbtt__handle_clipped_edge(scanline, 0, x, e, x2, y2, x3, y3);
}
else if (x3 < x1 && x0 > x2)
{
stbtt__handle_clipped_edge(scanline, 0, x, e, x0, y0, x2, y2);
stbtt__handle_clipped_edge(scanline, 0, x, e, x2, y2, x1, y1);
stbtt__handle_clipped_edge(scanline, 0, x, e, x1, y1, x3, y3);
}
else if (x0 < x1 && x3 > x1)
{
stbtt__handle_clipped_edge(scanline, 0, x, e, x0, y0, x1, y1);
stbtt__handle_clipped_edge(scanline, 0, x, e, x1, y1, x3, y3);
}
else if (x3 < x1 && x0 > x1)
{
stbtt__handle_clipped_edge(scanline, 0, x, e, x0, y0, x1, y1);
stbtt__handle_clipped_edge(scanline, 0, x, e, x1, y1, x3, y3);
}
else if (x0 < x2 && x3 > x2)
{
stbtt__handle_clipped_edge(scanline, 0, x, e, x0, y0, x2, y2);
stbtt__handle_clipped_edge(scanline, 0, x, e, x2, y2, x3, y3);
}
else if (x3 < x2 && x0 > x2)
{
stbtt__handle_clipped_edge(scanline, 0, x, e, x0, y0, x2, y2);
stbtt__handle_clipped_edge(scanline, 0, x, e, x2, y2, x3, y3);
}
else
{
stbtt__handle_clipped_edge(scanline, 0, x, e, x0, y0, x3, y3);
}
}
}
}
e = e.next;
}
}
public static void stbtt__handle_clipped_edge(float[] scanline, int offset, int x, stbtt__active_edge e, float x0,
float y0, float x1, float y1)
{
if (y0 == y1)
{
return;
}
if (y0 > e.ey)
{
return;
}
if (y1 < e.sy)
{
return;
}
if (y0 < e.sy)
{
x0 += (x1 - x0) * (e.sy - y0) / (y1 - y0);
y0 = e.sy;
}
if (y1 > e.ey)
{
x1 += (x1 - x0) * (e.ey - y1) / (y1 - y0);
y1 = e.ey;
}
if (x0 <= x && x1 <= x)
{
scanline[x + offset] += e.direction * (y1 - y0);
}
else if (x0 >= x + 1 && x1 >= x + 1)
{
}
else
{
scanline[x + offset] += e.direction * (y1 - y0) * (1 - (x0 - x + (x1 - x)) / 2);
}
}