/*
* . v0
* / \
* v1 /___\ v2
*
*/
void BlitUpperTriangle(Vector2 v0, Vector2 v1, Vector2 v2, Vector2 uv0, Vector2 uv1, Vector2 uv2, PlotDelegate plotDelegate)
{
if (v1.x > v2.x)
{
MUtils.Swap(ref v1, ref v2);
}
var L1 = new RasterizedLine(v1, v0);
var i1 = L1.CreatePixelIterator();
int y0 = int.MinValue;
int x0;
int x1;
float dx = v2.x - v0.x;
float dy = v0.y - v2.y;
Vector2 newUv0 = Vector2.zero;
Vector3 newUv1 = Vector2.zero;
if (dy != 0)
{
while (NextY(i1, y0, out x0, out y0))
{
x1 = Mathf.RoundToInt(v2.x - dx * (y0 - v2.y) / dy);
BlitHorizontalLine(x0, x1, y0, newUv0, newUv1, plotDelegate);
}
}
}
void BlitHorizontalLine(int x0, int x1, int y, Vector2 uv0, Vector2 uv1, PlotDelegate plotDelegate)
{
if (x0 > x1)
{
MUtils.Swap(ref x0, ref x1);
}
float xx0, yy0;
Vector2 newUv = Vector2.zero;
for (int x = x0; x <= x1; ++x)
{
ToWorldSpace(x, y, out xx0, out yy0);
plotDelegate(new Vector2(xx0, yy0), newUv);
}
}
/*
* v0 ---- v1
\ /
\/
\ v2
*/
void BlitTriangle(Vector2 v0, Vector2 v1, Vector2 v2, Vector2 uv0, Vector2 uv1, Vector2 uv2, PlotDelegate plotDelegate)
{
if (v0.x > v1.x)
{
MUtils.Swap(ref v0, ref v1);
}
var L1 = new RasterizedLine(v0, v2);
var L2 = new RasterizedLine(v1, v2);
var i1 = L1.CreatePixelIterator();
var i2 = L2.CreatePixelIterator();
Vector2 newUv0 = Vector2.zero;
Vector3 newUv1 = Vector2.zero;
var pList1 = ArrayPool <RasterizedLine.Pixel> .Get();
var pList2 = ArrayPool <RasterizedLine.Pixel> .Get();
CacheYOnChanged(i1, pList1);
CacheYOnChanged(i2, pList2);
if (CheckSequence(pList1, pList2))
{
for (int i = 0; i < pList1.length; ++i)
{
var a = pList1[i];
var b = pList2[i];
BlitHorizontalLine(a.x, b.x, a.y, newUv0, newUv1, plotDelegate);
}
}
else
{
for (int i = 0; i < pList1.length; ++i)
{
var a = pList1[i];
var b = pList2[-i - 1];
BlitHorizontalLine(a.x, b.x, a.y, newUv0, newUv1, plotDelegate);
}
}
ArrayPool <RasterizedLine.Pixel> .Release(pList1);
ArrayPool <RasterizedLine.Pixel> .Release(pList2);
}
// Bresenham's line algorithm
IEnumerator <Pixel> Rasterize()
{
int x0 = Mathf.RoundToInt(start.x);
int y0 = Mathf.RoundToInt(start.y);
int x1 = Mathf.RoundToInt(end.x);
int y1 = Mathf.RoundToInt(end.y);
bool steep = Mathf.Abs(y1 - y0) > Mathf.Abs(x1 - x0);
if (steep)
{
MUtils.Swap(ref x0, ref y0);
MUtils.Swap(ref x1, ref y1);
}
if (x1 < x0)
{
MUtils.Swap(ref x0, ref x1);
MUtils.Swap(ref y0, ref y1);
}
int dy = y1 - y0;
int dx = x1 - x0;
int yi = 1;
if (dy < 0)
{
yi = -1;
dy = -dy;
}
int D = 2 * dy - dx;
int y = y0;
if (steep)
{
for (int x = x0; x <= x1; ++x)
{
yield return(new Pixel()
{
x = y, y = x, c = 1f,
});
if (D > 0)
{
y = y + yi;
D = D - 2 * dx;
}
D = D + 2 * dy;
}
}
else
{
for (int x = x0; x <= x1; ++x)
{
yield return(new Pixel()
{
x = x, y = y, c = 1f,
});
if (D > 0)
{
y = y + yi;
D = D - 2 * dx;
}
D = D + 2 * dy;
}
}
}