private void UpdateData(int mipmap)
{
if (Boxes.Count == 0)
{
return;
}
int floatCount = Boxes.Count * 2 * 4; // each box has 4 edges with 2 float component
if (positionBuffer == null || positionBuffer.ByteSize < floatCount * sizeof(float))
{
// resize buffer
positionBuffer?.Dispose();
positionBuffer = new UploadBuffer(floatCount * sizeof(float), BindFlags.VertexBuffer);
}
// fill buffer
var data = new float[floatCount];
var dim = images.Size.GetMip(mipmap);
// offset float coordinates by half a unit so the quad covers the area
var offset = Size2.Zero.ToCoords(dim.XY);
for (var i = 0; i < Boxes.Count; i++)
{
var box = Boxes[i];
// top left
data[i * 8] = ToCanonical(box.Start.X - offset.X);
data[i * 8 + 1] = ToCanonical(box.Start.Y - offset.Y);
// top right
data[i * 8 + 2] = ToCanonical(box.End.X + offset.X);
data[i * 8 + 3] = ToCanonical(box.Start.Y - offset.Y);
// bot left
data[i * 8 + 4] = ToCanonical(box.Start.X - offset.X);
data[i * 8 + 5] = ToCanonical(box.End.Y + offset.Y);
// bot right
data[i * 8 + 6] = ToCanonical(box.End.X + offset.X);
data[i * 8 + 7] = ToCanonical(box.End.Y + offset.Y);
}
// upload buffer
positionBuffer.SetData(data);
}
public void Dispose()
{
shader?.Dispose();
paramBuffer?.Dispose();
}