/// <summary>
/// <see cref="PrepareForDraw"/> prepares and updates the Material, ShapeBuilder and VertexBuilder if necessary
/// </summary>
public void PrepareForDraw(out bool vertexBufferHasChanged, out int vertexSize, out int vertexCount)
{
var fieldsList = new ParticlePoolFieldsList(pool);
// User changes to materials might cause vertex layout change
Material.PrepareVertexLayout(fieldsList);
// User changes to shape builders might cause vertex layout change
ShapeBuilder.PrepareVertexLayout(fieldsList);
// Recalculate the required vertex count and stride
VertexBuilder.SetRequiredQuads(ShapeBuilder.QuadsPerParticle, pool.LivingParticles, pool.ParticleCapacity);
vertexBufferHasChanged = (Material.HasVertexLayoutChanged || ShapeBuilder.VertexLayoutHasChanged || VertexBuilder.IsBufferDirty);
// Update the vertex builder and the vertex layout if needed
if (vertexBufferHasChanged)
{
VertexBuilder.ResetVertexElementList();
Material.UpdateVertexBuilder(VertexBuilder);
ShapeBuilder.UpdateVertexBuilder(VertexBuilder);
VertexBuilder.UpdateVertexLayout();
}
vertexSize = VertexBuilder.VertexDeclaration.CalculateSize();
vertexCount = VertexBuilder.VertexCount;
VertexBuilder.SetDirty(false);
}