In WinRT the border color texture address mode is not supported.
The best I came up with in emulating the border address mode, is doing this in my pixel shader:
float4 tcol = tex.Sample(texSampler, texCoord);
if(texCoord.x < 0 || texCoord.y < 0 || texCoord.x > 1 || texCoord.y > 1)
tcol = borderColor;
But as only ps_4_0_level_9_1
is supported as minimum requirement in WinRT, this conditional in the pixel shader is quite inefficient.
How would I emulate border texture addressing mode efficiently?