D3D11: Changed shadow sampler to SampleCmpLevelZero.

src/bgfx_shader.sh

@@ -59,13 +59,13 @@ struct BgfxSampler2DShadow
 
 float bgfxShadow2D(BgfxSampler2DShadow _sampler, vec3 _coord)
 {
-	return _sampler.m_texture.SampleCmp(_sampler.m_sampler, _coord.xy, _coord.z * 2.0 - 1.0);
+	return _sampler.m_texture.SampleCmpLevelZero(_sampler.m_sampler, _coord.xy, _coord.z * 2.0 - 1.0);
 }
 
 float bgfxShadow2DProj(BgfxSampler2DShadow _sampler, vec4 _coord)
 {
 	vec3 coord = _coord.xyz * rcp(_coord.w);
-	return _sampler.m_texture.SampleCmp(_sampler.m_sampler, coord.xy, coord.z * 2.0 - 1.0);
+	return _sampler.m_texture.SampleCmpLevelZero(_sampler.m_sampler, coord.xy, coord.z * 2.0 - 1.0);
 }
 
 struct BgfxSampler3D