tests: Add a shader test for texture sampling.

Signed-off-by: Zebediah Figura <zfigura@codeweavers.com>
Signed-off-by: Matteo Bruni <mbruni@codeweavers.com>
Signed-off-by: Henri Verbeet <hverbeet@codeweavers.com>
Signed-off-by: Giovanni Mascellani <gmascellani@codeweavers.com>
Signed-off-by: Alexandre Julliard <julliard@winehq.org>

tests/sampler.shader_test

@@ -0,0 +1,34 @@
+[sampler 0]
+filter linear linear linear
+address clamp clamp clamp
+
+[texture 0]
+size (2, 2)
+0.0 0.0 0.0 0.0     0.0 0.0 0.0 0.0
+0.0 0.0 0.0 0.0     1.0 0.0 1.0 0.0
+
+[pixel shader]
+sampler s;
+Texture2D t;
+
+float4 main() : sv_target
+{
+    return t.Sample(s, float2(0.5, 0.5));
+}
+
+[test]
+draw quad
+probe all rgba (0.25, 0, 0.25, 0)
+
+[pixel shader]
+SamplerState s;
+Texture2D t;
+
+float4 main() : sv_target
+{
+    return t.Sample(s, float2(0.5, 0.5));
+}
+
+[test]
+draw quad
+probe all rgba (0.25, 0, 0.25, 0)