Francisco Casas : tests: Make ddx() and ddy() test behave correctly for shader models < 4.

[Alexandre Julliard]

Module: vkd3d
Branch: master
Commit: f0584cad6279e7183d039ce31963c7025014591a
URL:    https://gitlab.winehq.org/wine/vkd3d/-/commit/f0584cad6279e7183d039ce31963c7...

Author: Francisco Casas <fcasas(a)codeweavers.com>
Date:   Mon Jun 19 10:40:57 2023 -0400

tests: Make ddx() and ddy() test behave correctly for shader models < 4.

---

 tests/hlsl/ddxddy.shader_test | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/tests/hlsl/ddxddy.shader_test b/tests/hlsl/ddxddy.shader_test
index 8becf524..da1414b1 100644
--- a/tests/hlsl/ddxddy.shader_test
+++ b/tests/hlsl/ddxddy.shader_test
@@ -1,3 +1,6 @@
+[require]
+shader model >= 3.0
+
 [pixel shader]
 float4 main(float4 pos : sv_position) : sv_target
 {
@@ -8,9 +11,15 @@ float4 main(float4 pos : sv_position) : sv_target
 draw quad
 probe all rgba (1.0, 1.0, 0.0, 0.0)
 
+
 [pixel shader]
 float4 main(float4 pos : sv_position) : sv_target
 {
+    // Shader models < 4 don't add 0.5 to sv_position, so this adjustment is required to get the
+    // same outputs.
+    pos.x = floor(pos.x) + 0.5;
+    pos.y = floor(pos.y) + 0.5;
+
     pos /= 10.0;
     float nonlinear = pos.x * pos.y - pos.x * (pos.x + 0.5);
     return float4(nonlinear, ddx(nonlinear), ddy(nonlinear), 0.0);