Fix winding issue in watertightness tests
The winding order of shared edge vertices wasn't consistent.
Add a check to ensure all triangles have same winding order.
Affects:
dEQP-VK.ray_tracing_pipeline.watertightness*
Components: Vulkan
VK-GL-CTS issue: 4009
Change-Id: I24607720fedcae2e903707dcd8f2d2d8b6ec12c0
diff --git a/external/vulkancts/modules/vulkan/ray_tracing/vktRayTracingWatertightnessTests.cpp b/external/vulkancts/modules/vulkan/ray_tracing/vktRayTracingWatertightnessTests.cpp
index 0ae3908..afd6224 100644
--- a/external/vulkancts/modules/vulkan/ray_tracing/vktRayTracingWatertightnessTests.cpp
+++ b/external/vulkancts/modules/vulkan/ray_tracing/vktRayTracingWatertightnessTests.cpp
@@ -104,6 +104,24 @@
return result;
}
+ static inline double doCrossProduct(tcu::DVec2 a, tcu::DVec2 b)
+ {
+ return a.x() * b.y() - a.y() * b.x();
+ }
+
+ static bool pointInTriangle2D(tcu::Vec3 p, tcu::Vec3 a, tcu::Vec3 b, tcu::Vec3 c)
+ {
+ tcu::DVec2 pa = { a.x() - p.x(), a.y() - p.y()} ;
+ tcu::DVec2 pb = { b.x() - p.x(), b.y() - p.y()};
+ tcu::DVec2 pc = { c.x() - p.x(), c.y() - p.y()};
+ double v1 = doCrossProduct(pa, pb);
+ double v2 = doCrossProduct(pb, pc);
+ double v3 = doCrossProduct(pc, pa);
+
+ // The winding of all the triangles in the test on XY plane is the same, so a negative value can be assumed
+ return v1 < 0 && v2 < 0 && v3 < 0;
+ }
+
deUint32 getShaderGroupSize(const InstanceInterface& vki,
const VkPhysicalDevice physicalDevice)
{
@@ -445,6 +463,11 @@
const tcu::Vec3 mixed = mixVec3(mixVec3(a, b, alfa), c, beta);
const float z = -rng.getFloat(0.01f, 0.99f);
const tcu::Vec3 d = tcu::Vec3(mixed.x(), mixed.y(), z);
+
+ // A check to avoid vertices that are outside the triangle in the XY plane due to floating-point precision,
+ // resulting in inconsistent winding order
+ if(!pointInTriangle2D(d, a, b, c)) continue;
+
const deUint32& p = t.x();
const deUint32& q = t.y();
deUint32& r = t.z();
@@ -453,7 +476,7 @@
vertices.push_back(d);
triangles.push_back(tcu::UVec3(q, r, R));
- triangles.push_back(tcu::UVec3(p, r, R));
+ triangles.push_back(tcu::UVec3(p, R, r));
r = R;
}