init tests

tests/test_cov2d_bounds.py

@@ -0,0 +1,32 @@
+import pytest
+import torch
+
+
+device = torch.device("cuda:0")
+
+
+@pytest.mark.skipif(not torch.cuda.is_available, reason="No CUDA device")
+def compare_binding_to_pytorch():
+    from diff_rast._torch_impl import compute_cov2d_bounds as _compute_cov2d_bounds
+    from diff_rast.cov2d_bounds import compute_cov2d_bounds
+
+    torch.manual_seed(42)
+
+    num_cov2ds = 2
+
+    _covs2d = torch.rand((num_cov2ds, 2, 2), dtype=torch.float32, device=device, requires_grad=True)
+    covs2d = torch.stack(
+        [torch.triu(_covs2d)[:, 0, 0], torch.triu(_covs2d)[:, 0, 1], torch.triu(_covs2d)[:, 1, 1]], dim=-1
+    )
+
+    conic, radii = compute_cov2d_bounds.apply(covs2d)
+    _conic, _radii, _ = _compute_cov2d_bounds(_covs2d)
+
+    radii = radii.squeeze(-1)
+
+    torch.testing.assert_close(conic, _conic)
+    torch.testing.assert_close(radii, _radii)
+
+
+if __name__ == "__main__":
+    compare_binding_to_pytorch()