[PATCH 10/15] dxgi: Implement d3d12_swapchain_GetMaximumFrameLatency().

[Henri Verbeet]

From: Philip Rebohle <philip.rebohle(a)tu-dortmund.de>

Signed-off-by: Philip Rebohle <philip.rebohle(a)tu-dortmund.de>
Signed-off-by: Henri Verbeet <hverbeet(a)codeweavers.com>
---
This supersedes patch 183594.
Mostly unmodified.

 dlls/dxgi/swapchain.c | 13 +++++++++++--
 1 file changed, 11 insertions(+), 2 deletions(-)

diff --git a/dlls/dxgi/swapchain.c b/dlls/dxgi/swapchain.c
index 8e0f2b2239b..bd200dddf08 100644
--- a/dlls/dxgi/swapchain.c
+++ b/dlls/dxgi/swapchain.c
@@ -2630,9 +2630,18 @@ static HRESULT STDMETHODCALLTYPE d3d12_swapchain_SetMaximumFrameLatency(IDXGISwa
 
 static HRESULT STDMETHODCALLTYPE d3d12_swapchain_GetMaximumFrameLatency(IDXGISwapChain3 *iface, UINT *max_latency)
 {
-    FIXME("iface %p, max_latency %p stub!\n", iface, max_latency);
+    struct d3d12_swapchain *swapchain = d3d12_swapchain_from_IDXGISwapChain3(iface);
 
-    return E_NOTIMPL;
+    TRACE("iface %p, max_latency %p.\n", iface, max_latency);
+
+    if (!(swapchain->desc.Flags & DXGI_SWAP_CHAIN_FLAG_FRAME_LATENCY_WAITABLE_OBJECT))
+    {
+        WARN("DXGI_SWAP_CHAIN_FLAG_FRAME_LATENCY_WAITABLE_OBJECT not set for swap chain %p.\n", iface);
+        return DXGI_ERROR_INVALID_CALL;
+    }
+
+    *max_latency = swapchain->frame_latency;
+    return S_OK;
 }
 
 static HANDLE STDMETHODCALLTYPE d3d12_swapchain_GetFrameLatencyWaitableObject(IDXGISwapChain3 *iface)
-- 
2.20.1