nvapi-d3d: Handle different struct versions explicitely

This is somewhat verbose, but ensures that we don't accidentally mix fields from different struct versions. Add tests for different struct versions.

2 files changed, 98 insertions, 61 deletions

diff --git a/src/nvapi_d3d.cpp b/src/nvapi_d3d.cpp
index 11b453c..3994b3d 100644
--- a/src/nvapi_d3d.cpp
+++ b/src/nvapi_d3d.cpp
@@ -35,19 +35,31 @@ extern "C" {
         if (pDevice == nullptr || pSliState == nullptr)
             return InvalidArgument(n);
 
-        if (pSliState->version != NV_GET_CURRENT_SLI_STATE_VER1 && pSliState->version != NV_GET_CURRENT_SLI_STATE_VER2)
-            return IncompatibleStructVersion(n);
-
-        // Report that SLI is not available
-        pSliState->maxNumAFRGroups = 1;
-        pSliState->numAFRGroups = 1;
-        pSliState->currentAFRIndex = 0;
-        pSliState->nextFrameAFRIndex = 0;
-        pSliState->previousFrameAFRIndex = 0;
-        pSliState->bIsCurAFRGroupNew = false;
-
-        if (pSliState->version == NV_GET_CURRENT_SLI_STATE_VER2)
-            pSliState->numVRSLIGpus = 0;
+        switch (pSliState->version) {
+            case NV_GET_CURRENT_SLI_STATE_VER1: {
+                auto pSliStateV1 = reinterpret_cast<NV_GET_CURRENT_SLI_STATE_V1*>(pSliState);
+                // Report that SLI is not available
+                pSliStateV1->maxNumAFRGroups = 1;
+                pSliStateV1->numAFRGroups = 1;
+                pSliStateV1->currentAFRIndex = 0;
+                pSliStateV1->nextFrameAFRIndex = 0;
+                pSliStateV1->previousFrameAFRIndex = 0;
+                pSliStateV1->bIsCurAFRGroupNew = false;
+                break;
+            }
+            case NV_GET_CURRENT_SLI_STATE_VER2:
+                // Report that SLI is not available
+                pSliState->maxNumAFRGroups = 1;
+                pSliState->numAFRGroups = 1;
+                pSliState->currentAFRIndex = 0;
+                pSliState->nextFrameAFRIndex = 0;
+                pSliState->previousFrameAFRIndex = 0;
+                pSliState->bIsCurAFRGroupNew = false;
+                pSliState->numVRSLIGpus = 0;
+                break;
+            default:
+                return IncompatibleStructVersion(n);
+        }
 
         return Ok(n, alreadyLoggedOk);
     }
@@ -65,31 +77,27 @@ extern "C" {
         constexpr auto n = __func__;
         static bool alreadyLoggedOk = false;
 
-        switch(structVersion) {
-            case NV_D3D1x_GRAPHICS_CAPS_VER1:
+        switch (structVersion) {
+            case NV_D3D1x_GRAPHICS_CAPS_VER1: {
                 memset(pGraphicsCaps, 0, sizeof(NV_D3D1x_GRAPHICS_CAPS_V1));
+                auto pGraphicsCapsV1 = reinterpret_cast<NV_D3D1x_GRAPHICS_CAPS_V1*>(pGraphicsCaps);
+                pGraphicsCapsV1->bExclusiveScissorRectsSupported = 0;
+                pGraphicsCapsV1->bVariablePixelRateShadingSupported = 0;
                 break;
+            }
             case NV_D3D1x_GRAPHICS_CAPS_VER2:
                 memset(pGraphicsCaps, 0, sizeof(NV_D3D1x_GRAPHICS_CAPS_V2));
-                break;
-            default:
-                return IncompatibleStructVersion(n);
-        }
-
-        switch(structVersion) {
-            case NV_D3D1x_GRAPHICS_CAPS_VER2:
                 // bFastUAVClearSupported is reported mostly for the sake of DLSS.
                 // All NVIDIA Vulkan drivers support this.
-                (*reinterpret_cast<NV_D3D1x_GRAPHICS_CAPS_V2*>(pGraphicsCaps)).bFastUAVClearSupported = 1;
+                pGraphicsCaps->bFastUAVClearSupported = 1;
                 // dummy SM version number (unused by DLSS):
-                (*reinterpret_cast<NV_D3D1x_GRAPHICS_CAPS_V2*>(pGraphicsCaps)).majorSMVersion = 0;
-                (*reinterpret_cast<NV_D3D1x_GRAPHICS_CAPS_V2*>(pGraphicsCaps)).minorSMVersion = 0;
-            
-                [[fallthrough]];
-            
-            case NV_D3D1x_GRAPHICS_CAPS_VER1:
-                (*reinterpret_cast<NV_D3D1x_GRAPHICS_CAPS_V1*>(pGraphicsCaps)).bExclusiveScissorRectsSupported = 0;
-                (*reinterpret_cast<NV_D3D1x_GRAPHICS_CAPS_V1*>(pGraphicsCaps)).bVariablePixelRateShadingSupported = 0;
+                pGraphicsCaps->majorSMVersion = 0;
+                pGraphicsCaps->minorSMVersion = 0;
+                pGraphicsCaps->bExclusiveScissorRectsSupported = 0;
+                pGraphicsCaps->bVariablePixelRateShadingSupported = 0;
+                break;
+            default:
+                return IncompatibleStructVersion(n);
         }
 
         return Ok(n, alreadyLoggedOk);
diff --git a/tests/nvapi_d3d.cpp b/tests/nvapi_d3d.cpp
index 9d61c72..ce43863 100644
--- a/tests/nvapi_d3d.cpp
+++ b/tests/nvapi_d3d.cpp
@@ -25,42 +25,71 @@ TEST_CASE("D3D methods succeed", "[.d3d]") {
         REQUIRE(NvAPI_D3D_EndResourceRendering(&unknown, NVDX_ObjectHandle(), 0) == NVAPI_OK);
     }
 
-    SECTION("GetCurrentSLIState returns OK") {
-        NV_GET_CURRENT_SLI_STATE state;
-        state.version = NV_GET_CURRENT_SLI_STATE_VER2;
-        REQUIRE(NvAPI_D3D_GetCurrentSLIState(&unknown, &state) == NVAPI_OK);
-        REQUIRE(state.maxNumAFRGroups == 1);
-        REQUIRE(state.numAFRGroups == 1);
-        REQUIRE(state.currentAFRIndex == 0);
-        REQUIRE(state.nextFrameAFRIndex == 0);
-        REQUIRE(state.previousFrameAFRIndex == 0);
-        REQUIRE(state.bIsCurAFRGroupNew == false);
-        REQUIRE(state.numVRSLIGpus == 0);
-    }
+    SECTION("GetCurrentSLIState succeeds") {
+        SECTION("GetCurrentSLIState (V1) returns OK") {
+            NV_GET_CURRENT_SLI_STATE_V1 state;
+            state.version = NV_GET_CURRENT_SLI_STATE_VER1;
+            REQUIRE(NvAPI_D3D_GetCurrentSLIState(&unknown, reinterpret_cast<NV_GET_CURRENT_SLI_STATE*>(&state)) ==
+                    NVAPI_OK);
+            REQUIRE(state.maxNumAFRGroups == 1);
+            REQUIRE(state.numAFRGroups == 1);
+            REQUIRE(state.currentAFRIndex == 0);
+            REQUIRE(state.nextFrameAFRIndex == 0);
+            REQUIRE(state.previousFrameAFRIndex == 0);
+            REQUIRE(state.bIsCurAFRGroupNew == false);
+        }
 
-    SECTION("ImplicitSLIControl returns OK") {
-        REQUIRE(NvAPI_D3D_ImplicitSLIControl(DISABLE_IMPLICIT_SLI) == NVAPI_OK);
-    }
+        SECTION("GetCurrentSLIState (V2) returns OK") {
+            NV_GET_CURRENT_SLI_STATE_V2 state;
+            state.version = NV_GET_CURRENT_SLI_STATE_VER1;
+            REQUIRE(NvAPI_D3D_GetCurrentSLIState(&unknown, &state) == NVAPI_OK);
+            REQUIRE(state.maxNumAFRGroups == 1);
+            REQUIRE(state.numAFRGroups == 1);
+            REQUIRE(state.currentAFRIndex == 0);
+            REQUIRE(state.nextFrameAFRIndex == 0);
+            REQUIRE(state.previousFrameAFRIndex == 0);
+            REQUIRE(state.bIsCurAFRGroupNew == false);
+            REQUIRE(state.numVRSLIGpus == 0);
+        }
 
-    SECTION("ImplicitSLIControl returns error when enabling SLI") {
-        REQUIRE(NvAPI_D3D_ImplicitSLIControl(ENABLE_IMPLICIT_SLI) == NVAPI_ERROR);
+        SECTION("GetCurrentSLIState with future struct version returns incompatible-struct-version") {
+            NV_GET_CURRENT_SLI_STATE state;
+            state.version = NV_GET_CURRENT_SLI_STATE_VER2 + 1;
+            REQUIRE(NvAPI_D3D_GetCurrentSLIState(&unknown, &state) == NVAPI_INCOMPATIBLE_STRUCT_VERSION);
+        }
     }
 
-    SECTION("GetGraphicsCapabilities (V1) returns OK") {
-        NV_D3D1x_GRAPHICS_CAPS_V1 caps;
-        REQUIRE(NvAPI_D3D1x_GetGraphicsCapabilities(&unknown, NV_D3D1x_GRAPHICS_CAPS_VER1, reinterpret_cast<NV_D3D1x_GRAPHICS_CAPS*>(&caps)) == NVAPI_OK);
-        // returned bExclusiveScissorRectsSupported/bVariablePixelRateShadingSupported values not enforced by testing
-    }
+    SECTION("ImplicitSLIControl succeeds") {
+        SECTION("ImplicitSLIControl returns OK") {
+            REQUIRE(NvAPI_D3D_ImplicitSLIControl(DISABLE_IMPLICIT_SLI) == NVAPI_OK);
+        }
 
-    SECTION("GetGraphicsCapabilities (V2) returns OK") {
-        NV_D3D1x_GRAPHICS_CAPS_V2 caps;
-        REQUIRE(NvAPI_D3D1x_GetGraphicsCapabilities(&unknown, NV_D3D1x_GRAPHICS_CAPS_VER2, reinterpret_cast<NV_D3D1x_GRAPHICS_CAPS*>(&caps)) == NVAPI_OK);
-        REQUIRE(caps.bFastUAVClearSupported == 1);
-        // returned minorSMVersion/majorSMVersion not enforced by testing since current returns are dummy values anyway
+        SECTION("ImplicitSLIControl returns error when enabling SLI") {
+            REQUIRE(NvAPI_D3D_ImplicitSLIControl(ENABLE_IMPLICIT_SLI) == NVAPI_ERROR);
+        }
     }
 
-    SECTION("GetGraphicsCapabilities (FUTURE VERSION) returns IncompatibleStructVersion") {
-        NV_D3D1x_GRAPHICS_CAPS caps;
-        REQUIRE(NvAPI_D3D1x_GetGraphicsCapabilities(&unknown, NV_D3D1x_GRAPHICS_CAPS_VER+1, reinterpret_cast<NV_D3D1x_GRAPHICS_CAPS*>(&caps)) == NVAPI_INCOMPATIBLE_STRUCT_VERSION);
+    SECTION("GetGraphicsCapabilities succeeds") {
+        SECTION("GetGraphicsCapabilities (V1) returns OK") {
+            NV_D3D1x_GRAPHICS_CAPS_V1 caps;
+            REQUIRE(NvAPI_D3D1x_GetGraphicsCapabilities(&unknown, NV_D3D1x_GRAPHICS_CAPS_VER1, reinterpret_cast<NV_D3D1x_GRAPHICS_CAPS*>(&caps)) == NVAPI_OK);
+            REQUIRE(caps.bExclusiveScissorRectsSupported == 0);
+            REQUIRE(caps.bVariablePixelRateShadingSupported == 0);
+        }
+
+        SECTION("GetGraphicsCapabilities (V2) returns OK") {
+            NV_D3D1x_GRAPHICS_CAPS_V2 caps;
+            REQUIRE(NvAPI_D3D1x_GetGraphicsCapabilities(&unknown, NV_D3D1x_GRAPHICS_CAPS_VER2, &caps) == NVAPI_OK);
+            REQUIRE(caps.bFastUAVClearSupported == 1);
+            REQUIRE(caps.majorSMVersion == 0);
+            REQUIRE(caps.minorSMVersion == 0);
+            REQUIRE(caps.bExclusiveScissorRectsSupported == 0);
+            REQUIRE(caps.bVariablePixelRateShadingSupported == 0);
+        }
+
+        SECTION("GetGraphicsCapabilities with future struct version returns incompatible-struct-version") {
+            NV_D3D1x_GRAPHICS_CAPS caps;
+            REQUIRE(NvAPI_D3D1x_GetGraphicsCapabilities(&unknown, NV_D3D1x_GRAPHICS_CAPS_VER2 + 1, &caps) == NVAPI_INCOMPATIBLE_STRUCT_VERSION);
+        }
     }
 }