rhi: Expose compute threadgroup limits in ResourceLimits

As OpenGL ES and Vulkan ruin the day with the spec mandated minimum
value for max threads per threadgroup being only 128, clients need
a way to decide if their compute shader (local_size_*) is suitable
for use at run time.

Change-Id: I72b4fc97032406340623add82ea4d9544ebe9fdc
Reviewed-by: Andy Nichols <andy.nichols@qt.io>

1 files changed, 12 insertions, 0 deletions

diff --git a/src/gui/rhi/qrhivulkan.cpp b/src/gui/rhi/qrhivulkan.cpp
index b172a8b16b..e4ad562805 100644
--- a/src/gui/rhi/qrhivulkan.cpp
+++ b/src/gui/rhi/qrhivulkan.cpp
@@ -4124,6 +4124,18 @@ int QRhiVulkan::resourceLimit(QRhi::ResourceLimit limit) const
         return QVK_FRAMES_IN_FLIGHT;
     case QRhi::MaxAsyncReadbackFrames:
         return QVK_FRAMES_IN_FLIGHT;
+    case QRhi::MaxThreadGroupsPerDimension:
+        return int(qMin(physDevProperties.limits.maxComputeWorkGroupCount[0],
+                   qMin(physDevProperties.limits.maxComputeWorkGroupCount[1],
+                        physDevProperties.limits.maxComputeWorkGroupCount[2])));
+    case QRhi::MaxThreadsPerThreadGroup:
+        return int(physDevProperties.limits.maxComputeWorkGroupInvocations);
+    case QRhi::MaxThreadGroupX:
+        return int(physDevProperties.limits.maxComputeWorkGroupSize[0]);
+    case QRhi::MaxThreadGroupY:
+        return int(physDevProperties.limits.maxComputeWorkGroupSize[1]);
+    case QRhi::MaxThreadGroupZ:
+        return int(physDevProperties.limits.maxComputeWorkGroupSize[2]);
     default:
         Q_UNREACHABLE();
         return 0;