rhi: vulkan: be nicer when binding empty buffers

vkUpdateDescriptorSets(): pDescriptorWrites[1].pBufferInfo[0].range is
not VK_WHOLE_SIZE and is zero.
The Vulkan spec states: If range is not equal to VK_WHOLE_SIZE, range
must be greater than 0 (https://docs.vulkan.org/spec/latest/chapters/
descriptorsets.html#VUID-VkDescriptorBufferInfo-range-00341)

As a drive-by, fix the wrong union member access.

Change-Id: I511cddd25f91a117ff181fd64b77079e6946c94c
Reviewed-by: Laszlo Agocs <[email protected]>

1 files changed, 3 insertions, 3 deletions

diff --git a/src/gui/rhi/qrhivulkan.cpp b/src/gui/rhi/qrhivulkan.cpp
index c0ade70bf7a..56195ddd692 100644
--- a/src/gui/rhi/qrhivulkan.cpp
+++ b/src/gui/rhi/qrhivulkan.cpp
@@ -3626,7 +3626,7 @@ void QRhiVulkan::updateShaderResourceBindings(QRhiShaderResourceBindings *srb)
             VkDescriptorBufferInfo bufInfo;
             bufInfo.buffer = bufD->m_type == QRhiBuffer::Dynamic ? bufD->buffers[currentFrameSlot] : bufD->buffers[0];
             bufInfo.offset = b->u.ubuf.offset;
-            bufInfo.range = b->u.ubuf.maybeSize ? b->u.ubuf.maybeSize : bufD->m_size;
+            bufInfo.range = b->u.ubuf.maybeSize ? b->u.ubuf.maybeSize : VK_WHOLE_SIZE;
             // be nice and assert when we know the vulkan device would die a horrible death due to non-aligned reads
             Q_ASSERT(aligned(bufInfo.offset, ubufAlign) == bufInfo.offset);
             bufferInfoIndex = bufferInfos.size();
@@ -3721,8 +3721,8 @@ void QRhiVulkan::updateShaderResourceBindings(QRhiShaderResourceBindings *srb)
             bd.sbuf.generation = bufD->generation;
             VkDescriptorBufferInfo bufInfo;
             bufInfo.buffer = bufD->m_type == QRhiBuffer::Dynamic ? bufD->buffers[currentFrameSlot] : bufD->buffers[0];
-            bufInfo.offset = b->u.ubuf.offset;
-            bufInfo.range = b->u.ubuf.maybeSize ? b->u.ubuf.maybeSize : bufD->m_size;
+            bufInfo.offset = b->u.sbuf.offset;
+            bufInfo.range = b->u.sbuf.maybeSize ? b->u.sbuf.maybeSize : VK_WHOLE_SIZE;
             bufferInfoIndex = bufferInfos.size();
             bufferInfos.append(bufInfo);
         }