rhi: Make QRhiRenderTarget's rp getter functional with swapchains

swapchain->currentFrameRenderTarget()->renderPassDescriptor() is not
functional at the moment, it returns null. This is because no backend
ensures that the internal renderpass descriptor object is exposed via
that getter in a QRhiSwapChainRenderTarget. Whereas in a
QRhiTextureRenderTarget this would work by design because there the
setter must be called by the user.

Fix this up, providing better API symmetry, and also reducing the need
to pass along QRhiRenderPassDescriptor objects seprately alongside a
QRhiRenderTarget in some places, e.g. in Qt Quick.

Change-Id: I42c4e9aaee3202c1d23bd093d840af80c5f8cd0f
Reviewed-by: Qt CI Bot <qt_ci_bot@qt-project.org>
Reviewed-by: Andy Nichols <andy.nichols@qt.io>

5 files changed, 5 insertions, 0 deletions

diff --git a/src/gui/rhi/qrhid3d11.cpp b/src/gui/rhi/qrhid3d11.cpp
index c90dbd6e7d..c521bdb19b 100644
--- a/src/gui/rhi/qrhid3d11.cpp
+++ b/src/gui/rhi/qrhid3d11.cpp
@@ -4827,6 +4827,7 @@ bool QD3D11SwapChain::createOrResize()
     frameCount = 0;
     ds = m_depthStencil ? QRHI_RES(QD3D11RenderBuffer, m_depthStencil) : nullptr;
 
+    rt.setRenderPassDescriptor(m_renderPassDesc); // for the public getter in QRhiRenderTarget
     QD3D11SwapChainRenderTarget *rtD = QRHI_RES(QD3D11SwapChainRenderTarget, &rt);
     rtD->d.rp = QRHI_RES(QD3D11RenderPassDescriptor, m_renderPassDesc);
     rtD->d.pixelSize = pixelSize;
diff --git a/src/gui/rhi/qrhigles2.cpp b/src/gui/rhi/qrhigles2.cpp
index 18defa36aa..bdcdfd908a 100644
--- a/src/gui/rhi/qrhigles2.cpp
+++ b/src/gui/rhi/qrhigles2.cpp
@@ -5795,6 +5795,7 @@ bool QGles2SwapChain::createOrResize()
         m_depthStencil->create();
     }
 
+    rt.setRenderPassDescriptor(m_renderPassDesc); // for the public getter in QRhiRenderTarget
     rt.d.rp = QRHI_RES(QGles2RenderPassDescriptor, m_renderPassDesc);
     rt.d.pixelSize = pixelSize;
     rt.d.dpr = float(m_window->devicePixelRatio());
diff --git a/src/gui/rhi/qrhimetal.mm b/src/gui/rhi/qrhimetal.mm
index 385aedbd7e..08d70d16fc 100644
--- a/src/gui/rhi/qrhimetal.mm
+++ b/src/gui/rhi/qrhimetal.mm
@@ -4179,6 +4179,7 @@ bool QMetalSwapChain::createOrResize()
         }
     }
 
+    rtWrapper.setRenderPassDescriptor(m_renderPassDesc); // for the public getter in QRhiRenderTarget
     rtWrapper.d->pixelSize = pixelSize;
     rtWrapper.d->dpr = float(window->devicePixelRatio());
     rtWrapper.d->sampleCount = samples;
diff --git a/src/gui/rhi/qrhinull.cpp b/src/gui/rhi/qrhinull.cpp
index f567894a9e..17d6df2c6f 100644
--- a/src/gui/rhi/qrhinull.cpp
+++ b/src/gui/rhi/qrhinull.cpp
@@ -1015,6 +1015,7 @@ bool QNullSwapChain::createOrResize()
 
     window = m_window;
     m_currentPixelSize = surfacePixelSize();
+    rt.setRenderPassDescriptor(m_renderPassDesc); // for the public getter in QRhiRenderTarget
     rt.d.rp = QRHI_RES(QNullRenderPassDescriptor, m_renderPassDesc);
     rt.d.pixelSize = m_currentPixelSize;
     frameCount = 0;
diff --git a/src/gui/rhi/qrhivulkan.cpp b/src/gui/rhi/qrhivulkan.cpp
index 4729bb51ca..483bf14a61 100644
--- a/src/gui/rhi/qrhivulkan.cpp
+++ b/src/gui/rhi/qrhivulkan.cpp
@@ -7507,6 +7507,7 @@ bool QVkSwapChain::createOrResize()
     if (!m_renderPassDesc)
         qWarning("QVkSwapChain: No renderpass descriptor set. See newCompatibleRenderPassDescriptor() and setRenderPassDescriptor().");
 
+    rtWrapper.setRenderPassDescriptor(m_renderPassDesc); // for the public getter in QRhiRenderTarget
     rtWrapper.d.rp = QRHI_RES(QVkRenderPassDescriptor, m_renderPassDesc);
     Q_ASSERT(rtWrapper.d.rp && rtWrapper.d.rp->rp);