vk: use real, not the default values when doing the swapchain's renderpass

Also revise how the renderpass is handled when wrapping a QVulkanWindow.

examples/rhi/vulkanwindow/renderer.cpp

@@ -71,23 +71,20 @@ void Renderer::initResources()
     params.gfxQueue = m_window->graphicsQueue();
     m_r = QRhi::create(QRhi::Vulkan, &params);
 
+    m_sc = m_r->newSwapChain();
+    m_sc->setTarget(m_window); // note: very different from setWindow(m_window)
+    m_scrp = m_sc->newCompatibleRenderPassDescriptor();
+    m_sc->setRenderPassDescriptor(m_scrp);
+
     m_triRenderer.setRhi(m_r);
     m_triRenderer.setSampleCount(SAMPLES);
-    m_initPending = true;
-
-    m_sc = m_r->newSwapChain();
+    m_triRenderer.initResources(m_scrp);
 }
 
 void Renderer::initSwapChainResources()
 {
-    m_sc->setTarget(m_window); // note: very different from setWindow(m_window)
     m_sc->buildOrResize(); // this just wraps the qvulkanwindow's swapchain and other resources
 
-    if (m_initPending) {
-        m_initPending = false;
-        // had to defer init until we can query the imported renderpass
-        m_triRenderer.initResources(m_sc->renderPassDescriptor());
-    }
     m_triRenderer.resize(m_sc->effectivePixelSize());
 }
 
@@ -103,6 +100,11 @@ void Renderer::releaseResources()
     delete m_sc;
     m_sc = nullptr;
 
+    if (m_scrp) {
+        m_scrp->releaseAndDestroy();
+        m_scrp = nullptr;
+    }
+
     delete m_r;
     m_r = nullptr;
 }

examples/rhi/vulkanwindow/renderer.h

@@ -69,6 +69,6 @@ protected:
     QVulkanWindow *m_window;
     QRhi *m_r = nullptr;
     QRhiSwapChain *m_sc = nullptr;
-    bool m_initPending = false;
+    QRhiRenderPassDescriptor *m_scrp = nullptr;
     TriangleRenderer m_triRenderer;
 };

src/rhi/qrhivulkan.cpp

@@ -2733,6 +2733,11 @@ void QVkRenderPassDescriptor::release()
     if (!rp)
         return;
 
+    if (!ownsRp) {
+        rp = VK_NULL_HANDLE;
+        return;
+    }
+
     QRhiVulkan::DeferredReleaseEntry e;
     e.type = QRhiVulkan::DeferredReleaseEntry::RenderPass;
     e.lastActiveFrameSlot = lastActiveFrameSlot;
@@ -2815,6 +2820,8 @@ QRhiRenderPassDescriptor *QVkTextureRenderTarget::newCompatibleRenderPassDescrip
         delete rp;
         return nullptr;
     }
+
+    rp->ownsRp = true;
     return rp;
 }
 
@@ -3217,11 +3224,8 @@ QVkSwapChain::QVkSwapChain(QRhiImplementation *rhi)
 
 void QVkSwapChain::release()
 {
-    if (wrapWindow) {
-        delete rtWrapper.d.rp;
-        rtWrapper.d.rp = nullptr;
+    if (wrapWindow)
         return;
-    }
 
     QRHI_RES_RHI(QRhiVulkan);
     rhiD->releaseSwapChainResources(this);
@@ -3246,44 +3250,38 @@ QRhiRenderPassDescriptor *QVkSwapChain::newCompatibleRenderPassDescriptor()
 {
     // not yet built so cannot rely on data computed in buildOrResize()
 
+    if (m_target) {
+        QVulkanWindow *vkw = qobject_cast<QVulkanWindow *>(m_target);
+        if (vkw) {
+            QVkRenderPassDescriptor *rp = new QVkRenderPassDescriptor(rhi);
+            rp->rp = vkw->defaultRenderPass();
+            rp->ownsRp = false;
+            return rp;
+        }
+        return nullptr;
+    }
+
+    if (!ensureSurface()) // make sure sampleCount and colorFormat reflect what was requested
+        return nullptr;
+
     QRHI_RES_RHI(QRhiVulkan);
     QVkRenderPassDescriptor *rp = new QVkRenderPassDescriptor(rhi);
     if (!rhiD->createDefaultRenderPass(&rp->rp,
                                        m_depthStencil != nullptr,
-                                       rhiD->effectiveSampleCount(m_sampleCount),
+                                       sampleCount,
                                        colorFormat))
     {
         delete rp;
         return nullptr;
     }
+
+    rp->ownsRp = true;
     return rp;
 }
 
-bool QVkSwapChain::buildOrResize()
+bool QVkSwapChain::ensureSurface()
 {
-    if (m_target) {
-        if (sc)
-            release();
-        QVulkanWindow *vkw = qobject_cast<QVulkanWindow *>(m_target);
-        if (vkw) {
-            rtWrapper.d.rp = new QVkRenderPassDescriptor(rhi);
-            rtWrapper.d.rp->rp = vkw->defaultRenderPass();
-            m_renderPassDesc = rtWrapper.d.rp;
-            m_requestedPixelSize = pixelSize = rtWrapper.d.pixelSize = vkw->swapChainImageSize();
-            rtWrapper.d.colorAttCount = 1;
-            rtWrapper.d.dsAttCount = 1;
-            rtWrapper.d.msaaAttCount = vkw->sampleCountFlagBits() > VK_SAMPLE_COUNT_1_BIT ? 1 : 0;
-            wrapWindow = vkw;
-            return true;
-        }
-        return false;
-    }
-
-    // Can be called multiple times due to window resizes - that is not the
-    // same as a simple release+build (as with other resources). Thus no
-    // release() here. See recreateSwapChain() below.
-
-    VkSurfaceKHR surface = QVulkanInstance::surfaceForWindow(m_window);
+    surface = QVulkanInstance::surfaceForWindow(m_window);
     if (!surface) {
         qWarning("Failed to get surface for window");
         return false;
@@ -3314,11 +3312,42 @@ bool QVkSwapChain::buildOrResize()
     }
 
     sampleCount = rhiD->effectiveSampleCount(m_sampleCount);
+
+    return true;
+}
+
+bool QVkSwapChain::buildOrResize()
+{
+    if (m_target) {
+        if (sc)
+            release();
+        QVulkanWindow *vkw = qobject_cast<QVulkanWindow *>(m_target);
+        if (vkw) {
+            rtWrapper.d.rp = QRHI_RES(QVkRenderPassDescriptor, m_renderPassDesc);
+            Q_ASSERT(rtWrapper.d.rp && rtWrapper.d.rp->rp);
+            m_requestedPixelSize = pixelSize = rtWrapper.d.pixelSize = vkw->swapChainImageSize();
+            rtWrapper.d.colorAttCount = 1;
+            rtWrapper.d.dsAttCount = 1;
+            rtWrapper.d.msaaAttCount = vkw->sampleCountFlagBits() > VK_SAMPLE_COUNT_1_BIT ? 1 : 0;
+            wrapWindow = vkw;
+            return true;
+        }
+        return false;
+    }
+
+    // Can be called multiple times due to window resizes - that is not the
+    // same as a simple release+build (as with other resources). Thus no
+    // release() here. See recreateSwapChain() below.
+
+    if (!ensureSurface())
+        return false;
+
     if (m_depthStencil && m_depthStencil->sampleCount() != m_sampleCount) {
         qWarning("Depth-stencil buffer's sampleCount (%d) does not match color buffers' sample count (%d). Expect problems.",
                  m_depthStencil->sampleCount(), m_sampleCount);
     }
 
+    QRHI_RES_RHI(QRhiVulkan);
     if (!rhiD->recreateSwapChain(surface, m_requestedPixelSize, m_flags, this))
         return false;
 

src/rhi/qrhivulkan_p.h

@@ -129,6 +129,7 @@ struct QVkRenderPassDescriptor : public QRhiRenderPassDescriptor
     void release() override;
 
     VkRenderPass rp = VK_NULL_HANDLE;
+    bool ownsRp = false;
     int lastActiveFrameSlot = -1;
 };
 
@@ -254,6 +255,8 @@ struct QVkSwapChain : public QRhiSwapChain
     QRhiRenderPassDescriptor *newCompatibleRenderPassDescriptor() override;
     bool buildOrResize() override;
 
+    bool ensureSurface();
+
     static const int DEFAULT_BUFFER_COUNT = 2;
     static const int MAX_BUFFER_COUNT = 3;
 
@@ -262,6 +265,7 @@ struct QVkSwapChain : public QRhiSwapChain
     bool supportsReadback = false;
     VkSwapchainKHR sc = VK_NULL_HANDLE;
     int bufferCount = 0;
+    VkSurfaceKHR surface = VK_NULL_HANDLE;
     VkFormat colorFormat = VK_FORMAT_B8G8R8A8_UNORM;
     VkColorSpaceKHR colorSpace = VK_COLOR_SPACE_SRGB_NONLINEAR_KHR;
     QVkRenderBuffer *ds = nullptr;