From 406bb6ae20471cf9bba6d910256b416792c99322 Mon Sep 17 00:00:00 2001
From: Laszlo Agocs <laszlo.agocs@qt.io>
Date: Mon, 24 Jan 2022 15:28:20 +0100
Subject: rhi: Make sure pixelSize() to a texture rt is always up to date
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This is an issue for QQuickWindow in practice, although it is not hit
by our current tests.

Pick-to: 6.3
Change-Id: Ia73704c1af6a82b2689ce7b844d3b0eb9a17ec18
Reviewed-by: Christian Strømme <christian.stromme@qt.io>
---
 src/gui/rhi/qrhi.cpp       | 12 ++++++++++++
 src/gui/rhi/qrhid3d11.cpp  |  3 +++
 src/gui/rhi/qrhigles2.cpp  |  3 +++
 src/gui/rhi/qrhimetal.mm   |  3 +++
 src/gui/rhi/qrhinull.cpp   |  3 +++
 src/gui/rhi/qrhivulkan.cpp |  3 +++
 6 files changed, 27 insertions(+)

(limited to 'src/gui')

diff --git a/src/gui/rhi/qrhi.cpp b/src/gui/rhi/qrhi.cpp
index 452a39642f..8196d107fe 100644
--- a/src/gui/rhi/qrhi.cpp
+++ b/src/gui/rhi/qrhi.cpp
@@ -2929,6 +2929,18 @@ QRhiResource::Type QRhiRenderTarget::resourceType() const
     \fn QSize QRhiRenderTarget::pixelSize() const
 
     \return the size in pixels.
+
+    Valid only after create() has been called successfully. Until then the
+    result is a default-constructed QSize.
+
+    With QRhiTextureRenderTarget the returned size is the size of the
+    associated attachments at the time of create(), in practice the size of the
+    first color attachment, or the depth/stencil buffer if there are no color
+    attachments. If the associated textures or renderbuffers are resized and
+    rebuilt afterwards, then pixelSize() performs an implicit call to create()
+    in order to rebuild the underlying data structures. This implicit check is
+    similar to what QRhiCommandBuffer::beginPass() does, and ensures that the
+    returned size is always up-to-date.
  */
 
 /*!
diff --git a/src/gui/rhi/qrhid3d11.cpp b/src/gui/rhi/qrhid3d11.cpp
index d029cd2fbf..fc6fd59f4f 100644
--- a/src/gui/rhi/qrhid3d11.cpp
+++ b/src/gui/rhi/qrhid3d11.cpp
@@ -3631,6 +3631,9 @@ bool QD3D11TextureRenderTarget::create()
 
 QSize QD3D11TextureRenderTarget::pixelSize() const
 {
+    if (!QRhiRenderTargetAttachmentTracker::isUpToDate<QD3D11Texture, QD3D11RenderBuffer>(m_desc, d.currentResIdList))
+        const_cast<QD3D11TextureRenderTarget *>(this)->create();
+
     return d.pixelSize;
 }
 
diff --git a/src/gui/rhi/qrhigles2.cpp b/src/gui/rhi/qrhigles2.cpp
index 0c2225f194..21dd8da229 100644
--- a/src/gui/rhi/qrhigles2.cpp
+++ b/src/gui/rhi/qrhigles2.cpp
@@ -5317,6 +5317,9 @@ bool QGles2TextureRenderTarget::create()
 
 QSize QGles2TextureRenderTarget::pixelSize() const
 {
+    if (!QRhiRenderTargetAttachmentTracker::isUpToDate<QGles2Texture, QGles2RenderBuffer>(m_desc, d.currentResIdList))
+        const_cast<QGles2TextureRenderTarget *>(this)->create();
+
     return d.pixelSize;
 }
 
diff --git a/src/gui/rhi/qrhimetal.mm b/src/gui/rhi/qrhimetal.mm
index dd79c77dc9..4198306ffc 100644
--- a/src/gui/rhi/qrhimetal.mm
+++ b/src/gui/rhi/qrhimetal.mm
@@ -3183,6 +3183,9 @@ bool QMetalTextureRenderTarget::create()
 
 QSize QMetalTextureRenderTarget::pixelSize() const
 {
+    if (!QRhiRenderTargetAttachmentTracker::isUpToDate<QMetalTexture, QMetalRenderBuffer>(m_desc, d->currentResIdList))
+        const_cast<QMetalTextureRenderTarget *>(this)->create();
+
     return d->pixelSize;
 }
 
diff --git a/src/gui/rhi/qrhinull.cpp b/src/gui/rhi/qrhinull.cpp
index 9544878350..2790b19ebc 100644
--- a/src/gui/rhi/qrhinull.cpp
+++ b/src/gui/rhi/qrhinull.cpp
@@ -860,6 +860,9 @@ bool QNullTextureRenderTarget::create()
 
 QSize QNullTextureRenderTarget::pixelSize() const
 {
+    if (!QRhiRenderTargetAttachmentTracker::isUpToDate<QNullTexture, QNullRenderBuffer>(m_desc, d.currentResIdList))
+        const_cast<QNullTextureRenderTarget *>(this)->create();
+
     return d.pixelSize;
 }
 
diff --git a/src/gui/rhi/qrhivulkan.cpp b/src/gui/rhi/qrhivulkan.cpp
index 025419d045..c27b55f885 100644
--- a/src/gui/rhi/qrhivulkan.cpp
+++ b/src/gui/rhi/qrhivulkan.cpp
@@ -6637,6 +6637,9 @@ bool QVkTextureRenderTarget::create()
 
 QSize QVkTextureRenderTarget::pixelSize() const
 {
+    if (!QRhiRenderTargetAttachmentTracker::isUpToDate<QVkTexture, QVkRenderBuffer>(m_desc, d.currentResIdList))
+        const_cast<QVkTextureRenderTarget *>(this)->create();
+
     return d.pixelSize;
 }
 
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