[WebGPU] Calling GPUTexture.destroy() on the result of GPUCanvasConte…

…xt.getCurrentTexture() is problematic

https://bugs.webkit.org/show_bug.cgi?id=267098
<radar://120494910>

Reviewed by Tadeu Zagallo.

Calling GPUTexture.destroy() on the result of GPUCanvasContext.getCurrentTexture() was
problematic because we don't continuously make new IOSurface backed MTLTexture instances
for the canvas.

We don't need to, we just need to ensure that calling destroy makes the Texture act
like an invalid texture and that calling getCurrentTexture() returns a non-destroyed
texture.

* Source/WebGPU/WebGPU/PresentationContextIOSurface.mm:
(WebGPU::PresentationContextIOSurface::configure):
(WebGPU::PresentationContextIOSurface::getCurrentTexture):
* Source/WebGPU/WebGPU/Texture.h:
* Source/WebGPU/WebGPU/Texture.mm:
(WebGPU::Texture::recreateIfNeeded):
(WebGPU::Texture::makeCanvasBacking):
(WebGPU::Texture::destroy):

Canonical link: https://commits.webkit.org/272711@main

Source/WebGPU/WebGPU/PresentationContextIOSurface.mm

@@ -121,6 +121,7 @@
         texture.label = fromAPI(descriptor.label);
         auto viewFormats = Vector<WGPUTextureFormat> { Texture::pixelFormat(descriptor.format) };
         auto parentTexture = Texture::create(texture, wgpuTextureDescriptor, WTFMove(viewFormats), device);
+        parentTexture->makeCanvasBacking();
         m_renderBuffers.append({ parentTexture, TextureView::create(texture, wgpuTextureViewDescriptor, { { width, height, 1 } }, parentTexture, device) });
     }
     ASSERT(m_ioSurfaces.count == m_renderBuffers.size());
@@ -143,7 +144,9 @@
 Texture* PresentationContextIOSurface::getCurrentTexture()
 {
     ASSERT(m_ioSurfaces.count == m_renderBuffers.size());
-    return m_renderBuffers[m_currentIndex].texture.ptr();
+    auto& texture = m_renderBuffers[m_currentIndex].texture;
+    texture->recreateIfNeeded();
+    return texture.ptr();
 }
 
 TextureView* PresentationContextIOSurface::getCurrentTextureView()

Source/WebGPU/WebGPU/Texture.h

@@ -109,6 +109,8 @@ class Texture : public WGPUTextureImpl, public RefCounted<Texture> {
     static bool hasStorageBindingCapability(WGPUTextureFormat, const Device&, WGPUStorageTextureAccess = WGPUStorageTextureAccess_Undefined);
     static bool supportsMultisampling(WGPUTextureFormat, const Device&);
     static bool supportsBlending(WGPUTextureFormat, const Device&);
+    void recreateIfNeeded();
+    void makeCanvasBacking();
 
 private:
     Texture(id<MTLTexture>, const WGPUTextureDescriptor&, Vector<WGPUTextureFormat>&& viewFormats, Device&);
@@ -136,6 +138,7 @@ class Texture : public WGPUTextureImpl, public RefCounted<Texture> {
     using ClearedToZeroContainer = HashMap<uint32_t, ClearedToZeroInnerContainer, DefaultHash<uint32_t>, WTF::UnsignedWithZeroKeyHashTraits<uint32_t>>;
     ClearedToZeroContainer m_clearedToZero;
     bool m_destroyed { false };
+    bool m_canvasBacking { false };
 };
 
 } // namespace WebGPU

Source/WebGPU/WebGPU/Texture.mm

@@ -2723,11 +2723,22 @@ static MTLPixelFormat resolvedPixelFormat(MTLPixelFormat viewPixelFormat, MTLPix
     return TextureView::create(texture, *descriptor, renderExtent, *this, m_device);
 }
 
+void Texture::recreateIfNeeded()
+{
+    RELEASE_ASSERT(m_texture.iosurface && m_canvasBacking);
+    m_destroyed = false;
+}
+
+void Texture::makeCanvasBacking()
+{
+    m_canvasBacking = true;
+}
+
 void Texture::destroy()
 {
     // https://gpuweb.github.io/gpuweb/#dom-gputexture-destroy
-
-    m_texture = nil;
+    if (!m_canvasBacking)
+        m_texture = nil;
     m_destroyed = true;
 }