wg_engine: hotfix

- initialize stage buffers before drawing
- confirm the surface size in sync stage

Co-authored-by: Jinny You <jinny@lottiefiles.com>

src/renderer/wg_engine/tvgWgCompositor.cpp

@@ -39,6 +39,8 @@ void WgCompositor::initialize(WgContext& context, uint32_t width, uint32_t heigh
     resize(context, width, height);
     // composition and blend geometries
     meshDataBlit.blitBox();
+    // force stage buffers initialization
+    flush(context);
 }
 
 

src/renderer/wg_engine/tvgWgCompositor.h

@@ -111,11 +111,11 @@ public:
     void beginRenderPass(WGPUCommandEncoder encoder, WgRenderTarget* target, bool clear, WGPUColor clearColor = { 0.0, 0.0, 0.0, 0.0 });
     void endRenderPass();
 
-    // request shapes for drawing (staging)
-        // stage data
+    // stage buffers operations
     void reset(WgContext& context);
     void flush(WgContext& context);
 
+    // request shapes for drawing (staging)
     void requestShape(WgRenderDataShape* renderData);
     void requestImage(WgRenderDataPicture* renderData);
 

src/renderer/wg_engine/tvgWgRenderer.cpp

@@ -341,22 +341,24 @@ bool WgRenderer::sync()
     // there is no external dest buffer
     if (!dstTexture) return false;
 
-    // get external dest buffer
-    WGPUTextureView dstTextureView = mContext.createTextureView(dstTexture);
+    // insure that surface and offscreen target have the same size
+    if ((wgpuTextureGetWidth(dstTexture) == mRenderTargetRoot.width) && 
+        (wgpuTextureGetHeight(dstTexture) == mRenderTargetRoot.height)) {
+        // get external dest buffer
+        WGPUTextureView dstTextureView = mContext.createTextureView(dstTexture);
+        // create command encoder
+        WGPUCommandEncoder commandEncoder = mContext.createCommandEncoder();
+        // show root offscreen buffer
+        mCompositor.blit(mContext, commandEncoder, &mRenderTargetRoot, dstTextureView);
+        mContext.submitCommandEncoder(commandEncoder);
+        mContext.releaseCommandEncoder(commandEncoder);
+        // release dest buffer view
+        mContext.releaseTextureView(dstTextureView);
+    }
 
-    // create command encoder
-    WGPUCommandEncoder commandEncoder = mContext.createCommandEncoder();
-    // show root offscreen buffer
-    mCompositor.blit(mContext, commandEncoder, &mRenderTargetRoot, dstTextureView);
-    mContext.submitCommandEncoder(commandEncoder);
-    mContext.releaseCommandEncoder(commandEncoder);
-
-    // release dest buffer view
-    mContext.releaseTextureView(dstTextureView);
     return true;
 }
 
-
 // render target handle
 bool WgRenderer::target(WGPUDevice device, WGPUInstance instance, void* target, uint32_t width, uint32_t height, int type)
 {