app/internal/d3d11: include depth buffer in current framebuffer query

Fixes rendering on Windows. Thanks to Egon Elbre for noticing.

Signed-off-by: Elias Naur <mail@eliasnaur.com>

app/internal/d3d11/backend_windows.go

@@ -279,12 +279,15 @@ func NewBackend(d *Device) (*Backend, error) {
 }
 
 func (b *Backend) BeginFrame() backend.Framebuffer {
-	renderTarget := b.dev.ctx.OMGetRenderTargets()
+	renderTarget, depthView := b.dev.ctx.OMGetRenderTargets()
+	// Assume someone else is holding on to the render targets.
 	if renderTarget != nil {
-		// Assume someone else is holding on to it.
 		_IUnknownRelease(unsafe.Pointer(renderTarget), renderTarget.vtbl.Release)
 	}
-	return &Framebuffer{dev: b.dev, renderTarget: renderTarget, foreign: true}
+	if depthView != nil {
+		_IUnknownRelease(unsafe.Pointer(depthView), depthView.vtbl.Release)
+	}
+	return &Framebuffer{dev: b.dev, renderTarget: renderTarget, depthView: depthView, foreign: true}
 }
 
 func (b *Backend) EndFrame() {

app/internal/d3d11/d3d11_windows.go

@@ -1197,18 +1197,21 @@ func (c *_ID3D11DeviceContext) IASetPrimitiveTopology(mode uint32) {
 	)
 }
 
-func (c *_ID3D11DeviceContext) OMGetRenderTargets() *_ID3D11RenderTargetView {
+func (c *_ID3D11DeviceContext) OMGetRenderTargets() (*_ID3D11RenderTargetView, *_ID3D11DepthStencilView) {
-	var target *_ID3D11RenderTargetView
+	var (
+		target           *_ID3D11RenderTargetView
+		depthStencilView *_ID3D11DepthStencilView
+	)
 	syscall.Syscall6(
 		c.vtbl.OMGetRenderTargets,
 		4,
 		uintptr(unsafe.Pointer(c)),
 		1, // NumViews
 		uintptr(unsafe.Pointer(&target)),
-		0, // pDepthStencilView
+		uintptr(unsafe.Pointer(&depthStencilView)),
 		0, 0,
 	)
-	return target
+	return target, depthStencilView
 }
 
 func (c *_ID3D11DeviceContext) OMSetRenderTargets(target *_ID3D11RenderTargetView, depthStencil *_ID3D11DepthStencilView) {