Metal: Fix glDisable(GL_DEPTH_TEST) didn't disable depth write

src/libANGLE/renderer/metal/ContextMtl.h

@@ -233,7 +233,7 @@ class ContextMtl : public ContextImpl, public mtl::Context
     uint32_t getClearStencilValue() const;
     // Return front facing stencil write mask
     uint32_t getStencilMask() const;
-    bool isDepthWriteEnabled() const;
+    bool getDepthMask() const;
 
     const mtl::Format &getPixelFormat(angle::FormatID angleFormatId) const;
     // See mtl::FormatTable::getVertexFormat()

src/libANGLE/renderer/metal/ContextMtl.mm

@@ -986,9 +986,9 @@ uint32_t ContextMtl::getStencilMask() const
     return getState().getDepthStencilState().stencilWritemask;
 }
 
-bool ContextMtl::isDepthWriteEnabled() const
+bool ContextMtl::getDepthMask() const
 {
-    return mDepthStencilDesc.depthWriteEnabled;
+    return getState().getDepthStencilState().depthMask;
 }
 
 const mtl::Format &ContextMtl::getPixelFormat(angle::FormatID angleFormatId) const

src/libANGLE/renderer/metal/FrameBufferMtl.mm

@@ -587,7 +587,7 @@ angle::Result FramebufferMtl::clearImpl(const gl::Context *context,
 
     MTLColorWriteMask colorMask = contextMtl->getColorMask();
     uint32_t stencilMask        = contextMtl->getStencilMask();
-    if (!contextMtl->isDepthWriteEnabled())
+    if (!contextMtl->getDepthMask())
     {
         // Disable depth clearing, since depth write is disable
         clearOpts.clearDepth.reset();

src/libANGLE/renderer/metal/mtl_state_cache.mm

@@ -270,16 +270,18 @@ void DepthStencilDesc::updateDepthTestEnabled(const gl::DepthStencilState &dsSta
     if (!dsState.depthTest)
     {
         depthCompareFunction = MTLCompareFunctionAlways;
+        depthWriteEnabled    = false;
     }
     else
     {
         updateDepthCompareFunc(dsState);
+        updateDepthWriteEnabled(dsState);
     }
 }
 
 void DepthStencilDesc::updateDepthWriteEnabled(const gl::DepthStencilState &dsState)
 {
-    depthWriteEnabled = dsState.depthMask;
+    depthWriteEnabled = dsState.depthTest && dsState.depthMask;
 }
 
 void DepthStencilDesc::updateDepthCompareFunc(const gl::DepthStencilState &dsState)