Metal: Fix missing image view for texture from IOSurface.

src/libANGLE/renderer/metal/TextureMtl.mm

@@ -767,6 +767,10 @@ angle::Result TextureMtl::bindTexImage(const gl::Context *context, egl::Surface
     mLayeredTextureViews.resize(1);
     mLayeredTextureViews[0] = mNativeTexture;
 
+    // Create image view for glTexSubImage* and glCopySubTexture*
+    ASSERT(mNativeTexture->mipmapLevels() == 1);
+    mTexImages[0][0] = mNativeTexture;
+
     // Tell context to rebind textures
     ContextMtl *contextMtl = mtl::GetImpl(context);
     contextMtl->invalidateCurrentTextures();

src/tests/egl_tests/EGLIOSurfaceClientBufferTest.cpp

@@ -256,6 +256,11 @@ class IOSurfaceClientBufferTest : public ANGLETest
         EGLSurface pbuffer;
         bindIOSurfaceToTexture(ioSurface, 1, 1, 0, internalFormat, type, &pbuffer, &texture);
 
+        doSampleTestWithTexture(texture, mask);
+    }
+
+    void doSampleTestWithTexture(const GLTexture &texture, int mask)
+    {
         constexpr char kVS[] =
             "attribute vec4 position;\n"
             "void main()\n"
@@ -571,6 +576,35 @@ TEST_P(IOSurfaceClientBufferTest, BlitToIOSurface)
     doBlitTest(false, 2, 2);
 }
 
+// Test using glCopyTexSubImage to copy to BGRX8888 IOSurfaces works.
+TEST_P(IOSurfaceClientBufferTest, CopySubImageToBGRX8888IOSurface)
+{
+    ANGLE_SKIP_TEST_IF(!hasIOSurfaceExt());
+
+    ScopedIOSurfaceRef ioSurface = CreateSinglePlaneIOSurface(1, 1, 'BGRA', 4);
+
+    GLTexture texture;
+    glBindTexture(getGLTextureTarget(), texture);
+    glTexParameteri(getGLTextureTarget(), GL_TEXTURE_MIN_FILTER, GL_NEAREST);
+    glTexParameteri(getGLTextureTarget(), GL_TEXTURE_MAG_FILTER, GL_NEAREST);
+
+    // Bind the IOSurface to a texture and clear it.
+    EGLSurface pbuffer;
+    bindIOSurfaceToTexture(ioSurface, 1, 1, 0, GL_RGB, GL_UNSIGNED_BYTE, &pbuffer, &texture);
+
+    // 1. Clear default framebuffer with desired color.
+    GLColor color(1, 2, 3, 4);
+    glClearColor(color.R / 255.f, color.G / 255.f, color.B / 255.f, color.A / 255.f);
+    glClear(GL_COLOR_BUFFER_BIT);
+
+    // 2. Copy color from default framebuffer to iosurface's bound texture.
+    glCopyTexSubImage2D(getGLTextureTarget(), 0, 0, 0, 0, 0, 1, 1);
+    EXPECT_GL_NO_ERROR();
+
+    // 3. Do texture sampling verification.
+    doSampleTestWithTexture(texture, R | G | B);
+}
+
 // Test the validation errors for missing attributes for eglCreatePbufferFromClientBuffer with
 // IOSurface
 TEST_P(IOSurfaceClientBufferTest, NegativeValidationMissingAttributes)