Update TextureState::getEnabledLevelCount.

src/libANGLE/Texture.cpp

@@ -564,16 +564,36 @@ GLuint TextureState::getEnabledLevelCount() const
 
     // The mip chain will have either one or more sequential levels, or max levels,
     // but not a sparse one.
-    for (size_t descIndex = baseLevel; descIndex < mImageDescs.size();)
+    Optional<Extents> expectedSize;
+    for (size_t enabledLevel = baseLevel; enabledLevel <= maxLevel; ++enabledLevel, ++levelCount)
     {
-        if (!mImageDescs[descIndex].size.empty())
+        // Note: for cube textures, we only check the first face.
+        TextureTarget target     = TextureTypeToTarget(mType, 0);
+        size_t descIndex         = GetImageDescIndex(target, enabledLevel);
+        const Extents &levelSize = mImageDescs[descIndex].size;
+
+        if (levelSize.empty())
+        {
+            break;
+        }
+        if (expectedSize.valid())
         {
-            levelCount++;
+            Extents newSize = expectedSize.value();
+            newSize.width   = std::max(1, newSize.width >> 1);
+            newSize.height  = std::max(1, newSize.height >> 1);
+
+            if (!IsArrayTextureType(mType))
+            {
+                newSize.depth = std::max(1, newSize.depth >> 1);
+            }
+
+            if (newSize != levelSize)
+            {
+                break;
+            }
         }
-        descIndex = (mType == TextureType::CubeMap) ? descIndex + 6 : descIndex + 1;
+        expectedSize = levelSize;
     }
-    // The original image already takes account into the levelCount.
-    levelCount = std::min(maxLevel - baseLevel + 1, levelCount);
 
     return levelCount;
 }

src/tests/gl_tests/TextureTest.cpp

@@ -8444,9 +8444,6 @@ TEST_P(Texture2DTestES3, GenerateMipmapAndBaseLevelLUMA)
 // Incompatible levels with non-mipmap filtering should work.
 TEST_P(Texture2DTestES3, IncompatibleMipsButNoMipmapFiltering)
 {
-    // http://anglebug.com/4780
-    ANGLE_SKIP_TEST_IF(IsVulkan());
-
     // http://anglebug.com/4782
     ANGLE_SKIP_TEST_IF(IsOpenGL() && IsWindows() && (IsAMD() || IsIntel()));