From 4c1ee4df925d3d8edccd8e7dad7d05f9b807b3a4 Mon Sep 17 00:00:00 2001
From: Shahbaz Youssefi <syoussefi@chromium.org>
Date: Mon, 04 May 2026 16:52:30 -0400
Subject: [PATCH] Vulkan: Fix removing staged updates during cube map redefine

When a texture is redefined, `stageSelfAsSubresourceUpdates` is used to
make the old VkImage the source of a data update to the new VkImage.
Later, when a subresource is redefined, the staged update is dropped.
For this reason, the updates are staged level-by-level.

Because cube maps can be redefined face-by-face, these updates can be
even more granularly staged (i.e. per face).  This was already the case
if the cube map was partially redefined, but wasn't done if it's fully
redefined.

This change makes staging updates always face-by-face for cube maps.
This way, `removeSingleSubresourceStagedUpdates` can always drop updates
to a face that is being redefined.  An assert is added to that function
to make sure that no update exists that intersects with the range being
dropped.

Bug: chromium:502738003
Change-Id: I4df95379a71e3da0fa482111cd44257cd3d103b4
Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/7818814
Commit-Queue: Shahbaz Youssefi <syoussefi@chromium.org>
Reviewed-by: Charlie Lao <cclao@google.com>
---

diff --git a/src/libANGLE/renderer/renderer_utils.cpp b/src/libANGLE/renderer/renderer_utils.cpp
index cd0e52d..6c9ff82 100644
--- a/src/libANGLE/renderer/renderer_utils.cpp
+++ b/src/libANGLE/renderer/renderer_utils.cpp
@@ -2452,9 +2452,20 @@
     // so it can be recreated immediately.  This is needed so that the texture can be reallocated
     // with the correct format/size.
     //
-    // This is not done for cubemaps because every face may be separately redefined.  Note
-    // that this is not possible for texture arrays in general.
-    bool shouldReleaseImage = !isCompatibleRedefinition && isUpdateToSingleLevelImage && !isCubeMap;
+    // For cubemaps, every face may be separately redefined, so only release the image if all faces
+    // have been redefined.  Note that this is not possible for texture arrays in general.
+    bool shouldReleaseImage = !isCompatibleRedefinition && isUpdateToSingleLevelImage;
+    if (shouldReleaseImage && isCubeMap)
+    {
+        for (uint32_t face = 0; face < 6; ++face)
+        {
+            if (!(*redefinedLevels)[face][levelIndexGL.get()])
+            {
+                shouldReleaseImage = false;
+                break;
+            }
+        }
+    }
     return shouldReleaseImage;
 }
 
diff --git a/src/libANGLE/renderer/vulkan/TextureVk.cpp b/src/libANGLE/renderer/vulkan/TextureVk.cpp
index a93ac6f..0ad33d8 100644
--- a/src/libANGLE/renderer/vulkan/TextureVk.cpp
+++ b/src/libANGLE/renderer/vulkan/TextureVk.cpp
@@ -1973,8 +1973,8 @@
         const gl::ImageIndex stagingIndex =
             gl::ImageIndex::Make2DArrayRange(level.get(), baseLayer, layerCount);
         mImage->stageSubresourceUpdateFromImage(stagingImage.release(), stagingIndex,
-                                                vk::LevelIndex(0), dstOffsetModified, extents,
-                                                imageType);
+                                                vk::LevelIndex(0), 0, dstOffsetModified, extents,
+                                                VK_IMAGE_TYPE_2D, imageType);
     }
 
     return angle::Result::Continue;
@@ -2148,8 +2148,8 @@
         const gl::ImageIndex stagingIndex =
             gl::ImageIndex::Make2DArrayRange(level.get(), baseLayer, layerCount);
         mImage->stageSubresourceUpdateFromImage(stagingImage.release(), stagingIndex,
-                                                vk::LevelIndex(0), dstOffsetModified, extents,
-                                                imageType);
+                                                vk::LevelIndex(0), 0, dstOffsetModified, extents,
+                                                VK_IMAGE_TYPE_2D, imageType);
     }
 
     return angle::Result::Continue;
diff --git a/src/libANGLE/renderer/vulkan/vk_helpers.cpp b/src/libANGLE/renderer/vulkan/vk_helpers.cpp
index b70b7d7..064cd64 100644
--- a/src/libANGLE/renderer/vulkan/vk_helpers.cpp
+++ b/src/libANGLE/renderer/vulkan/vk_helpers.cpp
@@ -8264,6 +8264,10 @@
         }
         else
         {
+            // The layer range should either match the update, or not intersect with it.  If this
+            // assertion fails, the update should be pertially removed, but is retained which is
+            // incorrect.
+            ASSERT(!update->intersectsLayerRange(layerIndex, layerCount, mLayerCount));
             index++;
         }
     }
@@ -9458,9 +9462,11 @@
 void ImageHelper::stageSubresourceUpdateFromImage(RefCounted<ImageHelper> *image,
                                                   const gl::ImageIndex &index,
                                                   LevelIndex srcMipLevel,
+                                                  uint32_t srcLayerIndex,
                                                   const gl::Offset &destOffset,
                                                   const gl::Extents &glExtents,
-                                                  const VkImageType imageType)
+                                                  const VkImageType srcImageType,
+                                                  const VkImageType dstImageType)
 {
     gl::LevelIndex updateLevelGL(index.getLevelIndex());
     VkImageAspectFlags imageAspectFlags = vk::GetFormatAspectFlags(image->get().getActualFormat());
@@ -9468,26 +9474,31 @@
     VkImageCopy copyToImage               = {};
     copyToImage.srcSubresource.aspectMask = imageAspectFlags;
     copyToImage.srcSubresource.mipLevel   = srcMipLevel.get();
+    copyToImage.srcSubresource.baseArrayLayer = srcLayerIndex;
     copyToImage.srcSubresource.layerCount = index.getLayerCount();
     copyToImage.dstSubresource.aspectMask = imageAspectFlags;
     copyToImage.dstSubresource.mipLevel   = updateLevelGL.get();
+    copyToImage.dstSubresource.layerCount     = index.getLayerCount();
 
-    if (imageType == VK_IMAGE_TYPE_3D)
+    // These values must be set explicitly to follow the Vulkan spec:
+    // https://www.khronos.org/registry/vulkan/specs/1.1-extensions/man/html/VkImageCopy.html
+    // If either of the calling command's srcImage or dstImage parameters are of VkImageType
+    // VK_IMAGE_TYPE_3D, the baseArrayLayer and layerCount members of the corresponding
+    // subresource must be 0 and 1, respectively.
+    if (srcImageType == VK_IMAGE_TYPE_3D)
     {
-        // These values must be set explicitly to follow the Vulkan spec:
-        // https://www.khronos.org/registry/vulkan/specs/1.1-extensions/man/html/VkImageCopy.html
-        // If either of the calling command's srcImage or dstImage parameters are of VkImageType
-        // VK_IMAGE_TYPE_3D, the baseArrayLayer and layerCount members of the corresponding
-        // subresource must be 0 and 1, respectively
-        copyToImage.dstSubresource.baseArrayLayer = 0;
-        copyToImage.dstSubresource.layerCount     = 1;
+        ASSERT(srcLayerIndex == 0);
+        copyToImage.srcSubresource.layerCount = 1;
+    }
+    if (dstImageType == VK_IMAGE_TYPE_3D)
+    {
+        copyToImage.dstSubresource.layerCount = 1;
         // Preserve the assumption that destOffset.z == "dstSubresource.baseArrayLayer"
         ASSERT(destOffset.z == (index.hasLayer() ? index.getLayerIndex() : 0));
     }
     else
     {
         copyToImage.dstSubresource.baseArrayLayer = index.hasLayer() ? index.getLayerIndex() : 0;
-        copyToImage.dstSubresource.layerCount     = index.getLayerCount();
     }
 
     gl_vk::GetOffset(destOffset, &copyToImage.dstOffset);
@@ -9506,9 +9517,9 @@
         const gl::ImageIndex index =
             gl::ImageIndex::Make2DArrayRange(levelGL.get(), 0, image->get().getLayerCount());
 
-        stageSubresourceUpdateFromImage(image, index, levelVk, gl::kOffsetZero,
+        stageSubresourceUpdateFromImage(image, index, levelVk, 0, gl::kOffsetZero,
                                         image->get().getLevelExtents(levelVk),
-                                        image->get().getType());
+                                        image->get().getType(), image->get().getType());
     }
 }
 
@@ -9824,15 +9835,7 @@
     for (LevelIndex levelVk(0); levelVk < LevelIndex(levelCount); ++levelVk)
     {
         gl::LevelIndex levelGL = toGLLevel(levelVk);
-        if (!skipLevelsAllFaces.test(levelGL.get()))
-        {
-            const gl::ImageIndex index =
-                gl::ImageIndex::Make2DArrayRange(levelGL.get(), 0, mLayerCount);
-
-            stageSubresourceUpdateFromImage(prevImage.get(), index, levelVk, gl::kOffsetZero,
-                                            getLevelExtents(levelVk), mImageType);
-        }
-        else if (textureType == gl::TextureType::CubeMap)
+        if (textureType == gl::TextureType::CubeMap)
         {
             for (uint32_t face = 0; face < gl::kCubeFaceCount; ++face)
             {
@@ -9841,12 +9844,20 @@
                     const gl::ImageIndex index =
                         gl::ImageIndex::Make2DArrayRange(levelGL.get(), face, 1);
 
-                    stageSubresourceUpdateFromImage(prevImage.get(), index, levelVk,
+                    stageSubresourceUpdateFromImage(prevImage.get(), index, levelVk, face,
                                                     gl::kOffsetZero, getLevelExtents(levelVk),
-                                                    mImageType);
+                                                    mImageType, mImageType);
                 }
             }
         }
+        else if (!skipLevelsAllFaces.test(levelGL.get()))
+        {
+            const gl::ImageIndex index =
+                gl::ImageIndex::Make2DArrayRange(levelGL.get(), 0, mLayerCount);
+
+            stageSubresourceUpdateFromImage(prevImage.get(), index, levelVk, 0, gl::kOffsetZero,
+                                            getLevelExtents(levelVk), mImageType, mImageType);
+        }

diff --git a/src/tests/gl_tests/TextureTest.cpp b/src/tests/gl_tests/TextureTest.cpp
index 9d18f5e..d84daf1 100644
--- a/src/tests/gl_tests/TextureTest.cpp
+++ b/src/tests/gl_tests/TextureTest.cpp
@@ -2375,7 +2375,7 @@
     EXPECT_PIXEL_COLOR_EQ(0, 0, kMipColors[0][0]);
 }
 
-// Test drawing with two texture types, to trigger an ANGLE bug in validation
+// Test drawing with two texture types, regression test for an old bug in validation.
 TEST_P(TextureCubeTest, CubeMapBug)
 {
     glActiveTexture(GL_TEXTURE0);
@@ -2391,7 +2391,8 @@
     EXPECT_GL_NO_ERROR();
 }
 
-// Duplicate of CubeMapBug test and change texture bind unit to trigger an ANGLE bug in validation
+// Duplicate of CubeMapBug test and change texture bind unit, regression test for an old bug in
+// validation.
 TEST_P(TextureCubeTest, CubeMapBug2)
 {
     const char *vertexShaderSource   = getVertexShaderSource();
@@ -2560,8 +2561,8 @@
     EXPECT_PIXEL_COLOR_EQ(px, py, GLColor::green);
 }
 
-// Test creating a FBO with a cube map render target, to test an ANGLE bug
-// https://code.google.com/p/angleproject/issues/detail?id=849
+// Test creating a FBO with a cube map render target, regression test for
+// http://anglebug.com/42266912
 TEST_P(TextureCubeTest, CubeMapFBO)
 {
     // http://anglebug.com/42261821
@@ -2645,6 +2646,237 @@
     ASSERT_GL_NO_ERROR();
 }
 
+// Test modifying level 0 while BASE_LEVEL is not 0.  Level 0 is allocated, so staged updated when
+// the base level is changed is from the old image allocation.
+TEST_P(TextureCubeTestES3, UpdateLevelZeroWhileBaseLevelIsOne)
+{
+    constexpr uint32_t kSize = 128;
+
+    const std::vector<GLColor> kCubeData(kSize * kSize, GLColor::red);
+    const std::vector<GLColor> kCubeData2(kSize * kSize, GLColor::green);
+    const std::vector<GLColor> kCubeData3(kSize * kSize / 4, GLColor::blue);
+
+    // Create a mutable cube texture
+    GLTexture cube;
+    glActiveTexture(GL_TEXTURE0);
+    glBindTexture(GL_TEXTURE_CUBE_MAP, cube);
+    for (GLenum face = 0; face < 6; face++)
+    {
+        glTexImage2D(GL_TEXTURE_CUBE_MAP_POSITIVE_X + face, 0, GL_RGBA, kSize, kSize, 0, GL_RGBA,
+                     GL_UNSIGNED_BYTE, kCubeData.data());
+    }
+    glTexParameteri(GL_TEXTURE_CUBE_MAP, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
+    glTexParameteri(GL_TEXTURE_CUBE_MAP, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
+
+    // Draw to flush staged updates
+    glUseProgram(mProgram);
+    glUniform1i(mTextureCubeUniformLocation, 0);
+    glUniform1i(mTexture2DUniformLocation, 1);
+
+    const int w = getWindowWidth();
+    const int h = getWindowHeight();
+
+    for (uint32_t i = 0; i < 6; ++i)
+    {
+        glUniform1i(mTextureCubeFaceUniformLocation, i);
+        glClear(GL_COLOR_BUFFER_BIT);
+        drawQuad(mProgram, "position", 0.5f);
+
+        EXPECT_PIXEL_COLOR_EQ(w / 2, h / 2, GLColor::red) << i;
+    }
+
+    // Set its base level to 1, so any updates to level 0 looks like it's outside the range of the
+    // texture
+    glTexParameteri(GL_TEXTURE_CUBE_MAP, GL_TEXTURE_BASE_LEVEL, 1);
+
+    // Populate level 1 so it can be drawn with.
+    for (GLenum face = 0; face < 6; face++)
+    {
+        glTexImage2D(GL_TEXTURE_CUBE_MAP_POSITIVE_X + face, 1, GL_RGBA, kSize, kSize, 0, GL_RGBA,
+                     GL_UNSIGNED_BYTE, kCubeData2.data());
+    }
+
+    // Again, sync the texture
+    for (uint32_t i = 0; i < 6; ++i)
+    {
+        glUniform1i(mTextureCubeFaceUniformLocation, i);
+        glClear(GL_COLOR_BUFFER_BIT);
+        drawQuad(mProgram, "position", 0.5f);
+
+        EXPECT_PIXEL_COLOR_EQ(w / 2, h / 2, GLColor::green) << i;
+    }
+
+    // Redefine level 0 to a smaller size.  Regression test for a bug where the data from the old /
+    // larger definition is applied to the new dimensions.
+    for (GLenum face = 0; face < 6; face++)
+    {
+        glTexImage2D(GL_TEXTURE_CUBE_MAP_POSITIVE_X + face, 0, GL_RGBA, kSize / 2, kSize / 2, 0,
+                     GL_RGBA, GL_UNSIGNED_BYTE, kCubeData3.data());
+    }
+
+    // Reset base level back to 0 and draw.
+    glTexParameteri(GL_TEXTURE_CUBE_MAP, GL_TEXTURE_BASE_LEVEL, 0);
+
+    for (uint32_t i = 0; i < 6; ++i)
+    {
+        glUniform1i(mTextureCubeFaceUniformLocation, i);
+        glClear(GL_COLOR_BUFFER_BIT);
+        drawQuad(mProgram, "position", 0.5f);
+
+        EXPECT_PIXEL_COLOR_EQ(w / 2, h / 2, GLColor::blue) << i;
+    }
+}
+
+// Test modifying level 0 while BASE_LEVEL is not 0.  Level 0 has pending data uploads.
+TEST_P(TextureCubeTestES3, UpdateLevelZeroWhileBaseLevelIsOneWithPendingUploads)
+{
+    constexpr uint32_t kSize = 128;
+
+    const std::vector<GLColor> kCubeData(kSize * kSize, GLColor::red);
+    const std::vector<GLColor> kCubeData2(kSize * kSize, GLColor::green);
+    const std::vector<GLColor> kCubeData3(kSize * kSize / 4, GLColor::blue);
+
+    // Create a mutable cube texture
+    GLTexture cube;
+    glActiveTexture(GL_TEXTURE0);
+    glBindTexture(GL_TEXTURE_CUBE_MAP, cube);
+    for (GLenum face = 0; face < 6; face++)
+    {
+        glTexImage2D(GL_TEXTURE_CUBE_MAP_POSITIVE_X + face, 0, GL_RGBA, kSize, kSize, 0, GL_RGBA,
+                     GL_UNSIGNED_BYTE, kCubeData.data());
+    }
+    glTexParameteri(GL_TEXTURE_CUBE_MAP, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
+    glTexParameteri(GL_TEXTURE_CUBE_MAP, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
+
+    // Keep the updates unflushed.
+    // Set its base level to 1, so any updates to level 0 looks like it's outside the range of the
+    // texture
+    glTexParameteri(GL_TEXTURE_CUBE_MAP, GL_TEXTURE_BASE_LEVEL, 1);
+
+    // Populate level 1 so it can be drawn with.
+    for (GLenum face = 0; face < 6; face++)
+    {
+        glTexImage2D(GL_TEXTURE_CUBE_MAP_POSITIVE_X + face, 1, GL_RGBA, kSize, kSize, 0, GL_RGBA,
+                     GL_UNSIGNED_BYTE, kCubeData2.data());
+    }
+
+    // Draw to flush staged updates to level 1
+    glUseProgram(mProgram);
+    glUniform1i(mTextureCubeUniformLocation, 0);
+    glUniform1i(mTexture2DUniformLocation, 1);
+
+    const int w = getWindowWidth();
+    const int h = getWindowHeight();
+
+    for (uint32_t i = 0; i < 6; ++i)
+    {
+        glUniform1i(mTextureCubeFaceUniformLocation, i);
+        glClear(GL_COLOR_BUFFER_BIT);
+        drawQuad(mProgram, "position", 0.5f);
+
+        EXPECT_PIXEL_COLOR_EQ(w / 2, h / 2, GLColor::green) << i;
+    }
+
+    // Redefine level 0 to a smaller size.
+    for (GLenum face = 0; face < 6; face++)
+    {
+        glTexImage2D(GL_TEXTURE_CUBE_MAP_POSITIVE_X + face, 0, GL_RGBA, kSize / 2, kSize / 2, 0,
+                     GL_RGBA, GL_UNSIGNED_BYTE, kCubeData3.data());
+    }
+
+    // Reset base level back to 0 and draw.
+    glTexParameteri(GL_TEXTURE_CUBE_MAP, GL_TEXTURE_BASE_LEVEL, 0);
+
+    for (uint32_t i = 0; i < 6; ++i)
+    {
+        glUniform1i(mTextureCubeFaceUniformLocation, i);
+        glClear(GL_COLOR_BUFFER_BIT);
+        drawQuad(mProgram, "position", 0.5f);
+
+        EXPECT_PIXEL_COLOR_EQ(w / 2, h / 2, GLColor::blue) << i;
+    }
+}
+
+// Test modifying level 0 while BASE_LEVEL is not 0.  Level 0 has pending clears.
+TEST_P(TextureCubeTestES3, UpdateLevelZeroWhileBaseLevelIsOneWithPendingClears)
+{
+    constexpr uint32_t kSize = 128;
+
+    const std::vector<GLColor> kCubeData(kSize * kSize, GLColor::green);
+    const std::vector<GLColor> kCubeData2(kSize * kSize / 4, GLColor::blue);
+
+    // Create a mutable cube texture
+    GLTexture cube;
+    glActiveTexture(GL_TEXTURE0);
+    glBindTexture(GL_TEXTURE_CUBE_MAP, cube);
+    for (GLenum face = 0; face < 6; face++)
+    {
+        glTexImage2D(GL_TEXTURE_CUBE_MAP_POSITIVE_X + face, 0, GL_RGBA, kSize, kSize, 0, GL_RGBA,
+                     GL_UNSIGNED_BYTE, nullptr);
+    }
+    glTexParameteri(GL_TEXTURE_CUBE_MAP, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
+    glTexParameteri(GL_TEXTURE_CUBE_MAP, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
+
+    GLFramebuffer clearFbo;
+    glBindFramebuffer(GL_FRAMEBUFFER, clearFbo);
+    glClearColor(1, 0, 0, 1);
+    for (GLenum face = 0; face < 6; face++)
+    {
+        glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0,
+                               GL_TEXTURE_CUBE_MAP_POSITIVE_X + face, cube, 0);
+        glClear(GL_COLOR_BUFFER_BIT);
+    }
+    glBindFramebuffer(GL_FRAMEBUFFER, 0);
+
+    // Keep the updates unflushed.
+    // Set its base level to 1, so any updates to level 0 looks like it's outside the range of the
+    // texture
+    glTexParameteri(GL_TEXTURE_CUBE_MAP, GL_TEXTURE_BASE_LEVEL, 1);
+
+    // Populate level 1 so it can be drawn with.
+    for (GLenum face = 0; face < 6; face++)
+    {
+        glTexImage2D(GL_TEXTURE_CUBE_MAP_POSITIVE_X + face, 1, GL_RGBA, kSize, kSize, 0, GL_RGBA,
+                     GL_UNSIGNED_BYTE, kCubeData.data());
+    }
+
+    // Draw to flush staged updates to level 1
+    glUseProgram(mProgram);
+    glUniform1i(mTextureCubeUniformLocation, 0);
+    glUniform1i(mTexture2DUniformLocation, 1);
+
+    const int w = getWindowWidth();
+    const int h = getWindowHeight();
+
+    for (uint32_t i = 0; i < 6; ++i)
+    {
+        glUniform1i(mTextureCubeFaceUniformLocation, i);
+        glClear(GL_COLOR_BUFFER_BIT);
+        drawQuad(mProgram, "position", 0.5f);
+
+        EXPECT_PIXEL_COLOR_EQ(w / 2, h / 2, GLColor::green) << i;
+    }
+
+    // Redefine level 0 to a smaller size.
+    for (GLenum face = 0; face < 6; face++)
+    {
+        glTexImage2D(GL_TEXTURE_CUBE_MAP_POSITIVE_X + face, 0, GL_RGBA, kSize / 2, kSize / 2, 0,
+                     GL_RGBA, GL_UNSIGNED_BYTE, kCubeData2.data());
+    }
+
+    // Reset base level back to 0 and draw.
+    glTexParameteri(GL_TEXTURE_CUBE_MAP, GL_TEXTURE_BASE_LEVEL, 0);
+
+    for (uint32_t i = 0; i < 6; ++i)
+    {
+        glUniform1i(mTextureCubeFaceUniformLocation, i);
+        glClear(GL_COLOR_BUFFER_BIT);
+        drawQuad(mProgram, "position", 0.5f);
+
+        EXPECT_PIXEL_COLOR_EQ(w / 2, h / 2, GLColor::blue) << i;
+    }
+}
+
 // Test that glTexSubImage2D works properly when glTexStorage2DEXT has initialized the image with a
 // default color.
 TEST_P(Texture2DTest, TexStorage)
@@ -14400,6 +14632,61 @@
     }
 }
 
+// Test incompatible redefinition of all the faces of a cubemap after the cubemap is allocated.
+TEST_P(TextureCubeTestES3, EntirelyRedefine)
+{
+    constexpr uint32_t kSize = 128;
+
+    const std::vector<GLColor> kCubeData(kSize * kSize, GLColor::red);
+    const std::vector<GLColor> kCubeData2(kSize * kSize / 4, GLColor::blue);
+
+    // Create a mutable cube texture
+    GLTexture cube;
+    glActiveTexture(GL_TEXTURE0);
+    glBindTexture(GL_TEXTURE_CUBE_MAP, cube);
+    for (GLenum face = 0; face < 6; face++)
+    {
+        glTexImage2D(GL_TEXTURE_CUBE_MAP_POSITIVE_X + face, 0, GL_RGBA, kSize, kSize, 0, GL_RGBA,
+                     GL_UNSIGNED_BYTE, kCubeData.data());
+    }
+    glTexParameteri(GL_TEXTURE_CUBE_MAP, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
+    glTexParameteri(GL_TEXTURE_CUBE_MAP, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
+
+    // Draw to flush staged updates
+    glUseProgram(mProgram);
+    glUniform1i(mTextureCubeUniformLocation, 0);
+    glUniform1i(mTexture2DUniformLocation, 1);
... (truncated)