D3D11: Add support for pack parameters when packing to PBOs.

src/libANGLE/renderer/d3d/d3d11/Buffer11.cpp

@@ -1267,9 +1267,16 @@ gl::ErrorOrResult<CopyResult> Buffer11::PackStorage::copyFromStorage(BufferStora
                                                                      size_t size,
                                                                      size_t destOffset)
 {
-    // We copy through a staging buffer when drawing with a pack buffer,
-    // or for other cases where we access the pack buffer
-    UNREACHABLE();
+    ANGLE_TRY(flushQueuedPackCommand());
+
+    // We copy through a staging buffer when drawing with a pack buffer, or for other cases where we
+    // access the pack buffer
+    ASSERT(source->isMappable() && source->getUsage() == BUFFER_USAGE_STAGING);
+    uint8_t *sourceData = nullptr;
+    ANGLE_TRY(source->map(sourceOffset, size, GL_MAP_READ_BIT, &sourceData));
+    ASSERT(destOffset + size <= mMemoryBuffer.size());
+    memcpy(mMemoryBuffer.data() + destOffset, sourceData, size);
+    source->unmap();
     return CopyResult::NOT_RECREATED;
 }
 

src/libANGLE/renderer/d3d/d3d11/Framebuffer11.cpp

@@ -262,13 +262,6 @@ gl::Error Framebuffer11::readPixelsImpl(const gl::Rectangle &area,
     gl::Buffer *packBuffer = pack.pixelBuffer.get();
     if (packBuffer != nullptr)
     {
-        if (pack.rowLength != 0 || pack.skipRows != 0 || pack.skipPixels != 0)
-        {
-            UNIMPLEMENTED();
-            return gl::Error(GL_INVALID_OPERATION,
-                             "Unimplemented pixel store parameters in readPixelsImpl");
-        }
-
         Buffer11 *packBufferStorage = GetImplAs<Buffer11>(packBuffer);
         PackPixelsParams packParams(area, format, type, static_cast<GLuint>(outputPitch), pack,
                                     reinterpret_cast<ptrdiff_t>(pixels));