fix [2167050] glTexImage2D code path buggy in SurfaceFlinger

When EGLImage extension is not available, SurfaceFlinger will fallback to using
glTexImage2D and glTexSubImage2D instead, which requires 50% more memory and an
extra copy. However this code path has never been exercised and had some bugs
which this patch fix.

Mainly the scale factor wasn't computed right when falling back on glDrawElements.
We also fallback to this mode of operation if a buffer doesn't have the adequate
usage bits for EGLImage usage.

This changes only code that is currently not executed. Some refactoring was needed to
keep the change clean. This doesn't change anything functionaly.

1 files changed, 64 insertions, 0 deletions

diff --git a/include/ui/GraphicBufferMapper.h b/include/ui/GraphicBufferMapper.h
new file mode 100644
index 0000000..697a02a
--- /dev/null
+++ b/include/ui/GraphicBufferMapper.h
@@ -0,0 +1,64 @@
+/*
+ * Copyright (C) 2007 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#ifndef ANDROID_UI_BUFFER_MAPPER_H
+#define ANDROID_UI_BUFFER_MAPPER_H
+
+#include <stdint.h>
+#include <sys/types.h>
+
+#include <utils/Singleton.h>
+
+#include <hardware/gralloc.h>
+
+
+struct gralloc_module_t;
+
+namespace android {
+
+// ---------------------------------------------------------------------------
+
+class Rect;
+
+class GraphicBufferMapper : public Singleton<GraphicBufferMapper>
+{
+public:
+    static inline GraphicBufferMapper& get() { return getInstance(); }
+
+    status_t registerBuffer(buffer_handle_t handle);
+
+    status_t unregisterBuffer(buffer_handle_t handle);
+    
+    status_t lock(buffer_handle_t handle,
+            int usage, const Rect& bounds, void** vaddr);
+
+    status_t unlock(buffer_handle_t handle);
+    
+    // dumps information about the mapping of this handle
+    void dump(buffer_handle_t handle);
+
+private:
+    friend class Singleton<GraphicBufferMapper>;
+    GraphicBufferMapper();
+    gralloc_module_t const *mAllocMod;
+};
+
+// ---------------------------------------------------------------------------
+
+}; // namespace android
+
+#endif // ANDROID_UI_BUFFER_MAPPER_H
+