[RenderEngine] Organize RenderEngine directory.

This patch:
1. adds proper namespace renderengine to all RenderEngine code,
   and namespace gl to all GLES related code
2. creates gl/ directory for GLES backend code
3. Reorder include header files, remove unused header files.

BUG: 112585051
Test: Build, flash, run display validation
Change-Id: I81f0b8831213607cde08562958f7c38ddaf4c9e6
diff --git a/services/surfaceflinger/RenderEngine/gl/GLES20RenderEngine.h b/services/surfaceflinger/RenderEngine/gl/GLES20RenderEngine.h
new file mode 100644
index 0000000..c830184
--- /dev/null
+++ b/services/surfaceflinger/RenderEngine/gl/GLES20RenderEngine.h
@@ -0,0 +1,117 @@
+/*
+ * Copyright 2013 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 SF_GLES20RENDERENGINE_H_
+#define SF_GLES20RENDERENGINE_H_
+
+#include <stdint.h>
+#include <sys/types.h>
+
+#include <GLES2/gl2.h>
+#include <renderengine/RenderEngine.h>
+#include <renderengine/private/Description.h>
+
+namespace android {
+
+class String8;
+
+namespace renderengine {
+
+class Mesh;
+class Texture;
+
+namespace gl {
+
+class GLES20RenderEngine : public impl::RenderEngine {
+    GLuint mProtectedTexName;
+    GLint mMaxViewportDims[2];
+    GLint mMaxTextureSize;
+    GLuint mVpWidth;
+    GLuint mVpHeight;
+
+    struct Group {
+        GLuint texture;
+        GLuint fbo;
+        GLuint width;
+        GLuint height;
+        mat4 colorTransform;
+    };
+
+    Description mState;
+
+    virtual void bindImageAsFramebuffer(EGLImageKHR image, uint32_t* texName, uint32_t* fbName,
+                                        uint32_t* status);
+    virtual void unbindFramebuffer(uint32_t texName, uint32_t fbName);
+
+public:
+    GLES20RenderEngine(uint32_t featureFlags); // See RenderEngine::FeatureFlag
+    virtual ~GLES20RenderEngine();
+
+protected:
+    virtual void dump(String8& result);
+    virtual void setViewportAndProjection(size_t vpw, size_t vph, Rect sourceCrop, size_t hwh,
+                                          bool yswap, ui::Transform::orientation_flags rotation);
+    virtual void setupLayerBlending(bool premultipliedAlpha, bool opaque, bool disableTexture,
+                                    const half4& color) override;
+
+    // Color management related functions and state
+    void setSourceY410BT2020(bool enable) override;
+    void setSourceDataSpace(ui::Dataspace source) override;
+    void setOutputDataSpace(ui::Dataspace dataspace) override;
+    void setDisplayMaxLuminance(const float maxLuminance) override;
+
+    virtual void setupLayerTexturing(const Texture& texture);
+    virtual void setupLayerBlackedOut();
+    virtual void setupFillWithColor(float r, float g, float b, float a);
+    virtual void setupColorTransform(const mat4& colorTransform);
+    virtual void disableTexturing();
+    virtual void disableBlending();
+
+    virtual void drawMesh(const Mesh& mesh);
+
+    virtual size_t getMaxTextureSize() const;
+    virtual size_t getMaxViewportDims() const;
+
+    // Current dataspace of layer being rendered
+    ui::Dataspace mDataSpace = ui::Dataspace::UNKNOWN;
+
+    // Current output dataspace of the render engine
+    ui::Dataspace mOutputDataSpace = ui::Dataspace::UNKNOWN;
+
+    // Whether device supports color management, currently color management
+    // supports sRGB, DisplayP3 color spaces.
+    const bool mUseColorManagement = false;
+    mat4 mSrgbToDisplayP3;
+    mat4 mDisplayP3ToSrgb;
+    mat3 mSrgbToXyz;
+    mat3 mBt2020ToXyz;
+    mat3 mDisplayP3ToXyz;
+    mat4 mXyzToSrgb;
+    mat4 mXyzToDisplayP3;
+    mat4 mXyzToBt2020;
+
+private:
+    // A data space is considered HDR data space if it has BT2020 color space
+    // with PQ or HLG transfer function.
+    bool isHdrDataSpace(const ui::Dataspace dataSpace) const;
+    bool needsXYZTransformMatrix() const;
+};
+
+}  // namespace gl
+}  // namespace renderengine
+}  // namespace android
+
+#endif /* SF_GLES20RENDERENGINE_H_ */