add macOS implementation

macos/include/backend/platforms/PlatformEGL.h

@@ -0,0 +1,153 @@
+/*
+ * Copyright (C) 2017 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 TNT_FILAMENT_BACKEND_OPENGL_OPENGL_PLATFORM_EGL_H
+#define TNT_FILAMENT_BACKEND_OPENGL_OPENGL_PLATFORM_EGL_H
+
+#include <stdint.h>
+
+#include <EGL/egl.h>
+#include <EGL/eglext.h>
+
+#include <backend/platforms/OpenGLPlatform.h>
+
+#include <backend/DriverEnums.h>
+
+#include <utility>
+#include <vector>
+
+namespace filament::backend {
+
+/**
+ * A concrete implementation of OpenGLPlatform that supports EGL.
+ */
+class PlatformEGL : public OpenGLPlatform {
+public:
+
+    PlatformEGL() noexcept;
+    bool isExtraContextSupported() const noexcept override;
+    void createContext(bool shared) override;
+
+protected:
+
+    // --------------------------------------------------------------------------------------------
+    // Helper for EGL configs and attributes parameters
+
+    class Config {
+    public:
+        Config();
+        Config(std::initializer_list<std::pair<EGLint, EGLint>> list);
+        EGLint& operator[](EGLint name);
+        EGLint operator[](EGLint name) const;
+        void erase(EGLint name) noexcept;
+        EGLint const* data() const noexcept {
+            return reinterpret_cast<EGLint const*>(mConfig.data());
+        }
+        size_t size() const noexcept {
+            return mConfig.size();
+        }
+    private:
+        std::vector<std::pair<EGLint, EGLint>> mConfig = {{ EGL_NONE, EGL_NONE }};
+    };
+
+    // --------------------------------------------------------------------------------------------
+    // Platform Interface
+
+    /**
+     * Initializes EGL, creates the OpenGL context and returns a concrete Driver implementation
+     * that supports OpenGL/OpenGL ES.
+     */
+    Driver* createDriver(void* sharedContext,
+            const Platform::DriverConfig& driverConfig) noexcept override;
+
+    /**
+     * This returns zero. This method can be overridden to return something more useful.
+     * @return zero
+     */
+    int getOSVersion() const noexcept override;
+
+    // --------------------------------------------------------------------------------------------
+    // OpenGLPlatform Interface
+
+    void terminate() noexcept override;
+
+    bool isSRGBSwapChainSupported() const noexcept override;
+    SwapChain* createSwapChain(void* nativewindow, uint64_t flags) noexcept override;
+    SwapChain* createSwapChain(uint32_t width, uint32_t height, uint64_t flags) noexcept override;
+    void destroySwapChain(SwapChain* swapChain) noexcept override;
+    void makeCurrent(SwapChain* drawSwapChain, SwapChain* readSwapChain) noexcept override;
+    void commit(SwapChain* swapChain) noexcept override;
+
+    bool canCreateFence() noexcept override;
+    Fence* createFence() noexcept override;
+    void destroyFence(Fence* fence) noexcept override;
+    FenceStatus waitFence(Fence* fence, uint64_t timeout) noexcept override;
+
+    OpenGLPlatform::ExternalTexture* createExternalImageTexture() noexcept override;
+    void destroyExternalImage(ExternalTexture* texture) noexcept override;
+    bool setExternalImage(void* externalImage, ExternalTexture* texture) noexcept override;
+
+    /**
+     * Logs glGetError() to slog.e
+     * @param name a string giving some context on the error. Typically __func__.
+     */
+    static void logEglError(const char* name) noexcept;
+    static void logEglError(const char* name, EGLint error) noexcept;
+    static const char* getEglErrorName(EGLint error) noexcept;
+
+    /**
+     * Calls glGetError() to clear the current error flags. logs a warning to log.w if
+     * an error was pending.
+     */
+    static void clearGlError() noexcept;
+
+    /**
+     * Always use this instead of eglMakeCurrent().
+     */
+    EGLBoolean makeCurrent(EGLSurface drawSurface, EGLSurface readSurface) noexcept;
+
+    // TODO: this should probably use getters instead.
+    EGLDisplay mEGLDisplay = EGL_NO_DISPLAY;
+    EGLContext mEGLContext = EGL_NO_CONTEXT;
+    EGLSurface mCurrentDrawSurface = EGL_NO_SURFACE;
+    EGLSurface mCurrentReadSurface = EGL_NO_SURFACE;
+    EGLSurface mEGLDummySurface = EGL_NO_SURFACE;
+    EGLConfig mEGLConfig = EGL_NO_CONFIG_KHR;
+    Config mContextAttribs;
+    std::vector<EGLContext> mAdditionalContexts;
+
+    // supported extensions detected at runtime
+    struct {
+        struct {
+            bool OES_EGL_image_external_essl3 = false;
+        } gl;
+        struct {
+            bool ANDROID_recordable = false;
+            bool KHR_create_context = false;
+            bool KHR_gl_colorspace = false;
+            bool KHR_no_config_context = false;
+        } egl;
+    } ext;
+
+    void initializeGlExtensions() noexcept;
+
+private:
+    EGLConfig findSwapChainConfig(uint64_t flags) const;
+};
+
+} // namespace filament::backend
+
+#endif // TNT_FILAMENT_BACKEND_OPENGL_OPENGL_PLATFORM_EGL_H