Wrap EGLImage with a C++ API

Change-Id: I0fa3282ea7e2ace3ba2aadd929b32232b3d41628
diff --git a/libs/hwui/Image.h b/libs/hwui/Image.h
new file mode 100644
index 0000000..3f2978f
--- /dev/null
+++ b/libs/hwui/Image.h
@@ -0,0 +1,103 @@
+/*
+ * Copyright (C) 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 ANDROID_HWUI_IMAGE_H
+#define ANDROID_HWUI_IMAGE_H
+
+#define LOG_TAG "OpenGLRenderer"
+
+#include <EGL/egl.h>
+#include <EGL/eglext.h>
+
+#include <GLES2/gl2.h>
+#include <GLES2/gl2ext.h>
+
+#include <ui/GraphicBuffer.h>
+
+#include <utils/Log.h>
+
+namespace android {
+namespace uirenderer {
+
+/**
+ * A simple wrapper that creates an EGLImage and a texture for a GraphicBuffer.
+ */
+class Image {
+public:
+    /**
+     * Creates a new image from the specified graphic buffer. If the image
+     * cannot be created, getTexture() will return 0 and getImage() will
+     * return EGL_NO_IMAGE_KHR.
+     */
+    Image(sp<GraphicBuffer> buffer) {
+        // Create the EGLImage object that maps the GraphicBuffer
+        EGLDisplay display = eglGetDisplay(EGL_DEFAULT_DISPLAY);
+        EGLClientBuffer clientBuffer = (EGLClientBuffer) buffer->getNativeBuffer();
+        EGLint attrs[] = { EGL_IMAGE_PRESERVED_KHR, EGL_TRUE, EGL_NONE };
+
+        mImage = eglCreateImageKHR(display, EGL_NO_CONTEXT,
+                EGL_NATIVE_BUFFER_ANDROID, clientBuffer, attrs);
+
+        if (mImage == EGL_NO_IMAGE_KHR) {
+            ALOGW("Error creating image (%#x)", eglGetError());
+            mTexture = 0;
+        } else {
+            // Create a 2D texture to sample from the EGLImage
+            glGenTextures(1, &mTexture);
+            glBindTexture(GL_TEXTURE_2D, mTexture);
+            glEGLImageTargetTexture2DOES(GL_TEXTURE_2D, mImage);
+
+            GLenum status = GL_NO_ERROR;
+            while ((status = glGetError()) != GL_NO_ERROR) {
+                ALOGW("Error creating image (%#x)", status);
+            }
+        }
+    }
+
+    ~Image() {
+        if (mImage != EGL_NO_IMAGE_KHR) {
+            eglDestroyImageKHR(eglGetDisplay(EGL_DEFAULT_DISPLAY), mImage);
+            mImage = EGL_NO_IMAGE_KHR;
+
+            glDeleteTextures(1, &mTexture);
+            mTexture = 0;
+        }
+    }
+
+    /**
+     * Returns the name of the GL texture that can be used to sample
+     * from this image.
+     */
+    GLuint getTexture() const {
+        return mTexture;
+    }
+
+    /**
+     * Returns the name of the EGL image represented by this object.
+     */
+    EGLImageKHR getImage() const {
+        return mImage;
+    }
+
+private:
+    GLuint mTexture;
+    EGLImageKHR mImage;
+}; // class Image
+
+}; // namespace uirenderer
+}; // namespace android
+
+#endif // ANDROID_HWUI_IMAGE_H