libs/hwui/Image.h

/*
 * 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