include/private/hwui/DrawGlInfo.h

/*
 * Copyright (C) 2011 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_DRAW_GL_INFO_H
#define ANDROID_HWUI_DRAW_GL_INFO_H

namespace android {
namespace uirenderer {

/**
 * Structure used by OpenGLRenderer::callDrawGLFunction() to pass and
 * receive data from OpenGL functors.
 */
struct DrawGlInfo {
    // Input: current clip rect
    int clipLeft;
    int clipTop;
    int clipRight;
    int clipBottom;

    // Input: current width/height of destination surface
    int width;
    int height;

    // Input: is the render target an FBO
    bool isLayer;

    // Input: current transform matrix, in OpenGL format
    float transform[16];

    // Output: dirty region to redraw
    float dirtyLeft;
    float dirtyTop;
    float dirtyRight;
    float dirtyBottom;

    /**
     * Values used as the "what" parameter of the functor.
     */
    enum Mode {
        // Indicates that the functor is called to perform a draw
        kModeDraw,
        // Indicates the the functor is called only to perform
        // processing and that no draw should be attempted
        kModeProcess,
        // Same as kModeProcess, however there is no GL context because it was
        // lost or destroyed
        kModeProcessNoContext,
        // Invoked every time the UI thread pushes over a frame to the render thread
        // *and the owning view has a dirty display list*. This is a signal to sync
        // any data that needs to be shared between the UI thread and the render thread.
        // During this time the UI thread is blocked.
        kModeSync
    };

    /**
     * Values used by OpenGL functors to tell the framework
     * what to do next.
     */
    enum Status {
        // The functor is done
        kStatusDone = 0x0,
        // DisplayList actually issued GL drawing commands.
        // This is used to signal the HardwareRenderer that the
        // buffers should be flipped - otherwise, there were no
        // changes to the buffer, so no need to flip. Some hardware
        // has issues with stale buffer contents when no GL
        // commands are issued.
        kStatusDrew = 0x4
    };
}; // struct DrawGlInfo

}; // namespace uirenderer
}; // namespace android

#endif // ANDROID_HWUI_DRAW_GL_INFO_H