libs/surfaceflinger/LayerDim.cpp

/*
 * Copyright (C) 2007 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.
 */

#include <stdlib.h>
#include <stdint.h>
#include <sys/types.h>

#include <utils/Errors.h>
#include <utils/Log.h>

#include "LayerDim.h"
#include "SurfaceFlinger.h"
#include "DisplayHardware/DisplayHardware.h"

namespace android {
// ---------------------------------------------------------------------------

const uint32_t LayerDim::typeInfo = LayerBaseClient::typeInfo | 0x10;
const char* const LayerDim::typeID = "LayerDim";

// ---------------------------------------------------------------------------

LayerDim::LayerDim(SurfaceFlinger* flinger, DisplayID display,
        Client* client, int32_t i)
     : LayerBaseClient(flinger, display, client, i)
{
}

void LayerDim::initDimmer(SurfaceFlinger* flinger, uint32_t w, uint32_t h)
{
}

LayerDim::~LayerDim()
{
}

void LayerDim::onDraw(const Region& clip) const
{
    // FIXME: on some h/w (like msm7K, it will be faster to use a texture)
    
    const State& s(drawingState());
    Region::iterator iterator(clip);
    if (s.alpha>0 && iterator) {
        const DisplayHardware& hw(graphicPlane(0).displayHardware());
        const GGLfixed alpha = (s.alpha << 16)/255;
        const uint32_t fbHeight = hw.getHeight();
        glDisable(GL_TEXTURE_2D);
        glDisable(GL_DITHER);
        glEnable(GL_BLEND);
        glBlendFunc(GL_ONE, GL_ONE_MINUS_SRC_ALPHA);
        glColor4x(0, 0, 0, alpha);
        glVertexPointer(2, GL_FIXED, 0, mVertices);
        Rect r;
        while (iterator.iterate(&r)) {
            const GLint sy = fbHeight - (r.top + r.height());
            glScissor(r.left, sy, r.width(), r.height());
            glDrawArrays(GL_TRIANGLE_FAN, 0, 4); 
        }
    }
}

// ---------------------------------------------------------------------------

}; // namespace android