path: root/Source/WebCore/platform/graphics/android/layers/BaseLayerAndroid.cpp

/*
 * Copyright 2012, The Android Open Source Project
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *  * Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 *  * Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS ``AS IS'' AND ANY
 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE COPYRIGHT OWNER OR
 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
 * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

#define LOG_TAG "BaseLayerAndroid"
#define LOG_NDEBUG 1

#include "config.h"
#include "BaseLayerAndroid.h"

#include "AndroidLog.h"
#include "CachedImage.h"
#include "ClassTracker.h"
#include "DrawQuadData.h"
#include "FixedPositioning.h"
#include "GLWebViewState.h"
#include "ImagesManager.h"
#include "LayerContent.h"
#include "RenderStyle.h"
#include "StyleCachedImage.h"
#include "TilesManager.h"

namespace WebCore {

// Note: this must match the use of ID 0 specifying the base layer in DrawExtra
#define BASE_UNIQUE_ID 0

BaseLayerAndroid::BaseLayerAndroid(LayerContent* content)
    : LayerAndroid((RenderLayer*)0)
    , m_color(Color::white)
    , m_positionsCalculated(false)
{
    if (content) {
        setContent(content);
        setSize(content->width(), content->height());
    }
    m_uniqueId = BASE_UNIQUE_ID;
}

void BaseLayerAndroid::getLocalTransform(SkMatrix* matrix) const
{
    matrix->reset();
    // base layer doesn't use size in transform calculation
    matrix->preConcat(getMatrix());
}

IFrameLayerAndroid* BaseLayerAndroid::updatePosition(SkRect viewport,
                                                     IFrameLayerAndroid* parentIframeLayer)
{
    if (viewport.fRight > getWidth() || viewport.fBottom > getHeight()) {
        // To handle the viewport expanding past the layer's size with HW accel,
        // expand the size of the layer, so that tiles will cover the viewport.
        setSize(std::max(viewport.fRight, getWidth()),
                std::max(viewport.fBottom, getHeight()));
    }

    return LayerAndroid::updatePosition(viewport, parentIframeLayer);
}

void BaseLayerAndroid::updatePositionsRecursive(const SkRect& visibleContentRect)
{
    TRACE_METHOD();

    updateLayerPositions(visibleContentRect);
    TransformationMatrix ident;

    // Start with an unnecessarily large clip, since the base layer can
    // dynamically increase in size to cover the viewport, and we cache its draw
    // clip. This way the base layer will never have it's visible area clipped
    // by its m_clippingRect, only the viewport.
    // Note: values larger than this suffer from floating point rounding issues
    FloatRect clip(0, 0, 1e7, 1e7);

    bool forcePositionCalculation = !m_positionsCalculated;
    float scale = 1.0f;
    // To minimize tearing in single surface mode, don't update the fixed element
    // when scrolling. The fixed element will move incorrectly when scrolling,
    // but its position will be corrected after scrolling.
    bool disableFixedElemUpdate = false;
    GLWebViewState* webViewState = state();
    if (webViewState) {
        scale = webViewState->scale();
        disableFixedElemUpdate = webViewState->isScrolling()
                                 && webViewState->isSingleSurfaceRenderingMode();
    }
    updateGLPositionsAndScale(ident, clip, 1, scale, forcePositionCalculation,
                              disableFixedElemUpdate);

    m_positionsCalculated = true;
}

ForegroundBaseLayerAndroid::ForegroundBaseLayerAndroid(LayerContent* content)
    : LayerAndroid((RenderLayer*)0)
{
    setIntrinsicallyComposited(true);
}

FixedBackgroundImageLayerAndroid::FixedBackgroundImageLayerAndroid(PassRefPtr<RenderStyle> aStyle,
                                                                   int w, int h)
    : LayerAndroid((RenderLayer*)0)
    , m_width(w)
    , m_height(h)
{
    RefPtr<RenderStyle> style = aStyle;
    FillLayer* layers = style->accessBackgroundLayers();
    StyleImage* styleImage = layers->image();
    CachedImage* cachedImage = static_cast<StyleCachedImage*>(styleImage)->cachedImage();
    WebCore::Image* image = cachedImage->image();
    setContentsImage(image->nativeImageForCurrentFrame());
    setSize(image->width(), image->height());

    setIntrinsicallyComposited(true);

    SkLength left, top;
    left = SkLength::convertLength(style->backgroundXPosition());
    top = SkLength::convertLength(style->backgroundYPosition());

    BackgroundImagePositioning* position = new BackgroundImagePositioning(this);
    position->setRepeatX(style->backgroundRepeatX() != WebCore::NoRepeatFill);
    position->setRepeatY(style->backgroundRepeatY() != WebCore::NoRepeatFill);

    setFixedPosition(position);
    position->setPosition(left, top);

#ifdef DEBUG_COUNT
    ClassTracker::instance()->increment("FixedBackgroundImageLayerAndroid");
#endif
}

FixedBackgroundImageLayerAndroid::FixedBackgroundImageLayerAndroid(const FixedBackgroundImageLayerAndroid& layer)
    : LayerAndroid(layer)
    , m_width(layer.m_width)
    , m_height(layer.m_height)
{
#ifdef DEBUG_COUNT
    ClassTracker::instance()->increment("FixedBackgroundImageLayerAndroid");
#endif
}

FixedBackgroundImageLayerAndroid::~FixedBackgroundImageLayerAndroid()
{
#ifdef DEBUG_COUNT
    ClassTracker::instance()->decrement("FixedBackgroundImageLayerAndroid");
#endif
}

static bool needToDisplayImage(bool repeatX, bool repeatY, float dx, float dy)
{
    // handles the repeat attribute for the background image
    if (repeatX && repeatY)
        return true;
    if (repeatX && !repeatY && dy == 0)
        return true;
    if (!repeatX && repeatY && dx == 0)
        return true;
    if (dx == 0 && dy == 0)
        return true;

    return false;
}

// Return true when fast draw succeeds.
// For the repeated image content, we just need to draw a single quad and use
// the GL shader to repeat.
bool FixedBackgroundImageLayerAndroid::drawSimpleQuad(ImageTexture* imageTexture,
                                                      BackgroundImagePositioning* position,
                                                      const IntPoint& repeatTimes,
                                                      const FloatPoint& startPoint,
                                                      const FloatPoint& origin,
                                                      const Color& backgroundColor)
{
    // The limitation for current implementation is that we can only speed up
    // single tile size image.
    // TODO: add the fast path to imageTexture which contains >1 tiles.
    GLuint imageTextureId = imageTexture->getImageTextureId();
    if (!imageTextureId)
        return false;

    int nbX = repeatTimes.x();
    int nbY = repeatTimes.y();
    float startX = startPoint.x();
    float startY = startPoint.y();
    bool repeatX = position->repeatX();
    bool repeatY = position->repeatY();

    // Draw the entire background when repeat only in one direction or no repeat.
    if (!repeatX || !repeatY) {
        SkRect backgroundRect;
        backgroundRect.fLeft = origin.x() - startX;
        backgroundRect.fTop = origin.y() - startY;
        backgroundRect.fRight = backgroundRect.fLeft + getWidth() * nbX;
        backgroundRect.fBottom = backgroundRect.fTop + getHeight() * nbY;
        PureColorQuadData backgroundData(backgroundColor, BaseQuad,
                                         0, &backgroundRect, 1.0, true);
        TilesManager::instance()->shader()->drawQuad(&backgroundData);
    }

    // Now draw the repeated images.
    // We set the quad size as the image size, then imageRepeatRanges will
    // control how many times the image will be repeated by expanding the
    // quad and texture coordinates.
    // The image size can be smaller than a tile, so repeatScale will passed
    // into the shader to scale the texture coordinates.
    SkRect imageRect = SkRect::MakeXYWH(0, 0, getWidth(), getHeight());
    FloatRect imageRepeatRanges(0, 0, repeatX ? nbX : 1, repeatY ? nbY : 1);

    FloatSize repeatScale(float(getWidth()) / TilesManager::tileWidth(),
                          float(getHeight()) / TilesManager::tileHeight());

    ALOGV("repeatedQuadData: startX %f, startY %f , getWidth() %f, getHeight() %f,"
          " nbX %d, nbY %d, repeatImageTimesX, repeatImageTimesY %d %d"
          " repeatScale width %f, height %f, origin x %f y %f",
          startX , startY  , getWidth(), getHeight(), nbX , nbY,
          imageRepeatRanges.width(), imageRepeatRanges.height(),
          repeatScale.width(), repeatScale.height(), origin.x(), origin.y());

    // Adding startX and startY into the transform can handle the fixed right /
    // fixed bottom case.
    TransformationMatrix matrix = *drawTransform();
    matrix.translate(repeatX ? -startX : 0, repeatY ? -startY : 0);

    TextureQuadData repeatedQuadData(imageTextureId, GL_TEXTURE_2D, GL_LINEAR,
                                     LayerQuad, &matrix, &imageRect, getOpacity(),
                                     true, imageRepeatRanges, repeatScale);
    TilesManager::instance()->shader()->drawQuad(&repeatedQuadData);
    return true;
}

void FixedBackgroundImageLayerAndroid::drawRepeatedGrid(ImageTexture* imageTexture,
                                                        BackgroundImagePositioning* position,
                                                        const IntPoint& repeatTimes,
                                                        const FloatPoint& startPoint,
                                                        const FloatPoint& origin,
                                                        const Color& backgroundColor)
{
    // Cover the entire background
    int nbX = repeatTimes.x();
    int nbY = repeatTimes.y();
    float startX = startPoint.x();
    float startY = startPoint.y();
    for (int i = 0; i < nbY; i++) {
        float dy = (i * getHeight()) - startY;
        for (int j = 0; j < nbX; j++) {
            float dx = (j * getWidth()) - startX;
            if (needToDisplayImage(position->repeatX(),
                                   position->repeatY(),
                                   dx, dy)) {
                FloatPoint p(dx, dy);
                imageTexture->drawGL(this, getOpacity(), &p);
            } else {
                // If the image is not displayed, we still need to fill
                // with the background color
                SkRect rect;
                rect.fLeft = origin.x() + dx;
                rect.fTop = origin.y() + dy;
                rect.fRight = rect.fLeft + getWidth();
                rect.fBottom = rect.fTop + getHeight();
                PureColorQuadData backgroundData(backgroundColor, BaseQuad,
                                                 0, &rect, 1.0);
                TilesManager::instance()->shader()->drawQuad(&backgroundData);
            }
        }
    }
}

bool FixedBackgroundImageLayerAndroid::drawGL(bool layerTilesDisabled)
{
    if (layerTilesDisabled)
        return false;
    if (!m_imageCRC)
        return false;

    ImageTexture* imageTexture = ImagesManager::instance()->retainImage(m_imageCRC);
    if (!imageTexture) {
        ImagesManager::instance()->releaseImage(m_imageCRC);
        return false;
    }

    // We have a fixed background image, let's draw it
    if (m_fixedPosition && m_fixedPosition->isBackgroundImagePositioning()) {
        BackgroundImagePositioning* position =
            static_cast<BackgroundImagePositioning*>(m_fixedPosition);

        IntPoint repeatTimes(position->nbRepeatX(), position->nbRepeatY());
        FloatPoint startPoint(position->offsetX() * getWidth(),
                              position->offsetY() * getHeight());

        FloatPoint origin;
        origin = drawTransform()->mapPoint(origin);

        Color backgroundColor = Color((int)SkColorGetR(m_backgroundColor),
                                      (int)SkColorGetG(m_backgroundColor),
                                      (int)SkColorGetB(m_backgroundColor),
                                      (int)SkColorGetA(m_backgroundColor));

        bool drawSimpleQuadSuccess = drawSimpleQuad(imageTexture, position,
                                                    repeatTimes, startPoint,
                                                    origin, backgroundColor);

        if (!drawSimpleQuadSuccess) {
            drawRepeatedGrid(imageTexture, position, repeatTimes, startPoint,
                             origin, backgroundColor);
        }
    } else
        imageTexture->drawGL(this, getOpacity());

    ImagesManager::instance()->releaseImage(m_imageCRC);

    return false;
}

Image* FixedBackgroundImageLayerAndroid::GetCachedImage(PassRefPtr<RenderStyle> aStyle)
{
    RefPtr<RenderStyle> style = aStyle;
    if (!style)
        return 0;

    if (!style->hasFixedBackgroundImage())
        return 0;

    FillLayer* layers = style->accessBackgroundLayers();
    StyleImage* styleImage = layers->image();

    if (!styleImage)
        return 0;

    if (!styleImage->isLoaded())
        return 0;

    if (!styleImage->isCachedImage())
        return 0;

    CachedImage* cachedImage = static_cast<StyleCachedImage*>(styleImage)->cachedImage();

    Image* image = cachedImage->image();

    if (image && !image->nativeImageForCurrentFrame())
        return 0;

    if (image == Image::nullImage())
        return 0;

    return image;
}

} // namespace WebCore