WebCore/platform/graphics/svg/cg/SVGResourceFilterCg.mm

/*
 * Copyright (C) 2005 Apple Computer, Inc.  All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. 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 APPLE COMPUTER, INC. ``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 APPLE COMPUTER, INC. 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. 
 */

#include "config.h"

#if ENABLE(SVG) && ENABLE(SVG_EXPERIMENTAL_FEATURES)
#include "AffineTransform.h"
#include "FoundationExtras.h"
#include "GraphicsContext.h"
#include "SVGResourceFilter.h"

#include "SVGFEBlend.h"
#include "SVGFEColorMatrix.h"
#include "SVGFEComponentTransfer.h"
#include "SVGFEComposite.h"
#include "SVGFEDiffuseLighting.h"
#include "SVGFEDisplacementMap.h"
#include "SVGFEFlood.h"
#include "SVGFEGaussianBlur.h"
#include "SVGFEImage.h"
#include "SVGFEMerge.h"
#include "SVGFEOffset.h"
#include "SVGFESpecularLighting.h"
#include "SVGFETile.h"

#include <QuartzCore/CoreImage.h>

namespace WebCore {

static const char* const SVGPreviousFilterOutputName = "__previousOutput__";

SVGResourceFilter::SVGResourceFilter()
    : m_filterCIContext(0)
    , m_filterCGLayer(0)
    , m_savedContext(0)
{
    m_imagesByName = HardRetainWithNSRelease([[NSMutableDictionary alloc] init]);
}

SVGResourceFilter::~SVGResourceFilter()
{
    ASSERT(!m_filterCGLayer);
    ASSERT(!m_filterCIContext);
    HardRelease(m_imagesByName);
}

SVGFilterEffect* SVGResourceFilter::createFilterEffect(const SVGFilterEffectType& type)
{
    switch(type)
    {
    /* Light sources are contained by the diffuse/specular light blocks 
    case FE_DISTANT_LIGHT: 
    case FE_POINT_LIGHT: 
    case FE_SPOT_LIGHT: 
    */
    case FE_BLEND: return new SVGFEBlend();
    case FE_COLOR_MATRIX: return new SVGFEColorMatrix();
    case FE_COMPONENT_TRANSFER: return new SVGFEComponentTransfer();
    case FE_COMPOSITE: return new SVGFEComposite();
//  case FE_CONVOLVE_MATRIX:
    case FE_DIFFUSE_LIGHTING: return new SVGFEDiffuseLighting();
    case FE_DISPLACEMENT_MAP: return new SVGFEDisplacementMap();
    case FE_FLOOD: return new SVGFEFlood();
    case FE_GAUSSIAN_BLUR: return new SVGFEGaussianBlur();
    case FE_IMAGE: return new SVGFEImage();
    case FE_MERGE: return new SVGFEMerge();
//  case FE_MORPHOLOGY:
    case FE_OFFSET: return new SVGFEOffset();
    case FE_SPECULAR_LIGHTING: return new SVGFESpecularLighting();
    case FE_TILE: return new SVGFETile();
//  case FE_TURBULENCE:
    default:
        return 0;
    }
}

void SVGResourceFilter::prepareFilter(GraphicsContext*& context, const FloatRect& bbox)
{
    if (bbox.isEmpty() || m_effects.isEmpty())
        return;

    CGContextRef cgContext = context->platformContext();

    // Use of CGBegin/EndTransparencyLayer around this call causes over release
    // of cgContext due to it being created on an autorelease pool, and released
    // after CGEndTransparencyLayer. Create local pool to fix.
    // <http://bugs.webkit.org/show_bug.cgi?id=8425>
    // <http://bugs.webkit.org/show_bug.cgi?id=6947>
    // <rdar://problem/4647735>
    NSAutoreleasePool* filterContextPool = [[NSAutoreleasePool alloc] init];
    m_filterCIContext = HardRetain([CIContext contextWithCGContext:cgContext options:nil]);
    [filterContextPool drain];

    m_filterCGLayer = [m_filterCIContext createCGLayerWithSize:CGRect(bbox).size info:NULL];
    m_savedContext = context;

    context = new GraphicsContext(CGLayerGetContext(m_filterCGLayer));
    context->save();
    context->concatCTM(AffineTransform().translate(-1.0f * bbox.x(), -1.0f * bbox.y()));
}

void SVGResourceFilter::applyFilter(GraphicsContext*& context, const FloatRect& bbox)
{
    if (bbox.isEmpty() || m_effects.isEmpty())
        return;

    // actually apply the filter effects
    CIImage* inputImage = [CIImage imageWithCGLayer:m_filterCGLayer];
    NSArray* filterStack = getCIFilterStack(inputImage);
    if ([filterStack count]) {
        CIImage* outputImage = [[filterStack lastObject] valueForKey:@"outputImage"];
        if (outputImage) {
            CGRect filterRect = CGRect(filterBBoxForItemBBox(bbox));
            CGRect translated = filterRect;
            CGPoint bboxOrigin = CGRect(bbox).origin;
            CGRect sourceRect = CGRectIntersection(translated,[outputImage extent]);

            CGPoint destOrigin = sourceRect.origin;
            destOrigin.x += bboxOrigin.x;
            destOrigin.y += bboxOrigin.y;

            [m_filterCIContext drawImage:outputImage atPoint:destOrigin fromRect:sourceRect];
        }
    }

    CGLayerRelease(m_filterCGLayer);
    m_filterCGLayer = 0;

    HardRelease(m_filterCIContext);
    m_filterCIContext = 0;

    delete context;
    context = m_savedContext;
    m_savedContext = 0;
}

NSArray* SVGResourceFilter::getCIFilterStack(CIImage* inputImage)
{
    NSMutableArray* filterEffects = [NSMutableArray array];

    setImageForName(inputImage, "SourceGraphic"); // input

    for (unsigned int i = 0; i < m_effects.size(); i++) {
        CIFilter* filter = m_effects[i]->getCIFilter(this);
        if (filter)
            [filterEffects addObject:filter];
    }

    [m_imagesByName removeAllObjects]; // clean up before next time.

    return filterEffects;
}

CIImage *SVGResourceFilter::imageForName(const String& name) const
{
    return [m_imagesByName objectForKey:name];
}

void SVGResourceFilter::setImageForName(CIImage *image, const String &name)
{
    [m_imagesByName setValue:image forKey:name];
}

void SVGResourceFilter::setOutputImage(const SVGFilterEffect *filterEffect, CIImage *output)
{
    if (!filterEffect->result().isEmpty())
        setImageForName(output, filterEffect->result());
    setImageForName(output, SVGPreviousFilterOutputName);
}

static inline CIImage *alphaImageForImage(CIImage *image)
{
    CIFilter *onlyAlpha = [CIFilter filterWithName:@"CIColorMatrix"];
    CGFloat zero[4] = {0, 0, 0, 0};
    [onlyAlpha setDefaults];
    [onlyAlpha setValue:image forKey:@"inputImage"];
    [onlyAlpha setValue:[CIVector vectorWithValues:zero count:4] forKey:@"inputRVector"];
    [onlyAlpha setValue:[CIVector vectorWithValues:zero count:4] forKey:@"inputGVector"];
    [onlyAlpha setValue:[CIVector vectorWithValues:zero count:4] forKey:@"inputBVector"];
    return [onlyAlpha valueForKey:@"outputImage"];
}

CIImage *SVGResourceFilter::inputImage(const SVGFilterEffect *filterEffect)
{
    if (filterEffect->in().isEmpty()) {
        CIImage *inImage = imageForName(SVGPreviousFilterOutputName);
        if (!inImage)
            inImage = imageForName("SourceGraphic");
        return inImage;
    } else if (filterEffect->in() == "SourceAlpha") {
        CIImage *sourceAlpha = imageForName(filterEffect->in());
        if (!sourceAlpha) {
            CIImage *sourceGraphic = imageForName("SourceGraphic");
            if (!sourceGraphic)
                return nil;
            sourceAlpha = alphaImageForImage(sourceGraphic);
            setImageForName(sourceAlpha, "SourceAlpha");
        }
        return sourceAlpha;
    }

    return imageForName(filterEffect->in());
}

}

#endif // ENABLE(SVG) ENABLE(SVG_EXPERIMENTAL_FEATURES)