graphicscontextcg.cpp

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void GraphicsContext::setLineCap(LineCap cap)
{
    if (paintingDisabled())
        return;
    switch (cap) {
        case ButtCap:
            CGContextSetLineCap(platformContext(), kCGLineCapButt);
            break;
        case RoundCap:
            CGContextSetLineCap(platformContext(), kCGLineCapRound);
            break;
        case SquareCap:
            CGContextSetLineCap(platformContext(), kCGLineCapSquare);
            break;
    }
}

void GraphicsContext::setLineDash(const DashArray& dashes, float dashOffset)
{
    CGContextSetLineDash(platformContext(), dashOffset, dashes.data(), dashes.size());
}

void GraphicsContext::setLineJoin(LineJoin join)
{
    if (paintingDisabled())
        return;
    switch (join) {
        case MiterJoin:
            CGContextSetLineJoin(platformContext(), kCGLineJoinMiter);
            break;
        case RoundJoin:
            CGContextSetLineJoin(platformContext(), kCGLineJoinRound);
            break;
        case BevelJoin:
            CGContextSetLineJoin(platformContext(), kCGLineJoinBevel);
            break;
    }
}

void GraphicsContext::beginPath()
{
    CGContextBeginPath(platformContext());
}

void GraphicsContext::addPath(const Path& path)
{
    CGContextAddPath(platformContext(), path.platformPath());
}

void GraphicsContext::clip(const Path& path)
{
    if (paintingDisabled())
        return;
    CGContextRef context = platformContext();
    CGContextBeginPath(context);
    CGContextAddPath(context, path.platformPath());
    CGContextClip(context);
    m_data->clip(path);
}

void GraphicsContext::clipOut(const Path& path)
{
    if (paintingDisabled())
        return;
        
    CGContextBeginPath(platformContext());
    CGContextAddRect(platformContext(), CGContextGetClipBoundingBox(platformContext()));
    CGContextAddPath(platformContext(), path.platformPath());
    CGContextEOClip(platformContext());
}

void GraphicsContext::scale(const FloatSize& size)
{
    if (paintingDisabled())
        return;
    CGContextScaleCTM(platformContext(), size.width(), size.height());
    m_data->scale(size);
    m_data->m_userToDeviceTransformKnownToBeIdentity = false;
}

void GraphicsContext::rotate(float angle)
{
    if (paintingDisabled())
        return;
    CGContextRotateCTM(platformContext(), angle);
    m_data->rotate(angle);
    m_data->m_userToDeviceTransformKnownToBeIdentity = false;
}

void GraphicsContext::translate(float x, float y)
{
    if (paintingDisabled())
        return;
    CGContextTranslateCTM(platformContext(), x, y);
    m_data->translate(x, y);
    m_data->m_userToDeviceTransformKnownToBeIdentity = false;
}

void GraphicsContext::concatCTM(const TransformationMatrix& transform)
{
    if (paintingDisabled())
        return;
    CGContextConcatCTM(platformContext(), transform);
    m_data->concatCTM(transform);
    m_data->m_userToDeviceTransformKnownToBeIdentity = false;
}

TransformationMatrix GraphicsContext::getCTM() const
{
    CGAffineTransform t = CGContextGetCTM(platformContext());
    return TransformationMatrix(t.a, t.b, t.c, t.d, t.tx, t.ty);
}

FloatRect GraphicsContext::roundToDevicePixels(const FloatRect& rect)
{
    // It is not enough just to round to pixels in device space. The rotation part of the 
    // affine transform matrix to device space can mess with this conversion if we have a
    // rotating image like the hands of the world clock widget. We just need the scale, so 
    // we get the affine transform matrix and extract the scale.

    if (m_data->m_userToDeviceTransformKnownToBeIdentity)
        return rect;

    CGAffineTransform deviceMatrix = CGContextGetUserSpaceToDeviceSpaceTransform(platformContext());
    if (CGAffineTransformIsIdentity(deviceMatrix)) {
        m_data->m_userToDeviceTransformKnownToBeIdentity = true;
        return rect;
    }

    float deviceScaleX = sqrtf(deviceMatrix.a * deviceMatrix.a + deviceMatrix.b * deviceMatrix.b);
    float deviceScaleY = sqrtf(deviceMatrix.c * deviceMatrix.c + deviceMatrix.d * deviceMatrix.d);

    CGPoint deviceOrigin = CGPointMake(rect.x() * deviceScaleX, rect.y() * deviceScaleY);
    CGPoint deviceLowerRight = CGPointMake((rect.x() + rect.width()) * deviceScaleX,
        (rect.y() + rect.height()) * deviceScaleY);

    deviceOrigin.x = roundf(deviceOrigin.x);
    deviceOrigin.y = roundf(deviceOrigin.y);
    deviceLowerRight.x = roundf(deviceLowerRight.x);
    deviceLowerRight.y = roundf(deviceLowerRight.y);
    
    // Don't let the height or width round to 0 unless either was originally 0
    if (deviceOrigin.y == deviceLowerRight.y && rect.height() != 0)
        deviceLowerRight.y += 1;
    if (deviceOrigin.x == deviceLowerRight.x && rect.width() != 0)
        deviceLowerRight.x += 1;

    FloatPoint roundedOrigin = FloatPoint(deviceOrigin.x / deviceScaleX, deviceOrigin.y / deviceScaleY);
    FloatPoint roundedLowerRight = FloatPoint(deviceLowerRight.x / deviceScaleX, deviceLowerRight.y / deviceScaleY);
    return FloatRect(roundedOrigin, roundedLowerRight - roundedOrigin);
}

void GraphicsContext::drawLineForText(const IntPoint& point, int width, bool printing)
{
    if (paintingDisabled())
        return;

    if (width <= 0)
        return;

    float x = point.x();
    float y = point.y();
    float lineLength = width;

    // Use a minimum thickness of 0.5 in user space.
    // See http://bugs.webkit.org/show_bug.cgi?id=4255 for details of why 0.5 is the right minimum thickness to use.
    float thickness = max(strokeThickness(), 0.5f);

    bool restoreAntialiasMode = false;

    if (!printing) {
        // On screen, use a minimum thickness of 1.0 in user space (later rounded to an integral number in device space).
        float adjustedThickness = max(thickness, 1.0f);

        // FIXME: This should be done a better way.
        // We try to round all parameters to integer boundaries in device space. If rounding pixels in device space
        // makes our thickness more than double, then there must be a shrinking-scale factor and rounding to pixels
        // in device space will make the underlines too thick.
        CGRect lineRect = roundToDevicePixels(FloatRect(x, y, lineLength, adjustedThickness));
        if (lineRect.size.height < thickness * 2.0) {
            x = lineRect.origin.x;
            y = lineRect.origin.y;
            lineLength = lineRect.size.width;
            thickness = lineRect.size.height;
            if (shouldAntialias()) {
                CGContextSetShouldAntialias(platformContext(), false);
                restoreAntialiasMode = true;
            }
        }
    }
    
    if (fillColor() != strokeColor())
        setCGFillColor(platformContext(), strokeColor());
    CGContextFillRect(platformContext(), CGRectMake(x, y, lineLength, thickness));
    if (fillColor() != strokeColor())
        setCGFillColor(platformContext(), fillColor());
        
    if (restoreAntialiasMode)
        CGContextSetShouldAntialias(platformContext(), true);
}

void GraphicsContext::setURLForRect(const KURL& link, const IntRect& destRect)
{
    if (paintingDisabled())
        return;
        
    CFURLRef urlRef = link.createCFURL();
    if (urlRef) {
        CGContextRef context = platformContext();
        
        // Get the bounding box to handle clipping.
        CGRect box = CGContextGetClipBoundingBox(context);

        IntRect intBox((int)box.origin.x, (int)box.origin.y, (int)box.size.width, (int)box.size.height);
        IntRect rect = destRect;
        rect.intersect(intBox);

        CGPDFContextSetURLForRect(context, urlRef,
            CGRectApplyAffineTransform(rect, CGContextGetCTM(context)));

        CFRelease(urlRef);
    }
}

void GraphicsContext::setImageInterpolationQuality(InterpolationQuality mode)
{
    if (paintingDisabled())
        return;
    
    CGInterpolationQuality quality = kCGInterpolationDefault;
    switch (mode) {
        case InterpolationDefault:
            quality = kCGInterpolationDefault;
            break;
        case InterpolationNone:
            quality = kCGInterpolationNone;
            break;
        case InterpolationLow:
            quality = kCGInterpolationLow;
            break;

        // Fall through to InterpolationHigh if kCGInterpolationMedium is not available
        case InterpolationMedium:
#if HAVE(CG_INTERPOLATION_MEDIUM)
            quality = kCGInterpolationMedium;
            break;
#endif
        case InterpolationHigh:
            quality = kCGInterpolationHigh;
            break;
    }
    CGContextSetInterpolationQuality(platformContext(), quality);
}

InterpolationQuality GraphicsContext::imageInterpolationQuality() const
{
    if (paintingDisabled())
        return InterpolationDefault;

    CGInterpolationQuality quality = CGContextGetInterpolationQuality(platformContext());
    switch (quality) {
        case kCGInterpolationDefault:
            return InterpolationDefault;
        case kCGInterpolationNone:
            return InterpolationNone;
        case kCGInterpolationLow:
            return InterpolationLow;
#if HAVE(CG_INTERPOLATION_MEDIUM)
        case kCGInterpolationMedium:
            return InterpolationMedium;
#endif
        case kCGInterpolationHigh:
            return InterpolationHigh;
    }
    return InterpolationDefault;
}

void GraphicsContext::setPlatformTextDrawingMode(int mode)
{
    if (paintingDisabled())
        return;

    // Wow, wish CG had used bits here.
    CGContextRef context = platformContext();
    switch (mode) {
        case cTextInvisible: // Invisible
            CGContextSetTextDrawingMode(context, kCGTextInvisible);
            break;
        case cTextFill: // Fill
            CGContextSetTextDrawingMode(context, kCGTextFill);
            break;
        case cTextStroke: // Stroke
            CGContextSetTextDrawingMode(context, kCGTextStroke);
            break;
        case 3: // Fill | Stroke
            CGContextSetTextDrawingMode(context, kCGTextFillStroke);
            break;
        case cTextClip: // Clip
            CGContextSetTextDrawingMode(context, kCGTextClip);
            break;
        case 5: // Fill | Clip
            CGContextSetTextDrawingMode(context, kCGTextFillClip);
            break;
        case 6: // Stroke | Clip
            CGContextSetTextDrawingMode(context, kCGTextStrokeClip);
            break;
        case 7: // Fill | Stroke | Clip
            CGContextSetTextDrawingMode(context, kCGTextFillStrokeClip);
            break;
        default:
            break;
    }
}

void GraphicsContext::setPlatformStrokeColor(const Color& color)
{
    if (paintingDisabled())
        return;
    setCGStrokeColor(platformContext(), color);
}

void GraphicsContext::setPlatformStrokeThickness(float thickness)
{
    if (paintingDisabled())
        return;
    CGContextSetLineWidth(platformContext(), thickness);
}

void GraphicsContext::setPlatformFillColor(const Color& color)
{
    if (paintingDisabled())
        return;
    setCGFillColor(platformContext(), color);
}

void GraphicsContext::setPlatformShouldAntialias(bool enable)
{
    if (paintingDisabled())
        return;
    CGContextSetShouldAntialias(platformContext(), enable);
}

#ifndef BUILDING_ON_TIGER // Tiger's setCompositeOperation() is defined in GraphicsContextMac.mm.
void GraphicsContext::setCompositeOperation(CompositeOperator mode)
{   
    if (paintingDisabled())
        return;

    CGBlendMode target = kCGBlendModeNormal;   
    switch (mode) {
        case CompositeClear:
            target = kCGBlendModeClear;
            break;
        case CompositeCopy:
            target = kCGBlendModeCopy;
            break;
        case CompositeSourceOver:
            //kCGBlendModeNormal
            break;
        case CompositeSourceIn:
            target = kCGBlendModeSourceIn;
            break;
        case CompositeSourceOut:
            target = kCGBlendModeSourceOut;
            break;
        case CompositeSourceAtop:
            target = kCGBlendModeSourceAtop; 
            break;
        case CompositeDestinationOver:
            target = kCGBlendModeDestinationOver;
            break;
        case CompositeDestinationIn:
            target = kCGBlendModeDestinationIn;
            break;
        case CompositeDestinationOut:
            target = kCGBlendModeDestinationOut;
            break;
        case CompositeDestinationAtop:
            target = kCGBlendModeDestinationAtop;
            break;
        case CompositeXOR:
            target = kCGBlendModeXOR;
            break;
        case CompositePlusDarker:
            target = kCGBlendModePlusDarker;
            break;
        case CompositeHighlight:
            // currently unsupported
            break;
        case CompositePlusLighter:
            target = kCGBlendModePlusLighter;
            break;
    }
    CGContextSetBlendMode(platformContext(), target);
}
#endif

}