LayoutRect FilterEffectRenderer::computeSourceImageRectForDirtyRect(const LayoutRect& filterBoxRect, const LayoutRect& dirtyRect)
{
if (hasCustomShaderFilter()) {
// When we have at least a custom shader in the chain, we need to compute the whole source image, because the shader can
// reference any pixel and we cannot control that.
return filterBoxRect;
}
// The result of this function is the area in the "filterBoxRect" that needs to be repainted, so that we fully cover the "dirtyRect".
FloatRect rectForRepaint = dirtyRect;
rectForRepaint.move(-filterBoxRect.location().x(), -filterBoxRect.location().y());
float inf = std::numeric_limits<float>::infinity();
FloatRect clipRect = FloatRect(FloatPoint(-inf, -inf), FloatSize(inf, inf));
rectForRepaint = lastEffect()->getSourceRect(rectForRepaint, clipRect);
rectForRepaint.move(filterBoxRect.location().x(), filterBoxRect.location().y());
rectForRepaint.intersect(filterBoxRect);
return LayoutRect(rectForRepaint);
}
LayoutRect FilterEffectRenderer::computeSourceImageRectForDirtyRect(const LayoutRect& filterBoxRect, const LayoutRect& dirtyRect)
{
#if ENABLE(CSS_SHADERS)
if (hasCustomShaderFilter()) {
// When we have at least a custom shader in the chain, we need to compute the whole source image, because the shader can
// reference any pixel and we cannot control that.
return filterBoxRect;
}
#endif
// The result of this function is the area in the "filterBoxRect" that needs to be repainted, so that we fully cover the "dirtyRect".
LayoutRect rectForRepaint = dirtyRect;
if (hasFilterThatMovesPixels()) {
// Note that the outsets are reversed here because we are going backwards -> we have the dirty rect and
// need to find out what is the rectangle that might influence the result inside that dirty rect.
rectForRepaint.move(-m_rightOutset, -m_bottomOutset);
rectForRepaint.expand(m_leftOutset + m_rightOutset, m_topOutset + m_bottomOutset);
}
rectForRepaint.intersect(filterBoxRect);
return rectForRepaint;
}
