void Layer::localToAncestor(const Layer* ancestor, SkMatrix* matrix) const {
if (this == ancestor) {
matrix->setIdentity();
return;
}
getLocalTransform(matrix);
// Fixed position layers simply use the root layer's transform.
if (shouldInheritFromRootTransform()) {
ASSERT(!ancestor);
matrix->postConcat(getRootLayer()->getMatrix());
return;
}
// Apply the local and child transforms for every layer between this layer
// and ancestor.
ASSERT(isAncestor(ancestor));
for (const Layer* layer = this->fParent; layer != ancestor; layer = layer->fParent) {
SkMatrix tmp;
layer->getLocalTransform(&tmp);
tmp.preConcat(layer->getChildrenMatrix());
matrix->postConcat(tmp);
}
// If ancestor is not the root layer, apply its child transformation too.
if (ancestor)
matrix->postConcat(ancestor->getChildrenMatrix());
}
void SkLayer::draw(SkCanvas* canvas, SkScalar opacity) {
#if 0
SkString str1, str2;
// this->getMatrix().toDumpString(&str1);
// this->getChildrenMatrix().toDumpString(&str2);
SkDebugf("--- drawlayer %p opacity %g size [%g %g] pos [%g %g] matrix %s children %s\n",
this, opacity * this->getOpacity(), m_size.width(), m_size.height(),
m_position.fX, m_position.fY, str1.c_str(), str2.c_str());
#endif
opacity = SkScalarMul(opacity, this->getOpacity());
if (opacity <= 0) {
// SkDebugf("---- abort drawing %p opacity %g\n", this, opacity);
return;
}
SkAutoCanvasRestore acr(canvas, true);
// apply our local transform
{
SkMatrix tmp;
this->getLocalTransform(&tmp);
if (this->isInheritFromRootTransform()) {
// should we also apply the root's childrenMatrix?
canvas->setMatrix(getRootLayer()->getMatrix());
}
canvas->concat(tmp);
}
this->onDraw(canvas, opacity);
#ifdef DEBUG_DRAW_LAYER_BOUNDS
{
SkRect r = SkRect::MakeSize(this->getSize());
SkPaint p;
p.setAntiAlias(true);
p.setStyle(SkPaint::kStroke_Style);
p.setStrokeWidth(SkIntToScalar(2));
p.setColor(0xFFFF44DD);
canvas->drawRect(r, p);
canvas->drawLine(r.fLeft, r.fTop, r.fRight, r.fBottom, p);
canvas->drawLine(r.fLeft, r.fBottom, r.fRight, r.fTop, p);
}
#endif
int count = this->countChildren();
if (count > 0) {
canvas->concat(this->getChildrenMatrix());
for (int i = 0; i < count; i++) {
this->getChild(i)->draw(canvas, opacity);
}
}
}