GrStencilAttachment* GrResourceProvider::attachStencilAttachment(GrRenderTarget* rt) {
SkASSERT(rt);
if (rt->renderTargetPriv().getStencilAttachment()) {
return rt->renderTargetPriv().getStencilAttachment();
}
if (!rt->wasDestroyed() && rt->canAttemptStencilAttachment()) {
GrUniqueKey sbKey;
int width = rt->width();
int height = rt->height();
#if 0
if (this->caps()->oversizedStencilSupport()) {
width = SkNextPow2(width);
height = SkNextPow2(height);
}
#endif
bool newStencil = false;
GrStencilAttachment::ComputeSharedStencilAttachmentKey(width, height,
rt->numStencilSamples(), &sbKey);
GrStencilAttachment* stencil = static_cast<GrStencilAttachment*>(
this->findAndRefResourceByUniqueKey(sbKey));
if (!stencil) {
// Need to try and create a new stencil
stencil = this->gpu()->createStencilAttachmentForRenderTarget(rt, width, height);
if (stencil) {
stencil->resourcePriv().setUniqueKey(sbKey);
newStencil = true;
}
}
if (rt->renderTargetPriv().attachStencilAttachment(stencil)) {
if (newStencil) {
// Right now we're clearing the stencil attachment here after it is
// attached to a RT for the first time. When we start matching
// stencil buffers with smaller color targets this will no longer
// be correct because it won't be guaranteed to clear the entire
// sb.
// We used to clear down in the GL subclass using a special purpose
// FBO. But iOS doesn't allow a stencil-only FBO. It reports unsupported
// FBO status.
this->gpu()->clearStencil(rt);
}
}
}
return rt->renderTargetPriv().getStencilAttachment();
}
bool GrGpu::attachStencilAttachmentToRenderTarget(GrRenderTarget* rt) {
SkASSERT(NULL == rt->renderTargetPriv().getStencilAttachment());
GrUniqueKey sbKey;
int width = rt->width();
int height = rt->height();
#if 0
if (this->caps()->oversizedStencilSupport()) {
width = SkNextPow2(width);
height = SkNextPow2(height);
}
#endif
GrStencilAttachment::ComputeSharedStencilAttachmentKey(width, height,
rt->numStencilSamples(), &sbKey);
SkAutoTUnref<GrStencilAttachment> sb(static_cast<GrStencilAttachment*>(
this->getContext()->getResourceCache()->findAndRefUniqueResource(sbKey)));
if (sb) {
if (this->attachStencilAttachmentToRenderTarget(sb, rt)) {
rt->renderTargetPriv().didAttachStencilAttachment(sb);
return true;
}
return false;
}
if (this->createStencilAttachmentForRenderTarget(rt, width, height)) {
// Right now we're clearing the stencil buffer here after it is
// attached to an RT for the first time. When we start matching
// stencil buffers with smaller color targets this will no longer
// be correct because it won't be guaranteed to clear the entire
// sb.
// We used to clear down in the GL subclass using a special purpose
// FBO. But iOS doesn't allow a stencil-only FBO. It reports unsupported
// FBO status.
this->clearStencil(rt);
GrStencilAttachment* sb = rt->renderTargetPriv().getStencilAttachment();
sb->resourcePriv().setUniqueKey(sbKey);
return true;
} else {
return false;
}
}
