int mlt_animation_get_item( mlt_animation self, mlt_animation_item item, int position )
{
int error = 0;
// Need to find the nearest keyframe to the position specifed
animation_node node = self->nodes;
// Iterate through the keyframes until we reach last or have
while ( node && node->next && position >= node->next->item.frame )
node = node->next;
if ( node )
{
item->keyframe_type = node->item.keyframe_type;
// Position is before the first keyframe.
if ( position < node->item.frame )
{
item->is_key = 0;
if ( item->property )
mlt_property_pass( item->property, node->item.property );
}
// Item exists.
else if ( position == node->item.frame )
{
item->is_key = node->item.is_key;
if ( item->property )
mlt_property_pass( item->property, node->item.property );
}
// Position is after the last keyframe.
else if ( !node->next )
{
item->is_key = 0;
if ( item->property )
mlt_property_pass( item->property, node->item.property );
}
// Interpolation needed.
else
{
double progress;
mlt_property points[4];
points[0] = node->prev? node->prev->item.property : node->item.property;
points[1] = node->item.property;
points[2] = node->next->item.property;
points[3] = node->next->next? node->next->next->item.property : node->next->item.property;
progress = position - node->item.frame;
progress /= node->next->item.frame - node->item.frame;
mlt_property_interpolate( item->property, points, progress,
self->fps, self->locale, item->keyframe_type );
item->is_key = 0;
}
}
else
{
item->frame = item->is_key = 0;
error = 1;
}
item->frame = position;
return error;
}
int mlt_animation_key_get( mlt_animation self, mlt_animation_item item, int index )
{
int error = 0;
animation_node node = self->nodes;
// Iterate through the keyframes.
int i = index;
while ( i-- && node )
node = node->next;
if ( node )
{
item->is_key = node->item.is_key;
item->frame = node->item.frame;
item->keyframe_type = node->item.keyframe_type;
if ( item->property )
mlt_property_pass( item->property, node->item.property );
}
else
{
item->frame = item->is_key = 0;
error = 1;
}
return error;
}
int mlt_animation_insert( mlt_animation self, mlt_animation_item item )
{
int error = 0;
animation_node node = calloc( 1, sizeof( *node ) );
node->item.frame = item->frame;
node->item.is_key = 1;
node->item.keyframe_type = item->keyframe_type;
node->item.property = mlt_property_init();
mlt_property_pass( node->item.property, item->property );
// Determine if we need to insert or append to the list, or if it's a new list
if ( self->nodes )
{
// Get the first item
animation_node current = self->nodes;
// Locate an existing nearby item
while ( current->next && item->frame > current->item.frame )
current = current->next;
if ( item->frame < current->item.frame )
{
if ( current == self->nodes )
self->nodes = node;
if ( current->prev )
current->prev->next = node;
node->next = current;
node->prev = current->prev;
current->prev = node;
}
else if ( item->frame > current->item.frame )
{
if ( current->next )
current->next->prev = node;
node->next = current->next;
node->prev = current;
current->next = node;
}
else
{
// Update matching node.
current->item.frame = item->frame;
current->item.is_key = 1;
current->item.keyframe_type = item->keyframe_type;
mlt_property_close( current->item.property );
current->item.property = node->item.property;
free( node );
}
}
else
{
// Set the first item
self->nodes = node;
}
return error;
}
int mlt_animation_prev_key( mlt_animation self, mlt_animation_item item, int position )
{
animation_node node = self->nodes;
while ( node && node->next && position >= node->next->item.frame )
node = node->next;
if ( node )
{
item->frame = node->item.frame;
item->is_key = node->item.is_key;
item->keyframe_type = node->item.keyframe_type;
mlt_property_pass( item->property, node->item.property );
}
return ( node == NULL );
}
