#define DALI_LAYER_H
/*
- * Copyright (c) 2016 Samsung Electronics Co., Ltd.
+ * Copyright (c) 2017 Samsung Electronics Co., Ltd.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
/**
* @brief Layers provide a mechanism for overlaying groups of actors on top of each other.
*
- * When added to the stage, a layer can be ordered relative to other layers. The bottom
- * layer is at depth zero. The stage provides a default layer for it's children (see Stage::GetRootLayer()).
+ * When added to the stage, a layer can be ordered relative to other
+ * layers. The bottom layer is at depth zero. The stage provides a default
+ * layer for it's children (see Stage::GetRootLayer()).
*
- * Layered actors inherit position etc. as normal, but are drawn in an order determined
- * by the layers. In case of LAYER_3D, the depth buffer is cleared before each layer is rendered unless depth
- * test is disabled or there's no need for it based on the layers contents;
- * actors in lower layers cannot obscure actors in higher layers.
+ * Layered actors inherit position etc. as normal, but are drawn in an order
+ * determined by the layers. In case of LAYER_3D, the depth buffer is cleared
+ * before each layer is rendered unless depth test is disabled or there's no
+ * need for it based on the layer's contents; actors in lower layers cannot
+ * obscure actors in higher layers.
*
- * A layer has either LAYER_2D or LAYER_3D mode. LAYER_2D has better performance,
- * the depth test is disabled, and a child actor hides its parent actor.
- * LAYER_3D uses the depth test, thus a close actor hides a farther one.
- * LAYER_2D is the default mode and recommended for general cases.
- * See Layer::Behavior and SetBehavior() for more information.
+ * A layer has either LAYER_2D or LAYER_3D mode. LAYER_2D has better
+ * performance, the depth test is disabled, and a child actor hides its
+ * parent actor. LAYER_3D uses the depth test, thus a close actor hides a
+ * farther one. LAYER_2D is the default mode and recommended for general
+ * cases. See Layer::Behavior and SetBehavior() for more information.
*
- * Layer is a type of Actor, thus can have parent or children actors.
- * A layer influences rendering of its all descendant actors,
- * until another layer appears in the actor tree and manages its own subtree.
+ * Layer is a type of Actor, thus can have parent or children actors. A
+ * layer influences rendering of its all descendant actors, until another
+ * layer appears in the actor tree and manages its own subtree.
*
- * If depth test is disabled, there is no performance overhead from clearing the depth buffer.
+ * If depth test is disabled, there is no performance overhead from clearing
+ * the depth buffer.
*
* Actions
* | %Action Name | %Layer method called |
/**
* @brief UI control rendering mode (default mode).
*
- * This mode is designed for UI controls. In this mode renderer order will be respective to tree hierarchy of Actors.
- * This mode is expected to have better performance than LAYER_3D as renderers can be sorted more efficiently.
+ * This mode is designed for UI controls that can overlap. In this
+ * mode renderer order will be respective to the tree hierarchy of
+ * Actors.
*
- * For the following actor tree the rendering order will be A first, then B & C and finally D,E,F regardless of their
- * Z positions.
- * Rendering order between siblings, such as D, E & F or B & C, is determined based on the renderers depth index.
- * In UI we don't normally expect overlap. If you have two overlapped actors, make them parent-child to guarantee order of all renderers.
+ * The rendering order is depth first, so for the following actor tree,
+ * A will be drawn first, then B, D, E, then C, F. This ensures that
+ * overlapping actors are drawn as expected (whereas, with breadth first
+ * traversal, the actors would interleave).
*
* @code
*
*
* @endcode
*
+ * To change the order of sibling actors, use the Actor::Raise and
+ * Actor::Lower APIs. Within an actor, the Renderer depth index dictates
+ * the order the renderers are drawn.
+ *
* @SINCE_1_1.45
*/
LAYER_UI = LAYER_2D,
/**
* @brief Layer will use depth test.
*
- * When using this mode, depth test will be used. A depth clear will happen for each layer,
- * which means actors in a layer "above" other layers will be rendered in front of actors in
- * those layers regardless of their Z positions (see Layer::Raise() and Layer::Lower()).
- * Opaque renderers are drawn first and write to the depth buffer.
- * Then transparent renderers are drawn with depth test enabled but depth write switched off.
- * Transparent renderers are drawn based on their distance from the camera.
- * A renderers DEPTH_INDEX property is used to offset the distance to the camera when ordering transparent renderers.
- * This is useful if you want to define the draw order of two or more transparent renderers that are
- * equal distance from the camera.
- * Unlike LAYER_UI, parent-child relationship does not affect rendering order at all.
+ * This mode is designed for a 3 dimensional scene where actors in front
+ * of other actors will obscure them, i.e. the actors are sorted by the
+ * distance from the camera.
+ *
+ * When using this mode, a depth test will be used. A depth clear will
+ * happen for each layer, which means actors in a layer "above" other
+ * layers will be rendered in front of actors in those layers regardless
+ * of their Z positions (see Layer::Raise() and Layer::Lower()).
+ *
+ * Opaque renderers are drawn first and write to the depth buffer. Then
+ * transparent renderers are drawn with depth test enabled but depth
+ * write switched off. Transparent renderers are drawn based on their
+ * distance from the camera. A renderer's DEPTH_INDEX property is used to
+ * offset the distance to the camera when ordering transparent renderers.
+ *
+ * This is useful if you want to define the draw order of two or more
+ * transparent renderers that are equal distance from the camera. Unlike
+ * LAYER_UI, parent-child relationship does not affect rendering order at
+ * all.
*
* @SINCE_1_0.0
*/