1 #ifndef __DALI_RENDER_TASK_H__
2 #define __DALI_RENDER_TASK_H__
5 * Copyright (c) 2014 Samsung Electronics Co., Ltd.
7 * Licensed under the Apache License, Version 2.0 (the "License");
8 * you may not use this file except in compliance with the License.
9 * You may obtain a copy of the License at
11 * http://www.apache.org/licenses/LICENSE-2.0
13 * Unless required by applicable law or agreed to in writing, software
14 * distributed under the License is distributed on an "AS IS" BASIS,
15 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
16 * See the License for the specific language governing permissions and
17 * limitations under the License.
22 #include <dali/public-api/math/viewport.h>
23 #include <dali/public-api/object/constrainable.h>
24 #include <dali/public-api/signals/dali-signal.h>
31 class FrameBufferImage;
34 namespace Internal DALI_INTERNAL
40 * @brief RenderTasks describe how the Dali scene should be rendered.
42 * The Stage::GetRenderTaskList() method provides access to an ordered list of render-tasks.
44 * Each RenderTask must specify the source actors to be rendered, and a camera actor from
45 * which the scene is viewed.
47 * RenderTasks may optionally target a frame-buffer, otherwise the default GL surface is used;
48 * typically this is a window provided by the native system.
50 * By default Dali provides a single RenderTask, which renders the entire actor hierachy using
51 * a default camera actor and GL surface. If stereoscopic rendering is enabled, Dali will create
52 * two additional render tasks, on for each eye. Each render task will have its own camera parented
53 * to the default camera actor.
55 * The first RenderTask used for input handling will be the last one rendered, which also has input enabled,
56 * and has a valid source & camera actor; see SetInputEnabled().
58 * If none of the actors are hit in the last RenderTask rendered, then input handling will continue
59 * with the second last RenderTask rendered, and so on.
61 * All RenderTasks which target a frame-buffer (i.e. off screen) will be rendered before all RenderTasks
62 * which target the default GL surface. This allows the user to render intermediate targets which are used
63 * later when targetting the screen.
65 * A RenderTask targetting a frame-buffer can still be hit-tested, provided that the
66 * screen->frame-buffer coordinate conversion is successful; see SetScreenToFrameBufferFunction().
68 * If the refresh rate id REFRESH_ONCE and a "Finish" signal is connected, it will be emitted when the RenderTask is completed.
69 * Note that all connected signals must be disconnected before the object is destroyed. This is typically done in the
70 * object destructor, and requires either the Dali::Connection object or Dali::RenderTask handle to be stored.
73 * | %Signal Name | Method |
74 * |--------------|-----------------------|
75 * | finished | @ref FinishedSignal() |
77 class DALI_IMPORT_API RenderTask : public Constrainable
81 * @brief Typedef for signals sent by this class.
83 typedef Signal< void (RenderTask& source) > RenderTaskSignalType;
86 static const Property::Index VIEWPORT_POSITION; ///< Property 0, name "viewport-position", type VECTOR2
87 static const Property::Index VIEWPORT_SIZE; ///< Property 1, name "viewport-size", type VECTOR2
88 static const Property::Index CLEAR_COLOR; ///< Property 2, name "clear-color", type VECTOR4
91 * @brief A pointer to a function for converting screen to frame-buffer coordinates.
92 * @param[in,out] coordinates The screen coordinates to convert where (0,0) is the top-left of the screen.
93 * @return True if the conversion was successful, otherwise coordinates should be unmodified.
95 typedef bool (* ScreenToFrameBufferFunction)( Vector2& coordinates );
98 * @brief A pointer to a function for converting screen to frame-buffer coordinates.
99 * @param[in,out] coordinates The screen coordinates to convert where (0,0) is the top-left of the screen.
100 * @return True if the conversion was successful, otherwise coordinates should be unmodified.
102 typedef bool (* const ConstScreenToFrameBufferFunction)( Vector2& coordinates );
105 * @brief The default conversion function returns false for any screen coordinates.
107 * This effectively disables hit-testing for RenderTasks rendering to a frame buffer.
108 * See also FULLSCREEN_FRAMEBUFFER_FUNCTION below.
110 static ConstScreenToFrameBufferFunction DEFAULT_SCREEN_TO_FRAMEBUFFER_FUNCTION;
113 * @brief This conversion function outputs the (unmodified) screen coordinates as frame-buffer coordinates.
115 * Therefore the contents of an off-screen image is expected to be rendered "full screen".
117 static ConstScreenToFrameBufferFunction FULLSCREEN_FRAMEBUFFER_FUNCTION;
120 * @brief The refresh-rate of the RenderTask.
124 REFRESH_ONCE = 0, ///< Process once only e.g. take a snap-shot of the scene.
125 REFRESH_ALWAYS = 1 ///< Process every frame.
128 static const bool DEFAULT_EXCLUSIVE; ///< false
129 static const bool DEFAULT_INPUT_ENABLED; ///< true
130 static const Vector4 DEFAULT_CLEAR_COLOR; ///< Color::BLACK
131 static const bool DEFAULT_CLEAR_ENABLED; ///< false
132 static const bool DEFAULT_CULL_MODE; ///< true
133 static const unsigned int DEFAULT_REFRESH_RATE; ///< REFRESH_ALWAYS
136 * @brief Create an empty RenderTask handle.
138 * This can be initialised with RenderTaskList::CreateRenderTask().
143 * @brief Downcast a handle to RenderTask handle.
145 * If handle points to a RenderTask the
146 * downcast produces valid handle. If not the returned handle is left uninitialized.
147 * @param[in] handle A handle to an object.
148 * @return A handle to a RenderTask or an uninitialized handle.
150 static RenderTask DownCast( BaseHandle handle );
155 * This is non-virtual since derived Handle types must not contain data or virtual methods.
160 * @brief This copy constructor is required for (smart) pointer semantics.
162 * @param [in] handle A reference to the copied handle
164 RenderTask(const RenderTask& handle);
167 * @brief This assignment operator is required for (smart) pointer semantics.
169 * @param [in] rhs A reference to the copied handle
170 * @return A reference to this
172 RenderTask& operator=(const RenderTask& rhs);
175 * @brief Set the actors to be rendered.
176 * @param[in] actor This actor and its children will be rendered.
177 * If actor is an empty handle, then nothing will be rendered.
179 void SetSourceActor( Actor actor );
182 * @brief Retrieve the actors to be rendered.
183 * @return This actor and its children will be rendered.
185 Actor GetSourceActor() const;
188 * @brief Set whether the RenderTask has exclusive access to the source actors; the default is false.
189 * @param[in] exclusive True if the source actors will only be rendered by this render-task.
191 void SetExclusive( bool exclusive );
194 * @brief Query whether the RenderTask has exclusive access to the source actors.
195 * @return True if the source actors will only be rendered by this render-task.
197 bool IsExclusive() const;
200 * @brief Set whether the render-task should be considered for input handling; the default is true.
202 * The task used for input handling will be last task in the RenderTaskList which has input enabled,
203 * and has a valid source & camera actor.
204 * A RenderTask targetting a frame-buffer can still be hit-tested, provided that the screen->frame-buffer
205 * coordinate conversion is successful; see also SetScreenToFrameBufferFunction().
206 * @param[in] enabled True if the render-task should be considered for input handling.
208 void SetInputEnabled( bool enabled );
211 * @brief Query whether the render-task should be considered for input handling.
212 * @return True if the render-task should be considered for input handling.
214 bool GetInputEnabled() const;
217 * @brief Set the actor from which the scene is viewed.
218 * @param[in] cameraActor The scene is viewed from the perspective of this actor.
220 void SetCameraActor( CameraActor cameraActor );
223 * @brief Retrieve the actor from which the scene is viewed.
224 * @return The scene is viewed from the perspective of this actor.
226 CameraActor GetCameraActor() const;
229 * @brief Set the frame-buffer used as a render target.
230 * @param[in] frameBuffer A valid frame-buffer handle to enable off-screen rendering, or an uninitialized handle to disable.
232 void SetTargetFrameBuffer( FrameBufferImage frameBuffer );
235 * @brief Retrieve the frame-buffer used as a render target.
236 * @return A valid frame-buffer handle, or an uninitialised handle if off-screen rendering is disabled.
238 FrameBufferImage GetTargetFrameBuffer() const;
241 * @brief Set the function used to convert screen coordinates to frame-buffer coordinates.
243 * This is useful for hit-testing actors which are rendered off-screen.
244 * @param[in] conversionFunction The conversion function.
246 void SetScreenToFrameBufferFunction( ScreenToFrameBufferFunction conversionFunction );
249 * @brief Retrieve the function used to convert screen coordinates to frame-buffer coordinates.
250 * @return The conversion function.
252 ScreenToFrameBufferFunction GetScreenToFrameBufferFunction() const;
255 * @brief Set the actor used to convert screen coordinates to frame-buffer coordinates.
257 * The local coordinates of the actor are mapped as frame-buffer coordinates.
258 * This is useful for hit-testing actors which are rendered off-screen.
259 * Note: The mapping actor needs to be rendered by the default render task to make the mapping work properly.
260 * @param[in] mappingActor The actor used for conversion.
262 void SetScreenToFrameBufferMappingActor( Actor mappingActor );
265 * @brief Retrieve the actor used to convert screen coordinates to frame-buffer coordinates.
266 * @return The actor used for conversion.
268 Actor GetScreenToFrameBufferMappingActor() const;
271 * @brief Set the GL viewport position used when rendering.
273 * This specifies the transformation between normalized device coordinates and target window (or frame-buffer) coordinates.
274 * By default this will match the target window or frame-buffer size.
275 * @note Unlike the glViewport method, the x & y coordinates refer to the top-left of the viewport rectangle.
276 * @param[in] position The viewports position (x,y)
278 void SetViewportPosition( Vector2 position );
281 * @brief Retrieve the GL viewport position used when rendering.
282 * @return The viewport.
284 Vector2 GetCurrentViewportPosition() const;
287 * @brief Set the GL viewport size used when rendering.
289 * This specifies the transformation between normalized device coordinates and target window (or frame-buffer) coordinates.
290 * By default this will match the target window or frame-buffer size.
291 * @param[in] size The viewports size (width,height)
293 void SetViewportSize( Vector2 size );
296 * @brief Retrieve the GL viewport size used when rendering.
297 * @return The viewport.
299 Vector2 GetCurrentViewportSize() const;
302 * @brief Set the GL viewport used when rendering.
304 * This specifies the transformation between normalized device coordinates and target window (or frame-buffer) coordinates.
305 * By default this will match the target window or frame-buffer size.
306 * @note Unlike the glViewport method, the x & y coordinates refer to the top-left of the viewport rectangle.
307 * @param[in] viewport The new viewport.
309 void SetViewport( Viewport viewport );
312 * @brief Retrieve the GL viewport used when rendering.
313 * @return The viewport.
315 Viewport GetViewport() const;
318 * @brief Set the clear color used when SetClearEnabled(true) is used.
319 * @param[in] color The new clear color.
321 void SetClearColor( const Vector4& color );
324 * @brief Retrieve the clear color used when SetClearEnabled(true) is used.
325 * @note This property can be animated; the return value may not match the value written with SetClearColor().
326 * @return The clear color.
328 Vector4 GetClearColor() const;
331 * @brief Set whether the render-task will clear the results of previous render-tasks.
333 * The default is false.
335 * @note The default GL surface is cleared automatically at the
336 * beginning of each frame; this setting is only useful when 2+
337 * render-tasks are used, and the result of the first task needs to
338 * be (partially) cleared before rendering the second.
340 * @param[in] enabled True if the render-task should clear.
342 void SetClearEnabled( bool enabled );
345 * @brief Query whether the render-task will clear the results of previous render-tasks.
346 * @return True if the render-task should clear.
348 bool GetClearEnabled() const;
351 * @brief Set whether the render task will cull the actors to the camera's view frustum.
353 * Note that this will only affect image actors that use the default vertex shader.
354 * The default mode is to cull actors.
355 * @param[in] cullMode True if the renderers should be culled.
357 void SetCullMode( bool cullMode );
360 * @brief Get the cull mode.
362 * @return True if the render task should cull the actors to the camera's view frustum
364 bool GetCullMode() const;
367 * @brief Set the refresh-rate of the RenderTask.
369 * The default is REFRESH_ALWAYS (1), meaning that the RenderTask
370 * will be processed every frame if the scene graph is changing. It
371 * may be desirable to process less frequently. For example,
372 * SetRefreshRate(3) will process once every 3 frames if the scene
373 * graph is changing. If the scene graph is not changing, then the
374 * render task will not be rendered, regardless of this value.
376 * The REFRESH_ONCE value means that the RenderTask will be
377 * processed once only, to take a snap-shot of the scene.
378 * Repeatedly calling SetRefreshRate(REFRESH_ONCE) will cause more
379 * snap-shots to be taken.
381 * @param[in] refreshRate The new refresh rate.
383 void SetRefreshRate( unsigned int refreshRate );
386 * @brief Query the refresh-rate of the RenderTask.
387 * @return The refresh-rate.
389 unsigned int GetRefreshRate() const;
394 * @brief If the refresh rate is REFRESH_ONCE, connect to this signal to be notified when a RenderTask has finished.
396 RenderTaskSignalType& FinishedSignal();
398 public: // Not intended for application developers
401 * @brief This constructor is used by Dali New() methods.
402 * @param [in] renderTask A pointer to a newly allocated render-task
404 explicit DALI_INTERNAL RenderTask( Internal::RenderTask* renderTask );
409 #endif //__DALI_RENDER_TASK_H__