# GraphicsEngine

from pandac.PandaModules import GraphicsEngine

Class : GraphicsEngine
Description : This class is the main interface to controlling the render process. There is typically only one GraphicsEngine in an application, and it synchronizes rendering to all all of the active windows; although it is possible to have multiple GraphicsEngine objects if multiple synchronicity groups are required.
The GraphicsEngine is responsible for managing the various cull and draw threads. The application simply calls engine->render_frame() and considers it done.

## Inheritance:

GraphicsEngine:

## Methods of GraphicsEngine:

extractTextureData
flipFrame
getAutoFlip
getNumWindows
getPortalCull
getThreadingModel
getWindow
isEmpty
makeBuffer
makeOutput
makeParasite
openWindows
removeAllWindows
removeWindow
renderFrame
resetAllWindows
setAutoFlip
setPortalCull
setThreadingModel
syncFrame

extractTextureData bool GraphicsEngine::extract_texture_data(Texture *tex, GraphicsStateGuardian *gsg); Description: Asks the indicated GraphicsStateGuardian to retrieve the texture memory image of the indicated texture and store it in the texture's ram_image field. The image can then be written to disk via Texture::write(), or otherwise manipulated on the CPU. This is useful for retrieving the contents of a texture that has been somehow generated on the graphics card, instead of having been loaded the normal way via Texture::read() or Texture::load(). It is particularly useful for getting the data associated with a compressed texture image. Since this requires a round-trip to the draw thread, it may require waiting for the current thread to finish rendering if it is called in a multithreaded environment. However, you can call this several consecutive times on different textures for little additional cost. If the texture has not yet been loaded to the GSG in question, it will be loaded immediately. The return value is true if the operation is successful, false otherwise.

flipFrame void GraphicsEngine::flip_frame(void); Description: Waits for all the threads that started drawing their last frame to finish drawing, and then flips all the windows. It is not usually necessary to call this explicitly, unless you need to see the previous frame right away.

getAutoFlip bool GraphicsEngine::get_auto_flip(void) const; Description: Returns the current setting for the auto-flip flag. See set_auto_flip.

getNumWindows int GraphicsEngine::get_num_windows(void) const; Description: Returns the number of windows (or buffers) managed by the engine.

getPortalCull bool GraphicsEngine::get_portal_cull(void) const; Description: Returns the current setting for the portal culling flag.

getThreadingModel GraphicsThreadingModel GraphicsEngine::get_threading_model(void) const; Description: Returns the threading model that will be applied to future objects. See set_threading_model().

getWindow GraphicsOutput *GraphicsEngine::get_window(int n) const; Description: Returns the nth window or buffers managed by the engine, in sorted order.

isEmpty bool GraphicsEngine::is_empty(void) const; Description: Returns true if there are no windows or buffers managed by the engine, false if there is at least one.

makeBuffer GraphicsOutput *GraphicsEngine::make_buffer(GraphicsStateGuardian *gsg, string const &name, int sort, int x_size, int y_size); Syntactic shorthand versions of make_output Description: Syntactic shorthand for make_output

makeOutput GraphicsOutput *GraphicsEngine::make_output(GraphicsPipe *pipe, string const &name, int sort, FrameBufferProperties const &fb_prop, WindowProperties const &win_prop, int flags, GraphicsStateGuardian *gsg = ((void *)(0)), GraphicsOutput *host = ((void *)(0))); THIS IS THE OLD CODE FOR make_gsg PT(GraphicsStateGuardian) gsg = pipe->make_gsg(properties, share_with); Description: Creates a new window (or buffer) and returns it. The GraphicsEngine becomes the owner of the window, it will persist at least until remove_window() is called later. If a null pointer is supplied for the gsg, then this routine will create a new gsg. This routine is only called from the app thread.

makeParasite GraphicsOutput *GraphicsEngine::make_parasite(GraphicsOutput *host, string const &name, int sort, int x_size, int y_size); Description: Syntactic shorthand for make_buffer.

openWindows void GraphicsEngine::open_windows(void); Description: Fully opens (or closes) any windows that have recently been requested open or closed, without rendering any frames. It is not necessary to call this explicitly, since windows will be automatically opened or closed when the next frame is rendered, but you may call this if you want your windows now without seeing a frame go by.

removeAllWindows void GraphicsEngine::remove_all_windows(void); Description: Removes and closes all windows from the engine. This also cleans up and terminates any threads that have been started to service those windows.

removeWindow bool GraphicsEngine::remove_window(GraphicsOutput *window); Description: Removes the indicated window or offscreen buffer from the set of windows that will be processed when render_frame() is called. This also closes the window if it is open, and removes the window from its GraphicsPipe, allowing the window to be destructed if there are no other references to it. (However, the window may not be actually closed until next frame, if it is controlled by a sub-thread.) The return value is true if the window was removed, false if it was not found. Unlike remove_all_windows(), this function does not terminate any of the threads that may have been started to service this window; they are left running (since you might open a new window later on these threads). If your intention is to clean up before shutting down, it is better to call remove_all_windows() then to call remove_window() one at a time.

renderFrame void GraphicsEngine::render_frame(void); Description: Renders the next frame in all the registered windows, and flips all of the frame buffers.

resetAllWindows void GraphicsEngine::reset_all_windows(bool swapchain); Description: Resets the framebuffer of the current window. This is currently used by DirectX 8 only. It calls a reset_window function on each active window to release/create old/new framebuffer

setAutoFlip void GraphicsEngine::set_auto_flip(bool auto_flip); Filename: graphicsEngine.I Created by: drose (24Feb02) PANDA 3D SOFTWARE Copyright (c) 2001 - 2004, Disney Enterprises, Inc. All rights reserved All use of this software is subject to the terms of the Panda 3d Software license. You should have received a copy of this license along with this source code; you will also find a current copy of the license at http://etc.cmu.edu/panda3d/docs/license/ . To contact the maintainers of this program write to panda3d-general@lists.sourceforge.net . Description: Set this flag true to indicate the GraphicsEngine should automatically cause windows to sync and flip as soon as they have finished drawing, rather than waiting for all of the windows to finish drawing first so they can flip together. This only affects the timing of when the flip occurs. If this is true (the default), the flip occurs before render_frame() returns. If this is false, the flip occurs whenever flip_frame() is called, or at the beginning of the next call to render_frame(), if flip_frame() is never called.

setPortalCull void GraphicsEngine::set_portal_cull(bool value); Description: Set this flag true to indicate the GraphicsEngine should start portal culling

setThreadingModel void GraphicsEngine::set_threading_model(GraphicsThreadingModel const &threading_model); Description: Specifies how future objects created via make_gsg(), make_buffer(), and make_window() will be threaded. This does not affect any already-created objects.

syncFrame void GraphicsEngine::sync_frame(void); Description: Waits for all the threads that started drawing their last frame to finish drawing. The windows are not yet flipped when this returns; see also flip_frame(). It is not usually necessary to call this explicitly, unless you need to see the previous frame right away.