diff -r 51a74ef9ed63 -r ae94777fff8f Symbian3/SDK/Source/GUID-F64E6551-670E-5E12-8103-DE504D3EC94F.dita --- a/Symbian3/SDK/Source/GUID-F64E6551-670E-5E12-8103-DE504D3EC94F.dita Wed Mar 31 11:11:55 2010 +0100 +++ b/Symbian3/SDK/Source/GUID-F64E6551-670E-5E12-8103-DE504D3EC94F.dita Fri Jun 11 12:39:03 2010 +0100 @@ -1,71 +1,71 @@ - - - - - -The -Non-ScreenPlay Graphics ArchitectureScreenPlay provides improved support for graphics hardware acceleration -and some other new features. However, it is possible to use the Symbian platform -without enabling ScreenPlay. This is called the non-ScreenPlay variant (sometimes -referred to as the non-NGA variant). This topic provides an introduction -to the graphics architecture when ScreenPlay is not enabled. -

The following diagram shows the non-ScreenPlay architecture. It includes -the components in the Graphics package and some closely related components -in other packages.

- -The Symbian Foundation non-ScreenPlay graphics architecture - - -

The software model is as follows:

- -

In addition, the non-ScreenPlay architecture provides support for EGL, -OpenGL and OpenVG.

-

The following diagram shows the rendering stack in the non-ScreenPlay variant.

- -The rendering stack in the non-ScreenPlay variant - - - -

Although DSA provides a solution for applications that require high frame -rates, the non-ScreenPlay architecture has limitations when used on graphics -accelerated hardware and non-uniform memory models. The architecture may require -the copying of buffers between CPU and GPU memory as shown in the following -diagram. ScreenPlay provides a solution that requires less copying of buffers -in this type of use case.

- - Example non-uniform memory, non-ScreenPlay hardware model - - - -The ScreenPlay -Architecture -Graphics -Hardware Acceleration -Graphics -Concepts + + + + + +The +Non-ScreenPlay Graphics ArchitectureScreenPlay provides improved support for graphics hardware acceleration +and some other new features. However, it is possible to use the Symbian platform +without enabling ScreenPlay. This is called the non-ScreenPlay variant (sometimes +referred to as the non-NGA variant). This topic provides an introduction +to the graphics architecture when ScreenPlay is not enabled. +

The following diagram shows the non-ScreenPlay architecture. It includes +the components in the Graphics package and some closely related components +in other packages.

+ +The Symbian Foundation non-ScreenPlay graphics architecture + + +

The software model is as follows:

+
    +

  • The Hardware Adaptation +Layer (HAL) consists of the frame buffer and basic attributes. All processes +have equal access to the frame buffer and can both read and write to it.

    • +

  • The Screen Driver provides +simple pixel, scan-line and bitmap operations. The Screen Driver has the same +interface for both bitmaps and the frame buffer. Hardware manufacturers can +adapt the Screen Driver to suit the available hardware.

    • +

  • The BitGDI component +provides support for higher-level geometric primitives and text. The BitGDI +component is implemented in terms of Screen Driver operations. All BitGDI +rendering operations are synchronous.

    • +

  • The Window Server multiplexes +access to the screen and provides a BitGDI-like interface.

    • +

  • The Window Server provides +Direct Screen Access (DSA) support for applications that require high frame +rates (such as video and games) to bypass the Window Server and write to the +frame buffer directly. However, some interaction with the Window Server is +needed to prevent the application from drawing over other application's data.

    • +
+

In addition, the non-ScreenPlay architecture provides support for EGL, +OpenGL and OpenVG.

+

The following diagram shows the rendering stack in the non-ScreenPlay variant.

+ +The rendering stack in the non-ScreenPlay variant + + + +

Although DSA provides a solution for applications that require high frame +rates, the non-ScreenPlay architecture has limitations when used on graphics +accelerated hardware and non-uniform memory models. The architecture may require +the copying of buffers between CPU and GPU memory as shown in the following +diagram. ScreenPlay provides a solution that requires less copying of buffers +in this type of use case.

+ + Example non-uniform memory, non-ScreenPlay hardware model + + + +The ScreenPlay +Architecture +Graphics +Hardware Acceleration +Graphics +Concepts \ No newline at end of file