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1 <?xml version="1.0" encoding="utf-8"?> |
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2 <!-- Copyright (c) 2007-2010 Nokia Corporation and/or its subsidiary(-ies) All rights reserved. --> |
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3 <!-- This component and the accompanying materials are made available under the terms of the License |
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4 "Eclipse Public License v1.0" which accompanies this distribution, |
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5 and is available at the URL "http://www.eclipse.org/legal/epl-v10.html". --> |
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6 <!-- Initial Contributors: |
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7 Nokia Corporation - initial contribution. |
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8 Contributors: |
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9 --> |
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10 <!DOCTYPE concept |
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11 PUBLIC "-//OASIS//DTD DITA Concept//EN" "concept.dtd"> |
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12 <concept id="GUID-59C9EF92-8207-5FA5-AA20-0DB00C211BF1" xml:lang="en"><title>Graphics |
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13 Resource Services Collection Overview</title><shortdesc>This topic provides an introduction to the Graphics Resource Services |
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14 collection. </shortdesc><prolog><metadata><keywords/></metadata></prolog><conbody> |
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15 <p><b>Target audience</b>: Device creators. </p> |
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16 <note type="note">The Graphics Resource component is deprecated in Symbian^3 |
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17 and will be removed in Symbian^4.</note> |
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18 <p>In ScreenPlay, a <b>graphics resource</b> is a data buffer that is suitable |
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19 for use by graphics acceleration hardware. The requirement for the data buffer |
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20 to be capable of hardware acceleration imposes certain restrictions on the |
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21 way that it is implemented and used. An <b>image</b> is a particular type |
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22 of data buffer—a two-dimensional (2D) pixel buffer. Symbian documentation |
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23 has traditionally called 2D pixel buffers bitmaps. However, they are called |
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24 images in this context in order to avoid confusion with the existing <xref href="GUID-683A1D42-2764-3EB7-BD19-9E12559199AB.dita"><apiname>CFbsBitmap</apiname></xref> class. </p> |
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25 <p>Another important concept when working with the Graphics Resource components |
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26 is <b>rendering pipeline</b>. This is a set of primitives that perform rendering |
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27 and usually (but not necessarily) implement a pipeline model. The Graphics |
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28 Resource components do not define the rendering pipeline. However, when you |
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29 create a graphics resource, particularly an image, you need to specify its |
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30 usage in terms of the rendering pipeline it is to be used with. Typical examples |
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31 of rendering pipelines are DirectGDI, OpenVG and OpenGLES. </p> |
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32 <section id="GUID-AA3EF65D-E876-44DE-8E45-0BC2850F75CA"><title>Purpose</title> <p>The |
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33 Graphics Resource collection provides the following functionality: </p> <ul> |
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34 <li id="GUID-5100C135-C881-5907-BCD3-08818EB5117D"><p> <b>The creation and |
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35 sharing of hardware acceleration-capable two-dimensional (2D) pixel buffers </b> </p> <p>The |
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36 Graphics Resource collection provides functions to create 2D pixel buffers |
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37 of fixed size in such a way that they can be shared between several user-side |
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38 processes and the device drivers of the graphics acceleration hardware if |
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39 present. </p> <p>As mentioned above these 2D pixel buffers are called images. |
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40 They are encapsulated by the <xref href="GUID-EDC0E03F-37F6-3BEC-8FF3-D03C3CDB949C.dita"><apiname>RSgImage</apiname></xref> class. </p> </li> |
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41 <li id="GUID-ADE65736-3D6F-5FFB-B160-A4AD876D3CAD"><p> <b>Interoperability |
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42 with the composition components</b> </p> <p>The Graphics Resource collection |
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43 provides functions to create surfaces that can be used by the <xref href="GUID-0DC3E5AA-1706-5255-ACD6-E7AB732E1095.dita">composition |
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44 components</xref>. A surface is identified by a unique ID called the surface |
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45 ID. </p> <p>Interoperability with the composition components is encapsulated |
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46 by the <xref href="GUID-FCF750E4-526C-3789-89D8-DEF02BB7A5A7.dita"><apiname>RSgImageCollection</apiname></xref> class. This class enables the |
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47 retrieval of the surface ID for passing in calls to the Surface Manager and |
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48 Surface Update Server. <xref href="GUID-FCF750E4-526C-3789-89D8-DEF02BB7A5A7.dita"><apiname>RSgImageCollection</apiname></xref> provides an alternative |
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49 view of the surface as a collection of images that are accessible through <xref href="GUID-EDC0E03F-37F6-3BEC-8FF3-D03C3CDB949C.dita"><apiname>RSgImage</apiname></xref> handles. </p> </li> |
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50 <li id="GUID-E6513288-B612-5CAB-AF58-40F0A9FF088F"><p> <b> Support for new |
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51 types of graphics resources </b> </p> <p>The Graphics Resource collection |
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52 also provides an abstraction so that device creators can add new types of |
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53 graphics resources—for example, for handling vector data. </p> <p>Symbian |
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54 provides the <xref href="GUID-6F23F34A-A0BE-349C-ADE7-61A5AEF48018.dita"><apiname>RSgDrawable</apiname></xref> class for this purpose. Symbian |
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55 provides only one concrete type of graphics resource—the image (2D pixel buffer). |
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56 However, device creators can create additional types of resources. </p> </li> |
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57 <li id="GUID-E93EB750-03AB-578C-B2A7-E7400971AE8B"><p> <b> Extensibility and |
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58 adaptability</b> </p> <p>The Graphics Resource collection consists of a thin |
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59 generic layer and an adaptation layer. Symbian provides a product-quality |
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60 reference implementation of the adaptation layer. Device creators can extend, |
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61 modify or replace this implementation to suit specific graphics hardware. </p> </li> |
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62 </ul> <p>In addition, the Graphics Resource collection provides a number of <xref href="GUID-29C7FBFB-2F33-58CA-86BE-978E3187E4D6.dita">image compatibility guarantees</xref>. </p> <p> <i>Note</i>: |
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63 Although the DirectGDI component depends on the Graphics Resource components, |
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64 the Graphics Resource components do not depend on DirectGDI. The Graphics |
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65 Resource components can be used in isolation from DirectGDI—for example, by |
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66 a render stage that does not use DirectGDI. </p> </section> |
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67 <section id="GUID-C5E1043E-062E-41EF-A00C-E0072CB90D0F"><title>Components</title> <p>Graphics |
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68 Resource collection consists of the following components: </p> <ul> |
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69 <li id="GUID-A99A8B07-02C6-570A-A957-26924DDAE206"><p><xref href="GUID-82B0B4B9-6BC2-5BEF-B3B0-D57AC57F8D8A.dita">Graphics |
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70 Resource Component</xref>. This is the generic layer. </p> </li> |
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71 <li id="GUID-1C4E6CF8-D331-5AF8-9CC3-B0CC825BAFC3"><p><xref href="GUID-5E46C0EE-BD7D-5C85-8083-575BB2888AA7.dita">Graphics |
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72 Resource Adaptation component</xref>. This is the adaptation layer, which |
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73 device creators can extend, modify or replace. </p> </li> |
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74 </ul> </section> |
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75 </conbody><related-links> |
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76 <link href="GUID-26E51AB0-C0FC-55EA-B747-C834E2D4FD27.dita"><linktext>Graphics |
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77 Resources Services Collection</linktext></link> |
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78 <link href="GUID-E2A886E1-39FD-517F-870E-3B1BCD49E8CD.dita"><linktext>Off-Screen |
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79 Rendering with DirectGDI Tutorial</linktext></link> |
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80 </related-links></concept> |