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| <title xmlns:xlink="http://www.w3.org/1999/xlink">eglQuerySurface - EGL Reference Pages</title> | |
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| <body> | |
| <header/> | |
| <div class="refentry" id="eglQuerySurface"> | |
| <div class="titlepage"/> | |
| <div class="refnamediv"> | |
| <h2>Name</h2> | |
| <p>eglQuerySurface — | |
| return <abbr class="acronym">EGL</abbr> surface information | |
| </p> | |
| </div> | |
| <div class="refsynopsisdiv"> | |
| <h2>C Specification</h2> | |
| <div class="funcsynopsis"> | |
| <table style="border: 0; cellspacing: 0; cellpadding: 0;" class="funcprototype-table"> | |
| <tr> | |
| <td> | |
| <code class="funcdef">EGLBoolean <strong class="fsfunc">eglQuerySurface</strong>(</code> | |
| </td> | |
| <td>EGLDisplay <var class="pdparam">display</var>, </td> | |
| </tr> | |
| <tr> | |
| <td> </td> | |
| <td>EGLSurface <var class="pdparam">surface</var>, </td> | |
| </tr> | |
| <tr> | |
| <td> </td> | |
| <td>EGLint <var class="pdparam">attribute</var>, </td> | |
| </tr> | |
| <tr> | |
| <td> </td> | |
| <td>EGLint * <var class="pdparam">value</var><code>)</code>;</td> | |
| </tr> | |
| </table> | |
| <div class="funcprototype-spacer"> </div> | |
| </div> | |
| </div> | |
| <div class="refsect1" id="parameters"> | |
| <h2>Parameters</h2> | |
| <div class="variablelist"> | |
| <dl class="variablelist"> | |
| <dt> | |
| <span class="term"> | |
| <em class="parameter"> | |
| <code>display</code> | |
| </em> | |
| </span> | |
| </dt> | |
| <dd> | |
| <p> | |
| Specifies the EGL display connection. | |
| </p> | |
| </dd> | |
| <dt> | |
| <span class="term"> | |
| <em class="parameter"> | |
| <code>surface</code> | |
| </em> | |
| </span> | |
| </dt> | |
| <dd> | |
| <p> | |
| Specifies the EGL surface to query. | |
| </p> | |
| </dd> | |
| <dt> | |
| <span class="term"> | |
| <em class="parameter"> | |
| <code>attribute</code> | |
| </em> | |
| </span> | |
| </dt> | |
| <dd> | |
| <p> | |
| Specifies the EGL surface attribute to be returned. | |
| </p> | |
| </dd> | |
| <dt> | |
| <span class="term"> | |
| <em class="parameter"> | |
| <code>value</code> | |
| </em> | |
| </span> | |
| </dt> | |
| <dd> | |
| <p> | |
| Returns the requested value. | |
| </p> | |
| </dd> | |
| </dl> | |
| </div> | |
| </div> | |
| <div class="refsect1" id="description"> | |
| <h2>Description</h2> | |
| <p> | |
| <code class="function">eglQuerySurface</code> returns in | |
| <em class="parameter"><code>value</code></em> the value of | |
| <em class="parameter"><code>attribute</code></em> for <em class="parameter"><code>surface</code></em>. | |
| <em class="parameter"><code>attribute</code></em> can be one of the following: | |
| </p> | |
| <div class="variablelist"> | |
| <dl class="variablelist"> | |
| <dt> | |
| <span class="term"> | |
| <code class="constant">EGL_CONFIG_ID</code> | |
| </span> | |
| </dt> | |
| <dd> | |
| <p> | |
| Returns the ID of the EGL frame buffer configuration | |
| with respect to which the surface was created. | |
| </p> | |
| </dd> | |
| <dt> | |
| <span class="term"> | |
| <code class="constant">EGL_GL_COLORSPACE</code> | |
| </span> | |
| </dt> | |
| <dd> | |
| <p> | |
| Returns the color space used by OpenGL and OpenGL ES | |
| when rendering to the surface, either | |
| <code class="constant">EGL_GL_COLORSPACE_SRGB</code> or | |
| <code class="constant">EGL_GL_COLORSPACE_LINEAR</code>. | |
| </p> | |
| </dd> | |
| <dt> | |
| <span class="term"> | |
| <code class="constant">EGL_HEIGHT</code> | |
| </span> | |
| </dt> | |
| <dd> | |
| <p> | |
| Returns the height of the surface in pixels. | |
| </p> | |
| </dd> | |
| <dt> | |
| <span class="term"> | |
| <code class="constant">EGL_HORIZONTAL_RESOLUTION</code> | |
| </span> | |
| </dt> | |
| <dd> | |
| <p> | |
| Returns the horizontal dot pitch of the display on | |
| which a window surface is visible. The value | |
| returned is equal to the actual dot pitch, in | |
| pixels/meter, multiplied by the constant value | |
| <code class="constant">EGL_DISPLAY_SCALING</code>. | |
| </p> | |
| </dd> | |
| <dt> | |
| <span class="term"> | |
| <code class="constant">EGL_LARGEST_PBUFFER</code> | |
| </span> | |
| </dt> | |
| <dd> | |
| <p> | |
| Returns the same attribute value specified when the | |
| surface was created with | |
| <a class="citerefentry" href="eglCreatePbufferSurface.xhtml"><span class="citerefentry"><span class="refentrytitle">eglCreatePbufferSurface</span></span></a>. | |
| For a window or pixmap surface, | |
| <em class="parameter"><code>value</code></em> is not modified. | |
| </p> | |
| </dd> | |
| <dt> | |
| <span class="term"> | |
| <code class="constant">EGL_MIPMAP_LEVEL</code> | |
| </span> | |
| </dt> | |
| <dd> | |
| <p> | |
| Returns which level of the mipmap to render to, if | |
| texture has mipmaps. | |
| </p> | |
| </dd> | |
| <dt> | |
| <span class="term"> | |
| <code class="constant">EGL_MIPMAP_TEXTURE</code> | |
| </span> | |
| </dt> | |
| <dd> | |
| <p> | |
| Returns <code class="constant">EGL_TRUE</code> if texture has | |
| mipmaps, <code class="constant">EGL_FALSE</code> otherwise. | |
| </p> | |
| </dd> | |
| <dt> | |
| <span class="term"> | |
| <code class="constant">EGL_MULTISAMPLE_RESOLVE</code> | |
| </span> | |
| </dt> | |
| <dd> | |
| <p> | |
| Returns the filter used when resolving the | |
| multisample buffer. The filter may be either | |
| <code class="constant">EGL_MULTISAMPLE_RESOLVE_DEFAULT</code> | |
| or <code class="constant">EGL_MULTISAMPLE_RESOLVE_BOX</code>, | |
| as described for | |
| <a class="citerefentry" href="eglSurfaceAttrib.xhtml"><span class="citerefentry"><span class="refentrytitle">eglSurfaceAttrib</span></span></a>. | |
| </p> | |
| </dd> | |
| <dt> | |
| <span class="term"> | |
| <code class="constant">EGL_PIXEL_ASPECT_RATIO</code> | |
| </span> | |
| </dt> | |
| <dd> | |
| <p> | |
| Returns the aspect ratio of an individual pixel (the | |
| ratio of a pixel's width to its height). The value | |
| returned is equal to the actual aspect ratio | |
| multiplied by the constant value | |
| <code class="constant">EGL_DISPLAY_SCALING</code>. | |
| </p> | |
| </dd> | |
| <dt> | |
| <span class="term"> | |
| <code class="constant">EGL_RENDER_BUFFER</code> | |
| </span> | |
| </dt> | |
| <dd> | |
| <p> | |
| Returns the buffer which client API rendering is | |
| requested to use. For a window surface, this is the | |
| same attribute value specified when the surface was | |
| created. For a pbuffer surface, it is always | |
| <code class="constant">EGL_BACK_BUFFER</code>. For a pixmap | |
| surface, it is always | |
| <code class="constant">EGL_SINGLE_BUFFER</code>. To determine | |
| the actual buffer being rendered to by a context, | |
| call | |
| <a class="citerefentry" href="eglQueryContext.xhtml"><span class="citerefentry"><span class="refentrytitle">eglQueryContext</span></span></a>. | |
| </p> | |
| </dd> | |
| <dt> | |
| <span class="term"> | |
| <code class="constant">EGL_SWAP_BEHAVIOR</code> | |
| </span> | |
| </dt> | |
| <dd> | |
| <p> | |
| Returns the effect on the color buffer when posting | |
| a surface with | |
| <a class="citerefentry" href="eglSwapBuffers.xhtml"><span class="citerefentry"><span class="refentrytitle">eglSwapBuffers</span></span></a>. | |
| Swap behavior may be either | |
| <code class="constant">EGL_BUFFER_PRESERVED</code> or | |
| <code class="constant">EGL_BUFFER_DESTROYED</code>, as | |
| described for | |
| <a class="citerefentry" href="eglSurfaceAttrib.xhtml"><span class="citerefentry"><span class="refentrytitle">eglSurfaceAttrib</span></span></a>. | |
| </p> | |
| </dd> | |
| <dt> | |
| <span class="term"> | |
| <code class="constant">EGL_TEXTURE_FORMAT</code> | |
| </span> | |
| </dt> | |
| <dd> | |
| <p> | |
| Returns format of texture. Possible values are | |
| <code class="constant">EGL_NO_TEXTURE</code>, | |
| <code class="constant">EGL_TEXTURE_RGB</code>, and | |
| <code class="constant">EGL_TEXTURE_RGBA</code>. | |
| </p> | |
| </dd> | |
| <dt> | |
| <span class="term"> | |
| <code class="constant">EGL_TEXTURE_TARGET</code> | |
| </span> | |
| </dt> | |
| <dd> | |
| <p> | |
| Returns type of texture. Possible values are | |
| <code class="constant">EGL_NO_TEXTURE</code>, or | |
| <code class="constant">EGL_TEXTURE_2D</code>. | |
| </p> | |
| </dd> | |
| <dt> | |
| <span class="term"> | |
| <code class="constant">EGL_VERTICAL_RESOLUTION</code> | |
| </span> | |
| </dt> | |
| <dd> | |
| <p> | |
| Returns the vertical dot pitch of the display on | |
| which a window surface is visible. The value | |
| returned is equal to the actual dot pitch, in | |
| pixels/meter, multiplied by the constant value | |
| <code class="constant">EGL_DISPLAY_SCALING</code>. | |
| </p> | |
| </dd> | |
| <dt> | |
| <span class="term"> | |
| <code class="constant">EGL_VG_ALPHA_FORMAT</code> | |
| </span> | |
| </dt> | |
| <dd> | |
| <p> | |
| Returns the interpretation of alpha values used by | |
| OpenVG when rendering to the surface, either | |
| <code class="constant">EGL_VG_ALPHA_FORMAT_NONPRE</code> or | |
| <code class="constant">EGL_VG_ALPHA_FORMAT_PRE</code>. | |
| </p> | |
| </dd> | |
| <dt> | |
| <span class="term"> | |
| <code class="constant">EGL_VG_COLORSPACE</code> | |
| </span> | |
| </dt> | |
| <dd> | |
| <p> | |
| Returns the color space used by OpenVG when rendering to | |
| the surface, either | |
| <code class="constant">EGL_VG_COLORSPACE_sRGB</code> or | |
| <code class="constant">EGL_VG_COLORSPACE_LINEAR</code>. | |
| </p> | |
| </dd> | |
| <dt> | |
| <span class="term"> | |
| <code class="constant">EGL_WIDTH</code> | |
| </span> | |
| </dt> | |
| <dd> | |
| <p> | |
| Returns the width of the surface in pixels. | |
| </p> | |
| </dd> | |
| </dl> | |
| </div> | |
| </div> | |
| <div class="refsect1" id="notes"> | |
| <h2>Notes</h2> | |
| <p> | |
| Attribute <code class="constant">EGL_GL_COLORSPACE</code> is supported | |
| only if the EGL version is 1.5 or greater. | |
| </p> | |
| <p> | |
| Attribute <code class="constant">EGL_MULTISAMPLE_RESOLVE</code> is | |
| supported only if the EGL version is 1.4 or greater. | |
| </p> | |
| <p> | |
| Attributes <code class="constant">EGL_DISPLAY_SCALING</code>. | |
| <code class="constant">EGL_HORIZONTAL_RESOLUTION</code>, | |
| <code class="constant">EGL_PIXEL_ASPECT_RATIO</code>, | |
| <code class="constant">EGL_RENDER_BUFFER</code>, | |
| <code class="constant">EGL_SWAP_BEHAVIOR</code>, and | |
| <code class="constant">EGL_VERTICAL_RESOLUTION</code> are supported | |
| only if the EGL version is 1.2 or greater. | |
| </p> | |
| <p> | |
| Querying attributes <code class="constant">EGL_TEXTURE_FORMAT</code>, | |
| <code class="constant">EGL_TEXTURE_TARGET</code>, | |
| <code class="constant">EGL_MIPMAP_TEXTURE</code>, or | |
| <code class="constant">EGL_MIPMAP_LEVEL</code> for a non-pbuffer | |
| surface is not an error, but <em class="parameter"><code>value</code></em> is | |
| not modified. | |
| </p> | |
| <p> | |
| <code class="constant">EGL_DISPLAY_SCALING</code> is the constant | |
| value 10000. Floating-point values such as resolution and | |
| pixel aspect ratio are scaled by this value before being | |
| returned as integers so that sufficient precision to be | |
| meaningful will be retained in the returned value. | |
| </p> | |
| <p> | |
| For an offscreen (pbuffer or pixmap) surface, or a surface | |
| whose pixel dot pitch or aspect ratio are unknown, querying | |
| <code class="constant">EGL_HORIZONTAL_RESOLUTION</code>, | |
| <code class="constant">EGL_PIXEL_ASPECT_RATIO</code>, or | |
| <code class="constant">EGL_VERTICAL_RESOLUTION</code> will return the | |
| constant value <code class="constant">EGL_UNKNOWN</code> (-1). | |
| </p> | |
| </div> | |
| <div class="refsect1" id="errors"> | |
| <h2>Errors</h2> | |
| <p> | |
| <code class="constant">EGL_FALSE</code> is returned on failure, | |
| <code class="constant">EGL_TRUE</code> otherwise. | |
| <em class="parameter"><code>value</code></em> is not modified when | |
| <code class="constant">EGL_FALSE</code> is returned. | |
| </p> | |
| <p> | |
| <code class="constant">EGL_BAD_DISPLAY</code> is generated if | |
| <em class="parameter"><code>display</code></em> is not an EGL display connection. | |
| </p> | |
| <p> | |
| <code class="constant">EGL_NOT_INITIALIZED</code> is generated if | |
| <em class="parameter"><code>display</code></em> has not been initialized. | |
| </p> | |
| <p> | |
| <code class="constant">EGL_BAD_SURFACE</code> is generated if | |
| <em class="parameter"><code>surface</code></em> is not an EGL surface. | |
| </p> | |
| <p> | |
| <code class="constant">EGL_BAD_ATTRIBUTE</code> is generated if | |
| <em class="parameter"><code>attribute</code></em> is not a valid surface attribute. | |
| </p> | |
| </div> | |
| <div class="refsect1" id="seealso"> | |
| <h2>See Also</h2> | |
| <p> | |
| <a class="citerefentry" href="eglCreatePbufferSurface.xhtml"><span class="citerefentry"><span class="refentrytitle">eglCreatePbufferSurface</span></span></a>, | |
| <a class="citerefentry" href="eglCreatePixmapSurface.xhtml"><span class="citerefentry"><span class="refentrytitle">eglCreatePixmapSurface</span></span></a>, | |
| <a class="citerefentry" href="eglCreateWindowSurface.xhtml"><span class="citerefentry"><span class="refentrytitle">eglCreateWindowSurface</span></span></a>, | |
| <a class="citerefentry" href="eglSurfaceAttrib.xhtml"><span class="citerefentry"><span class="refentrytitle">eglSurfaceAttrib</span></span></a>, | |
| <a class="citerefentry" href="eglSwapBuffers.xhtml"><span class="citerefentry"><span class="refentrytitle">eglSwapBuffers</span></span></a> | |
| </p> | |
| </div> | |
| <p> | |
| </p> | |
| <div class="refsect3" id="copyright"> | |
| <img src="KhronosLogo.jpg"/> | |
| <p> | |
| Copyright © 2003-2014 The Khronos Group Inc. | |
| Permission is hereby granted, free of charge, to any person obtaining a | |
| copy of this software and/or associated documentation files (the | |
| "Materials"), to deal in the Materials without restriction, including | |
| without limitation the rights to use, copy, modify, merge, publish, | |
| distribute, sublicense, and/or sell copies of the Materials, and to | |
| permit persons to whom the Materials are furnished to do so, subject to | |
| the condition that this copyright notice and permission notice shall be included | |
| in all copies or substantial portions of the Materials. | |
| </p> | |
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