M7350/base/docs/html/guide/topics/drawing/opengl.jd
2024-09-09 08:52:07 +00:00

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page.title=OpenGL
@jd:body
<p>Android includes support for 3D hardware acceleration. This functionality is
accessed via the OpenGL API &mdash; specifically, the OpenGL ES API.</p>
<p>OpenGL ES is a flavor of the OpenGL specification intended for embedded
devices. Versions of OpenGL ES are loosely peered to versions of the primary
OpenGL standard. Android currently supports OpenGL ES 1.0, which corresponds
to OpenGL 1.3. So, if the application you have in mind is possible with OpenGL
1.3 on a desktop system, it should be possible on Android.</p>
<p>The specific API provided by Android is similar to the J2ME JSR239 OpenGL
ES API. However, it may not be identical, so watch out for deviations.</p>
<h2>Using the API</h2>
<p>Here's how to use the API at an extremely high level:</p>
<ol>
<li>Write a custom View subclass.</li>
<li>Obtain a handle to an OpenGLContext, which provides access to the OpenGL functionality.</li>
<li>In your View's onDraw() method, get a handle to a GL object, and use its methods to perform GL operations.</li>
</ol>
<p>For an example of this usage model (based on the classic GL ColorCube),
see
<a href="{@docRoot}samples/ApiDemos/src/com/example/android/apis/graphics/GLView1.html">com.android.samples.graphics.GLView1.java</a>
in the ApiDemos sample code project. A slightly more sophisticated version showing how to use
it with threads can be found in
<a href="{@docRoot}samples/ApiDemos/src/com/example/android/apis/graphics/GLSurfaceViewActivity.html">com.android.samples.graphics.GLSurfaceViewActivity.java</a>.
</p>
<p>Writing a summary of how to actually write 3D applications using OpenGL is
beyond the scope of this text and is left as an exercise for the reader.</p>
<h2>Links to Additional Information</h2>
<p>Information about OpenGL ES can be
found at <a title="http://www.khronos.org/opengles/"
href="http://www.khronos.org/opengles/">http://www.khronos.org/opengles/</a>.</p>
<p>Information specifically
about OpenGL ES 1.0 (including a detailed specification) can be found
at <a title="http://www.khronos.org/opengles/1_X/"
href="http://www.khronos.org/opengles/1_X/">http://www.khronos.org/opengles/1_X/</a>.</p>
<p>The documentation for the Android {@link javax.microedition.khronos.opengles.GL
OpenGL ES implementations} are also available.</p>
<p>Finally, note that though Android does include some basic support for
OpenGL ES 1.1, the support is <strong>not complete</strong>, and should not be relied
upon at this time.</p>