Class QCOMWriteonlyRendering

  • public final class QCOMWriteonlyRendering
    extends java.lang.Object
    Native bindings to the QCOM_writeonly_rendering extension.

    This extension defines a specialized "write-only" rendering mode that may offer a performance boost for simple 2D rendering.

    Some applications render large frame buffers with simple geometry, very little overdraw, and no need for the following per-fragment stages: depth/stencil testing, Multisampling, blending, and Logic Operations. Applications rendering a windowed desktop or other 2D GUI might fit into this profile.

    Applications that match this profile can enable �write-only� rendering mode. Performance may be improved in this mode through single-pass rendering directly to system memory as compared with multipass tile-based rendering into on-chip memory. However, since the write-path to system memory is generally lower bandwidth, any gains are most likely for 2D applications rendering to large frame buffers with little overdraw.

    On some HW, the GPU is not able to simultaneously read and write to system memory framebuffers, so enabling this mode also implicitly disables any per- fragment operations that may read from the frame buffer. In addition, this mode implicitly disables any reads and writes from the depth buffer.

    To enable write-only rendering, an OpenGL application will call glEnable(GL_WRITEONLY_RENDERING_QCOM). When write-only rendering is enabled, the following per-fragment stages are disabled regardless of the associated GL enables: multisample, depth_test, stencil_test, blending, and color_logic_Op. In addition, write-only rendering will implicitly disable all depth writes regardless of the value set via glDepthMask(). The alpha_test and scissor_test stages function as normal.

    To disable fast-rendering, call glDisable(GL_ WRITEONLY_RENDERING_QCOM). Any stages previously disabled by write-only rendering will return to their current GL state.

    • Field Summary

      Modifier and Type Field Description
      Accepted by the cap parameter of Enable, Disable.
    • Method Summary

      • Methods inherited from class java.lang.Object

        equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
    • Field Detail


        public static final int GL_WRITEONLY_RENDERING_QCOM
        Accepted by the cap parameter of Enable, Disable.
        See Also:
        Constant Field Values