2003-2018 The Khronos Group Inc.
eglCreatePlatformWindowSurface 3G
eglCreatePlatformWindowSurface create a new EGL on-screen rendering surface

## C Specification

EGLSurface `eglCreatePlatformWindowSurface` EGLDisplay display EGLConfig config void * native_window EGLAttrib const * attrib_list

## Parameters

display

  Specifies the EGL display connection.

config

  Specifies the EGL frame buffer configuration that defines the frame buffer resource available to the surface.

native_window

  Specifies the native window.

attrib_list

  Specifies a list of attributes for the window surface. May be `NULL` or empty (first attribute is `EGL_NONE`).

## Description

`eglCreatePlatformWindowSurface` creates an on-screen EGL window surface and returns a handle to it. Any EGL context created with a compatible EGLConfig can be used to render into this surface.

If `eglCreatePlatformWindowSurface` fails to create a window surface, `EGL_NO_SURFACE` is returned.

native_window must belong to the same platform as display, and EGL considers the returned EGLSurface as belonging to that same platform. The EGL extension that defines the platform to which display belongs also defines the requirements for the native_window parameter.

Surface attributes are specified as a list of attribute-value pairs, terminated with `EGL_NONE`. Accepted attributes are:

`EGL_GL_COLORSPACE`

  Specifies the color space used by OpenGL and OpenGL ES when rendering to the surface. If its value is `EGL_GL_COLORSPACE_SRGB`, then a non-linear, perceptually uniform color space is assumed, with a corresponding `GL_FRAMEBUFFER_ATTACHMENT_COLOR_ENCODING` value of `GL_SRGB`. If its value is `EGL_GL_COLORSPACE_LINEAR`, then a linear color space is assumed, with a corresponding `GL_FRAMEBUFFER_ATTACHMENT_COLOR_ENCODING` value of `GL_LINEAR`. The default value of `EGL_GL_COLORSPACE` is `EGL_GL_COLORSPACE_LINEAR`.

  Note that the `EGL_GL_COLORSPACE` attribute is used only by OpenGL and OpenGL ES contexts supporting sRGB framebuffers. EGL itself does not distinguish multiple colorspace models. Refer to the ``sRGB Conversion'' sections of the OpenGL 4.6 and OpenGL ES 3.2 Specifications for more information.

`EGL_RENDER_BUFFER`

  Specifies which buffer should be used for client API rendering to the window. If its value is `EGL_SINGLE_BUFFER`, then client APIs should render directly into the visible window. If its value is `EGL_BACK_BUFFER`, then client APIs should render into the back buffer. The default value of `EGL_RENDER_BUFFER` is `EGL_BACK_BUFFER`.

  Client APIs may not be able to respect the requested rendering buffer. To determine the actual buffer being rendered to by a context, call eglQueryContext.

`EGL_VG_ALPHA_FORMAT`

  Specifies how alpha values are interpreted by OpenVG when rendering to the surface. If its value is `EGL_VG_ALPHA_FORMAT_NONPRE`, then alpha values are not premultipled. If its value is `EGL_VG_ALPHA_FORMAT_PRE`, then alpha values are premultiplied. The default value of `EGL_VG_ALPHA_FORMAT` is `EGL_VG_ALPHA_FORMAT_NONPRE`.

`EGL_VG_COLORSPACE`

  Specifies the color space used by OpenVG when rendering to the surface. If its value is `EGL_VG_COLORSPACE_sRGB`, then a non-linear, perceptually uniform color space is assumed, with a corresponding VGImageFormat of form `VG_s*`. If its value is `EGL_VG_COLORSPACE_LINEAR`, then a linear color space is assumed, with a corresponding VGImageFormat of form `VG_l*`. The default value of `EGL_VG_COLORSPACE` is `EGL_VG_COLORSPACE_sRGB`.

Any EGL rendering context that was created with respect to config can be used to render into the surface. Use eglMakeCurrent to attach an EGL rendering context to the surface.

Use eglQuerySurface to retrieve the ID of config.

Use eglDestroySurface to destroy the surface.

## Notes

`eglCreatePlatformWindowSurface` is supported only if the EGL version is 1.5 or greater.

The `EGL_VG_ALPHA_FORMAT` and `EGL_VG_COLORSPACE` attributes are used only by OpenVG and EGL itself. Refer to section 11.2 of the OpenVG 1.0 specification for more information. The platform's use and interpretation of alpha values is outside the scope of EGL. However, the preferred behavior is for platforms to ignore the value of `EGL_VG_ALPHA_FORMAT` when compositing window surfaces.

## Errors

If display and native_window do not belong to the same platform, then undefined behavior occurs.

`EGL_NO_SURFACE` is returned if creation of the surface fails.

`EGL_BAD_DISPLAY` is generated if display is not an EGL display connection.

`EGL_NOT_INITIALIZED` is generated if display has not been initialized.

`EGL_BAD_CONFIG` is generated if config is not a valid EGL frame buffer configuration.

`EGL_BAD_NATIVE_WINDOW` may be generated if native_window is not a valid native window for the same platform as display.

`EGL_BAD_ATTRIBUTE` is generated if attrib_list contains an invalid window attribute or if an attribute value is not recognized or is out of range.

`EGL_BAD_ALLOC` is generated if there is already an EGLSurface associated with native_window (as a result of a previous `eglCreatePlatformWindowSurface` call).

`EGL_BAD_ALLOC` is generated if the implementation cannot allocate resources for the new EGL window.

`EGL_BAD_MATCH` is generated if the pixel format of native_window does not correspond to the format, type, and size of the color buffers required by config.

`EGL_BAD_MATCH` is generated if config does not support rendering to windows (the `EGL_SURFACE_TYPE` attribute does not contain `EGL_WINDOW_BIT`).

`EGL_BAD_MATCH` is generated if config does not support the specified OpenVG alpha format attribute (the value of `EGL_VG_ALPHA_FORMAT` is `EGL_VG_ALPHA_FORMAT_PRE` and the `EGL_VG_ALPHA_FORMAT_PRE_BIT` is not set in the `EGL_SURFACE_TYPE` attribute of config) or colorspace attribute (the value of `EGL_VG_COLORSPACE` is `EGL_VG_COLORSPACE_LINEAR` and the `EGL_VG_COLORSPACE_LINEAR_IT` is not set in the `EGL_SURFACE_TYPE` attribute of config).

## See Also

eglCreateWindowSurface, eglDestroySurface, eglChooseConfig, eglGetConfigs, eglMakeCurrent, eglQuerySurface