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author | marha <marha@users.sourceforge.net> | 2010-11-22 19:42:40 +0000 |
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committer | marha <marha@users.sourceforge.net> | 2010-11-22 19:42:40 +0000 |
commit | 85ef9930f56bf15181f9a0b238f03d55303cf411 (patch) | |
tree | 63b43286956ebd1c35c96e9b3d5305aabdf71a0f /mesalib/docs/MESA_drm_image.spec | |
parent | 94810d19989336862251dbf69c3f3acb18a9b06d (diff) | |
download | vcxsrv-85ef9930f56bf15181f9a0b238f03d55303cf411.tar.gz vcxsrv-85ef9930f56bf15181f9a0b238f03d55303cf411.tar.bz2 vcxsrv-85ef9930f56bf15181f9a0b238f03d55303cf411.zip |
Updated to mesalib 7.9
Diffstat (limited to 'mesalib/docs/MESA_drm_image.spec')
-rw-r--r-- | mesalib/docs/MESA_drm_image.spec | 149 |
1 files changed, 149 insertions, 0 deletions
diff --git a/mesalib/docs/MESA_drm_image.spec b/mesalib/docs/MESA_drm_image.spec new file mode 100644 index 000000000..118501c3d --- /dev/null +++ b/mesalib/docs/MESA_drm_image.spec @@ -0,0 +1,149 @@ +Name + + MESA_drm_image + +Name Strings + + EGL_MESA_drm_image + +Contact + + Kristian Høgsberg <krh@bitplanet.net> + +Status + + Proposal + +Version + + Version 2, August 25, 2010 + +Number + + EGL Extension #not assigned + +Dependencies + + Reguires EGL 1.4 or later. This extension is written against the + wording of the EGL 1.4 specification. + + EGL_KHR_base_image is required. + +Overview + + This extension provides entry points for integrating EGLImage with the + Linux DRM mode setting and memory management drivers. The extension + lets applications create EGLImages without a client API resource and + lets the application get the DRM buffer handles. + +IP Status + + Open-source; freely implementable. + +New Procedures and Functions + + EGLImageKHR eglCreateDRMImageMESA(EGLDisplay dpy, + const EGLint *attrib_list); + + EGLBoolean eglExportDRMImageMESA(EGLDisplay dpy, + EGLImageKHR image, + EGLint *name, + EGLint *handle, + EGLint *stride); + +New Tokens + + Accepted in the <attrib_list> parameter of eglCreateDRMImageMESA: + + EGL_DRM_BUFFER_FORMAT_MESA 0x31D0 + EGL_DRM_BUFFER_USE_MESA 0x31D1 + + Accepted as values for the EGL_IMAGE_FORMAT_MESA attribute: + + EGL_DRM_BUFFER_FORMAT_ARGB32_MESA 0x31D2 + + Bits accepted in EGL_DRM_BUFFER_USE_MESA: + + EGL_DRM_BUFFER_USE_SCANOUT_MESA 0x0001 + EGL_DRM_BUFFER_USE_SHARE_MESA 0x0002 + + Accepted in the <target> parameter of eglCreateImageKHR: + + EGL_DRM_BUFFER_MESA 0x31D3 + + Use when importing drm buffer: + + EGL_DRM_BUFFER_STRIDE_MESA 0x31D4 + EGL_DRM_BUFFER_FORMAT_MESA 0x31D0 + +Additions to the EGL 1.4 Specification: + + To create a DRM EGLImage, call + + EGLImageKHR eglCreateDRMImageMESA(EGLDisplay dpy, + const EGLint *attrib_list); + + In the attribute list, pass EGL_WIDTH, EGL_EIGHT and format and + use in the attrib list using EGL_DRM_BUFFER_FORMAT_MESA and + EGL_DRM_BUFFER_USE_MESA. The only format specified by this + extension is EGL_DRM_BUFFER_FORMAT_ARGB32_MESA, where each pixel + is a CPU-endian, 32-bit quantity, with alpha in the upper 8 bits, + then red, then green, then blue. The bit values accepted by + EGL_DRM_BUFFER_USE_MESA are EGL_DRM_BUFFER_USE_SCANOUT_MESA and + EGL_DRM_BUFFER_USE_SHARE_MESA. EGL_DRM_BUFFER_USE_SCANOUT_MESA + requests that the created EGLImage should be usable as a scanout + buffer with the DRM kernel modesetting API. The + EGL_DRM_BUFFER_USE_SHARE_MESA bit requests that the EGLImage can + be shared with other processes by passing the underlying DRM + buffer name. + + To create a process local handle or a global DRM name for a + buffer, call + + EGLBoolean eglExportDRMImageMESA(EGLDisplay dpy, + EGLImageKHR image, + EGLint *name, + EGLint *handle, + EGLint *stride); + + If <name> is non-NULL, a global name is assigned to the image and + written to <name>, the handle (local to the DRM file descriptor, + for use with DRM kernel modesetting API) is written to <handle> if + non-NULL and the stride (in bytes) is written to <stride>, if + non-NULL. + + Import a shared buffer by calling eglCreateImageKHR with + EGL_DRM_BUFFER_MESA as the target, using EGL_WIDTH, EGL_HEIGHT, + EGL_DRM_BUFFER_FORMAT_MESA, EGL_DRM_BUFFER_STRIDE_MESA + in the attrib list. + +Issues + + 1. Why don't we use eglCreateImageKHR with a target that + indicates that we want to create an EGLImage from scratch? + + RESOLVED: The eglCreateImageKHR entry point is reserved for + creating an EGLImage from an already existing client API + resource. This is fine when we're creating the EGLImage from + an existing DRM buffer name, it doesn't seem right to overload + the function to also allocate the underlying resource. + + 2. Why don't we use an eglQueryImageMESA type functions for + querying the DRM EGLImage attributes (name, handle, and stride)? + + RESOLVED: The eglQueryImage function has been proposed often, + but it goes against the EGLImage design. EGLImages are opaque + handles to a 2D array of pixels, which can be passed between + client APIs. By referenceing an EGLImage in a client API, the + EGLImage target (a texture, a renderbuffer or such) can be + used to query the attributes of the EGLImage. We don't have a + full client API for creating and querying DRM buffers, though, + so we use a new EGL extension entry point instead. + +Revision History + + Version 1, June 3, 2010 + Initial draft (Kristian Høgsberg) + Version 2, August 25, 2010 + Flesh out the extension a bit, add final EGL tokens, capture + some of the original discussion in the issues section. |