notes/wayland.md

At XDC2014, Nvidia employee Andy Ritger proposed to enhance EGL in order to replace GBM.[68]

• https://lists.freedesktop.org/archives/mesa-commit/2012-January/035225.html => avec gbm_device_get_fd, pas besoin de stocker le descripteur de fichier

• gbm_device_get_backend_name => quel backend ?

• gbm_device_is_format_supported => utiliser pour vérifier le format qu'on veut ?

• https://jan.newmarch.name/Wayland/ProgrammingClient/#heading_toc_j_5

• http://jylee-world.blogspot.com/2013/12/analyzing-simplest-wayland-clinet-test.html

• wl_surface_set_user_data ?

• https://groleo.wordpress.com/2012/07/24/ion-buffer-sharing-mechanism/

• The android ION memory allocation https://lwn.net/Articles/480055/

• https://dvdhrm.wordpress.com/2013/09/01/splitting-drm-and-kms-device-nodes/

• gbm_bo_import avec GBM_BO_IMPORT_FD

• https://ppaalanen.blogspot.com/2012/03/what-does-egl-do-in-wayland-stack.html

• https://jan.newmarch.name/Wayland/DRM/

• https://github.com/msisov/chromium/commit/c11899c3e7e41d170b65024d3d712c264e586b75

• https://github.com/rawoul/v4l2-decode/blob/master/video.c

en particulier https://github.com/rawoul/v4l2-decode/blob/master/video.c#L1041 pour les formats

• https://lists.freedesktop.org/archives/mesa-dev/2012-March/020364.html interesting link on using BGM surface with EGL

dma-buf and exporting from ION

• https://www.mjmwired.net/kernel/Documentation/dma-buf-sharing.txt

• https://bugzilla.gnome.org/attachment.cgi?id=331464&action=edit

• https://gitlab.com/Codeaurora/platform_hardware_qcom_display/commit/42037d87d588b231d30d956d99442427e4e456c0

dma-buf and wayland, EGL, rendering

• https://github.com/robclark/libgbm/blob/master/gbm.h#L193 => use GBM_BO_USE_SCANOUT and GBM_BO_USE_RENDERING

• https://forum.mqmaker.com/t/opengl-drm-direct-rendering-manager-examples/629 => full example OpenGL DRM

https://github.com/geomatsi/drm_test/blob/master/drm_gl_test1a.c#L145 https://gist.github.com/dvdhrm/1364994

• gbm buffer object <-> EGL image <-> GL renderbuffer

https://www.khronos.org/registry/EGL/extensions/KHR/EGL_KHR_image_pixmap.txt

• KHR_image_pixmap for gbm_bo -> EGL image

• wl_drm_create_prime_buffer

• https://cgit.freedesktop.org/wayland/weston/tree/libweston/compositor-drm.c#n1189

• https://github.com/WebPlatformForEmbedded/WPEBackend-mesa/blob/master/src/nc/view-backend-wayland.cpp#L182

• look at media/msm_vpu.h

• https://bugaevc.gitbooks.io/writing-wayland-clients/content/black-square/global-objects.html

• WAYLAND_DEBUG=1 so as to inspect gdm-buffer-backend

• subsurfaces in wayland https://ppaalanen.blogspot.com/2013/11/sub-surfaces-now.html

other links found

• https://01.org/chromium/blogs/zero-copy-texture-uploads-chrome-os

• https://airlied.livejournal.com/78704.html

• use weston-info to get supported format and global objects (extensions)

• https://ppaalanen.blogspot.com/2016/02/a-programmers-view-on-digital-images.html pixel format and digital images

Implementation

// Prepare
    if (vd->fmt.i_chroma == VLC_CODEC_FBX_OPAQUE)
    {
        struct gbm_devide gbm = sys->gbm.device;
        struct gbm_import_fd_data import_fd =
        {
            .fd = picture->p_sys, // todo: extract fd
            .width = width,
            .height = height,
            .stride = stride,
            .format = GBM_FORMAT_YUV_420
        };

        struct gbm_bo *bo = gbm_bo_import(gbm, GBM_BO_IMPORT_FD, &import_fd, GBM_BO_USE_RENDERING);
        //fixme map to wl
        picture_Release(pic);
        return;
    }
    else
    {
        struct wl_buffer *buf = pic->p_sys;
        wl_buffer_set_user_data(buf, pic);
    }

Available EGL extensions

egl_wl gl debug: extensions: EGL_KHR_image EGL_KHR_image_base EGL_QCOM_create_image EGL_KHR_lock_surface EGL_KHR_lock_surface2 EGL_KHR_lock_surface3 EGL_KHR_gl_texture_2D_image EGL_KHR_gl_texture_cubemap_image EGL_KHR_gl_texture_3D_image EGL_KHR_gl_renderbuffer_image EGL_ANDROID_blob_cache EGL_KHR_create_context EGL_KHR_surfaceless_context EGL_KHR_create_context_no_error EGL_KHR_get_all_proc_addresses EGL_QCOM_lock_image2 EGL_EXT_protected_content EGL_KHR_no_config_context EGL_EXT_image_dma_buf_import EGL_EXT_yuv_surface EGL_WL_bind_wayland_display EGL_WL_create_wayland_buffer_from_image

Available wayland objects

1) wl_compositor version 4 2) wl_subcompositor version 1 3) wp_viewporter version 1 4) wp_presentation version 1 5) wl_pll version 1 6) zwp_relative_pointer_manager_v1 version 1 7) zwp_pointer_constraints_v1 version 1 8) zwp_input_timestamps_manager_v1 version 1 9) wl_data_device_manager version 3 10) wl_shm version 1 11) wl_seat version 5 12) fbx_pointer version 1 13) fbx_text version 1 14) fbx_gamepad version 1 15) wayland_buffer_backend version 2 16) zwp_linux_dmabuf_v1 version 3 17) gbm_buffer_backend version 1 18) zfbx_hdr_info_v1 version 1 19) zxdg_shell_v6 version 1 20) xdg_shell version 1 21) wl_shell version 1 22) weston_screenshooter version 1 23) wl_hid_device version 1 24) wl_output version 3 25) wl_hid_device version 1