+\begin{frame}
+ \frametitle{DMA buffers for the win!}
+
+ \begin{center}
+ \textbf{\color{coolblack}Fortunately we are on Linux!}
+
+ \setbeamercolor{block body}{bg=white}
+ \setbeamercolor{block title}{bg=white, fg=coolblack}
+ \begin{block}{\scriptsize{There is a Linux kernel framework that can be used for
+ content sharing between different Linux drivers!}}
+
+ \vspace{-0.1cm}
+ \begin{table}[t]
+ \centering
+ \begin{tabular}{l}
+ \begin{adjustbox}{max width=\textwidth}
+ \adjustbox{valign=t}{\includegraphics[height=3.1cm]{data/dma_buf_sharing.png}}
+ \end{adjustbox}
+ \end{tabular}
+ \end{table}
+
+ \textbf{\scriptsize{\color{coolblack}A few things that need our attention:}}\\
+ \vspace{0.1cm}
+
+ \setbeamertemplate{itemize/enumerate body begin}{\tiny}
+ \begin{itemize}
+ \item There are {\color{coolblack}EGL and OpenGL/GLESv2
+ extensions} to make this content sharing easier!
+ \item It's {\color{coolblack}driver independent}!
+ \item It works with {\color{coolblack}multiple processes}!
+ \item As long as ANGLE can expose the required extensions to
+ import a dma\_buf file descriptor this method is
+ {\color{coolblack}"ANGLE backend
+ independent"}!
+ \item Works {\color{coolblack}only on Linux}... but in case of
+ WPE we won't need to support other systems! (Žan Doberšek)
+ \end{itemize}
+ \end{block}
+ \end{center}
+\end{frame}
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+
+\begin{frame}
+ \frametitle{Extensions and new approach}
+
+ \setbeamercolor{block body}{bg=white}
+ \setbeamertemplate{itemize/enumerate body begin}{\tiny}
+
+ \begin{block}{\scriptsize{How the kernel DMA buffers would help us avoid copying
+ the WebGL texture data?}}
+
+ \begin{center}
+ \begin{itemize}
+ \item Each texture is backed by a Linux kernel dma\_buffer.
+ \item Multiple textures can use the same dma buffer as backing
+ storage if they meet some requirements.
+ \item We can export the file descriptor of one buffer from one
+ driver and use it to access the buffer from the other
+ driver.
+ \item So we can export the FD that corresponds to the compositor
+ texture, import it in WebGL when we create the render target
+ and when the WebGL texture is filled, the compositor texture
+ will be also filled, as they share the backing storage!
+ \end{itemize}
+ \end{center}
+ \end{block}
+ \begin{block}{\scriptsize{EGL and GL extensions that can be used:}}
+ \begin{center}
+ \begin{itemize}
+ \item
+ \href{https://www.khronos.org/registry/EGL/extensions/MESA/EGL\_MESA\_image\_dma\_buf\_export.txt}{EGL\_MESA\_image\_dma\_buf\_export}:
+ \\ This extension allows creating one or multiple Linux dma\_buf
+ file descriptors from the EGLImage that corresponds to a texture.
+ \item \href{https://www.khronos.org/registry/EGL/extensions/EXT/EGL\_EXT\_image\_dma\_buf\_import.txt}{EGL\_EXT\_image\_dma\_buf\_import}:
+ \\ This extension allows creating an EGLImage (that will be used to create a
+ texture) from one or multiple Linux dma\_buf file
+ descriptors.
+ \item \href{https://www.khronos.org/registry/EGL/extensions/EXT/EGL\_EXT\_image\_dma\_buf\_import\_modifiers.txt}{EGL\_EXT\_image\_dma\_buf\_import\_modifiers}:
+ \\ This extension builds on EGL\_EXT\_image\_dma\_buf\_import, in order to support
+ format modifiers used for tiling, compression, and additional non-linear
+ modes.
+ \item \href{https://www.khronos.org/registry/OpenGL/extensions/OES/OES\_EGL\_image\_external.txt}{OES\_EGL\_image\_external}:
+ \\ This extension provides a mechanism for creating EGLImage texture targets
+ from EGLImages.
+ \end{itemize}
+ \end{center}
+ \end{block}
+\end{frame}
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+
+\begin{frame}
+ \frametitle{Example:}
+
+ \setbeamercolor{block body}{bg=white}{\scriptsize}
+ \setbeamertemplate{itemize/enumerate body begin}{\tiny}
+
+ \begin{block}{\scriptsize{I've written an example:}}
+ \begin{center}
+ \begin{itemize}
+ \item First using EGL!\\
+ Blog post: \url{https://eleni.mutantstargoat.com/hikiko/egl-dma-1/} \\
+ Code: \url{https://gistof.com/dma-egl-version}
+ \item Then using a native EGL context and a context from ANGLE!\\
+ Blog post: \url{https://eleni.mutantstargoat.com/hikiko/angle-dma/}\\
+ Code: \url{https://gistof.com/dmaangleeglversion}
+ \end{itemize}
+ \end{center}
+ \end{block}
+ \vspace{-0.3cm}
+ \begin{block}{\scriptsize{Snippet from the exporter:}}
+ \vspace{-0.1cm}
+ \tiny{
+ \begin{table}[t]
+ \centering
+ \begin{tabular}{l}
+ {\color{coolblack}Exporting a dma buffer from a texture
+ \texttt{texA}:}\\
+ \begin{adjustbox}{max width=\textwidth}
+ \adjustbox{valign=t}{\includegraphics[height=4cm]{data/dma_export_and_struct.png}}
+ \end{adjustbox}\\
+ \end{tabular}
+ \end{table}
+ }
+ \end{block}
+\end{frame}
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+
+\begin{frame}
+ \frametitle{Example continued}
+ \setbeamercolor{block body}{bg=white}{\scriptsize}
+ \setbeamertemplate{itemize/enumerate body begin}{\tiny}
+
+ \begin{block}{\scriptsize{Snippets from the importer:}}
+ \vspace{-0.1cm}
+ \tiny{
+ \begin{table}[t]
+ \centering
+ \begin{tabular}{l}
+ {\color{coolblack}Creating an EGLImage from the dma buffer using
+ the exported fd and the exported modifiers:}\\
+ \\
+ \begin{adjustbox}{max width=\textwidth}
+ \adjustbox{valign=t}{\includegraphics[height=3.5cm]{data/dma_import.png}}
+ \end{adjustbox}\\
+\\
+\\
+ {\color{coolblack}Creating a texture using that external
+ EGLImage:}\\
+ \\
+ \begin{adjustbox}{max width=\textwidth}
+ \adjustbox{valign=t}{\includegraphics[height=2cm]{data/dma_targetteture2does.png}}
+ \end{adjustbox}\\
+ \end{tabular}
+ \end{table}
+ }
+ \end{block}
+\end{frame}
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+
projects / webkit_codecamp / blobdiff