The blog post "Hands-On Graphics Without X11" on blogsystem5.substack.com explores the landscape of graphics programming on NetBSD, specifically focusing on alternatives to the X Window System (X11). The author emphasizes a desire to move away from the perceived complexity and overhead of X11, seeking a simpler, more direct approach to graphics manipulation. They detail their experiences experimenting with several different libraries and frameworks that enable this.
The post begins by highlighting the historical dominance of X11 in Unix-like operating systems and its role as the de facto standard for graphical user interfaces. However, the author argues that X11's architecture, including its client-server model and network transparency, adds unnecessary complexity for applications that don't require these features. This complexity, they contend, contributes to a steeper learning curve and increased development time.
The exploration of alternatives begins with libdrm, the Direct Rendering Manager, a kernel subsystem that provides userspace programs with direct access to graphics hardware. The author explains how libdrm forms the foundation for many modern graphics systems and how it allows bypassing X11 for improved performance and simplified code.
The post then delves into specific libraries built on top of libdrm. First among these is libggi, the General Graphics Interface, an older library designed for cross-platform graphics programming. While acknowledging its age, the author appreciates its simplicity and lightweight nature, demonstrating its use with a basic example. However, the limited current development and documentation of libggi are noted as potential drawbacks.
Next, the exploration turns to DirectFB, a graphics library targeted at embedded systems. The author describes DirectFB's focus on performance and its suitability for resource-constrained environments. They walk through setting up DirectFB on NetBSD and demonstrate its capabilities with a simple graphical application, showcasing its relative ease of use.
The author also examines the SDL library, Simple DirectMedia Layer, highlighting its popularity for game development and its cross-platform compatibility. They discuss how SDL can be used as a higher-level abstraction over libdrm and demonstrate its usage for basic graphics rendering on NetBSD. The broader utility of SDL beyond just graphical output, including input handling and audio, is also mentioned.
Finally, the post briefly touches upon Wayland, a more modern display server protocol designed as a potential successor to X11. While acknowledging Wayland's increasing adoption, the author positions it as a less radical departure from X11's architecture than the other explored options, implying it might still retain some of the complexities they wish to avoid.
Throughout the post, the author emphasizes the benefits of working directly with libdrm and related libraries, highlighting improved performance, reduced resource consumption, and simplified development as key advantages. The overall tone suggests a preference for these leaner approaches to graphics programming, particularly in contexts where X11’s full feature set is not required.
This GitHub repository, titled "pseudo3d," showcases a remarkably concise implementation of a raycasting engine written entirely in Bash script. The provided code leverages the shell's built-in string manipulation capabilities and arithmetic functionalities to render a pseudo-3D perspective of a simple world map defined within the script itself. The world map is represented as a two-dimensional array of characters, where different characters signify different types of walls or empty space.
The core of the raycasting algorithm involves iterating through the screen's horizontal pixels, calculating the viewing angle for each pixel based on the player's position and viewing direction. For each pixel, a "ray" is cast from the player's position into the world map, effectively tracing a line until it intersects with a wall character. The distance to the wall intersection is then calculated using a simplified distance formula.
This distance value determines the height of the wall segment to be drawn on the screen for that particular pixel. Closer walls result in taller wall segments, creating the illusion of perspective. The rendering process utilizes ANSI escape codes to directly manipulate the terminal output, drawing vertical lines of varying heights representing the walls. Different wall characters in the map are visually distinguished by using different colors for the rendered wall segments, again achieved through ANSI escape codes. The rendering process updates the terminal output in real-time, providing a dynamic view as the player navigates the world.
The player's movement and rotation are handled through basic keyboard input. The script detects specific key presses, updating the player's position and viewing angle accordingly. This dynamic update combined with the real-time rendering loop creates an interactive experience where the player can explore the defined world from a first-person perspective. While rudimentary, the implementation successfully demonstrates the fundamental principles of raycasting in a surprisingly minimal and accessible manner using the Bash scripting environment. The code's brevity and reliance on built-in shell functionalities serve as a testament to the versatility and unexpected capabilities of the Bash scripting language beyond typical system administration tasks.
The Hacker News post titled "A Raycaster in Bash" (https://news.ycombinator.com/item?id=42475703) has generated several comments discussing the project, its performance, and potential applications.
Several commenters express fascination with the project, praising the author's ingenuity and ability to implement a raycaster in a language like Bash, which isn't typically used for such computationally intensive tasks. They admire the technical achievement and the demonstration of what's possible even with limited tools.
Performance is a recurring theme. Commenters acknowledge that the Bash implementation is slow, with some sharing their own experiences and benchmarks. Suggestions are made for potential optimizations, including using a different shell like zsh for potential performance gains, leveraging awk, and exploring alternative algorithms. The inherent limitations of Bash for this type of application are recognized, and the discussion explores the trade-offs between performance and the novelty of the implementation.
The practical applications of the project are also debated. While some view it primarily as a technical demonstration or a fun experiment, others suggest potential use cases where performance isn't critical. One commenter proposes using it for generating simple visualizations in constrained environments where other tools might not be available.
The choice of Bash itself is discussed. Some commenters question the rationale behind using Bash, suggesting more suitable languages for such a project. Others defend the choice, highlighting the value of exploring unconventional approaches and pushing the boundaries of what's possible with a familiar scripting language. The discussion touches upon the educational aspects of the project and its potential to inspire creative solutions.
Beyond the technical aspects, there's appreciation for the author's clear and well-documented code. The readability and organization of the project are commended, making it easier for others to understand and learn from the implementation. The project is also seen as a testament to the flexibility and power of Bash, even beyond its typical use cases. Some commenters express interest in exploring the code further and potentially contributing to its development.
Summary of Comments ( 28 )
https://news.ycombinator.com/item?id=42741155
HN commenters largely praised the elegance and simplicity of NetBSD's native graphics stack, contrasting it favorably with the complexity of X11. Several pointed out the historical context, noting that this approach harkens back to simpler times and offers a refreshing alternative to the bloat of modern desktop environments. Some expressed interest in exploring NetBSD specifically because of this feature. A few commenters questioned the practicality for everyday use, citing the limited software ecosystem that supports it. Others discussed the performance implications, with some suggesting it could be faster than X11 in certain scenarios. There was also discussion of similar approaches in other operating systems, such as Framebuffer and Wayland.
The Hacker News post "Hands-On Graphics Without X11" discussing a blog post about NetBSD graphics without X11 sparked a lively discussion with several insightful comments.
One commenter pointed out the historical significance of framebuffer consoles and how they were commonplace before X11 became dominant. They highlighted the simplicity and directness of framebuffer access, contrasting it with the complexity of X11. This sparked further discussion about the evolution of graphics systems and the trade-offs between simplicity and features.
Another commenter expressed enthusiasm for the resurgence of framebuffer-based applications and saw it as a positive trend towards simpler, more robust systems. They specifically mentioned the appeal for embedded systems and specialized applications where the overhead of X11 isn't desirable.
The topic of Wayland was also raised, with some commenters discussing its potential as a modern alternative to both X11 and framebuffers. The conversation touched on Wayland's architectural differences and the challenges of transitioning from an X11-centric ecosystem.
Some users shared their personal experiences with framebuffer applications and libraries, mentioning specific tools and projects they had used. These anecdotes provided practical context to the broader discussion about the merits and drawbacks of different graphics approaches.
Several commenters expressed interest in exploring NetBSD and its framebuffer capabilities further, indicating the blog post had successfully piqued their curiosity. They inquired about specific hardware compatibility and the ease of setting up a framebuffer environment.
The performance benefits of bypassing X11 were also mentioned, with commenters suggesting it could lead to more responsive graphics and reduced resource consumption. This resonated with users interested in optimizing their systems for performance-sensitive tasks.
Finally, some comments focused on the security implications of different graphics architectures, highlighting the potential attack surface of complex systems like X11. The simplicity of framebuffers was seen as a potential advantage in this regard.