The blog post explores the recently released and surprisingly readable Macintosh QuickDraw and MacPaint 1.3 source code. The author dives into the inner workings of the software, highlighting the efficient use of assembly language and clever programming techniques employed to achieve impressive performance on limited hardware. Specific examples discussed include the rectangle drawing algorithm, region handling for complex shapes, and the "FatBits" zoomed editing mode, illustrating how these features were implemented with minimal resources. The post celebrates the code's clarity and elegance, demonstrating how the original Macintosh developers managed to create a powerful and user-friendly application within the constraints of early 1980s technology.
The Blend2D project developed a new high-performance PNG decoder, significantly outperforming existing libraries like libpng, stb_image, and lodepng. This achievement stems from a focus on low-level optimizations, including SIMD vectorization, optimized Huffman decoding, prefetching, and careful memory management. These improvements were integrated directly into Blend2D's image pipeline, further boosting performance by eliminating intermediate copies and format conversions when loading PNGs for rendering. The decoder is designed to be robust, handling invalid inputs gracefully, and emphasizes correctness and standard compliance alongside speed.
HN commenters generally praise Blend2D's PNG decoder for its speed and clean implementation. Some appreciate the detailed blog post explaining its design and optimization strategies, highlighting the clever use of SIMD intrinsics and the decision to avoid complex dependencies. One commenter notes the impressive performance compared to LodePNG, particularly for large images. Others discuss potential further optimizations, such as using pre-calculated tables for faster filtering, and the challenges of achieving peak performance with varying image characteristics and hardware platforms. A few users also share their experiences integrating or considering Blend2D in their projects.
Driven by a desire to understand how Photoshop worked under the hood, the author embarked on a personal project to recreate core functionalities in C++. Focusing on fundamental image manipulation like layers, blending modes, filters (blur, sharpen), and transformations, they built a simplified version without aiming for feature parity. This exercise provided valuable insights into image processing algorithms and the complexities of software development, highlighting the importance of optimization for performance, especially when dealing with large images and complex operations. The project, while not a full Photoshop replacement, served as a profound learning experience.
Hacker News users generally praised the author's project, "Recreating Photoshop in C++," for its ambition and educational value. Some questioned the practical use of such an undertaking, given the existence of Photoshop and other mature image editors. Several commenters pointed out the difficulty in replicating Photoshop's full feature set, particularly the more advanced tools. Others discussed the choice of C++ and suggested alternative languages or libraries that might be more suitable for certain aspects of image processing. The author's focus on performance optimization and leveraging SIMD instructions also sparked discussion around efficient image manipulation techniques. A few comments highlighted the importance of UI/UX design, often overlooked in such projects, for a truly "Photoshop-like" experience. A recurring theme was the project's value as a learning exercise, even if it wouldn't replace existing professional tools.
Summary of Comments ( 16 )
https://news.ycombinator.com/item?id=43589156
Hacker News commenters on the MacPaint source code release generally expressed fascination with the code's simplicity, small size, and cleverness, especially given the hardware limitations of the time. Several pointed out interesting details like the use of hand-unrolled loops for performance and the efficient drawing algorithms. Some discussed the historical context, marveling at Bill Atkinson's programming skill and the impact of MacPaint on the graphical user interface. A few users shared personal anecdotes about using early Macintosh computers and the excitement surrounding MacPaint's innovative features. There was also some discussion of the licensing and copyright status of the code, and how it compared to modern software development practices.
The Hacker News post "Investigating MacPaint's Source Code" generated a lively discussion with several insightful comments. Many commenters expressed fascination with the historical significance of the code and the ingenuity of the original Macintosh development team.
Several commenters focused on the technical aspects of the code. Some marveled at the efficiency and compactness of the code, particularly given the hardware limitations of the time. Others pointed out interesting programming techniques used, such as the use of assembly language for performance-critical sections and the clever handling of memory management. One commenter highlighted the use of fixed-point arithmetic due to the lack of a floating-point unit on the original Macintosh. Another discussed the implications of the code's reliance on QuickDraw, the Macintosh's graphics library, and how it contributed to the system's overall responsiveness.
A few comments delved into the historical context of MacPaint's development. One commenter recounted their personal experience using MacPaint in its early days, highlighting its revolutionary user interface and the impact it had on the creative landscape. Another discussed Bill Atkinson's role as the primary developer of MacPaint and his other contributions to the early Macintosh. There was also some discussion of the challenges faced by the development team, including the limited hardware resources and the tight deadlines.
Some comments also touched upon the broader implications of making historical source code available. Commenters argued that studying such code can provide valuable insights into the evolution of software development practices and inspire future generations of programmers. They also emphasized the importance of preserving and sharing such historical artifacts for educational and research purposes.
A few commenters shared links to related resources, including the Computer History Museum's exhibit on the Macintosh and other online repositories of historical software. Some also suggested tools and techniques for analyzing and understanding the MacPaint source code.
Overall, the comments on the Hacker News post demonstrated a strong appreciation for the historical significance and technical brilliance of MacPaint's source code. The discussion provided valuable insights into the early days of personal computing and the ingenuity of the pioneers who shaped the industry.