Why You Can Draw a Cat on Your Computer

Retro cats & funny tech.
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Footnotes:
- In coloured image, a CRT may have multiple beams of RGB with different intensities to create a spectrum of colours. CRTs were later superceded by LCD, plasma, and OLED displays which are significantly cheaper and less bulky as they do not require a vacuum tube.
- Ivan Sutherland also created The Sword of Damocles in 1968 with the help of a few of his students. This was a head-mounted display and tracking system, considered one of the first augmented reality systems.
- One of the most important features of Sutherland's Sketchpad was that it could draw perfect lines and circle arcs from a draw path. This was via geometric constraints (e.g. the radius of the circle arc or the angle of the line), set by a combination of the light pen and push button inputs. Sketchpad also supported zooming and clipping.
- During the development of the Lisa and Macintosh, how a screen should look had not yet been standardised. The Lisa has a 720 × 364 screen with rectangular pixels. Atkinson advocated for square pixels, which did not end up making it to the Lisa but did make it to the Macintosh.
- While most raster systems at the time used 1 for white and 0 for black (much like a light switch on/off), the Macintosh did the opposite, to reflect the black-on-white design of the GUI (you set a pixel to 1 to write a black dot on a white page).
- Bresenham's line algorithm was named after Jack Bresenham, who developed the algorithm in 1962 at IBM for the Calcomp plotter, a sort of printer-like device that directly draws on a roll of paper using a pen (often just a ball-point pen) that strictly moves horizontally and vertically.
- A MacDraw file is called a PICT file, or a Picture, which is a sequence of QuickDraw calls. The buffer which stores the copy-and-paste image is also a Picture, even if copied from MacPaint. This is to allow for copy-and-paste to be shared across MacDraw, MacPaint, MacWrite, and any other applications that support it.
- While MacPaint was still called SketchPad (before MacSketch), it was also called LisaSketch.
- Because of the limited memory, MacPaint was programmed to fit in only 5,822 lines of Pascal with an additional 3,583 lines of assembly. QuickDraw fits in a total of 17,101 lines across 36 assembly files. The "Objects" referred to in the video are instances of Pascal Records.
- MacPaint also has rectangular selection, which selects both black and white pixels into a Rect which then gets passed to maskBits. This can be flipped and rotated by 90 degrees.
- While making MacPaint, Atkinson also attempted to build an early OCR tool that allowed for text to be edited after already being rasterised. This was eventually abandoned.
- MacPaint 2.0 and MacDraw II were released by Claris, a subsidary of Apple. MacDraw became MacDraw Pro and finally ClarisDraw in 1992.
- A major competitor to Adobe Illustrator was Aldus FreeHand, which had its own file format but could also make encapsulated PostScript files. Adobe acquired FreeHand in 2005, 10 years after being barred from acquiring FreeHand while acquiring Aldus in 1994. FreeHand was discontinued in 2006. Aldus also created SuperPaint, one of the first applications to combine vector and raster drawing by taking inspiration from both MacDraw and MacPaint. Today, professional drawing softwares combine vector and raster drawing (such as with vector/raster layers).
- Other application-level proprietary 2D graphics libraries also exist, such as Windows GDI/GDI+ and Core Graphics for macOS long after the original QuickDraw. Today, many of them have either been deprecated or very likely use 3D graphics libraries under the hood for many functionalities (such as OpenGL, DirectX, or Metal). Regardless, any optimisation from directly drawing as a 2D raster as opposed to drawing an abstract space is negligible. Photoshop allows for drawing with CPU or with DirectX/Metal/OpenGL, which is faster and with more features.
- Susan Kare later went on to design for Microsoft, IBM, Sony Pictures, Facebook, Pinterest, and Niantic Labs. Some of her other notable work includes the card deck in Windows 3.0 Solitaire.
References: www.junferno.com/references/#...
Photos courtesy of Folklore, Computer History Museum, Apple Inc., Wikimedia Commons, basalgangster
3D Models via Sketchfab courtesy of sev, Jakob Henerey, Paper Bandit
3D Models via Free3d courtesy of mahmed195, ingham18
Junferno is not endorsed by nor associated with any artists or creators featured. Artwork/video credits in video. EDIT: Unknown artist at 20:03 is Nek0Galleta.
Special thanks to the McGill Library, Internet Archive, Macintosh Repository, and my fellow editors on Wikipedia
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