DropCloth Version 2.2 By Eric Lavitsky 10-November-1987 (C) 1987 by Eric Lavitsky DropCloth lets you place a pattern, a 2 bitplane IFF image or a combination of a pattern and image into your Amiga's WorkBench backdrop. To use DropCloth from the CLI, type: 1>dropcloth [-d number] [-i filename] where "number" is between 0 and 64 inclusive and "filename" is a valid 2 bitplane (4 color) IFF image file. The number specifies the intensity of the pattern used for the backdrop, 0 will render a clear pattern into the display, while 64 will render a solid backdrop. If you don't specify a pattern, DropCloth will default to 0, a clear pattern. To remove DropCloth and any pattern or image it has rendered into the backdrop, simply run DropCloth a second time. It is generally recommended that DropCloth be "RUN" or "RUNBACKED" from the CLI. To use DropCloth from the WorkBench: Double click directly on the DropCloth Icon or Double click on an IFF image Icon whose default tool points to DropCloth. The image must be an IFF image (ILBM). Change it's default tool to point to DropCloth. Assuming DropCloth resides in the C: directory, select the image icon and then select "Info" from the WorkBench menu. The next to last field in the Icon is the default tool: ____________________________ DEFAULT TOOL | C:DropCloth | ---------------------------- If your image does not have an Icon, you may create an Icon for it by copying one of the Icons normally created by DPaint. If you want DropCloth to render a pattern, specify the pattern you want in the ToolTypes of the DropCloth Icon (if you are rendering a pattern only) or in the ToolTypes of the image Icon (if you are rendering an image along with a pattern). Again, select the Icon in question, pull down "Info" from the WorkBench menu, go down to the ToolTypes field, select "ADD", click in the ToolTypes text gadget and enter: _________________________________ |PATTERN=n | --------------------------------- where n is again a number between 0 and 64 inclusive. To remove dropcloth and any pattern or image it has rendered into the WorkBench backdrop, simply run DropCloth a second time by double clicking on it's Icon. - Features and Limitations - Current version wants 640x200x2 images - patterns work fine in any size screen including "morerowed" (overscan) screens. - We make a few assumptions about the IFF image that limit us to accepting only 2 bitplane images. - The fuel gauge in main disk windows is not properly refreshed by RefreshWindowFrame() ... (sigh) - Requires V1.2 or greater of KickStart to run - Future considerations - We could give an option to add bitplanes to the workbench screen for images > 2 bitplanes or try and map colors to 2 bitplanes. This would slow things down and eat lots of CHIP memory (ugh!). HISTORY - How it started - When I first got my Amiga way back in August '85, I was dissapointed to find that I couldn't put an image or pattern in my backdrop like we could on the AI workstations and Macintoshes at Rutgers. - One day, someone posted on the net that at a gathering in the Apple Computer cafeteria one day, Andy Hertzfeld, of Macintosh design team fame, was quoted as saying that the Amiga wasn't a serious machine: "C'mon, a user interface with windows the same color as the screen?!!!". I vowed that one day, I'd show him! :-) - One day, in one of our usual hacking sessions, Perry Kivolowitz and I started fooling with the layers library to see what we could make it do. It was here we discovered that the WorkBench backdrop was a backdrop borderless window and that we could look at it as a layer. - On Sunday February 8th, 1987, Perry and I decided to take a trip over to Rutgers (just 10 minutes away) to take a look at how the Suns and Macintoshes allowed you to change backdrop patterns and images. - That same night we went to his apartment to begin writing our own backdrop enhancer for the Amiga. At eight o'clock the next morning we had DropCloth in what essentially became release 1.0 (it was heavily cleaned up first :-) - We had hoped that DropCloth would be part of a complete package of tools and enhancments for the Amiga, but soon decided that it couldn't be supported well since it could degrade the preformance of the workbench (notice the delay incurred from clicking a disk icon to it's being available to be dragged). So, the project was shelved in favor of other things. - Suddenly, we saw other people on Usenet attempting the very same thing (doesn't it always happen this way, Amiga hackers are always on the same wavelength). We posted the V1.0 binary so people could have patterns at last. The V1.0 release was also placed on Fish Disk 59 - About two weeks before the first AmiExpo in New York, Perry and I were talking about DropCloth again. He asked me if we really couldn't put an image into the backdrop (at one point we thought we couldn't for some silly reason). A large rock promptly hit me in the back of the head and voila! (Get the source to see how it's done). - Perry's wrote the initial code for rendering more than just a pattern into the backdrop for a nice little demo at AmiExpo. I took his prototype and extended it to allow all IFF images and put in WorkBench support as well. - What it does - Things we had to realize about the workbench: - The Workbench renders it's icons into a backdrop borderless window. - When an icon is moved SetRast() is called to clear the layer and all the icons are redrawn. This is fairly fast, but destroys anything you render yourself into the backdrop. - So, get the source to see how it's done! (plug, plug :-) Thanks to: Perry Kivolowitz - Spurring me on, helping fix my bugs Jon Trudel - The DropCloth Icon Andy Hertzfeld - The original fire ( Copyright and Shareware Notice: DropCloth is Copyright 1987 by Eric Lavitsky. DropCloth is a shareware product. If you feel this product enhances your environment, please send a contribution to: Eric Lavitsky 34 Maplehurst Ln. Piscatway, NJ 08854 Keep the shareware concept alive! Suggested donation is $10. Donations of $15 or more will yield a disk replete with the source code to the latest version of DropCloth ($20 would be greatly appreciated). The source code was written using Manx Aztec C, V3.5a (Yes Jim, a plug! :-), remains proprietary to Eric Lavitsky and may not be redistributed or sold without the expressed written consent of Eric Lavitsky. The executable version of DropCloth and it's associated icons may be freely redistributed provided this document is included in the distribution.