Classic Computer Magazine Archive COMPUTE! ISSUE 90 / NOVEMBER 1987 / PAGE 34

Digi-Paint For The Amiga

Rhett Anderson

Requirements: Amiga with 512K or more RAM.

Up until now, the best paint programs for the Amiga have allowed you to choose 32 colors from a palette of 4096 for your pictures. While 32 colors are more than any other home computer can handle, it's only natural to wish for more. Digi-Paint, a new paint program from NewTek, gives you almost unlimited freedom—all 4096 colors can be used on the screen at once.

Digi-Paint may be the first program that makes you feel as if you are actually painting. It's possible to make your pictures look like oil paintings, watercolor paintings, or chalk drawings. For the most adventurous artists, it's a whole new medium: painting with light. Jaggies—those stairstep squares that appear in other paint programs when you draw diagonal lines—disappear completely in Digi-Paint.

Digi-Paint works in the Amiga's hold-and-modify graphics mode. My hat is off to the author of the program, because it is a difficult mode in which to program. Each pixel can either be chosen from a palette of 16 colors, or retain the color of its neighbor to the left, only with the red, blue, or green value modified. For fast response in this unusual graphics mode, Digi-Paint is written entirely in machine language. According to the manual, it uses speed-optimized code to find the best color transition from pixel to pixel. I found Digi-Paint's algorithm to produce clear and clean pictures.

The default palette—which contains several grays, a blue, a red, a yellow, a green, and a couple of flesh tones—works very well with most pictures. If you like, you can alter the palette color-by-color. You might, for example, want to include a variety of blues, greens, and purples for an under-sea image.

There are two versions of the program. One lets you draw in medium resolution (320 × 200); the other, in high resolution (320 × 400). Although you may not be impressed by these numbers, the huge amount of colors available makes the apparent resolution much higher. This is similar to the way a color television works—although the resolution is not spectacularly high, the great number of colors available makes it easy to fake reality.

It does take a while to get used to having so many colors to choose from. When you first use the program you may find yourself getting bogged down in color selection: "Which blue is best?" Digi-Paint's dynamic color selection is a great help. You don't see all 4096 colors at once—only a fraction of them. By clicking on a color, you get a new group of colors close to the color you selected. After you get used to this system, you'll fly through reds, browns, yellows, greens, blues, and grays. If you would prefer to choose colors in a more conventional way, you can use the red, blue, and green sliders next to the dynamic color menus.

Digitized pictures can be altered in a variety of interesting ways with Digi-Paint, a 4096-color, hold-and-modify paint program for the Amiga.

Digi-Paint's dithered gradient-fill and shading options were used to create this bit of original art.

Pictures can be taken from any paint program that supports the IFF graphics standard. For this screen, several drawings from a Deluxe Paint art disk were superimposed onto the reviewer's artwork.

Pictures From Anywhere

An important consideration in reviewing any Amiga paint program is compatibility. Thankfully, Digi-Paint goes above and beyond the call of duty. Digi-Paint is fully IFF-compatible. (IFF is a file format standard developed by Electronic Arts and Commodore.) Since virtually all paint programs for the Amiga generate IFF files, you can read them into Digi-Paint. Amazingly, Digi-Paint reads in pictures of all resolutions, converting them to hold-and-modify mode as it reads them in. High-resolution screens (640 pixels across) are converted into Digi-Paint's screen format by blending together adjacent pixels. The conversion is excellent—text that is converted is still readable. You can even combine pictures that were drawn with different palettes.

Digi-Paint works well with Digi-View, NewTek's video digitizer. With Digi-View, you capture an image from a photograph or a still scene and then load it into Digi-Paint. You can now alter the picture in any way you like. Add a worm coring into a still-life apple. Draw a mustache on your favorite model. Paint graffiti on your house. Take a bird from a Deluxe Paint art disk and place it on your shoulder. More subtle effects are possible—the Digi-Paint manual steps through tutorials showing how to add makeup to a black-and-white photo of a woman, and how to add a third eye to the forehead of a little girl. Both of these digitized photos are included on the Digi-Paint disk.

While you can get nearly any picture in any format into Digi-Paint, you can only get hold-and-modify pictures out of Digi-Paint. This prevents you, for example, from working on a picture in Digi-Paint and then transferring it to Deluxe Paint II.

Of what use are the pictures that you get out of Digi-Paint? If you're interested in paint programs for art's sake, you're in luck—Digi-Paint is just what you've been looking for. If you're a programmer, there's plenty of potential, but there are a few problems. You could use a hold-and-modify screen as a title screen for a game. You could use a hold-and-modify screen as a back-ground screen, but only if you plan to use only sprites and vsprites. (Since blitter objects are really part of the main display screen, they'll interfere with the background screen, throwing chromatic ghosts across it.)

A Set Of Artistic Tools

Aside from the artist and the capabilities of the medium, the tools available are the most crucial elements of a successful paint program. In this category, Digi-Paint scores high, though not so high as Deluxe Paint II. Among the things you can't do: Rotate a brush by an arbitrary angle, scale the brush to an arbitrary size, flood-fill an empty area, add text to the screen, and distort brushes. Until a Digi-Paint II comes along, you can perform these operations in Deluxe Paint II and transfer the results to Digi-Paint.

There are several brushes to choose from in Digi-Paint. Besides the standard fixed-sized brushes, you can select an expanding circle, a variable-size rectangle, and a polygon-drawing line tool. With any brush, you can select fill as an option. Each brush can be used in any of the 12 available modes. Here is a list of these modes: solid, blend, tint, light-tint, minimum, maximum, add, subtract, XOR (eXclusive OR), AND, OR, and shading.

Solid, the first mode, is used to draw solid objects on the screen. Pick a color, pick a brush, and draw. Anything you draw over will disappear. Blend, tint, and light-tint let you tint an area of the screen with a certain color. Blend is the most severe of the three; light-tint is the most delicate.

Minimum, maximum, add, subtract, XOR, AND, and OR combine the brush with the background in various ways. Each of these modes work on the red, blue, and green components of the color seperately. Many, many possibilities exist. For instance, by using a white brush in XOR mode, you can create a negative image of your drawing.

Shading is the most impressive and versatile of the 12 modes. With it you can create realistic shading and highlighting, and smooth color changes. Shading works with any brush. You can even alter the shape and position of the "hot spot" within the shading area.

By using the scissor tool, you can "cut" your own brushes. This is the only way to get multicolor brushes. Any operation that can be performed with a normal brush can be done with your custom brush.

By clicking on RubThrough, you can selectively bring areas of an alternative screen into view. This is similar to Captain Kangaroo's Magic Drawing Board, only better. You can rub through in any mode and with any brush. When used with the shading mode, Rub-Through can be used to mix pictures on the screen seamlessly.

Special Effects

Digi-Paint offers an interesting variety of special effects. From the effects menu you can double the screen, halve the screen, soften the screen, mirror the screen, and switch halves of the screen. Each of these effects can be performed vertically or horizontally. By using vertical soften on an interlace picture, you can remove nearly all traces of the flicker associated with interlace mode.

Digi-Paint utilizes menus and file selectors to make the user interface comfortable and quick to learn. After you save a picture, you'll notice that Digi-Paint picture icons feature an interesting twist—they are four-color miniature copies of your artwork.

The 56-page manual that comes with Digi-Paint is well-written and informative. Many difficult-to-explain features are dealt with clearly. The three tutorials included are nice, but I wish there were more.

Digi-Paint employs the increasingly popular "keyword" protection system. The program disk is unprotected, but when the program is run, it asks you for a certain word on a certain line of a certain page. The program selects the word randomly. If you fail to answer correctly, you're dumped unceremoniously back into the Workbench. While this method of protection is slightly annoying, it is better than copy-protecting the disk. NewTek has provided us with an excellent program—and they have every right to discourage illegal distribution.

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