Category Archives: Graphics

Second mid-summer update: Post-roadtrip, TextEdit progress, Clipboard…

Okay, so both members of development team have been busy being on vacation trips for the past few weeks, but we’re again back (although still on “kind of” summer break). To celebrate this we decided to each post a picture of what we’ve been up to, but to make this appropriate to topic of this blog, we do this by showing the photos using M.A.C.E running Photoshop 🙂

Road trip vacations

First, Pukka went on a road trip to Eastern Finland with his good old trusty Volvo station wagon for one week:

Pukka went on a road trip to Eastern Finland with his good old trusty Volvo station wagon for one week

Toni went on a two-week road trip to Northern Germany, visiting 12 cities in 14 days, including taking this amazing train from Hamburg to Kiel:

Toni went on a two-week road trip to Northern Germany, visiting 12 cities in 14 days, including taking this amazing train from Hamburg to Kiel

TextEdit progress (and Scrap Manager)

During this two weeks of visiting a lot of places, Toni had a couple evenings time to do some work on (non-styled) Text Edit, which now is nearly complete, and is able to run TeachText with almost all text editing features working:

TeachText works now on M.A.C.E.!

These are the notable features which work now in TextEdit:

  • Multi-line text display, with scrolling support (viewRect/destRect offsetting)
  • TEKey text input (still a bit hacky but functional)
  • TEClick with autoscrolling support, double-click word selection (using TEFindWord), and fExtend support for “shift-key”-type extending of selection, and recognition of left/right side of character for proper caret positioning
  • TextEdit hook support for nearly all TE Hooks (TEDoText, TERecalc, TEWordBreak, ClikLoop, TEFindWord, TEFindLine, TETrimMeasure, EOLHook, HighHook, etc…) which can be customized by 68K apps
  • Caret support with TEIdle blinking, TEKey cursor key movement (including multi-line support), and multi-line selection range support
  • Nearly all “quirks” of regular System 7.x TextEdit implemented as they work on real Mac; including the weird way caret gets positioned when moving across line boundaries using left/right arrow keys if previously clicked on right-hand side of a character, etc…
  • Dialog Manager edit field support, with System 7-type multi-line text support (i.e. edit fields with one line get extended horizontally 2x size, and scroll both horizontally and vertically, while multi-line edit fields only scroll vertically), “tabbing” between edit fields, and complete TEKey/TEClick support
  • Maybe some others I’ve forgotten to mention

Additionally, as TeachText wanted to use also Scrap Manager for edit functions, in parallel to implementing TECut/TECopy which use private TextEdit scrap, the implementation of generic Scrap Manager was finalized so that Clipboard file is fully supported (previously only in-memory state of scrap was implemented).

However, TEPaste still needs to be added for a 100% completion of “Edit” menu features for TeachText – and also, styled TextEdit work has not yet been started, which will be required in future to support more complex apps such as SimpleText and HyperCard 2.x.

Next up, on Toolbox API side, work is being done on Resource Manager’s resource fork write support, mostly just because after Scrap Manager was implemented, SuperPaint was able to progress a bit further in it’s startup, but wants to create “SuperPaint Prefs” file using Resource Manager’s functions, so might as well add that next. As of writing this, there’s already support for AddResource, ChangedResource and WriteResource, but we need to add resource fork compacting support to UpdateResFile to actually write the file properly. But we’ll get back to that later.

Bonus pic – for fun 🙂

Meanwhile, here’s a funny pic of what it looks when we run 28 M.A.C.E. instances at once 🙂 All quite responsive even though they’re all in full debug mode, although same can’t be said about the old Mac Pro when it was running them… 😀

28 individual M.A.C.E. applications (in debug mode) running at once 🙂

Experimenting with INIT/cdev support

This previous weekend, while helping Pukka to fix a mysterious coordinate calculation bug in Fool’s Errand intro, I decided to experiment with one weird idea: How about adding support for System Extensions and Control Panels? Therefore, yesterday I added the After Dark ‘cdev’ control panel to MacPaint app’s build settings to be included in the System Folder, and took some time to look what it would take to make it work.

Basically, INITs and cdevs are loaded during the startup by Mac OS by checking a few bits (such as file type, visibility, etc), opening the resource map of each file, and executing the first ‘INIT’ code resource found. At this experimental stage, we don’t yet have full INIT/cdev scanning, but instead have just a hard-coded filename to load INIT code from which works ok enough for this test case.

Our boot-time heap wasn’t quite properly set up yet, as the boot stack was too high, not leaving enough space between MemTop and BufPtr, which on the first attempt of running the INIT caused After Dark’s InitZone call to actually end up at top of the stack, causing all sorts of havoc. Besides that, there were a ton of bugs/improvements:

  • 68k-to-68k trap calls did not work correctly (i.e. calling a trap patched with 68k from 68k code)
  • InitZone parameter block handling was completely broken from the last year’s trap refactor, so it was fixed
  • Memory Manager’s Handle validation had not taken into account the case where handle’s “relative handle” field would point to invalid memory location in some “fake” handles (as one in After Dark), for which validation was added
  • Empty stubs were added for Notification Manager calls to allow After Dark to call them during activation/deactivation of screen saver
  • Locking of 68k mutex was not done early enough, so After Dark’s VBL handler was making the initial call Launch trap to have invalid register values
  • After Dark uses grafProcs to call QuickDraw, so one missing case used by it was added (ovalProc for ovals)

After that bunch of minor tweaks, we have now at least After Dark working nicely!

After Dark icon displayed during loading of MacPaint

Although the INIT code itself works, there is not yet any UI for displaying cdevs (Control Panels), so modules cannot be configured yet, and thus only the default “Starry Night” built-in module is displayed.

“Starry Night” (default module) running in After Dark inside MacPaint application bundle

There’s also a short video to demonstrate After Dark running:

Although not very usable feature at the moment, this will definitely allow interesting possibilities in the future, as theoretically we should be able to run applications requiring certain application-specific extensions to be present in the System Folder. This experimenting with After Dark has anyway allowed us to find a number of important bugs (as previously mentioned), and also works as a very good “compatibility” test to see how well our Toolbox API and 68k implementation can handle one very quirky control panel, as it patches a ton of toolbox traps and does a lot of low-level stuff which all appear to be compatible with our emulation.

File system write support (and MacPaint kind of works)

This week we reached a major milestone! From the encouragement on the work on HyperCard on 68KMLA forums, we got inspired to attempt tackling one major obstacle that was preventing it from working – file system write support!

As we mentioned earlier last year, when we last fall added the file system API, we did so using abstraction on top of AppleDouble file format. As Mac file system has the special dual nature of being split to data and resource forks, the AppleDouble format helps managing this in the emulated file system. Data fork, as mentioned earlier, is saved directly in its own file, while resource fork is merged with other file metadata in the AppleDouble header file. With this distinction, adding support for writing to data forks was really just trivial mapping of file manager write calls to the data file. Resource fork writing is a bit tricky, but we currently force the AppleDouble headers to keep resource fork as last element in the file, which allows us to offset also write operations from the beginning of resource data, and allows us to expand/shrink file easily, as end of resource fork is the actual end of header file. (One side note, setting EOF of files doesn’t have a standard C file operation, so we’re for now using the POSIX extension “ftruncate” which works at least on Mac OS X, but may lead to portability issues.)

Currently there’s very limited set of features for writing to file system implemented, basically just “Create” and “Write” file manager calls. For example, resource manipulation does not yet work as it will require a number of routines added to the Resource Manager to support it. However, one test application that directly benefited from this new feature was our beloved MacPaint, as it requires two scratch files to be present on startup volume/folder to function. This was nice, as it allowed us to add a few other missing features, such as PackBits (which also benefitted other apps and picture recording).

Hello from MacPaint!

Although all tools don’t yet work perfectly, most of basic drawing functions are solid enough to not only allow drawing, but the experimental file writing also allows saving of MacPaint files, which appear to be readable by the Preview application in development host system Mac OS X 10.12!

FatBits and some test pixels drawn (including ‘hello’ done with the MacPaint text tool)

Additionally, many other applications have seen improvements from this, as now we can save Civilization games and continue playing them! (Although Standard File package is still using hard-coded SFReply records).

Photoshop 1.0 (and MacApp support)

The past week we’ve been busy working on optimizations on the 68k CPU and various improvements to the toolbox API. One of the improvements has been adding support for Apple’s MacApp MethodDispatch routine, which is used by Object Pascal and C+- (yes, that’s “C plus minus”, Apple’s proprietary C++ version which was briefly out before official C++ came to Mac). Basically, MethodDispatch is the virtual function table dispatcher commonly seen in C++ programs, but instead of being bundled in the application, it is actually implemented by the operating system as a toolbox trap – although with special calling convention, which cannot be called directly through A-line traps, but needs to be invoked through jump from 68k code. It handles selecting the correct implementation for class functions which can be inherited and overridden.

With the new MacApp method dispatching support, we should now be able to try running any MacApp-based applications – one cool such application, which is written in Objective-Pascal, is the first version of Adobe Photoshop:

About box and intro screen of Adobe Photoshop 1.0

Most of the dialog boxes appear to display (almost) correctly, although color picker, text input and popup menu support are missing so there’s little that can be done here:

Color separation preferences dialog in Photoshop

And just to test out how it works, we did a quick “Hello world” drawing using Photoshop drawing tools inside MACE:

“Hello world” from MACE!

Although implementing the method dispatching routine was fairly trivial, some time was taken by other features used by Photoshop, such as crude International Utilities/Script Manager support, PrGlue dispatcher for printing (or as in current case, telling application that printers are not available), proper Gestalt support, and various bug fixes even to some fairly low-level things as handling of empty regions in UnionRgn calls, rewriting the 80-bit “Extended” floating-point format conversion in SANE, etc… A few other test applications did benefit of those additions, but we’ll post more about them later!

Ps. In case you are interested how MacApp-based application code looks like, the original Object Pascal source code for the first Mac Photoshop was at some time ago published as open-source and is available on github: https://github.com/amix/photoshop

StretchBits (and font scaling)

An important feature which was implemented a few days ago is the StretchBits trap. It was actually implemented for the first “Stunt Copter” prototype, but as it’s effects are visible in many places, I felt proper to write a separate blog entry for it just to demonstrate a few cases where it had big impact on the content:

Railroad Tycoon map & minimap AFTER adding StretchBits
Railroad Tycoon map & minimap BEFORE adding StretchBits

Before implementing StretchBits, calls to it were directed as a placeholder to StdBits, which would show the content partially depending on the context, but causing graphic glitches as can be seen. On the Railroad Tycoon map, the “Map” uses both double-size scaling to draw the map, and half-size scaling for the mini-map on the right hand side. Also, the “New Train” screen uses stretching to scale locomotive PICT resources to fit the List Manager list it uses:

Railroad Tycoon “New Train” screen AFTER adding StretchBits
Railroad Tycoon “New Train” screen BEFORE adding StretchBits

Also the text rendering benefits of this, as text can now be scaled to arbitrary sizes, which is quite important when drawing bitmapped fonts in non-exact resolutions, such as in Missile:

Missile AFTER adding StretchBits/font scaling

Missile BEFORE adding StretchBits/font scaling

The scaling algorithm has some room for improvement, as it for now only has the generic method for scaling bits one pixel at a time. For now, this seems to be enough to allow working on other missing features.

Old-style FONTs (and Harrier Strike Mission II)

Today we tried running Harrier Strike Mission II for the first time. The game appears stable, but runs way too fast, and the 3D drawing has some minor glitches causing some polygons to go to wrong place.

However, the most interesting part of this game was how it’s drawing its user interface. On the first run, this is the weirdness that we got:

Main menu, before old-style FONT support
In-game UI, before old-style FONT support

As you can see, there was a lot of text all over the place, as we didn’t have yet old-style FONT loading in place (up to this point only FOND & FONT/NFNT combination, which most of previously tested apps/games used). So, after implementing some “TODO” parts in our Font Manager implementation, we ended up with this:

Main menu after implementing old-style “FONT” loading support
In-game view after implementing old-style “FONT” loading support

It’s rather interesting to see fonts used in such way. As a nice bonus of this, we also got the tool palette icons to appear in MacPaint, which are also implemented as a custom old-style FONT:

The tool palette of MacPaint is now visible too!

MacDraw & basic shapes

After some effort, we now have basic shape drawing working in MacDraw. One fun part of this was implementing FixDiv, which uses the binary long division algorithm like the original one on Mac. MacDraw uses this routine excessively to handle document grid sizing and coordination of all shapes drawn on the canvas.

“Hello” from the MACE team (with MacDraw’s custom MDEFs usable). No scrollbars visible yet though, have to get on finishing the CDEF 1 soon…

There was also a minor bug in MenuSelect causing zero item selections in MacDraw’s custom menus, but after a quick fix we can now also use them.

Contrary to many other applications, MacDraw uses a different approach to implementing custom menus – instead of providing a MDEF and assigning it to the menu using the menu definition proc ID in resource, it has its MDEF code as part of the program, and creates a fake handle which it assigns to the menu manually. Because of this, we had to tweak the memory manager handle operations to silently fail on such handles, and instead return the proper memAZErr (-113) in D0/MemErr.

Still no text drawing though, and there’s minor tweaking required for line drawing, but it’s looking promising at the moment.

The “About” box of MacDraw

Indiana Jones and the Last Crusade

Although we could make Indy launch already a while ago, for some reason we did not get any graphics to display. However, after Pukka fixed some more CPU bugs (including ror.l instruction), we suddenly got everything appear on the screen:

Lucasfilm Games logo

Indiana Jones title screen

Interestingly, the game uses Sound Driver to play intro music, *but* after intro completes, it switches to Sound Manager. As we don’t have yet Sound Manager implementation, we added some empty stubs that just return error for the caller, and it seems Indy is happy with that as we can now proceed in the game all the way until getting stuck on quests 🙂

Indy boxing

At this point we also noticed that we had accidentally handled the Style parameter of TextFace as 8-bit value instead of 16-bits as we should have, so the style calls had not been working until now that we fixed it. Indy uses these styles to adjust appearance of text on the UI buttons:

Game controls at bottom of the UI

Here’s also a short video of the intro (with audio), and few first minutes of the gameplay:

Indiana Jones and the Last Crusade running on MACE, intro with music and few first minutes of gameplay

Arcs and Masks

Time for some QuickDraw updates! Perhaps surprisingly, we already had at this point two cases which required Arc drawing: Dark Castle help screen (the “jump” arcs), and Railroad Tycoon signal circles. As the arc drawing is closely related to circle drawing, we had to just handle the arc begin/end angles and using them to control circle scanline rasterization, we had those cases working:

Arcs in Dark Castle help dialog

Another set of features in QuickDraw which we needed to implement at this point were the CalcMask and CopyMask routines. It appears that Glider 2 uses those to draw sprites:

The paper airplane in glider is now visible

…and Railroad Tycoon also uses those to calculate masks and draw everything dynamic on the map (tracks, stations, bridges, and lighthouses). A nice side feature of CalcMask is that it shares basic algorithm with SeedFill call, so with just adjusting a few values we could add support for that trap too. Hopefully we can soon run MacPaint or SuperPaint to test it…

Interestingly, the documentation on CopyMask has conflicting information between Inside Macintosh editions: The later books (IM: Imaging With QuickDraw) indicate that CopyMask scales image to destination rectangle, similar to CopyBits, but older IM:IV describes the correct “Classic” QuickDraw behaviour that it does *not* scale the image.

Tracks, stations, bridges and lighthouses are now visible on the map

SANE, and Railroad Tycoon map generation

After we got the Railroad Tycoon main menu to work, we were able to proceed all the way until map generation. This part of the code uses Pack4 (FP68K) dispatcher to run some certain floating-point operations, so we had to implement the following SANE operations:

  • FINTX
  • FMULS
  • FDIVS
  • FS2X
  • FX2S
  • FI2X
  • FX2I
  • FL2X

The tricky part was, that SANE operates on 80-bit extended floating-point numbers, but modern CPUs use only 32- and 64-bit floating point numbers. Following the conventions Apple used in the SANE implementation for PowerPC, we convert the 80-bit extended numbers into 64-bit “double” values for calculation, and convert them to required destination format (depending on operation, usually the 80-bit extended) again.

Map of europe in Railroad Tycoon, after passing through map generation

I’m however not sure if the 80-bit conversion is correctly implemented at the moment, but it seems to work for now, as after adding these couple operations, we immediately got the map generator to pass through successfully:

Railroad Tycoon runs now successfully through map generation, until crashing at unimplemented List Manager dispatcher