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FScapePlus Version 1.0 Nov. 1986 By Mike Steed CIS: 72207,463 PLink: MSTEED This program is in the public domain. Feel free to copy and distribute it as you see fit. Please retain the credits and genealogy information. If you improve this program, or have any comments or questions, please contact me via CompuServe or PeopleLink. Introduction [][][][][][][][][][][][][][][][][][][][][][][][][][][][][] FScapePlus is a program to create fractal landscapes. It does this by creating a a plane of triangles, the vertices of which are offset in the vertical dimension by random amounts. If the number of triangles is suff- icient, the plane takes on an appearance much like a landscape. This effect is heightened by coloring the triangles by altitude, and by the optional addition of a sea level. FScapePlus has several enhancements over its predecessors. It has been optimized to be much faster. When storing an fscape file to disk, only the seed and drawing parameters need to be saved, instead of the entire fractal array. And most importantly, an easy to use mouse operated control panel has been added, allowing easy adjustment of the various drawing parameters to encourage experimentation. Genealogy [][][][][][][][][][][][][][][][][][][]][][][][][][][][][][][] FScapePlus has an interesting history. It is based on the ABasiC program Fscape by David Milligan and Ted Ingalls, which was adapted for the Amiga from a Macintosh Basic program by Michiel van de Panne that appeared in the July, 1985 issue of Creative Computing, which was in turn based on an article in the September, 1984 issue of Scientific American. FScapePlus also incorporates several changes in the drawing routines suggested by Danny Cory in the November, 1985 issue of Creative Computing which increase its speed. I have made further speed enhancements, such that the program now runs three times as fast as the original. The control panel is also mine. It, and the text input and requester routines, are part of a library of pre-written routines I use when creating programs. Requirements [][][][][][][][][][][][][][][][][][][][][][][][][][][][][][] FScapePlus requires AmigaBasic. The program needs 80K in addition to the 130K or so that Basic requires, therefore a 512K or larger Amiga is also required. FScapePlus has been designed to use 80 column text only. The Menus [][][][][][][][][][][][][][][][][][][][][][][][][][][][][][][] The Project Menu ======================================================= The Project menu is the main control menu for FScapePlus. It is used to create and draw new fscapes, or to redraw existing ones. A cycle mode is provided to show off the program. New: Generates and draws a new fscape. If automatic seeding is enabled a new random seed will be generated, otherwise the current seed will be re-used. Redraw: Redraws the current fscape, if one exists. When experimenting with scaling factors, positions, or sea level, Redraw is faster than New. Redraw will not display a change in level or terrain. Cycle: Continuously creates and draws random fscapes. The auto-seed switch does not affect Cycle. Stop: Stops a New or Redraw in progress. Drawing must be stopped before other menu items will be enabled. Quit: Quits FScapePlus. You may exit to BASIC, or return to the Work- bench. The File Menu ========================================================== The File menu is where one comes to create and use disk files containing the information necessary to recreate any fscape. The File menu is enabled only when using the control panel, since AmigaDOS requesters only appear on this screen. Load: Prompts for a filename, then loads that file and displays the new control settings. The suffix ".fscape" will be added to the file- name; do not enter it yourself. Save: Prompts for a filename, then saves the current control settings to that file. Auto Seeding is always set to off. The suffix ".fscape" is appended to the filename. The Window Menu ======================================================== FScapePlus has two windows: the display window is where the fscapes appear, and the control panel is where one may adjust the various parameters that affect how the fscape is drawn. Display: Selects the display window, and enables the drawing menu commands. Control: Displays the control panel, and enables the File menu. The Color Menu ========================================================= FScapePlus can't actually dump an fscape to a printer, since that requires access to the printer.device, but it can make life easier for a screen print program like ScreenDump or Scrimper. Normal: Sets the display colors to their normal values. Color Print: Sets the background color to white, so that printing on a color printer won't wear out the black ribbon. B&W Print: Sets the background color to white, and all the other colors to black, suitable for printing on a black and white printer. The Control Panel [][][][[][][][][][][][][][][][][][][][][][][][][][][] The control panel greatly increases the "play value" of FScapePlus. It provides an easy, Intuition-like way to adjust numerous parameters that go into the drawing of an fscape. All of the control panel settings are saved when an fscape is saved to disk. Terrain: This slider varies the roughness of the fractal terrain. When set to Flatlands, very little variation in altitude will be ob- served. When set to Rugged, the peaks and valleys will be off the screen unless the Z Scale is reduced to compensate. Horizontal Position: Moves the fscape horizontally on the screen. Most useful when the size of the fscape has been reduced. Vertical Position: Moves the fscape vertically on the screen. Most useful when the size of the fscape has been reduced. X, Y, and Z Scale Factor: These sliders control the size of the three dimensions of the fscape. X and Y control the horizontal dimensions in a manner that is difficult to generalize, and Z controls the vertical dimension. They may be adjusted together or seperately to size and/or distort the image. Level: This selector controls the resolution, or number of triangles in the fscape. Level one has four, level 4 has 256, and level 7 has 16384. Each increase in level takes four times as long to draw. The default level of 5 results in a reasonably detailed fscape, without taking forever to draw. A level 7 fscape is very detailed, but takes nearly a half hour to draw. The overall terrain of the fscape remains the same regardless of level. Seed Number: This number is the seed to the random number generator that is used to create the fscape. A given seed will always create the same fscape. Clicking on the Seed box will allow you to enter a seed number of your choice. Manual Reseed: Click this button to generate a new random seed number. Auto Seeding: If this switch is set to On, a new random seed will be gen- erated whenever New is selected from the Project menu. Entering a seed manually will disable Auto Seeding, to prevent the new seed from being changed before it can be used. The Cycle option on the Project menu always generates random seeds, regardless of the setting of this switch. Auto Screen Clear: When this switch is On, the screen will be cleared before a new fscape is drawn. If you have scaled down the fscapes and would like to draw several on the screen at once, just click this switch to Off. Sea Level: When this switch is On, the portion of the fscape below altitude zero (the blue lines) will be clipped off. The resulting flat plane adds a sea or lake surface to the fscape. The sea level may be switched on or off without regenerating the fscape (just use Redraw). Restore Defaults: Clicking this button restores the default parameters for all controls except the seed number, which will remain unchanged. Hints [][][][][][][][][][][][][][][][][][][][][][][][][][][][][][][][][] --> When entering text, FScapePlus uses a routine similar to an Intuition string gadget. The <-, ->, DEL, and BACKSPACE keys work as you would expect. CTRL-X deletes the text, and CTRL-Q restores the initial text (AmigaBasic can't read the Amiga keys). Pressing RETURN accepts the entire line, regardless of the position of the cursor. --> FScapePlus uses an eight color screen, since a 16 color screen only lets the processor run during the blanking intervals, slowing the program dramatically. Even an eight color screen slows the pro- cessor somewhat, so when drawing high level fscapes you might want to bring the Workbench screen (the control panel) to the front. Note that there is one line of the screen title bar peeking above the window's title bar. This allows access to the screen's front-back gadget. You may also use left-Amiga N and M to switch screens. --> Since changing levels doesn't affect the terrain of the fscape, only the level of detail, you can try various seeds at level four or five, then increase the level when you get an fscape you like. --> Cycle may be used to try various seeds. When an fscape you like comes up, just Stop the cycling. You may now play with the various param- eters, or save the fscape to disk. When cycling, the fscape on the screen is valid until the next one begins to appear. --> The Terrain and Z Scale parameters interact to affect the appearance of the fscape. A rugged terrain and a small Z scale factor will appear much the same as a flat terrain and a large Z scale factor. The difference will be in the coloring. The former will have lots of white peaks and deep blue valleys, while the latter will be mostly green and light blue. --> If you would like to have an fscape that fills the entire screen, with no visible edges, just create a level six or seven fscape, then in- crease the scale factors until the edges are off the screen. --> AmigaBasic is always slower the first time it runs a given section of program. Things like the requesters will run faster once they have been used the first time. --> If you would like to use the custom fscape icon with fscape files you have created, instead of the standard Basic project icon, just go into the CLI and copy TestFile.fscape.info to YourFile.fscape.info. From the Workbench, drag the two icons apart and put the new one where you want it. Click on the new icon, then select Snapshot from the Workbench menu. Technical Details [][][][][][][][][][][][][][][][][][][][][][][][][][][] FScapePlus is actually two programs which were developed separately and then integrated to create the final product. The first is the FScape pro- gram itself. It is a fairly direct copy of the MacBasic one in the Creative Computing article, converted to an easier-to-read AmigaBasic style. The color routine from the ABasiC version was added, and I made changes to the routines wherever possible to increase the speed. Going from a 16 color to an eight color screen was the biggest speed increaser. The menu routines are part of this portion of the program, and were one of the trickier parts of the program to write. This is because Basic is slow to update the menus, and attempting to use the menus while thay are being updated is Guru- baiting of the worst kind. The HELP key isn't very helpful, but I didn't have room to do any more. The second program is the control panel and requesters. These were designed in a modular fashion, to allow them to be easily converted to use in other programs. Extensive use is made of subprograms, to draw the various controls and to handle the requesters. The locations and titles of the controls are initialized via DATA state- ments, allowing them to be easily changed to design different panel layouts. Parameters regarding the status and location of the controls are kept in arrays, where they may be easily accessed. The number of controls may be changed simply by adding or deleting a few DATA and DIM statements and adjusting some FOR..NEXT loops. CtrlLoop is responsible for reading the mouse, determining which control is selected, and performing the approp- riate action. It then calls one of the subprograms to draw the new control setting. SetControls and GetControls handle the transfer of important var- iables between the two "halves" of FScapePlus. Three general-purpose subprograms are used. GetString is used to input text in a manner approximating that of an Intuition string gadget. StringReq implements a pop-up requester that displays a prompt and gathers a line of text. It contains a version of GetString. YesNoReq implements a boolean, or Yes/No requester. It duplicates much of the code found in StringReq. Rather than trapping errors, I tried to design the program so that errors could not be generated. This is not possible in the area of disk access, so ErrorHandler was included to trap the more likely ones. Suggestions for FScapePlusPlus [][][][][][][][][][][][][][][]][][][][][] I've had a lot of fun creating FScapePlus, and learned a lot about Amiga- Basic as well. There is always room for improvement, however. If you start adding things to the program, note that it is extremely close to the maximum size that AmigaBasic will load without executing CLEAR first. To get more room either delete some comments, or have a "loader" program execute the CLEAR and then run the main program. Here are some things that got left out of FScapePlus 1.0: The variable rh, defined in FInit, controls the rotation of the fscape. The variable vt, also defined in FInit, controls the amount of tilt-down applied to the fscape. Making these two values variable would allow the fscape to be viewed from any point in space (edge on, straight down, etc.) Controls for letting the user adjust the colors could be added. The ability to create a script file of pre-saved fscapes to be shown sequentially would allow slide shows to be created. A lot of code is duplicated in the requester routines. By creating sub- programs containing the common code the amount of duplicated code, and thus the size of the program, could be reduced. The really enterprising programmer might even make the edges of all of the triangles black and color in the interiors, to create a more solid looking landscape. If you make any of these improvements, or any others, I'd like to see them. Contact me at the network numbers given earlier.