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QuickBASIC Tokenized Source | 1989-08-05 | 27.0 KB | 388 lines

@ GetConfig SetPalette TorusDefine @ TorusCalc TorusColor @ TorusSort HighE @ TorusDraw Index9 TileDraw TorusRotate First+ Delay" Seconds CountTiles9 Message` @ SetConfig Inside$ DegToRad) Degrees Rotated Lower Upper Current FALSEK TROWi START3 CONTINUE EGA256 EGA64] HERCu TColor ConfigP Colors Atribs6 XPix{ TORUS Panel SectC Thick XDegree YDegree Bordj InitRowsN BestMode Available TOR.Thick TOR.Panel TOR.XDegreek VC.Scrn MemErrY VideoErr EGAErr TOR.Sect RowErrq Begin Highest Lowest Border T.xcC IsUp_ IsDown VC.Colors VC.Atribs8 VC.XPix VC.YPix VC.TCOL VC.TROW XSect YPanel CXRot SXRot CYRotI SYRot> XInc' FirstY LastAtr ENTER ESCAPE{ DOWNARROW UPARROWl LEFTARROW RIGHTARROW Fields TOR.YDegree TOR.Bord TOR.Delay FirstClr LastClr Toggle Partition RandIndex TORUS This program draws a Torus figure. The program accepts user input to specify various TORUS parameters. It checks the current system configuration and takes appropriate action to set the best possible initial mode. General purpose constants Rotation flagse Constants for best available screen mode= User-defined type for tiles - an array of these make a torus= User-defined type to hold information about the mode User-defined type to hold information about current Torus A palette of colors to paint with Error variables to check screen typen The code of the module-level program begins heree Initialize defaults Get best configuration and set initial graphics mode to it Loop forever (exit is from within a SUB)m Get Torus definition from userf Dynamically dimension arrayse Array for indexes Turn on error trap for insufficient memorya Array for tiles Initialize array of indexes Calculate the points of each tile on the torusB Calculating"8 Color each tile in the torus. Sort the tiles by their "distance" from the screen Sorting"8 Set the screen mode Mix a palette of colors Set logical window with variable thicknesse Center is 0, up and right are positive, down and left are negative= Draw and paint the tiles, the farthest first and nearest last Rotate the torus by rotating the color paletten Restore original rows Error trap to make torus screen independent Fall through until something workst 12789" Sorry. Graphics not available. Can't run Torus." Trap to detect 64K EGAa 12789" Trap to detect insufficient memory for large Toruse Out of memory" Reducing panels from Reducing sections from Trap to determine initial number of rows so they can be restoredv GetConfig = GetConfig Get the starting number of lines and the video adapter. Assume 50 line display and fall through error until we get the actual numberl Assume best possible screen mode 12789BCD Fall through error trap until a mode worksr If EGA, then check pages to see whether more than 64K Reset text mode SetPalette = SetPalette Mixes palette colors in an array. Mix only if the adapter supports color attributes Red, green, blue, and intense in four bits of a byte= Bits: 0irgb Change the order of FOR loops to change color mix EGA red, green, and blue colors in 6 bits of a byte Capital letters repesent intense, lowercase normale Bits: 00rgbRGB Change the order of FOR loops to change color mix VGA colors in 6 bits of 3 bytes of a long integer Bits: 0 00 Change the order of FOR loops to change color mix Decrease the STEP and increase VC.Colors to get more colors Assign colors TorusDefine = TorusDefine Define the attributes of a Torus based on information from the= user, the video configuration, and the current screen mode. Constants for key codes and column positions= Display key instructions UP .............. Move to next field DOWN ........ Move to previous field LEFT ......... Rotate field value up RIGHT ...... Rotate field value down ENTER .... Start with current values ESCAPE .................. Quit Torus Block cursor. Display fields Thickness" [ # ]" Panels per Section [ ## ] Sections per Torus [ ## ] Tilt around Horizontal Axis" [ ### ]" Tilt around Vertical Axis" [ ### ]" Tile Border" [ & ] Screen Mode" [ ## ] Skip field 10 if there's only one value Update field values and position based on keystrokes Put cursor on field Get a key and strip null off if it's an extended code End program Adjust field location Adjust field Thickness Panels Sections Horizontal tilt Vertical tilt Border Available screen modes Set configuration data for graphics mode Draw Torus if ENTER Remove cursor Set different delays depending on moded Get new random seed for this torusm TorusCalc = TorusCalc Calculates the x and y coordinates for each tile. Calculate sine and cosine of the angles of rotation Calculate the angle to increment between one tile and the next. First calculate the first point, which will be used as a reference= for future points. This point must be calculated separately because it is both the beginning and the end of the center seam.e Starting point is x1 of 0 section, 0 panel last Also x2 of tile on last section, 0 panel ' | | last x3|x4 Also x3 of last section, last panel x2|x1 | 0' Also x4 of 0 section, last panel A similar pattern is used for assigning all points of Torus Starting Y point is 0 (center)a Only one z coordinate is used in sort, so other three can be ignored Starting at first point, work around the center seam of the Torus.e Assign points for each section. The seam must be calculated separately because it is both beginning and of each section. X, Y, and Z elements of equation Now start at the first seam between panel and assign points for each section of each panel. The outer loop assigns the initialr point for the panel. This point must be calculated separately since it is both the beginning and the end of the seam of panels. X, Y, and Z elements of equationn Assign X points for each panel Current ring, current sidea Current ring minus 1, next side Current ring minus 1, previous side Current ring, previous side Assign Y points for each panel Z point for each panel The inner loop assigns points for each ring (except the first) on the current side.n Display section and panel Erase message TorusColor = TorusColor Assigns color atributes to each tile. Skip first and last atributes Cycle through each attribute until all tiles are done TorusSort = TorusSort Sorts the tiles of the Torus according to their Z axis (distancet from the "front" of the screen). When the tiles are drawn, thec farthest will be drawn first, and nearer tiles will overwrite them to give a three-dimensional effect. To make sorting as fast as possible, the Quick Sort algorithm ise used. Also, the array of tiles is not actually sorted. Instead ae parallel array of tile indexes is sorted. This complicates things, but makes the sort much faster, since two-byte integers are swapped instead of 46-byte Tile variables.n If only one, compare and swap if necessary= The SUB procedure only stops recursing when it reaches this point If more than one, separate into two random groups Sort one group Find the largest Find the smallest Swap them if necessary Now get the other group and recursively sort it TorusDraw = TorusDraw Draws each tile of the torus starting with the farthest and working to the closest. Thus nearer tiles overwrite farther tiles to give a three-dimensional effect. Notice that the index of the tile being drawn is actually the index of an array of indexes. This is because the array of tiles is not sorted, but the parallel array of indexes is. See TorusSort for an explanation of how indexes are sorted. TileDraw = TileDraw Draw and optionally paint a tile. Tiles are painted if there are more than two atributes and if the inside of the tile can be found. Set border Draw and quit for two-color modes For other modes, draw in the border color (which must be different than any tile color) See if tile is large enough to be painted Black out the center to make sure it isn't paint color Paint tile black so colors of underlying tiles can't interfere= Fill with the final tile color. A border drawn with the background color looks like a border. One drawn with the tile color doesn't look like a border. Redraw with the final borderr TorusRotate = TorusRotate Rotates the Torus. This can be done more successfully in some modes than in others. There are three methods: 1. Rotate the palette colors assigned to each attribute 2. Draw, erase, and redraw the torus (two-color modes)e 3. Rotate between two palettes (CGA and MCGA screen 1)e Note that for EGA and VGA screen 2, methods 1 and 2 are both used.s For EGA and higher rotate colors through palette= Argument determines whether to start at next color, first color,= or random color Set last color to smaller of last possible color or last tile If color is too low, rotate to endp Set last attribute Last for two-color modes Smaller of last color or next-to-last attribute Cycle through attributes, assigning colorsi For two-color screens, the best we can do is erase and redraw the torus Set all tiles to color Draw Torus Toggle between color and background For CGA or MCGA screen 1, toggle palettes using the COLOR statement (these modes do not allow the PALETTE statement)t Delay = Delay Delay based on time so that wait will be the same on any processor. Notice the check for negative numbers so that the delay won't freeze at midnight when the delay could become negative.w CountTiles = CountTiles Displays number of the tiles currently being calculated or sorted. Erase previous If positive, display - give negative values to erase= Tile " Message = Message Displays a status message followed by blinking dots. White Blink . . . White SetConfig = SetConfig Sets the correct values for each field of the VC variable. They vary depending on Mode and on the current configuration.e Four-color graphics for CGA, EGA, VGA, and MCGA Two-color medium-res graphics for CGA, EGA, VGA, and MCGA Two-color high-res graphics for HerculesG 16-color medium-res graphics for EGA and VGAV 16-color high-res graphics for EGA and VGAG 16- or 4-color very high-res graphics for EGA and VGA Two-color high-res graphics for EGA or VGA monochrome Two-color very high-res graphics for VGA and MCGA Note that for VGA screens 11, 12, and 13, more colors are available, depending on how the colors are mixed. 16-color very high-res graphics for VGA 256-color medium-res graphics for VGA and MCGAs Inside = Inside Finds a point, T.xc and T.yc, that is mathematically within a tile. Then check to see if the point is actually inside. Because of the jagged edges of tiles, the center point is often actually insidee very thin tiles. Such tiles will not be painted, This causess imperfections that are often visible at the edge of the Torus. Return FALSE if a center point is not found inside a tile.r Find an inside point. Since some tiles are triangles, the diagonal center isn't good enough. Instead find the center by drawing a diagonal from the center of the outside to a bottom corner.g If we're on a border, no need to fill Find highest and lowest Y on the tile Convert coordinates to pixels Search for top and bottom tile borders until we either find them both, or check beyond the highest and lowest points.e Search up Search down If top and bottom are found, we're inside DegToRad = DegToRad Convert degrees to radians, since BASIC trigonometric functions require radians.t Rotated = Rotated Returns the Current value adjusted by Inc and rotated if necessary= so that it falls within the range of Lower and Upper. Calculate the next value Handle special cases of rotating off top or bottom=