Programmer 7500

home *** CD-ROM | disk | FTP | other *** search

/ Programmer 7500 / MAX_PROGRAMMERS.iso / CLIPPER / MISC / NOTES210.ZIP / FG-2-10.TXT

Wrap

Text File | 1992-01-31 | 36.5 KB | 1,208 lines

Release Notes Fastgraph (tm) v2.10 Fastgraph/Light (tm) v1.10 January 31, 1992 Ted Gruber Software PO Box 13408 Las Vegas, NV 89112 (702) 735-1980 voice (702) 735-4603 FAX (702) 796-7134 BBS 72000,1642 CIS Copyright (c) 1991,1992 Ted Gruber Software. All Rights Reserved. ------------------------------------------------------------------------------ Introduction ------------------------------------------------------------------------------ Fastgraph 2.10 offers two new video modes, new routines, new utilities, and optimizations and improvements to many existing routines. Some of the more important new features are: * Support for "Mode X" (320x240 256-color VGA graphics) and its 320x480 scan-doubled extension * Video page resizing that allows smooth, flicker-free panning * PCX display and creation functions * Logical video pages in conventional, expanded, or extended memory * An improved mode-specific bit map format in video modes 13 to 18 * Routines to read or write a block of video DAC registers * Suspension and resumption of asynchronous music * 43-line and 50-line text mode extensions * Turbo Pascal and Power C support * Updated User's Guide (now with an index) and Reference Manual To illustrate the Fastgraph routines introduced in version 2.10, we've added new example programs. The addition of the new examples has resulted in the resequencing of some of the examples from previous versions of Fastgraph. The correspondence between the old and new example numbers is: FG 2.00/2.01 example numbers FG 2.10 example numbers ---------------------------- ----------------------- 3-5 to 3-8 3-6 to 3-9 5-12 to 5-14 5-14 to 5-16 6-11 to 6-14 6-12 to 6-15 7-4 to 7-10 7-5 to 7-11 9-15 to 9-20 9-16 to 9-21 9-21 to 9-26 9-23 to 9-28 ------------------------------------------------------------------------------ New video modes ------------------------------------------------------------------------------ Fastgraph 2.10 offers two new extended VGA graphics video modes, as summarized in the following table: Mode No. of Page Size Physical Virtual Number Resolution Colors in Bytes Pages Pages ------ ---------- ------ --------- -------- ------- 22 320 x 240 256/256K 76,800 3+ none 23 320 x 480 256/256K 153,600 1+ none Mode 22 is the so-called "mode X" recently described by Michael Abrash in Dr. Dobb's Journal. To our knowledge, Fastgraph is the first commercial graphics library to support this video mode. Mode 22 is appealing because it offers 256 colors, has a 1:1 aspect ratio (i.e., pixels are square), and is very fast. The "+" following the number of physical pages means there is an additional partial video page available. In mode 22, there are three full physical pages (numbered 0 to 2) plus one partial page of 80 pixel rows (page 3). In mode 23, there is one full page (page 0) plus one partial page of 320 pixel rows (page 1). You can safely use the partial pages as long as you don't reference pixel rows beyond the last available row. Also, you cannot make the partial page the visual page. The size of hardware characters in modes 22 and 23 is 8 x 8. This means there are 30 character rows in mode 22 and 60 rows in mode 23. ------------------------------------------------------------------------------ Logical pages ------------------------------------------------------------------------------ In addition to physical and virtual video pages, Fastgraph 2.10 includes logical video pages. Logical pages can be created in any video mode and can exist in conventional memory, expanded memory (EMS), or extended memory (XMS). However, they are not as versatile as physical or virtual pages because the only operations you can perform with logical pages are: * Copy an entire physical or virtual page to a logical page * Copy an entire logical page to a physical or virtual page * Copy an entire logical page to another logical page Three new functions (fg_alloccms, fg_allocems, and fg_allocxms) are provided for creating logical pages in conventional memory, expanded memory, and extended memory, respectively. The fg_freepage function has been modified to release all three types of logical pages. Other new Fastgraph functions that deal with logical pages are summarized in the following section. ------------------------------------------------------------------------------ New mode-specific bit map format for modes 13 to 18 ------------------------------------------------------------------------------ The native EGA and VGA graphics modes (modes 13-18) now use a different format for mode-specific bit maps. In previous versions of Fastgraph, you had to call the fg_drwimage or fg_getimage routines once for each color in the image in these video modes. This is no longer true because these routines allow storage of all colors in a single bit map, just as the other video modes do. The new bit map format is identical to that of mode 9 (see pages 127-129 in the Fastgraph User's Guide). The old format is still supported (it was the same as the mode-independent format in these video modes), but you must now use fg_drawmap and fg_getmap instead of fg_drwimage and fg_getimage. It is our policy to maintain downward compatibility between all versions of Fastgraph. However, we feel the benefits offered by Fastgraph's new EGA and VGA mode-specific bit map format far outweigh the fact that it is different from eariler versions (especially since the fg_drawmap and fg_getmap functions offer the same bit map format as the previous versions of fg_drwimage and fg_getimage). ------------------------------------------------------------------------------ New functions ------------------------------------------------------------------------------ FG_ALLOCCMS Prototype int fg_alloccms (int page_number); Description The fg_alloccms routine creates a logical page in conventional memory. The amount of memory required depends on the current video mode and video buffer dimensions. Parameters page_number is the number by which the logical page will be referenced. It must be between 1 and 63. Return value 0 = logical page created in conventional memory -2 = invalid page number -3 = page already created, or page exists as a physical or virtual page -4 = insufficient expanded memory to create the page Restrictions This routine has no effect if page_number references a physical or virtual video page. The only function you can perform with logical pages is copying one entire page to another (with fg_copypage). See also fg_allocems, fg_allocxms, fg_copypage, fg_freepage Examples 8-9 ------------------------------------------------------------------------------ FG_ALLOCEMS Prototype int fg_allocems (int page_number); Description The fg_allocems routine creates a logical page in expanded memory (EMS). The amount of memory required depends on the current video mode and video buffer dimensions. Parameters page_number is the number by which the logical page will be referenced. It must be between 1 and 63. Return value 0 = logical page created in expanded memory -1 = Expanded Memory Manager not initialized -2 = invalid page number -3 = page already created, or page exists as a physical or virtual page -4 = insufficient expanded memory to create the page Restrictions This routine has no effect if page_number references a physical or virtual video page. Before using this routine, you must use the fg_initems routine to initialize the Expanded Memory Manager. The only function you can perform with EMS logical pages is copying one entire page to another (with fg_copypage). See also fg_alloccms, fg_allocxms, fg_copypage, fg_freepage, fg_initems Examples 8-9 ------------------------------------------------------------------------------ FG_ALLOCXMS Prototype int fg_allocxms (int page_number); Description The fg_allocxms routine creates a logical page in extended memory (XMS). The amount of memory required depends on the current video mode and video buffer dimensions. Parameters page_number is the number by which the logical page will be referenced. It must be between 1 and 63. Return value 0 = logical page created in extended memory -1 = XMS driver not present -2 = invalid page number -3 = page already created, or page exists as a physical or virtual page -4 = insufficient extended memory to create the page Restrictions This routine has no effect if page_number references a physical or virtual video page. Before using this routine, you must use the fg_initxms routine to initialize the XMS device driver. The only function you can perform with XMS logical pages is copying one entire page to another (with fg_copypage). See also fg_alloccms, fg_allocems, fg_copypage, fg_freepage, fg_initxms Examples 8-9 ------------------------------------------------------------------------------ FG_BOX Prototype void fg_box (int minx, int maxx, int miny, int maxy); Description The fg_box routine draws a hollow rectangle in screen space or character space, with respect to the clipping region. The width of the rectangle's edges is one pixel unless changed with the fg_boxdepth routine. Parameters minx is the x coordinate of the rectangle's left edge. maxx is the x coordinate of the rectangle's right edge. It must be greater than or equal to the value of minx. miny is the y coordinate of the rectangle's top edge. maxy is the y coordinate of the rectangle's bottom edge. It must be greater than or equal to the value of miny. Return value none Restrictions This routine has no effect in text video modes See also fg_boxdepth, fg_rect Examples 6-11, 11-7 ------------------------------------------------------------------------------ FG_BOXDEPTH Prototype void fg_boxdepth (int xwidth, int ywidth); Description The fg_boxdepth routine defines the depth of rectangles drawn with the fg_box routine. The fg_setmode routine initializes the box depth to one pixel in each direction. Parameters xdepth is the width in pixels of the rectangle's left and right sides. It must be greater than zero. ydepth is the width in pixels of the rectangle's top and bottom sides. It must be greater than zero. Return value none Restrictions none See also fg_box Exmaples 6-11 ------------------------------------------------------------------------------ FG_COPYPAGE Prototype void fg_copypage (int source_page, int dest_page); Description The fg_copypage routine transfers the contents of one video page to another. The pages may be physical, virtual, or logical video pages. The call fg_copypage(source,dest); is equivalent to fg_transfer(0,fg_getmaxx(),0,fg_getmaxy(),0,fg_getmaxx(),source,dest); Parameters source_page is the source video page number. It must be between 0 and 63. dest_page is the destination video page number. It must be between 0 and 63. Return value none Restrictions If source_page and dest_page both reference logical pages, the pages must exist in the same type of memory. For example, you cannot copy a logical page in extended memory to a logical page in conventional memory. See also fg_alloccms, fg_allocems, fg_allocxms, fg_initems, fg_initxms, fg_transfer Examples 8-9, 9-22 ------------------------------------------------------------------------------ FG_DISPPCX Prototype int fg_disppcx (char *filename, int flags); Description The fg_disppcx routine displays an image stored in a PCX file. The image will be positioned such that its upper left corner is at the graphics cursor position of the active video page. Parameters filename is the name of the PCX file. A device and path name may be included as part of the file name. The file name must be terminated by a null character (that is, a zero byte). flags is a bit mask that controls how the image is displayed. Bit 0 0 = use palette values stored in the PCX file 1 = use the current palette settings Bits 1-15 are reserved for future use and should be zero. Return value 0 = success 1 = file not found 2 = file is not a PCX file Restrictions PCX files are specific to certain video modes. The table below summarizes the compatible video modes for PCX files. If PCX file was You can display created in mode it in these modes --------------- ----------------- 4 or 5 4 or 5 6 or 11 6, 11, 13 to 18 9 9 13 to 18 13 to 18 19 19 to 23 Displaying a PCX file at a lower resolution (for example, a 640x480 PCX file at 320x200) will truncate the display on the right and on the bottom. This effectively displays the upper left corner of the PCX file. If you attempt to display a PCX file in an incompatible video mode, fg_disppcx will still display something, but it will be garbled. The fg_disppcx routine has no effect in text video modes or in the Hercules low-resolution graphics mode. See also fg_dispfile, fg_makepcx Examples 9-15 ------------------------------------------------------------------------------ FG_GETATTR Prototype int fg_getattr (int row, int column); Description The fg_getattr routine returns the character attribute stored at the specified position on the active video page. Parameters row is the row number of the character cell to examine, between 0 and 24 (unless you've called fg_setlines to increase the number of lines per page). column is the column number of the character cell to examine, between 0 and 39 for 40-column modes, or between 0 and 79 for 80-column modes. Return value The character attribute stored at the specified position. Restrictions This routine has no effect in graphics video modes. See also fg_getchar, fg_getimage Examples 7-4 ------------------------------------------------------------------------------ FG_GETCHAR Prototype int fg_getchar (int row, int column); Description The fg_getchar routine returns the character value stored at the specified position on the active video page. Parameters row is the row number of the character cell to examine, between 0 and 24 (unless you've called fg_setlines to increase the number of lines per page). column is the column number of the character cell to examine, between 0 and 39 for 40-column modes, or between 0 and 79 for 80-column modes. Return value The character value stored at the specified position. Restrictions This routine has no effect in graphics video modes. See also fg_getattr, fg_getimage Examples 7-4 ------------------------------------------------------------------------------ FG_GETDACS Prototype void fg_getdacs (int start, int count, char *values); Description The fg_getdacs routine retrieves the red, green, and blue color components of a contiguous block of video DAC registers. Each color component is a value between 0 and 63; increasing values produce more intense colors. Reading many DAC registers with fg_getdacs is considerably faster than doing so individually with fg_getrgb. Parameters start is the starting video DAC register number, between 0 and 255. count is the number of contiguous DAC registers to retrieve. If the sum of start and count exceeds 255, the register numbers wrap around and resume with register number 0. values is the array that will receive the color components. The first three bytes of this array receive the red, green, and blue components for DAC register start, the next three bytes receive the components for register start+1, and so forth. The size of the values array must be at least 3*count bytes. Return value none Restrictions This routine has no effect in text video modes, or in any graphics video mode numbered 16 or below (because these video modes do not use DAC registers). See also fg_getrgb, fg_setdacs, fg_setrgb Examples 5-12 ------------------------------------------------------------------------------ FG_GETLINES Prototype int fg_getlines (void); Description The fg_getlines routine returns the number of text rows per video page for the current video mode. Parameters none Return value The number of text rows per video page for the current video mode. Restrictions none See also fg_setlines Examples 3-5 ------------------------------------------------------------------------------ FG_IMAGESIZ Prototype long fg_imagesiz (int width, int height); Description The fg_imagesiz routine determines the number of bytes required to store a mode-specific bit-mapped image of specified dimensions. Parameters width specifies the image width in pixels. height specifies the image height in pixels. Return value The number of bytes required to store a mode-specific bit-mapped image of the specified size in the current video mode. Restrictions none See also fg_clpimage, fg_drwimage, fg_flpimage, fg_getimage, fg_revimage Examples 9-20 ------------------------------------------------------------------------------ FG_INITEMS Prototype int fg_initems (void); Description The fg_initems routine initializes expanded memory (EMS) for use with Fastgraph. Parameters none Return value 0 = success -1 = Expanded Memory Manager not installed or not accessible Restrictions This routine requires an Expanded Memory Manager (EMM) that conforms to the Lotus/Intel/Microsoft Expanded Memory Specification (LIM-EMS) version 3.2 or later. On 80386 and 80486 systems, the EMM386.EXE device driver supplied with DOS 5.0 can be used to treat some or all of extended memory as expanded memory. The Expanded Memory Manager uses interrupt 67h. As a result, this vector is not available for application programs. See also fg_allocems, fg_initxms Examples 8-9 ------------------------------------------------------------------------------ FG_INITXMS Prototype int fg_initxms (void); Description The fg_initxms routine initializes extended memory (XMS) for use with Fastgraph. Parameters none Return value 0 = success -1 = XMS driver not installed or not accessible Restrictions This routine requires an external device driver that conforms to the Lotus/Intel/Microsoft/AST eXtended Memory Specification (XMS) version 2.0, such as HIMEM.SYS. This driver requires an 80286, 80386, or 80486 system. See also fg_allocxms, fg_initems Examples 8-9 ------------------------------------------------------------------------------ FG_MAKEPCX Prototype int fg_makepcx (int minx, int maxx, int miny, int maxy, char *filename); Description The fg_makepcx routine creates a PCX file from the specified rectangular region of the active video page. The region's extremes are expressed in screen space units. Parameters minx is the x coordinate of the region's left edge. Its value is reduced to a byte boundary if necessary. maxx is the x coordinate of the region's right edge. It must be greater than or equal to the value of minx. miny is the y coordinate of the region's top edge. maxy is the y coordinate of the region's bottom edge. It must be greater than or equal to the value of miny. filename is the name of the PCX file to create. A device and path name may be included as part of the file name. The file name must be terminated by a null character (that is, a zero byte). If an identically named file already exists, it is overwritten. Return value 0 = success 1 = file not created Restrictions The fg_makepcx routine has no effect in text video modes or in the Hercules low-resolution graphics mode. Refer to the description of the fg_disppcx routine for information about PCX file compatibility between different video modes. In the Tandy/PCjr 16-color graphics mode (mode 9) and the native EGA graphics modes (modes 13 through 16), the palette registers are not readable. Hence, fg_makepcx will use the default palette settings when used in these video modes. See also fg_disppcx Examples 9-15 ------------------------------------------------------------------------------ FG_MAPRGB Prototype int fg_maprgb (int red, int green, int blue); Description The fg_maprgb routine maps six-bit red, green, and blue color components into a suitable palette value for the current video mode. You can then pass this value to the fg_palette routine. Parameters red, green, and blue respectively specify the color's red, green, and blue components. These values must be between 0 and 63; increasing values produce more intense colors. Return value The mode-specific palette value for the specified color components. Restrictions This routine is meaningful only in 16-color graphics video modes. See also fg_palette, fg_palettes, fg_setrgb Examples 5-13 ------------------------------------------------------------------------------ FG_RESIZE Prototype void fg_resize (int width, int height); Description The fg_resize routine changes the dimensions of a video page in EGA and VGA graphics modes. Parameters width specifies the new video page width in pixels. height specifies the new video page height in pixels. Return value none Restrictions The size of a video page is constrained only by the amount of memory on your video adapter. Increasing the size of a video page proportionally reduces the number of physical pages available. For example, increasing the page size from 320 x 200 to 640 x 400 decreases the number of video pages from 8 to 2. When you call fg_resize, the visual page must be page 0. If you have created any virtual or logical video pages, you must release them with fg_freepage before calling fg_resize, and then create them again afterward. If you have initialized the mouse (with fg_mouseini), joysticks (with fg_initjoy), expanded memory (with fg_initems), or extended memory (with fg_initxms), you should call re-initialize these resources after calling fg_resize. Most mouse drivers expect a fixed video page width, so the mouse cursor may become distorted after resizing video pages. The fg_setmode routine re-establishes the dimensions of a video page to the default resolution for the selected video mode. This routine is meaningful only in the native EGA graphics modes (13 to 16), native VGA graphics modes (17 and 18), and extended VGA graphics modes (20 to 23). It has no effect in other video modes. See also fg_pan Examples 8-10, 11-7 ------------------------------------------------------------------------------ FG_RESUME Prototype void fg_resume (void); Description The fg_resume routine restarts asynchronous music previously suspended by the fg_suspend routine. It has no effect if there is no suspended music. Parameters none Return value none Restrictions none See also fg_musicb, fg_suspend Examples 13-8 ------------------------------------------------------------------------------ FG_SETDACS Prototype void fg_setdacs (int start, int count, char *values); Description The fg_setdacs routine defines the values of a block of contiguous video DAC registers by specifying their red, green, and blue color components. Defining many DAC registers with fg_setdacs is considerably faster than doing so individually with fg_setrgb. Parameters start is the starting video DAC register number, between 0 and 255. count is the number of contiguous DAC registers to define. If the sum of start and count exceeds 255, the register numbers wrap around and resume with register number 0. values is the array containing the color components. The first three bytes of this array must contain the red, green, and blue components for DAC register start, the next three bytes contain the components for register start+1, and so forth. The size of the values array must be at least 3*count bytes. Return value none Restrictions This routine has no effect in text video modes, or in any graphics video mode numbered 16 or below (because these video modes do not use DAC registers). See also fg_getdacs, fg_getrgb, fg_setrgb Examples 5-12 ------------------------------------------------------------------------------ FG_SETLINES Prototype void fg_setlines (int lines); Description The fg_setlines routine extends an 80-column text mode to 25, 43, or 50 lines per screen. The fg_setmode routine sets the number of lines to 25 when establishing an 80-column text mode. Parameters lines is the number of text rows per screen. On EGA systems, the value of lines must be 25 or 43. On MCGA systems, it must be 25 or 50. On VGA systems, it must be 25, 43, or 50. Any other value is ignored. Before calling fg_setlines, you should call fg_testmode with pages=0 to see if the user's system supports the number of rows needed. Return value none Restrictions This routine is only meaningful when running in 80-column text modes on EGA or VGA systems (in other cases it does nothing). When you call fg_setlines, the visual page must be page 0. Calling fg_setlines makes the text cursor visible. If you have initialized the mouse (with fg_mouseini), joysticks (with fg_initjoy), expanded memory (with fg_initems), or extended memory (with fg_initxms), you should call re-initialize these resources after calling fg_setlines. See also fg_getlines, fg_testmode Examples 3-5 ------------------------------------------------------------------------------ FG_SUSPEND Prototype void fg_suspend (void); Description The fg_suspend routine suspends asynchronous music previously started by the fg_musicb routine. It has no effect if there is no asynchronous music in progress. Parameters none Return value none Restrictions A program must not exit to DOS with music suspended. You must call fg_hush to cancel the music first. See also fg_hush, fg_musicb, fg_resume Examples 13-8 ------------------------------------------------------------------------------ Optimizations and improvements to existing routines ------------------------------------------------------------------------------ In video modes that offer virtual pages, Fastgraph now allows up to 64 pages instead of 16. Usually, the amount of RAM available on your system will limit the number of virtual pages to a smaller number, however. Video modes 20 and 21 are as much as 16 times faster than in Fastgraph version 2.00 and 2.01. In fact, mode 20 is now three to four times faster than mode 19. Graphics in the native EGA and VGA modes (modes 13 to 18) are considerably faster when the mouse is active. The fg_clpimage and fg_flpimage routines no longer extend the clipping limits to byte boundaries in the native EGA and VGA graphics modes. These routines now clip to the exact limits specified in fg_setclip. The fg_dispfile routine now displays any size pixel run file. Previously, pixel run files were limited to 64K bytes. The fg_freepage routine releases virtual pages or logical pages. Logical pages may be in conventional memory, expanded memory (EMS), or extended memory (XMS). The fg_getmap routine in the large model libraries now works properly in video modes 20 and 21. The fg_rect and fg_clprect routines are nearly twice as fast in the native EGA and VGA graphics modes than in previous versions. The fg_tcxfer routine is over eight times faster in the native EGA and VGA graphics modes than in previous versions. The 640x480 VGA graphics modes (17 and 18) formerly offered one physical page and no virtual pages. These modes now offer a partial second partial page (page 1) containing 320 pixel rows. However, you cannot use the fg_setvpage or the fg_text routines on the partial video page. Fastgraph no longer uses interrupt 64h. Other miscellaneous code optimizations have been applied to several Fastgraph routines. ------------------------------------------------------------------------------ EDITSPR utility ------------------------------------------------------------------------------ The EDITSPR utility changes all pixel runs of one color to another color in an image file stored in Fastgraph's standard pixel run (.SPR) format. The syntax of the command for invoking the EDITSPR utility from the DOS command prompt is EDITSPR <input_file> <output_file> where <input_file> is the name of the original image file, and <output_file> is the name of the new image file. EDITSPR does not modify the <input_file> in any way, but it will overwrite the <output_file> if an identically named file exists in the current directory. After it reads the pixel runs from the <input_file>, EDITSPR will perform the requested color changes. It does this iteratively by asking for an old color value followed by a new color value (each value must be between 0 and 255). EDITSPR then finds the pixel runs of the old color value and changes them to the new color value. Following this, EDITSPR displays a message stating how many pixel runs it changed. This process repeats until you enter a negative number for either color value. EDITSPR will next combine adjacent pixel runs of like colors. For example, suppose the original image file contained a color 1 pixel run of length 50, followed by a color 2 pixel run of length 20, followed by another color 1 pixel run of length 10. If you changed all color 2 pixel runs to color 1, EDITSPR will combine these three pixel runs into a single run of length 80. Finally, EDITSPR will close the <output_file>. ------------------------------------------------------------------------------ GrabRGB utility ------------------------------------------------------------------------------ The GrabRGB utility is a terminate and stay resident program (TSR) to capture the current red, green, and blue color components of video DAC registers in the 256-color MCGA and VGA graphics modes. You can use GrabRGB together with Fastgraph's SNAPSHOT utility to preserve the original colors of a captured image (for more information on SNAPSHOT, see Appendix A of the "Fastgraph User's Guide"). To load GrabRGB, just enter the command GRABRGB at the DOS prompt. After GrabRGB loads, control returns to the DOS prompt. At this point, you can use any method whatsoever to display a 256-color graphic image and then press the Alt and right shift keys at the same time to capture the current DAC settings. You don't need to load GrabRGB for each image, just once per system boot. GrabRGB uses about 15,000 bytes of conventional memory once loaded. To illustrate the use of GrabRGB, suppose you have drawn and saved a 256-color image with a commercial paint program, and you want to incorporate this image into a Fastgraph application. Once you load SNAPSHOT and GrabRGB, activate the paint program and retrieve your image. Then press the Alt and left shift keys to capture the image with SNAPSHOT. After SNAPSHOT's success tone (three quick medium-pitched sounds), press Alt and right shift to capture the RGB components of each DAC register with GrabRGB, and wait for GrabRGB's success tone. Finally, exit the paint program and return to the DOS prompt. The sequence described in the preceding paragraph will write the RGB color components for each DAC register to a file named GRABRGB.nnn in the current directory. The file type "nnn" will be the first sequence of digits that does not result in a duplicate file name. That is, if there are no GrabRGB output files in the current directory, GrabRGB will use the file name GRABRGB.000. The next time you use GrabRGB, it will store the RGB information in GRABRGB.001, then GRABRGB.002, and so forth. If you rename or delete one of these files, GrabRGB will again use that file name. For example, if you delete GRABRGB.000 but keep GRABRGB.001, GrabRGB will next use the file name GRABRGB.000. If for some reason GrabRGB is unable to obtain the RGB components of each DAC register, it will produce its error tone (a single low-pitched sound). The most common cause of this is trying to capture an image from a text video mode, or from a graphics video mode with fewer than 256 colors. It will also occur if there is insufficient disk space or if all 1,000 output file names are already being used. Each line in the output file created by GrabRGB is of the form: nnn,rr,gg,bb, where "nnn" is a DAC register index (between 0 and 255), "rr" is the red component of that DAC register, "gg" is the green component, and "bb" is the blue component. Each color component is between 0 and 63. You can edit and reformat these lines as necessary for inclusion in a C initializer list, a QuickBASIC or FORTRAN data statement, or a Turbo Pascal array-type constant list. Such an array of RGB components, but without the "nnn" indices, is in the format expected by fg_getdacs. By default, GrabRGB captures information for all 256 DAC registers. If you want to consider only the DAC registers with color components different from their original values, just include the /D option when you load GrabRGB (that is, use the command GRABRGB /D). If you specify the /D option and all 256 DACs use their default values, the output file will contain a message stating this. ------------------------------------------------------------------------------ HERCFIX utility ------------------------------------------------------------------------------ The HERCFIX utility allows you to use SNAPSHOT (and perhaps other TSRs) with programs that do not update the BIOS data area when establishing the 720x348 Hercules graphics mode. If you use SNAPSHOT with such a program, SNAPSHOT will think the monochrome text mode (video mode 7) is active and will produce its low-pitched error tone when activated. If this occurs, use HERCFIX to load the application from which you are trying to capture the image. To do this, enter HERCFIX <command> at the DOS prompt, where <command> is the command line that activates the application. For example, suppose you use the command line "PAINTER /H" to run a commercial paint program in Hercules graphics mode. To load the paint program with HERCFIX, you would enter the command "HERCFIX PAINTER /H". For complete information about SNAPSHOT, please refer to Appendix A of the Fastgraph User's Guide.