--- /dev/null
+ Simple Graphics Package (SGP) Documentation
+ -------------------------------------------
+
+
+ Documentation and Software Written by Kevin Rosenberg
+ Copyright (c) 1984, Kevin Rosenberg
+
+
+
+
+
+ OVERVIEW
+ --------
+
+ +------------------------+
+ | World Coordinate level |
+ +-----------+------------+
+ |
+ |
+ +------------+-------------+
+ | Convert to Normalized |
+ | device coordinates (NDC) |
+ +------------+-------------+
+ |
+ |
+ +------+-------+ +--------------+
+ | Segmentation +-----------+ Disk Storage |
+ +------+-------+ +--------------+
+ |
+ +------------+-------------+
+ | Convert to Physical |
+ | device coordinates (PDC) |
+ +--------------------------+
+
+
+World Coordinate Level
+----------------------
+ initgrf2 () Initialize 2 dimensional graphics
+ termgrf2 () Terminate 2 dimensional graphics
+ window2 (xmin, ymin, xmax, ymax) Set window for world coord
+ viewprt2 (xmin, ymin, xmax, ymax) Viewport for window in NDC
+ moveabs2 (x, y) Move graphics cursor
+ moverel2 (dx, dy)
+ pntabs2 (x, y) Plot point at current position
+ pntrel2 (dx, dy)
+ lineabs2 (x, y) Draw line from current point to point
+ linerel2 (dx, dy)
+ markabs2 (x, y) Draw marker at current position
+ markrel2 (dx, dy)
+ polylnabs (x[], y[], n) Draw a set of lines
+ polylnrel (dx[]. dy[]. n)
+ wc_to_ndc (xwc, ywc, xndc, yndc) Convert from world coord to NDC
+ ndc_to_wc (xndc, yndc, xwc, ywc) Convert from NDC to world coord
+ drawtext (str) Draw text string at current positon
+
+ INTERNAL:
+ calc_map () Calculate wc to ndc factors
+ clip(rectangle[4], x1, y1, x2, y2) Clip a line againt rectangle
+
+
+Normalized Coordinate level
+--------------------------
+ stylus (x, y, beam) Draw a line from current position
+ opendevice (device) Open a device for output
+ closedevice (device) Close a device for output
+ flushdevice (device) Put all pending data on device
+ inqdev (device, xmax, ymax) Return data on device
+ setcolor (color) Set current drawing color
+ setlinestyle (style) Set current line style
+ setlinewidth (width) Set current line width
+ settext (h, w, orientation, dir, font) Set text attributes
+ settextclr (foreground, background) If back=-1, then transparent backg
+ inqtext(h, w, o, dir, font, fore, back) Get current text attributes
+ charndc (c, xndc, yndc) Draw char at NDC position
+ textndc (str, xndc, yndc) Draw text string at NDC position
+
+ setmarker (marker_type, color) Set marker attibutes
+ markndc (xndc, yndc) Draw marker at NDC position
+
+ ndc_to_pdc (device, xndc, yndc, xpdc, ypdc)
+ savescrn (filename, xmin, ymin, xmax, ymax)
+ readscrn (filename)
+
+Physical Device Level
+---------------------
+ crtdot (x, y, c)
+ crtline (x1, y1, x2, y2, color, style)
+ wrtchar (char, x, y, dotfunc())
+ wrttext (str, x, y, dotfunc())
+
+ readblock (array, xmin, ymin, xmax, ymax)
+ writeblock (array, xmin, ymin, mode)
+
+ prtdot (x, y, c)
+ prtline (func, x1, y1, x2, y2, color, style)
+
+
+Input Functions
+---------------
+Physical device level
+ joystk (sticknum, x, y)
+
+Normalized Coordinate level
+ readloc (xndc, yndc)
+ inithcur (height, width, color) Initialize haircross cursor
+ movhcurabs (xndc, yndc) Move haircross cursor to point
+ movhcurrel (dxndc, dyndc) Move relatively
+ termhcur () Turn off haircross cursor
+ readpnt (xndc, yndc) Have cursor track joystick
+ User press button at desired point
+
+ DATA STRUCTURES
+ ---------------
+struct DEVICE {
+ int xsize, ysize; Size of device in pixels
+ int xmax, ymax; Maximum coordinates
+ int colormax; Maximum color number of device
+ int style; Current linestyle of device
+ int width; Current width of device
+ int color; Current color of device
+ int curx, cury; Current position
+ int charwidth, charheight; Size of characters in pixels
+ float aspt Aspect ratio Multiple coord
+ int (*dot)(); Dot function for device
+ int (*line)(); Line function for device
+ int mode; Device mode
+};
+
+struct CHARSPEC {
+ float width, height; size of characters in NDC
+ int dirflag, orientflag text direction, character orientation
+ int fore, back; foreground & background color
+};
+
+struct CURRENT {
+ int color;
+ int linestyle;
+ int linewidth;
+ float xndc, yndc;
+}
+
+ Map directly from world coords to physical device coords
+ --------------------------------------------------------
+
+Window: xwmin, xwmax, ywmin, ywmax
+Viewport: xvmin, xvmax, yvmin, yvmax
+Physical: xpmax, ypmax
+
+To convert from wc to ndc:
+ xndc = xvmin + (xwc - xwmin) / (xwmax - xwmin)
+ yndc = yvmin + (ywc - ywmin) / (ywmax - ywmin)
+
+To convert from ndc to pdc:
+ xpdc = xndc * xpmax
+ ypdc = yndc * ypmax
+
+So, for each device set up the following composite transformation:
+ xpdc = xpmax * (xvmin + (xwc - xwmin) / (xwmax - xwmin))
+ ypdc = ypmax * (yvmin + (ywc - ywmin) / (ywmax - ywmin))
+
+ xpdc = xpmax * xvmin + (xwc - xwmin) * (xpmax / (xwmax - xwmin))
+ = xadd + (xwc - xsub) * xfact
+
+Characters
+----------
+ Fonts:
+ NORMAL Regular character set
+ BOLD Overstike chars with x offset by 1 pixel
+ ITALICS Shear characters along character height
+
+ NORMAL BOLD ITALICS
+ X XX X
+ XXX XXXX XXX
+ X X XX XX X X
+ X X XX XX X X
+ XXXXX XXXXXX XXXXX
+ X X XX XX X X
+ X X XX XX X X
+
+
+
+
+
projects / ctsim.git / blobdiff