/* * File: graphics.c * Version: 3.0 * Last modified on Wed Sep 21 23:53:53 1994 by eroberts * ----------------------------------------------------- * This file implements the graphics.h and extgraph.h interfaces * for the Borland/Windows platform. */#include <stdio.h>#include <stdlib.h>#include <string.h>#include <ctype.h>#include <math.h>#include <conio.h>#include <windows.h>#include <time.h>#include "genlib.h"#include "gcalloc.h"#include "strlib.h"#include "extgraph.h"/* * Parameters * ---------- * DesiredWidth    -- Desired width of the graphics window * DesiredHeight   -- Desired height of the graphics window * DefaultSize     -- Default point size * MaxTitle        -- Maximum window title length * MaxFontName     -- Maximum font name length * MaxFonts        -- Maximum number of fonts * LeftMargin      -- Margin from left of screen to both windows * RightMargin     -- Minimum margin to right of windows * TopMargin       -- Margin from top of screen to graphics window * BottomMargin    -- Minimum margin from bottom of screen to console window * WindowSep       -- Separation between graphics and console windows * ConsoleHeight   -- Height of the console window (pixels) * MinConsoleScale -- Smallest acceptable scale factor for the console * PStartSize      -- Starting size for polygon (must be greater than 1) * MaxColors       -- Maximum number of color names allowed * MinColors       -- Minimum number of colors the device must support * GWClassName     -- Class name of the graphics window * DefaultFont     -- Font that serves as the "Default" font */#define DesiredWidth       7.0#define DesiredHeight      4.0#define DefaultSize       12#define MaxTitle          75#define MaxFontName       50#define MaxFonts         100#define LeftMargin        10#define RightMargin       25#define TopMargin          2#define BottomMargin      30#define WindowSep          5#define ConsoleHeight    110#define MinConsoleScale    0.8#define PStartSize        50#define MaxColors        256#define MinColors         16#define GWClassName "Graphics Window"#define DefaultFont "System"/* * Other constants * --------------- * LargeInt  -- Integer too large for a coordinate value * Epsilon   -- Small arithmetic offset to reduce aliasing/banding * Pi        -- Mathematical constant pi * AnyButton -- Union of all mouse buttons */#define LargeInt 16000#define Epsilon  0.00000000001#define Pi       3.1415926535#define AnyButton (MK_LBUTTON | MK_RBUTTON | MK_MBUTTON)/* * Type: graphicsStateT * -------------------- * This structure holds the variables that make up the graphics state. */typedef struct graphicsStateT {    double cx, cy;    string font;    int size;    int style;    bool erase;    int color;    struct graphicsStateT *link;} *graphicsStateT;/* * Type: fontEntryT * ---------------- * This structure holds the data for a font. */typedef struct {    string name;    int size, style;    int points, ascent, descent, height;    HFONT font;} fontEntryT;/* * Type: regionStateT * ------------------ * The region assembly process has the character of a finite state * machine with the following four states: * *   NoRegion       Region has not yet been started *   RegionStarting Region is started but no line segments yet *   RegionActive   First line segment appears *   PenHasMoved    Pen has moved during definition * * The current state determines whether other operations are legal * at that point. */typedef enum {    NoRegion, RegionStarting, RegionActive, PenHasMoved} regionStateT;/* * Type: colorEntryT * ----------------- * This type is used for the entries in the color table. */typedef struct {    string name;    double red, green, blue;} colorEntryT;/* * Static table: fillList * ---------------------- * This table contains the bitmap patterns for the various density * values.  Adding more patterns to this list increases the * precision with which the client can control fill patterns. * Note that this bitmap is inverted from that used on most * systems, with 0 indicating foreground and 1 indicating background. */static short fillList[][8] = {    { 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF },    { 0x77, 0xDD, 0x77, 0xDD, 0x77, 0xDD, 0x77, 0xDD },    { 0x55, 0xAA, 0x55, 0xAA, 0x55, 0xAA, 0x55, 0xAA },    { 0x88, 0x22, 0x88, 0x22, 0x88, 0x22, 0x88, 0x22 },    { 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 },};#define NFills (sizeof fillList / sizeof fillList[0])/* * Global variables * ---------------- * initialized    -- TRUE if initialization has been done * pauseOnExit    -- TRUE if library should pause when exiting * consoleWindow  -- Window handle for console window * graphicsWindow -- Window handoe for graphics window * gdc            -- Graphics DC (screen) * osdc           -- Offscreen DC (memory backup) * osbits         -- Offscreen bitmap * drawPen        -- Pen used for drawing * erasePen       -- Pen used for erasing * nullPen        -- Pen used for filling * drawColor      -- Color used for drawing * eraseColor     -- Color used for erasing * windowTitle    -- Current window title (initialized statically) * xResolution    -- Horizontal resolution of screen (dots per inch) * yResolution    -- Vertical resolution of screen (dots per inch) * windowWidth    -- Width of graphics window (inches) * windowHeight   -- Height of graphics window (inches) * pixelWidth     -- Width of graphics window (pixels) * pixelHeight    -- Height of graphics window (pixels) * fontTable      -- Table of stored fonts * nFonts         -- Number of fonts in fontTable * currentFont    -- Index of current font in fontTable * regionState    -- Current state of the region * regionDensity  -- Fill density to apply to region * polygonPoints  -- Array of points used in current region * nPolygonPoints -- Number of active points * polygonSize    -- Number of allocated points * polygonBounds  -- Bounding box of polygon * colorTable     -- Table of defined colors * nColors        -- Number of defined colors * previousColor  -- Last color index set * stateStack     -- Stack of graphicStateT blocks * cx, cy         -- Current coordinates     | These * eraseMode      -- Setting of erase flag   | variables * textFont       -- Current font            | consititute * textStyle      -- Current style           | the current * pointSize      -- Current point size      | graphics * penColor       -- Color of pen            | state */static bool initialized = FALSE;static bool pauseOnExit = TRUE;static HWND consoleWindow, graphicsWindow;static HDC gdc, osdc;static HBITMAP osBits;static HPEN drawPen, erasePen, nullPen;static COLORREF drawColor, eraseColor;static PAINTSTRUCT ps;static string windowTitle = "Graphics Window";static double xResolution, yResolution;static double windowWidth = DesiredWidth;static double windowHeight = DesiredHeight;static int pixelWidth, pixelHeight;static fontEntryT fontTable[MaxFonts];static int nFonts;static int currentFont;static regionStateT regionState;static double regionDensity;static POINT *polygonPoints;static int nPolygonPoints;static int polygonSize;static RECT polygonBounds;static HBITMAP fillBitmaps[NFills];static colorEntryT colorTable[MaxColors];static int nColors;static int previousColor;static graphicsStateT stateStack;static double cx, cy;static bool eraseMode;static string textFont;static int textStyle;static int pointSize;static int penColor;static int mouseX, mouseY;static bool mouseButton = FALSE;/* Private function prototypes */static void InitCheck(void);static void InitGraphicsState(void);static void InitDisplay(void);static void InitDrawingTools(void);static void DisplayExit(void);static HWND FindConsoleWindow(void);static BOOL CALLBACK EnumerateProc(HWND window, LPARAM clientData);static void RegisterWindowClass(void);static LONG FAR PASCAL GraphicsEventProc(HWND w, UINT msg,                                         WPARAM p1, LPARAM p2);static void DoUpdate(void);static void DisplayClear(void);static void PrepareToDraw(void);static void DisplayLine(double x, double y, double dx, double dy);static void DisplayArc(double xc, double yc, double rx, double ry,                       double start, double sweep);static void RenderArc(double x, double y, double rx, double ry,                      double start, double sweep);static void DisplayText(double x, double y, string text);static void DisplayFont(string font, int size, int style);static int FindExistingFont(string name, int size, int style);static void SetLineBB(RECT *rp, double x, double y, double dx, double dy);static void SetArcBB(RECT *rp, double xc, double yc,                     double rx, double ry, double start, double sweep);static void SetTextBB(RECT *rp, double x, double y, string text);static void StartPolygon(void);static void AddSegment(int x0, int y0, int x1, int y1);static void DisplayPolygon(void);static void AddPolygonPoint(int x, int y);static void InitColors(void);static int FindColorName(string name);static bool StringMatch(string s1, string s2);static bool PrefixMatch(string prefix, string str);static int RectWidth(RECT *rp);static int RectHeight(RECT *rp);static void SetRectFromSize(RECT *rp, int x, int y, int width, int height);static double Radians(double degrees);static int Round(double x);static double InchesX(int x);static double InchesY(int y);static int PixelsX(double x);static int PixelsY(double y);static int ScaleX(double x);static int ScaleY(double y);static int Min(int x, int y);static int Max(int x, int y);/* Exported entries *//* Section 1 -- Basic functions from graphics.h */void InitGraphics(void){    if (!initialized) {        initialized = TRUE;        ProtectVariable(stateStack);        ProtectVariable(windowTitle);        ProtectVariable(textFont);        InitColors();        InitDisplay();    }    DisplayClear();    InitGraphicsState();}void MovePen(double x, double y){    InitCheck();    if (regionState == RegionActive) regionState = PenHasMoved;    cx = x;    cy = y;}void DrawLine(double dx, double dy){    InitCheck();    switch (regionState) {      case NoRegion:        DisplayLine(cx, cy, dx, dy);        break;      case RegionStarting: case RegionActive:        DisplayLine(cx, cy, dx, dy);        regionState = RegionActive;        break;      case PenHasMoved:        Error("Region segments must be contiguous");    }    cx += dx;    cy += dy;}void DrawArc(double r, double start, double sweep){    DrawEllipticalArc(r, r, start, sweep);}double GetWindowWidth(void){    InitCheck();    return (windowWidth);}double GetWindowHeight(void){    InitCheck();    return (windowHeight);}double GetCurrentX(void){    InitCheck();    return (cx);}double GetCurrentY(void){    InitCheck();    return (cy);}/* Section 2 -- Elliptical arcs */void DrawEllipticalArc(double rx, double ry,                       double start, double sweep){    double x, y;    InitCheck();    x = cx + rx * cos(Radians(start + 180));    y = cy + ry * sin(Radians(start + 180));    switch (regionState) {      case NoRegion:        DisplayArc(x, y, rx, ry, start, sweep);        break;      case RegionStarting: case RegionActive:        RenderArc(x, y, rx, ry, start, sweep);        regionState = RegionActive;        break;      case PenHasMoved:        Error("Region segments must be contiguous");    }    cx = x + rx * cos(Radians(start + sweep));    cy = y + ry * sin(Radians(start + sweep));}/* Section 3 -- Graphical structures */void StartFilledRegion(double grayScale){    InitCheck();    if (regionState != NoRegion) {        Error("Region is already in progress");    }    if (grayScale < 0 || grayScale > 1) {        Error("Gray scale for regions must be between 0 and 1");    }    regionState = RegionStarting;    regionDensity = grayScale;    StartPolygon();}void EndFilledRegion(void){    InitCheck();    if (regionState == NoRegion) {        Error("EndFilledRegion without StartFilledRegion");    }    DisplayPolygon();    regionState = NoRegion;}/* Section 4 -- String functions */void DrawTextString(string text){    InitCheck();    if (regionState != NoRegion) {        Error("Text strings are illegal inside a region");    }    DisplayText(cx, cy, text);    cx += TextStringWidth(text);