extgraph.h

These libraries are designed for use with Microsoft Visual C++ version 6.0. Install them by running

/*
 * File: extgraph.h
 * Version: 3.1
 * Last modified on Sat Nov  6 17:28:28 PST 1999 by magi
 * -----------------------------------------------------
 * This interface is the extended graphics interface.
 * It includes all of the facilities in graphics.h, plus
 * several additional functions that are designed to
 * support more sophisticated, interactive graphics.
 */

#ifdef __cplusplus
#pragma message ( "You are compiling in C++ mode which will probably cause compile errors with" )
#pragma message ( "the 'bool' type as well as link errors such as 'undefined external symbol'." )
#pragma message ( "Most likely, you have saved your source code with a name ending in .cpp;" )
#pragma message ( "it needs to end in .c." )
#endif

#ifndef _extgraph_h
#define _extgraph_h

#include "genlib.h"

/* Exported functions */

/* Section 1 -- Basic functions from graphics.h */

#include "graphics.h"

/* Section 2 -- Elliptical arcs */

/*
 * Function: DrawEllipticalArc
 * Usage: DrawEllipticalArc(rx, ry, start, sweep);
 * -----------------------------------------------
 * This procedure draws an elliptical arc.  It is exactly
 * the same in its operation as DrawArc in the graphics.h
 * interface, except that the radius is different along the
 * two axes.
 */

void DrawEllipticalArc(double rx, double ry,
                       double start, double sweep);

/* Section 3 -- Graphical regions*/

/*
 * Functions: StartFilledRegion, EndFilledRegion
 * Usage: StartFilledRegion(density);
 *        . . . other calls . . .
 *        EndFilledRegion();
 * ------------------------------
 * These calls make it possible to draw filled shapes on the
 * display.  After calling StartFilledRegion, any calls to
 * DrawLine and DrawArc are used to create a shape definition
 * and do not appear on the screen until EndFilledRegion is
 * called.  The lines and arcs must be consecutive, in the
 * sense that each new element must start where the last
 * one ended.  MovePen calls may occur at the beginning
 * or the end of the region, but not in the interior. When
 * EndFilledRegion is called, the entire region appears on the
 * screen, with its interior filled in.  The density parameter
 * is a number between 0 and 1 and indicates how the dot density
 * to be used for the fill pattern.  If density is 1, the shape
 * will be filled in a solid color; if it is 0, the fill will be
 * invisible.  In between, the implementation will use a dot
 * pattern that colors some of the screen dots but not others.
 */

void StartFilledRegion(double density);
void EndFilledRegion(void);

/* Section 4 -- String functions */

/*
 * Function: DrawTextString
 * Usage: DrawTextString(text);
 * ----------------------------
 * This function displays the string text at the current point
 * in the current font and size.  The current point is updated
 * so that the next DrawTextString command would continue from
 * the next character position.  The string may not include the
 * newline character.
 */

void DrawTextString(string text);

/*
 * Function: TextStringWidth
 * Usage: w = TextStringWidth(text);
 * ---------------------------------
 * This function returns the width of the text string if displayed
 * at the current font and size.
 */

double TextStringWidth(string text);

/*
 * Function: SetFont
 * Usage: SetFont(font);
 * ---------------------
 * This function sets a new font according to the font string,
 * which is case-independent.  Different systems support different
 * fonts, although common ones like "Times" and "Courier" are often
 * supported.  Initially, the font is set to "Default" which is
 * always supported, although the underlying font is system
 * dependent.  If the font name is unrecognized, no error is
 * generated, and the font remains unchanged.  If you need to
 * detect this condition, you can call GetFont to see if the
 * change took effect.  By not generating an error in this case,
 * programs become more portable.
 */

void SetFont(string font);

/*
 * Function: GetFont
 * Usage: font = GetFont();
 * ------------------------
 * This function returns the current font name as a string.
 */

string GetFont(void);

/*
 * Function: SetPointSize
 * Usage: SetPointSize(size);
 * --------------------------
 * This function sets a new point size.  If the point size is
 * not supported for a particular font, the closest existing
 * size is selected.
 */

void SetPointSize(int size);

/*
 * Function: GetPointSize
 * Usage: size = GetPointSize();
 * -----------------------------
 * This function returns the current point size.
 */

int GetPointSize(void);

/*
 * Text style constants
 * --------------------
 * The constants Bold and Italic are used in the SetStyle
 * command to specify the desired text style.  They may also
 * be used in combination by adding these constants together,
 * as in Bold + Italic.  The constant Normal indicates the
 * default style.
 */

#define Normal  0
#define Bold    1
#define Italic  2

/*
 * Function: SetStyle
 * Usage: SetStyle(style);
 * -----------------------
 * This function establishes the current style properties
 * for text based on the parameter style, which is an integer
 * representing the sum of any of the text style constants.
 */

void SetStyle(int style);

/*
 * Function: GetStyle
 * Usage: style = GetStyle();
 * --------------------------
 * This function returns the current style.
 */

int GetStyle(void);

/*
 * Functions: GetFontAscent, GetFontDescent, GetFontHeight
 * Usage: ascent = GetFontAscent();
 *        descent = GetFontDescent();
 *        height = GetFontHeight();
 * -------------------------------------------------------
 * These functions return properties of the current font that are
 * used to calculate how to position text vertically on the page.
 * The ascent of a font is the distance from the baseline to the
 * top of the largest character; the descent is the maximum
 * distance any character extends below the baseline.  The height
 * is the total distance between two lines of text, including the
 * interline space (which is called leading).
 *
 * Examples:
 *   To change the value of y so that it indicates the next text
 *   line, you need to execute
 *
 *        y -= GetFontHeight();
 *
 *   To center text vertically around the coordinate y, you need
 *   to start the pen at
 *
 *       y - GetFontAscent() / 2
 */

double GetFontAscent(void);
double GetFontDescent(void);
double GetFontHeight(void);

/* Section 5 -- Mouse support */

/*
 * Functions: GetMouseX, GetMouseY
 * Usage: x = GetMouseX();
 *        y = GetMouseY();
 * -------------------------------
 * These functions return the x and y coordinates of the mouse,
 * respectively.  The coordinate values are real numbers measured
 * in inches from the origin and therefore match the drawing
 * coordinates.
 */

double GetMouseX(void);
double GetMouseY(void);

/*
 * Functions: MouseButtonIsDown
 * Usage: if (MouseButtonIsDown()) . . .
 * -------------------------------------
 * This function returns TRUE if the mouse button is currently
 * down.  For maximum compatibility among implementations, the
 * mouse is assumed to have one button.  If the mouse has more
 * than one button, this function returns TRUE if any button
 * is down.
 */

bool MouseButtonIsDown(void);

/*
 * Functions: WaitForMouseDown, WaitForMouseUp
 * Usage: WaitForMouseDown();
 *        WaitForMouseUp();
 * -------------------------------------------
 * The WaitForMouseDown function waits until the mouse button
 * is pressed and then returns.  WaitForMouseUp waits for the
 * button to be released.
 */

void WaitForMouseDown(void);
void WaitForMouseUp(void);

/* Section 6 -- Color support */

/*
 * Function: HasColor
 * Usage: if (HasColor()) . . .
 * ----------------------------
 * This function returns TRUE if the graphics window can display a
 * color image.  Note that this condition is stronger than simply
 * checking whether a color display is available.  Because color
 * windows require more memory than black and white ones, this
 * function will return FALSE with a color screen if there is
 * not enough memory to store a colored image.  On the Macintosh,
 * for example, it is usually necessary to increase the partition
 * size to at least 1MB before color windows can be created.
 */

bool HasColor(void);

/*
 * Function: SetPenColor
 * Usage: SetPenColor(color);
 * --------------------------
 * This function sets the color of the pen used for any drawing,
 * including lines, text, and filled regions.  The color is a
 * string, which will ordinarily be one of the following
 * predefined color names: