pendulum68k/main.c

#include <math.h>
#include "common.h"
#include "pendulum.h"
#include "pendMenu.h"
#include "pendDialog.h"

#define SET_RECT(R,t,l,b,r) \
do { (R).top = (t); (R).left = (l); (R).bottom = (b); (R).right = (r); } while(0)

#define THETA (M_PI / 3)
#define D_THETA (0)
#define MU 0.1
#define LEN 2
#define GRAV 9.8

extern Boolean running = true;
extern Boolean resetting = true;
extern Boolean paused = false;
extern Boolean forceRedraw = false;
extern struct dialog_prefs_t pendPrefs = {
	THETA, D_THETA, MU, LEN, GRAV
};

Rect WINDOW_RECT = {50, 50, 250, 250};
char WINDOW_NAME[] = "\pPendulum";
WindowPtr pendWindow;
struct pendulum_t thePend;
static Rect dragRect; 					/* const */

static void InitMacintosh(void);
static void ExitError(void);
static long HandleEvent(int eventMask);
static void HandleMouseDown(EventRecord *theEvent);
static void WaitTicks(unsigned qty);
static void WindowCreate(void);
static void WindowDrawContent(WindowPtr theWin, double angle, Boolean force);

static int iround(double n) {
	double ipart, fpart;
	int sign;
	
	fpart = modf(n, &ipart);
	sign = (n >= 0 ? 1 : -1);
	if(fabs(fpart) >= 0.5) return (int)(ipart) + sign;
	return (int) ipart;
}

void InitMacintosh(void) {
	MaxApplZone();
	
	InitGraf(&thePort);
	InitFonts();
	InitWindows();
	InitMenus();
	TEInit();
	InitDialogs(0L);
	
	FlushEvents(everyEvent, 0);
	InitCursor();
}

void ExitError(void) {
	SysBeep(1);
	ExitToShell();
}

void WaitTicks(unsigned qty) {
	static long lastTick = 0;
	
	if(qty == 0) return;
	while(--qty) {
		while(lastTick == Ticks) {
			HandleEvent(updateMask);
			HandleEvent(everyEvent);
		}
	}
	
	lastTick = Ticks;
}

long HandleEvent(int eventMask) {
	int			res;
	EventRecord	theEvent;

	HiliteMenu(0);
	SystemTask();			/* Handle desk accessories */
	
	if (!GetNextEvent(eventMask, &theEvent)) return;
	switch (theEvent.what) {
	case mouseDown:
		HandleMouseDown(&theEvent);
		break;
		
	case keyDown:
		if(theEvent.modifiers & cmdKey) {
			MenuEvent(MenuKey(theEvent.message & 0xFF));
		}			
			
		/* FALLTHROUGH */
	case autoKey:
		break;
		
	case activateEvt:
		if(theEvent.modifiers & activeFlag) {
			MenuEditMode(false);
			paused = 0;
		} else {
			MenuEditMode(true);
			paused = 1;
		}
		break;
			
	case updateEvt:
		WindowDrawContent((WindowPtr) theEvent.message, 
			thePend.theta, paused || forceRedraw);
		forceRedraw = false;
		break;
	}
}

void HandleMouseDown(EventRecord *theEvent) {
	WindowPtr	theWindow;
	int			windowCode = FindWindow(theEvent->where, &theWindow);
	
    switch (windowCode) {
	case inSysWindow: 
		SystemClick (theEvent, theWindow);
		break;
	    
	case inDrag:
	  	DragWindow(theWindow, theEvent->where, &dragRect);
		break;
		
	case inMenuBar:
		MenuEvent(MenuSelect(theEvent->where));
		break;
	  	  
	case inContent:
  		if(theWindow != FrontWindow()) {
  			SelectWindow(theWindow);
  		}
		break;
	  	
	case inGoAway:
		if(TrackGoAway(theWindow, theEvent->where)) {
			HideWindow(theWindow);
			running = false;
		}
		break;
	}
}

void WindowCreate(void) {
	pendWindow = NewWindow(0L, &WINDOW_RECT, WINDOW_NAME,
			true, noGrowDocProc, (WindowPtr) -1L, true, 0);
			
	if(!pendWindow) ExitError();
}

void WindowDrawContent(WindowPtr theWin, double angle, Boolean force) {
	static Point lastPoint = {0, 0};
	Rect BallRect = {0, 0, 25, 25};
	Point lineEnd;
	
	lineEnd.h = 100 + iround(75.0 * sin(angle));
	lineEnd.v = 100 + iround(75.0 * cos(angle));
	if(!force &&
		lastPoint.h == lineEnd.h && lastPoint.v == lineEnd.v) {
		return;
	}

	/*HideCursor();*/
	BeginUpdate(theWin);

	EraseRect(&theWin->portRect);
	MoveTo(100, 100);
	LineTo(lineEnd.h, lineEnd.v);
	
	OffsetRect(&BallRect, lineEnd.h - 12, lineEnd.v - 12);
	PaintRoundRect(&BallRect, 25, 25);
	
	EndUpdate(theWin);
	/*ShowCursor();*/
	
	lastPoint.h = lineEnd.h;
	lastPoint.v = lineEnd.v;
}

int main(void) {
	InitMacintosh();
	WindowCreate();
	MenuCreate();
	SetPort(pendWindow);
	
	SET_RECT(dragRect, 4, 24, screenBits.bounds.right-4, 
		screenBits.bounds.bottom-4);
		
	thePend.timestep = 1.0/20.0;
	
	while(running) {
		if(resetting) {	
			thePend.theta = pendPrefs.theta;
			thePend.d_theta = pendPrefs.d_theta;
			thePend.mu = pendPrefs.mu;
			thePend.gl = pendPrefs.grav / pendPrefs.len;
			resetting = false;
		}
		
		if(!paused) {
			InvalRect(&pendWindow->portRect);
			WaitTicks(4);
			pendulum_iter(&thePend);
		} else {
			HandleEvent(everyEvent);
		}
	}
}