Tricks of the Mac Game Programming Gurus/TricksOfTheMacGameProgrammingGurus.iso/Book Chapters/14 - Glypha III/Glypha III source/GlyphaIII Code ƒ/Utilities.c

Text File | 1995-03-24 | 18KB | 506 lines

//============================================================================
//----------------------------------------------------------------------------
//                                    Utilities.c
//----------------------------------------------------------------------------
//============================================================================

// These functions are sort of universal utility functions.  They aren't specific…
// to Glypha per se.  I use these (and others) in many, many games.  Many of them…
// as well are useful for any app you might write for the Mac.

#include "Externs.h"


#define kActive                        0
#define kInactive                    255


GDHandle    thisGDevice;
long        tickNext;


//==============================================================  Functions
//--------------------------------------------------------------  RandomInt

// Takes a short (range) and returns a random number from zero to range - 1.

short RandomInt (short range)
{
    register long    rawResult;

    rawResult = Random();
    if (rawResult < 0L)
        rawResult *= -1L;
    rawResult = (rawResult * (long)range) / 32768L;

    return ((short)rawResult);
}

//--------------------------------------------------------------  RedAlert

// Generic error function.  This is called when there is no hope of recovering
// from the error.  A simple alert is brought up and the text passed in (theStr)
// is displayed.  When the user clicks the Okay button, we quit to the Finder.

void RedAlert (StringPtr theStr)
{
    #define        kRedAlertID        128
    short        whoCares;

    ParamText(theStr, "\p", "\p", "\p");        // Replace ^0 in alert with error mssg.
    whoCares = Alert(kRedAlertID, 0L);            // Bring up alert.
    ExitToShell();                                // Quit to Finder.
}

//--------------------------------------------------------------  FindOurDevice

// Get a handle to the MainDevice (monitor with the Menubar).

void FindOurDevice (void)
{
    thisGDevice = GetMainDevice();
    if (thisGDevice == 0L)                        // If a nil handle is returned...
        RedAlert("\pCouldn't Find Our Device");    // call our universal error alert.
}

//--------------------------------------------------------------  LoadGraphic

// Handy function that loads a PICT graphic, get's its bounds and draws it.
// The port drawn to is assumed the current port.  No scaling is done.

void LoadGraphic (short resID)
{
    Rect        bounds;
    PicHandle    thePicture;

    thePicture = GetPicture(resID);                // Load graphic from resource fork.
    if (thePicture == 0L)                        // Check to see if nil (did it load?)
        RedAlert("\pA Graphic Couldn't Be Loaded");

    HLock((Handle)thePicture);                    // If we made it this far, lock handle.
    bounds = (*thePicture)->picFrame;            // Get a copy of the picture's bounds.
    HUnlock((Handle)thePicture);                // We can unlock the picture now.
    OffsetRect(&bounds, -bounds.left, -bounds.top);    // Offset bounds rect to (0, 0).
    DrawPicture(thePicture, &bounds);            // Draw picture to current port.

    ReleaseResource((Handle)thePicture);        // Dispose of picture from heap.
}

//--------------------------------------------------------------  CreateOffScreenPixMap

// Handles the creation of an offscreen pixmap.  Depth is assumed to be that of the…
// current gDevice.  If the allocation fails (low memory, etc.) we quit to Finder.

void CreateOffScreenPixMap (Rect *theRect, CGrafPtr *offScreen)
{
    CTabHandle    thisColorTable;
    GDHandle    oldDevice;
    CGrafPtr    newCGrafPtr;
    Ptr            theseBits;
    long        sizeOfOff, offRowBytes;
    OSErr        theErr;
    short        thisDepth;

    oldDevice = GetGDevice();
    SetGDevice(thisGDevice);
    newCGrafPtr = 0L;
    newCGrafPtr = (CGrafPtr)NewPtrClear(sizeof(CGrafPort));
    if (newCGrafPtr != 0L)
    {
        OpenCPort(newCGrafPtr);
        thisDepth = (**(*newCGrafPtr).portPixMap).pixelSize;
        offRowBytes = ((((long)thisDepth *
                (long)(theRect->right - theRect->left)) + 15L) >> 4L) << 1L;
        sizeOfOff = (long)(theRect->bottom - theRect->top) * offRowBytes;
        OffsetRect(theRect, -theRect->left, -theRect->top);
        theseBits = NewPtr(sizeOfOff);
        if (theseBits != 0L)
        {
            (**(*newCGrafPtr).portPixMap).baseAddr = theseBits;
            (**(*newCGrafPtr).portPixMap).rowBytes = (short)offRowBytes + 0x8000;
            (**(*newCGrafPtr).portPixMap).bounds = *theRect;
            thisColorTable = (**(**thisGDevice).gdPMap).pmTable;
            theErr = HandToHand((Handle *)&thisColorTable);
            (**(*newCGrafPtr).portPixMap).pmTable = thisColorTable;
            ClipRect(theRect);
            RectRgn(newCGrafPtr->visRgn, theRect);
            ForeColor(blackColor);
            BackColor(whiteColor);
            EraseRect(theRect);
        }
        else
        {
            CloseCPort(newCGrafPtr);
            DisposePtr((Ptr)newCGrafPtr);
            newCGrafPtr = 0L;
            RedAlert("\pCouldn't Allocate Enough Memory");
        }
    }
    else
        RedAlert("\pCouldn't Allocate Enough Memory");

    *offScreen = newCGrafPtr;
    SetGDevice(oldDevice);
}

//--------------------------------------------------------------  CreateOffScreenBitMap

// Creates an offscreen bitmap.  Depth is of course 1 (b & w).  If this function…
// fails to create the bitmap, we post an alert and quit to the Finder.

void CreateOffScreenBitMap (Rect *theRect, GrafPtr *offScreen)
{
    GrafPtr        theBWPort;
    BitMap        theBitMap;
    long        theRowBytes;

    theBWPort = (GrafPtr)(NewPtr(sizeof(GrafPort)));
    OpenPort(theBWPort);
    theRowBytes = (long)((theRect->right - theRect->left + 15L) / 16L) * 2L;
    theBitMap.rowBytes = (short)theRowBytes;
    theBitMap.baseAddr = NewPtr((long)theBitMap.rowBytes *
        (theRect->bottom - theRect->top));
    if (theBitMap.baseAddr == 0L)
        RedAlert("\pCouldn't Create Bitmaps");
    theBitMap.bounds = *theRect;
    if (MemError() != noErr)
        RedAlert("\pCouldn't Create Bitmaps");
    SetPortBits(&theBitMap);
    ClipRect(theRect);
    RectRgn(theBWPort->visRgn, theRect);
    EraseRect(theRect);
    *offScreen = theBWPort;
}

//--------------------------------------------------------------  ZeroRectCorner

// Offset rect to (0, 0).  This means the upper left corner of the rect is
// moved to the origin - to (0, 0) - to the upperleft corner of the port.

void ZeroRectCorner (Rect *theRect)
{
    theRect->right -= theRect->left;    // Move right edge by amount of left.
    theRect->bottom -= theRect->top;    // Move bottom edge by amount of top.
    theRect->left = 0;                    // Can now set left to zero.
    theRect->top = 0;                    // Can set top edge to zero as well.
}

//--------------------------------------------------------------  FlashShort

// This is a simple debugging function that will display the short passed to it…
// in the upper left corner of the screen.  It's a handy way to watch the value…
// of a variable while the program is running.

void FlashShort (short theValue)
{
    GrafPtr            wasPort, tempPort;
    Str255            tempStr;
    Rect            tempRect;

    GetPort(&wasPort);                        // Remember old grafPort.

    tempPort = (GrafPtr)NewPtrClear(sizeof(GrafPort));
    OpenPort(tempPort);                        // Create a new empty port.

    NumToString((long)theValue, tempStr);    // Convert value passed in to a string.
    MoveTo(20, 40);                            // Move the pen to the upperleft corner.
    SetRect(&tempRect, 18, 20, 122, 42);    // Create a rect up there as well.
    EraseRect(&tempRect);                    // Erase the rect (to make a white hole).
    DrawString(tempStr);                    // And draw our text into that hole.

    ClosePort(tempPort);                    // Get rid of out temp port.
    SetPort((GrafPtr)wasPort);                // And set port back to the old one.
}

//--------------------------------------------------------------  LogNextTick

// Simple function to set a global (tickNext) to the current TickCount() plus…
// some offset.  We'll then wait for TickCount() to exceed that global.  We use…
// this function and the function below to regulate animation speeds (remember…
// your game may be run on a slow Mac or a fast one - we need a way to keep the…
// motion consistent.  I love when the comments are longer than the function.
// (Not really.)

void LogNextTick (long howMany)
{
    tickNext = TickCount() + howMany;        // Get machine's TickCount() and add to it.
}

//--------------------------------------------------------------  WaitForNextTick

// This is the companion function to the above function (LogNextTick()).
// We do nothing but loop until TickCount() catches up with (or passes) our…
// global variable tickNext.

void WaitForNextTick (void)
{
    do
    {
    }
    while (TickCount() < tickNext);            // Loop until TickCount() catches up.
}

//--------------------------------------------------------------  TrapExists

// A nice "test function" that test for the existence of some ToolBox trap.
// Returns TRUE if the function exists, FALSE if it doesn't.

Boolean TrapExists (short trapNumber)
{
    #define        kUnimpTrap        0x9F

                // Test trap number against unimplemented trap number.
    return ((NGetTrapAddress(trapNumber, ToolTrap) !=
            NGetTrapAddress(kUnimpTrap, ToolTrap)));
}

//--------------------------------------------------------------  DoWeHaveGestalt

// This function specifically tests for the availablity of the Gestalt() function.
// It returns TRUE if Gestalt() exists, FALSE if it doesn't.

Boolean DoWeHaveGestalt (void)
{
    #define        kGestaltTrap    0xAD

                // Call above function (TrapExists()) with the Gestalt() trap number.
    return (TrapExists(kGestaltTrap));
}

//--------------------------------------------------------------  CenterAlert

// Handy function to center any alert within the main monitor.

void CenterAlert (short alertID)
{
    AlertTHndl    alertHandle;
    Rect        theScreen, alertRect;
    short        horiOff, vertOff;
    Byte        wasState;

    theScreen = qd.screenBits.bounds;        // Get main monitor's bounds.
    theScreen.top += LMGetMBarHeight();        // Account for menubar height.
                                            // Get handle to alert resource.
    alertHandle = (AlertTHndl)GetResource('ALRT', alertID);
    if (alertHandle != 0L)                    // Make sure we got it!
    {                                        // Remember its "state" (locked, etc.)
        wasState = HGetState((Handle)alertHandle);
        HLock((Handle)alertHandle);            // We'll lock it.
                                            // Get a copy of it's bounds and zero.
        alertRect = (**alertHandle).boundsRect;
        OffsetRect(&alertRect, -alertRect.left, -alertRect.top);
                                            // Calculate offsets for centering bounds.
        horiOff = ((theScreen.right - theScreen.left) - alertRect.right) / 2;
        vertOff = ((theScreen.bottom - theScreen.top) - alertRect.bottom) / 3;
                                            // And offset the bounds copy.
        OffsetRect(&alertRect, horiOff, vertOff + LMGetMBarHeight());
                                            // Set alerts bounds to our centered rect.
        (**alertHandle).boundsRect = alertRect;
        HSetState((Handle)alertHandle, wasState);
    }
}

//--------------------------------------------------------------  RectWide

// Handy function for returning the absolute width of a rectangle.

short RectWide (Rect *theRect)
{
    return (theRect->right - theRect->left);
}

//--------------------------------------------------------------  RectTall

// Handy function for returning the absolute height of a rectangle.

short RectTall (Rect *theRect)
{
    return (theRect->bottom - theRect->top);
}

//--------------------------------------------------------------  CenterRectInRect

// Nice utility function that takes two rectangles and centers the first…
// rectangle within the second.

void CenterRectInRect (Rect *rectA, Rect *rectB)
{
    short    widthA, tallA;

    widthA = RectWide(rectA);                // Get width of 1st rect.
    tallA = RectTall(rectA);                // Get height of 1st rect.
                                            // Do the math (center horizontally).
    rectA->left = rectB->left + (RectWide(rectB) - widthA) / 2;
    rectA->right = rectA->left + widthA;
                                            // Do the math (center vertically).
    rectA->top = rectB->top + (RectTall(rectB) - tallA) / 2;
    rectA->bottom = rectA->top + tallA;
}

//--------------------------------------------------------------  PasStringCopy

// This is a nice function that helps to free you from dealing with C strings.
// It takes one Pascal-style string and copies it to a second.

void PasStringCopy (StringPtr p1, StringPtr p2)
{
    register short        stringLength;

    stringLength = *p2++ = *p1++;    // Get 1st string's length.
    while (--stringLength >= 0)        // Loop through each character in 1st string.
        *p2++ = *p1++;                // And copy to 2nd string.
}

//--------------------------------------------------------------  CenterDialog

// Like CenterAlert(), this function centers a Dialog on the main monitor.

void CenterDialog (short dialogID)
{
    DialogTHndl    dlogHandle;
    Rect        theScreen, dlogBounds;
    short        hPos, vPos;
    Byte        wasState;

    theScreen = qd.screenBits.bounds;            // Get main monitor's bounds.
    theScreen.top += LMGetMBarHeight();            // Add menuBar's height.
                                                // Load up dialog from resource.
    dlogHandle = (DialogTHndl)GetResource('DLOG', dialogID);
    if (dlogHandle != 0L)                        // If it loaded....!
    {                                            // Remember handle state.
        wasState = HGetState((Handle)dlogHandle);
        HLock((Handle)dlogHandle);                // We're going to lock it.
                                                // Get a copy of the dialog's bounds.
        dlogBounds = (**dlogHandle).boundsRect;
        OffsetRect(&dlogBounds, -dlogBounds.left, -dlogBounds.top);
                                                // Calculate how much to offset.
        hPos = ((theScreen.right - theScreen.left) - dlogBounds.right) / 2;
        vPos = ((theScreen.bottom - theScreen.top) - dlogBounds.bottom) / 3;
                                                // Offset ourt copy of the bounds.
        OffsetRect(&dlogBounds, hPos, vPos + LMGetMBarHeight());
                                                // Set dlg's bounds to centered rect.
        (**dlogHandle).boundsRect = dlogBounds;
        HSetState((Handle)dlogHandle, wasState);// Restore handle's state.
    }
}

//--------------------------------------------------------------  DrawDefaultButton

// A nice dialog function.  This draws the bold default outline around…
// item #1 in the dialog passed in.

void DrawDefaultButton (DialogPtr theDialog)
{
    Rect        itemRect;
    Handle        itemHandle;
    short        itemType;
                                        // Get at the item's bounds.
    GetDItem(theDialog, 1, &itemType, &itemHandle, &itemRect);
    InsetRect(&itemRect, -4, -4);        // Inset (outset?) bounds by -4 pixels.
    PenSize(3, 3);                        // Set the pen 3 pixels thick.
    FrameRoundRect(&itemRect, 16, 16);    // Draw the button outline.
    PenNormal();                        // And restore pen to 1 pixel thick.
}

//--------------------------------------------------------------  PasStringCopyNum

// Another function to keep you from using C strings.  This one copies only a…
// certain number of characters from one Pascal-style string to a second.

void PasStringCopyNum (StringPtr p1, StringPtr p2, short charsToCopy)
{
    short        i;

    if (charsToCopy > *p1)        // If trying to copy more chars than there are…
        charsToCopy = *p1;        // Reduce the number of chars to copy to this size

    *p2 = charsToCopy;            // Set 2nd string's length to charsToCopy.

    *p2++;                        // Point to first character in 2nd string.
    *p1++;                        // Point to first character in 1st string.

    for (i = 0; i < charsToCopy; i++)
        *p2++ = *p1++;            // Copy the specified number of chars over.
}

//--------------------------------------------------------------  GetDialogString

// Handy dialog function that returns a dialog item string.  This will be…
// especially handy for getting the high score name the player enters.

void GetDialogString (DialogPtr theDialog, short item, StringPtr theString)
{
    Rect        itemRect;
    Handle        itemHandle;
    short        itemType;
                                        // Get handle to dialog item.
    GetDItem(theDialog, item, &itemType, &itemHandle, &itemRect);
    GetIText(itemHandle, theString);    // Extract text from item handle.
}

//--------------------------------------------------------------  SetDialogString

// Like the above function, but this one sets a dialog items string to whatever…
// you pass in.  We'll use this to set a default high score name.

void SetDialogString (DialogPtr theDialog, short item, StringPtr theString)
{
    Rect        itemRect;
    Handle        itemHandle;
    short        itemType;
                                        // Get handle to dialog item.
    GetDItem(theDialog, item, &itemType, &itemHandle, &itemRect);
    SetIText(itemHandle, theString);    // Set the items text to theString.
}

//--------------------------------------------------------------  SetDialogNumToStr

// This one is like SetDialogString() above, but it takes a number (long)…
// instead of a string (the function will convert the long to a string for us).

void SetDialogNumToStr (DialogPtr theDialog, short item, long theNumber)
{
    Str255        theString;
    Rect        itemRect;
    Handle        itemHandle;
    short        itemType;

    NumToString(theNumber, theString);    // Convert long to a string.
    GetDItem(theDialog, item, &itemType, &itemHandle, &itemRect);
    SetIText(itemHandle, theString);    // Set the item's text to this number/string.
}

//--------------------------------------------------------------  GetDialogNumFromStr

// This one is like GetDialogString() above, but returns a long (number)…
// instead of a string (it does this by converting the string to a long).

void GetDialogNumFromStr (DialogPtr theDialog, short item, long *theNumber)
{
    Str255        theString;
    Rect        itemRect;
    Handle        itemHandle;
    short        itemType;
                                        // Get a handle to the dialog item.
    GetDItem(theDialog, item, &itemType, &itemHandle, &itemRect);
    GetIText(itemHandle, theString);    // Get the item's text.
    StringToNum(theString, theNumber);    // Convert the text to a long.
}

//--------------------------------------------------------------  DisableControl

// Another dialog utility for "graying out" buttons or other controls in a dialog.

void DisableControl (DialogPtr theDialog, short whichItem)
{
    Rect        iRect;
    Handle        iHandle;
    short        iType;
                                        // Get a handle to the dialog item.
    GetDItem(theDialog, whichItem, &iType, &iHandle, &iRect);
                                        // Set it's "hilite state" to "grayed out".
    HiliteControl((ControlHandle)iHandle, kInactive);
}