Tricks of the Mac Game Programming Gurus/TricksOfTheMacGameProgrammingGurus.iso/Book Chapters/00 - Game Programming Primer/MGW1Codeƒ/MGWUtilities1.c

Text File | 1995-06-29 | 14.9 KB | 352 lines | [TEXT/MMCC]

//==============================================================================================\\
//        -----------------------------------------------------------------------------------        \\
//        MGWUtilities1.c version 1.0.0    copyright © 1993…1995 Jamie McCornack, john calhoun        \\
//        -----------------------------------------------------------------------------------        \\
//         Alerts and other utilities for Macintosh GameWriter 1.0.0, a training program…            \\
//        …for beginning Mac game programmers. MGW1 includes MGWExterns1.h, MGWUtilities1.c,…        \\
//        …MGWSound1.c, MGWGraphics1.c, MGWGraphicsBWLite1.c, HelloWorld.rsrc and an assortment…    \\
//        …of demo programs; projects HelloWorld1.π etc. and source code files HelloWorld1.c etc.    \\
//         A tutorial is available in Tricks of the Mac Game Programming Gurus, published…        \\
//        …by Hayden Books, August 1995.                                                            \\
//                                                                                                \\
//        This code is offered by the copyright holders for no fee and for whatever use…            \\
//        …you care to make of it, but we do hope you remember where it came from.                \\
//                                                                                                \\
//        Please send bug reports to MacGameDev at America OnLine.    [e-mail]            \\
//        Suggestions and observations are also appreciated.                                        \\
//        Updates and upgrades will be available now and then from the above e-mail address.        \\
//==============================================================================================\\

// This unit checks and verifies the environment (which model Mac running which version System)…
// …and handles Alerts. It uses 'STR#' resources for alert messages, or your own strings.

// IMPORTANT NOTE: Thanks to a bit of late-breaking knowledge, this code departs slightly from…
// …the text of Chapter 0 of Tricks of the Mac Game Programming Gurus. It does not use the variable…
// …thisMac of variable type tMacEnvironment to store start-up information about a paticular Mac's…
// …hardware and system. Since generally, your program will only look at this data once, it's not…
// …worth hanging on to for the whole game.

#include "MGWExterns1.h"
#include <palettes.h>

GDHandle    gThisGDevice;        // Just this one variable.


//------------------------------------------------------------ Prototypes

Boolean    MacHasColorQD(void);
Boolean    MacIsAtLeastAMacII(void);
Boolean    MacHasSystem7(void);
Boolean    MacHasSystem605(void);
Boolean    MacHasSystem602(void);
Boolean MacIsAtLeastMacII (void);
Boolean CanWeDisplay8Bit (GDHandle theDevice);
void     SwitchToDepth (short newDepth, Boolean doColor);
void     CheckMacEnviro (void);
void    InitToolbox(void);
void    FindOurDevice (void);


//==============================================================  Functions


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

// Handy function to center any alert within the main monitor. Not dead center, the upper…
// …center, where Mac users (and Apple human interface guidelines) expect them.
// For System 6.x use, since System 7 can center alerts automatically (via ResEdit).

void CenterAlert (short theAlertID)
{
    AlertTHndl    alertHandle;
    Rect        theScreen, alertRect;
    short        horiOff, vertOff;            // Distance in pixels to offset the alert.
    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', theAlertID);
    if (alertHandle != 0L)                    // Make sure we got it!
    {                                        // Remember its "state" (locked, etc.)
        wasState = HGetState((Handle)alertHandle);
        HLock((Handle)alertHandle);            // Lock it so Memory Mnager can't move it.
                                            // Get a copy of its 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);    // Set it to its original state.
    }
}

//--------------------------------------------------------------  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 the whatGives field of the 'STR#'…
// rRedAlertStringIDs is displayed.  When the user clicks the Okay button, we quit to the Finder.

void RedAlert (short    whatGives)
{
    short        doWhat;
    Str255        errorString, errorNumberString;

    GetIndString(errorString, rRedAlertStringIDs, whatGives);
        // Set errorString to string number whatGives in 'STR#' resource rRedAlertStringIDs.
    NumToString(whatGives, errorNumberString);
        // Set errorNumberString to decimal digits representing whatGives. Useful if you (the…
        // …programmer) get an unexpected alert message. Check it against the constants and 'STR#'.
    ParamText(errorString, "\p", "\p", "\p");    // Replace ^0 in alert with error mssg.
//    CenterAlert(rRedAlertID);                // Not needed with System 7.x. Use for System 6.x.
    InitCursor();                            // Show arrow cursor.
    doWhat = Alert(rRedAlertID, 0L);        // Bring up alert.
    ExitToShell();                            // Quit to Finder.
}

//--------------------------------------------------------------  YellowAlert

// This error function is called when the player has an option between quitting or continuing.
// A simple alert is brought up and the text passed in the whatGives field of the 'STR#'…
// rYellowAlertStringIDs is displayed.  When the user clicks the Finder button, we quit…
// …to the Finder, when the user clicks the Play button, we continue to play.

void YellowAlert (short    whatGives)
{
    short        doWhat;
    Str255        errorString, errorNumberString;

    GetIndString(errorString, rYellowAlertStringIDs, whatGives);
        // Set errorString to string number whatGives in 'STR#' resource rRedAlertStringIDs.
    NumToString(whatGives, errorNumberString);
        // Set errorNumberString to decimal digits representing whatGives. Useful if you (the…
        // …programmer) get an unexpected alert message. Check it against the constants and 'STR#'.
    ParamText(errorString, errorNumberString, "\p", "\p");    // Replace ^0 in alert with error mssg.
//    CenterAlert(rRedAlertID);                // Not needed with System 7.x.
    ShowCursor();                            // Make sure the cursor is showing.
    doWhat = Alert(rYellowAlertID, 0L);        // Bring up alert, find out which item was chosen.
    if (doWhat == kYellowExitItem)            // This item# is the signal to exit the game.
        ExitToShell();                        // Quit to Finder.
    HideCursor();        // IMPORTANT NOTE: If you want the cursor to show when YellowAlert…
}                        // …is finished, the program's next call should be ShowCursor().

//--------------------------------------------------------------  RedAlertString

// 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 the StringPtr of some text imbedded…
// …in the program is displayed.  When the user clicks the Okay button, we quit to the Finder.

void RedAlertString (StringPtr theString)
{
    short        doWhat;

    ParamText(theString, "\p", "\p", "\p");    // Replace ^0 in alert with error mssg.
//    CenterAlert(rRedAlertID);                // Not needed with System 7.x.
    InitCursor();                            // Show arrow cursor.
    doWhat = Alert(rRedAlertID, 0L);        // Bring up alert.
    ExitToShell();                            // Quit to Finder.
}

//--------------------------------------------------------------  YellowAlertString

// This error function is called when the player has an option between quitting or continuing.
// A simple alert is brought up and the text passed in the StringPtr of some text imbedded…
// …in the program is displayed. When the user clicks the Finder button, we quit…
// …to the Finder, when the user clicks the Play button, we continue to play.

void YellowAlertString (StringPtr theString)
{
    short        doWhat;

    ParamText(theString, "\p", "\p", "\p");    // Replace ^0 in alert with error mssg.
//    CenterAlert(rRedAlertID);                // Not needed with System 7.x.
    ShowCursor();                            // Make sure the cursor is showing.
    doWhat = Alert(rYellowAlertID, 0L);        // Bring up alert, find out which item was chosen.
    if (doWhat == kYellowExitItem)            // This item# is the signal to exit the game.
        ExitToShell();                        // Quit to Finder.
    HideCursor();        // IMPORTANT NOTE: If you want the cursor to show when YellowAlertString…
}                        // …is finished, the program's next call should be ShowCursor().

//--------------------------------------------------------------  MacHasColorQD

// Simple function that returns TRUE if we're running on a Mac that…
// is running Color Quickdraw.

Boolean MacHasColorQD (void)
{
    SysEnvRec        thisWorld;

    SysEnvirons(2, &thisWorld);        // Call SysEnvirons() version 2.
    return (thisWorld.hasColorQD);    // Return whether it has Color QuickDraw.
}

//--------------------------------------------------------------  MacHasSystem7

// Returns TRUE if the Mac we're running on has System 7.0.0 or more recent.
// System 7 introduced…man, there are whole books on the subject.
// If your game is running routines that weren't introduced until System 7.x, call this first.
// You might also want to demand System 7 to save yourself hassles with compatability testing,…
// …but many older Macs were never upgraded to System 7 because System 7 is a memory hog,…
// …and many of those older Macs are in the kid's playroom now. I know many programmers feel…
// …old Macs and System 6.x are ready for the dumpster and the cutting edge is where it's at,…
// …but to paraphrase what Chinese mothers tell their kids when they won't eat their fried rice,…
// …there are children in Appalachia who would loooove to have your Mac II with System 6.0.8.

Boolean MacHasSystem7 (void)
{
    SysEnvRec        thisWorld;
    Boolean            haveIt;

    SysEnvirons(2, &thisWorld);        // Call the old SysEnvirons() function.
    if (thisWorld.systemVersion >= 0x0700)
        haveIt = TRUE;                // Check the System version for 6.0.2…
    else                            // or more recent
        haveIt = FALSE;
    return (haveIt);
}

//--------------------------------------------------------------  MacHasSystem605

// Returns TRUE if the Mac we're running on has System 6.0.5 or more recent.
// System 6.0.5 introduced the ability to switch color depths.

Boolean MacHasSystem605 (void)
{
    SysEnvRec        thisWorld;
    Boolean            haveIt;

    SysEnvirons(2, &thisWorld);        // Call the old SysEnvirons() function.
    if (thisWorld.systemVersion >= 0x0605)
        haveIt = TRUE;                // Check the System version for 6.0.5…
    else                            // or more recent
        haveIt = FALSE;
    return (haveIt);
}

//--------------------------------------------------------------  MacHasSystem602

// Returns TRUE if the Mac we're running on has System 6.0.2 or more recent.
// System 6.0.2 introduced lots of good sound routines. This may be all you need.

Boolean MacHasSystem602 (void)
{
    SysEnvRec        thisWorld;
    Boolean            haveIt;

    SysEnvirons(2, &thisWorld);        // Call the old SysEnvirons() function.
    if (thisWorld.systemVersion >= 0x0602)
        haveIt = TRUE;                // Check the System version for 6.0.2…
    else                            // or more recent
        haveIt = FALSE;
    return (haveIt);
}

//--------------------------------------------------------------  MacIsAtLeastMacII

// Returns TRUE if the Mac we're running is a Mac II or more recent.
// You may need more (or less), in which case this routine is easy to modify.

Boolean MacIsAtLeastMacII (void)
{
    SysEnvRec        thisWorld;
    Boolean            haveIt;

    SysEnvirons(2, &thisWorld);        // Call the old SysEnvirons() function.
    if (thisWorld.machineType >= envMacII)
        haveIt = TRUE;                // Check the System version for 6.0.2…
    else                            // or more recent
        haveIt = FALSE;
    return (haveIt);
}

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

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

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

//--------------------------------------------------------------  WhatsOurDepth

// Function returns the current bit depth.  For example, 4 = 16 colors, 8 = 256…
// colors.This function assumes System 6.0.5 or more recent and Color Quickdraw capable,…
// …so you should haved checked before attempting this call (see routines above).

short WhatsOurDepth (void)
{
    short            thisDepth;
    char            wasState;

    gThisGDevice = GetMainDevice();
    if (gThisGDevice != 0L)                            // Make sure we have device handle.
    {
        wasState = HGetState((Handle)gThisGDevice);    // Remember the handle's state.
        HLock((Handle)gThisGDevice);                    // Lock the device handle down.
                                                    // Get it's depth (pixelSize).
        thisDepth = (**(**gThisGDevice).gdPMap).pixelSize;
        HSetState((Handle)gThisGDevice, wasState);    // Restore handle's state.
    }
    else
        RedAlertString("\pUnknown Error.");                // Post generic error message.

    return (thisDepth);                                // Return screen depth.
}

//--------------------------------------------------------------  CheckMacEnviro

// This is the "wrapper" function that calls the above functions.
// After calling ToolBoxInit(), the program will call this function to see…
// …if the current Mac we're running on is capable of running this program.

void CheckMacEnviro (void)
{
    if (!MacHasColorQD())            // If the game is in color, it needs Color QuickDraw.
        RedAlert(kErrNoColor);

    if (!MacHasSystem7())            // Actually, System 6.0.5 would run this demo. If an…
        RedAlert(kErrOldSystem);    // …earlier system will do for you, change this.

    if (!MacIsAtLeastMacII())        // Your game may need more or less hardware.
        RedAlert(kErrOldMacintosh);    // Change this to suit your needs.
}


//--------------------------------------------------------------  InitToolbox

//                     A generic first function
//
//        The calls herein MUST be called before you do anything else.
//        Otherwise, you'll get all sorts of System Errors.

void InitToolbox (void)
{
    InitGraf(&qd.thePort);        // Initialize QuickDraw variables for our program.
    InitFonts();                // Initialize fonts.
    FlushEvents(everyEvent, 0);    // Clear event queue of any pending events.
    InitWindows();                // Initialize the Window Manager.
    InitMenus();                // Ditto for the Menu Manager.
    TEInit();                    // blah, blah Text Edit.
    InitDialogs(0L);            // blah, blah Dialog Manager.
    InitCursor();                // Set the cursor to the arrow cursor and init.

    MaxApplZone();                // Grab application memory.

    MoreMasters();                // Allocate a block of master pointers.
    MoreMasters();                // And allocate more.
    MoreMasters();                // And more.
    MoreMasters();                // Hey, lets do it again too.

    GetDateTime((unsigned long *)&qd.randSeed);        // Randomize random seed.
}

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//                                    End MGWUtilities1.c                                        \\
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