DSp Context Switch Main.c

/*
    File:       DSp Context Switch Main.c
 
    Contains:   Source file for demonstration of DSp 1.7 or 1.1.4 context switching
                right arrow for a larger context; left arrow for smaller; Cmd-Q to exit.
 
    Written by: Geoff Stahl (ggs)
 
    Copyright:  Copyright (c) 1999 Apple Computer, Inc., All Rights Reserved.
 
    Change History (most recent first):
 
        <3+>    10/11/99    ggs     
         <3>    10/10/99    ggs     Header clean up
         <2>    10/10/99    ggs     Added support for DSP 1.1.4  with code that does the equivalent
                                    of context switching
         <1>    10/10/99    ggs     Initial Add
 
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*/
 
 
// system includes ----------------------------------------------------------
 
#include <Events.h>
#include <Fonts.h>
#include <Windows.h>
#include <Dialogs.h>
#include <ToolUtils.h>
#include <Devices.h>
 
#include <DrawSprocket.h>
 
#include <stdio.h>
 
// project includes ---------------------------------------------------------
 
 
// function declarations ----------------------------------------------------
 
void InitToolbox(void);
void GraphicsInitAttributes(DSpContextAttributes *inAttributes);
Boolean SetUp (void);
void DoMenu (SInt32 menuResult);
void SwitchDSpContext(short context);
void DoKey (SInt8 theKey, SInt8 theCode);
void CToPStr (register const char *inString, Str255 * outString );
void DoUpdate (void);
void DoEvent (void);
void CleanUp (void);
 
// statics/globals (internal only) ------------------------------------------
 
// Menu defs
enum 
{
    kNumContexts = 8,
    kBitsPerPixel = 16,
 
    kMenuApple = 128,
    kMenuFile = 129,
    
    kAppleAbout = 1,
    kFileDoNothing = 1,
    kFileQuit
};
 
Boolean gDone = false;
UInt32 gSleepTime = 1;
 
RGBColor grgbColor = {0x5000,0x5000,0x5000};
 
short gContextCurrent = 0;
short gActualNumContexts = 0;
Point gapntResolution [kNumContexts] = {{480, 640}, {600, 800}, {624, 832}, {768, 1024}, {870, 1152}, {1024, 1280}, {1600, 1200}, {1920, 1440}};
DSpContextAttributes gaContextAttributes [kNumContexts];
DSpContextReference gaContextRef [kNumContexts];
DSpContextReference * gpContextRefUnused = NULL;
unsigned long gDisplayID;
GDHandle ghGD;
short gnumDevices = 0;
Boolean gfDSp17 = true;
 
 
 
// functions (internal/private) ---------------------------------------------
 
void InitToolbox (void)
{
    MenuHandle menu;
    SInt16 modifiers = 0;
    EventRecord event;
 
    MaxApplZone ();
 
    InitGraf((Ptr) &qd.thePort);
    InitFonts();
    InitWindows();
    InitMenus();
    TEInit();
    InitDialogs(nil);
    InitCursor();
    
    qd.randSeed =  (long) TickCount();
 
    // init events
    EventAvail(everyEvent, &event);
    modifiers |= event.modifiers;
    EventAvail(everyEvent, &event);
    modifiers |= event.modifiers;
    EventAvail(everyEvent, &event);
    modifiers |= event.modifiers;
 
    // Init Menus
    menu = NewMenu (kMenuApple, "\p\024");          // new  apple menu
    InsertMenu (menu, 0);                           // add menu to end
    AppendResMenu(menu, 'DRVR');
    
    menu = NewMenu (kMenuFile, "\pFile");           // new menu
    InsertMenu (menu, 0);                           // add menu to end
    AppendMenu (menu, "\pDo Nothing;Quit/Q"); // add items
    
    DrawMenuBar();
} 
 
// --------------------------------------------------------------------------
 
void GraphicsInitAttributes(DSpContextAttributes *inAttributes)
{
    BlockZero (inAttributes, sizeof (DSpContextAttributes));
}
 
// --------------------------------------------------------------------------
 
Boolean SetUp (void)
{
    OSStatus err = noErr;
    short i, context;
    
    InitToolbox ();
    
    // Do DrawSprocket Setup
    
    if ((Ptr) kUnresolvedCFragSymbolAddress == (Ptr) DSpStartup)
    {
        DebugStr("\pDSp extension not loaded\n");
        return false;
    }
    if (DSpStartup () != noErr)
    {
        DebugStr("\pUnable to startup DSp\n");
        return false;
    }
    if ((Ptr) kUnresolvedCFragSymbolAddress == (Ptr) DSpGetVersion) 
        gfDSp17 = false;
    else
    {
        // do not use built in DSpContext_Reserve and DSpContext_Queue prior to DSp 1.7.3
        NumVersion version = DSpGetVersion ();
        if ((version.majorRev < 0x01)  || ((version.majorRev == 0x01) && (version.minorAndBugRev < 0x73)))
            gfDSp17 = false;
    }
            
    context = 0;
    for (i = 0; i < kNumContexts; i++)  // get all of our possible contexts kNumContexts
    {
        GraphicsInitAttributes (&gaContextAttributes [context]);
        
        gaContextAttributes [context].displayWidth          = gapntResolution [i].h;
        gaContextAttributes [context].displayHeight         = gapntResolution [i].v;
        gaContextAttributes [context].colorNeeds            = kDSpColorNeeds_Require;
        gaContextAttributes [context].displayBestDepth      = kBitsPerPixel;
        gaContextAttributes [context].displayDepthMask      = kDSpDepthMask_All;
        // this is required prior to DSp 1.7.3, even if you only need one buffer
        gaContextAttributes [context].backBufferBestDepth   = kBitsPerPixel;
        gaContextAttributes [context].backBufferDepthMask   = kDSpDepthMask_All;
        gaContextAttributes [context].pageCount             = 1;                                // only the front buffer is needed
        // use two above if you want to swap buffers to animate
        
        if (0 == context)   // for the first context
        {
            // will display user dialog if context selection is required otherwise as find best context
            err = DSpUserSelectContext(&gaContextAttributes [context], 0, nil, &gaContextRef[context]);
            if (err != noErr)
            {
//              DebugStr("\pA suitable display context could not be found.");
            }
 
            if (noErr != DSpContext_GetAttributes (gaContextRef[context], &gaContextAttributes [context])) // see what we actually found
            {
                DebugStr("\pUnable to get attributes\n");
            }
            gaContextAttributes [context].displayWidth      = gapntResolution [i].h;
            gaContextAttributes [context].displayHeight     = gapntResolution [i].v;
            gaContextAttributes [context].pageCount         = 1;                                    // only the front buffer is needed
            gaContextAttributes [context].contextOptions    = 0 | kDSpContextOption_DontSyncVBL;    // no page flipping and no VBL sync needed
 
            // get our device for future use
            err =  DSpContext_GetDisplayID (gaContextRef [context], &gDisplayID);
            if (err != noErr)
            {
                DebugStr("\pDSpContext_GetDisplayID () had an error.");
                return false;
            }
 
            // get GDHandle for ID'd device
            err = DMGetGDeviceByDisplayID (gDisplayID, &ghGD, false);
            if (err != noErr)
            {
                DebugStr("\pDMGetGDeviceByDisplayID() had an error.");
                return false;
            }
            
            if (false == gfDSp17)   // reserve contexts on other screens to prevent selection
            {
                GDHandle hDevice = DMGetFirstScreenDevice (true); // check number of screens
                short indexDevice = 0;
                do
                {
                    gnumDevices++;
                    hDevice = DMGetNextScreenDevice (hDevice, true);
                }
                while (hDevice);
                gnumDevices--; // only count unsued screens
                if (gnumDevices)
                {
                    gpContextRefUnused = (DSpContextReference *) NewPtr ((long) sizeof (DSpContextReference) * gnumDevices);
                    hDevice = DMGetFirstScreenDevice (true); // check number of screens
                    do
                    {
                        if (hDevice != ghGD)    // if this device is not the one the user chose
                        {
                            unsigned long displayID;
                            DSpContextAttributes contextAttributes;
                            err = DMGetDisplayIDByGDevice (hDevice, &displayID, false);
                            err = DSpGetFirstContext (displayID, &gpContextRefUnused [indexDevice]); // get a context and
                            err = DSpContext_GetAttributes (gpContextRefUnused [indexDevice], &contextAttributes); // find attributes
                            err = DSpContext_Reserve (gpContextRefUnused [indexDevice], &contextAttributes); // reserve it
                            indexDevice++;
                        }
                        hDevice = DMGetNextScreenDevice (hDevice, true);
                    }
                    while (hDevice);
                }
            }
        }
        else
        {
            // find a context on the display used in the first context
            if (false == gfDSp17)
                err = DSpFindBestContext (&gaContextAttributes [context], &gaContextRef [context]);
            else // in this case we have reserved contexts on all other screens thus they will not be considered
                err = DSpFindBestContextOnDisplayID (&gaContextAttributes [context], &gaContextRef [context], gDisplayID);
            if (noErr == err) 
            {
                if (noErr != DSpContext_GetAttributes (gaContextRef[context], &gaContextAttributes [context])) // see what we actually found
                {
                    DebugStr("\pUnable to get attributes\n");
                }
                gaContextAttributes [context].displayWidth      = gapntResolution [context].h;
                gaContextAttributes [context].displayHeight     = gapntResolution [context].v;
                gaContextAttributes [context].pageCount         = 1;                                    // only the front buffer is needed
                gaContextAttributes [context].contextOptions    = 0 | kDSpContextOption_DontSyncVBL;    // no page flipping and no VBL sync needed
            }
            else
            {
//              DebugStr( "\pDSpFindBestContextOnDisplayID could not find context");
            }
        }
        if (gaContextRef[context])  // if we use that slot
        {
            context++;
            gActualNumContexts++;
        }
    }
    gContextCurrent = 0;    // start at the first
    
    // reserve our context
    err = DSpContext_Reserve (gaContextRef [gContextCurrent], &gaContextAttributes [gContextCurrent]);
    if (err != noErr)
    {
        DebugStr("\pUnable to create the display!");
        return false;
    }
 
    if (false == gfDSp17)
    {
        // do nothing
    }
    else
    {
        for (i = 1; i < gActualNumContexts; i++)    // get all of our contexts
        {
            // queue it for switch
            err = DSpContext_Queue(gaContextRef [gContextCurrent], gaContextRef [i], &gaContextAttributes [i]);
            if (err) 
                DebugStr( "\pDSpContext_Queue() had an error.");
        }
    }
 
    DSpSetBlankingColor(&grgbColor);
    HideCursor();
 
    err = DSpContext_FadeGammaOut (NULL, NULL);                 // remove for debug
    if (err != noErr)
        DebugStr("\pUnable to fade the display!");
 
    // activate our context
    err = DSpContext_SetState (gaContextRef [gContextCurrent], kDSpContextState_Active);
    if (err != noErr)
    {
        DebugStr("\pUnable to set the display!");
        return false;
    }
        
    err = DSpContext_FadeGammaIn (NULL, NULL);  
    if(err)
        DebugStr("\pUnable to fade the display!");
 
    return true;
}
 
// --------------------------------------------------------------------------
 
void DoMenu (SInt32 menuResult)
{
    SInt16 theMenu;
    SInt16 theItem;
    Str255 daName;
    MenuRef theMenuHandle;
        
    theMenu = HiWord(menuResult);
    theItem = LoWord(menuResult);
    theMenuHandle = GetMenuHandle(theMenu);
 
    switch (theMenu)
    {
        case kMenuApple:
            switch (theItem)
            {
                case kAppleAbout:
                    break;
                default:
                    OpenDeskAcc(daName);
                    break;
            }
            break;
        case kMenuFile:
            switch (theItem)
            {
                case kFileDoNothing:
                    break;
                case kFileQuit:
                    gDone = true;
                    break;
            }
            break;
    }
    HiliteMenu(0);
    DrawMenuBar();
}
 
// --------------------------------------------------------------------------
 
void SwitchDSpContext(short context)
{
    OSStatus err;
    if(gContextCurrent != context)
    {   
        if(gaContextRef[gContextCurrent] && gaContextRef[context]) 
        {       
            if (false == gfDSp17)
            {
                // fade out
                err = DSpContext_FadeGammaOut (NULL, NULL); // remove for debug
                if (err != noErr)
                    DebugStr("\pUnable to fade the display!");
 
                // deactivate our context
                err = DSpContext_SetState (gaContextRef [gContextCurrent], kDSpContextState_Inactive);
                if (err != noErr)
                    DebugStr("\pUnable to set the display!");
                    
                // release
                err = DSpContext_Release (gaContextRef [0]);
                if (err != noErr) 
                    DebugStr ("\pDSpContext_Release error");
                    
                // reserve
                err = DSpContext_Reserve (gaContextRef [context], &gaContextAttributes [context]);
                if (err != noErr)
                    DebugStr("\pUnable to create the display!");
                
                // activate
                err = DSpContext_SetState (gaContextRef [context], kDSpContextState_Active);
                if (err != noErr)
                    DebugStr("\pUnable to set the display!");
 
                // fade in
                err = DSpContext_FadeGammaIn (NULL, NULL);  
                if(err)
                    DebugStr("\pUnable to fade the display!");
                
                if(err) 
                    DebugStr ("\pUnable to switch displays");
                else
                    gContextCurrent = context;
            }
            else
            {
                err = DSpContext_Switch(gaContextRef[gContextCurrent], gaContextRef[context]);
                if(err) 
                    DebugStr ("\pUnable to switch displays");
                else
                    gContextCurrent = context;
            }
        }
    }
}   
 
// --------------------------------------------------------------------------
 
void DoKey (SInt8 theKey, SInt8 theCode)
{
    #pragma unused (theCode)
    short context = gContextCurrent;
    if (theKey == '\35')
    {
    
        if (++context == gActualNumContexts)
            context = 0;
        SwitchDSpContext (context);
        DoUpdate ();
    }
    else if (theKey == '\34')
    {
        if (--context < 0)
            context = (short) (gActualNumContexts - 1);
        SwitchDSpContext (context);
        DoUpdate ();
    }
}
 
//---------------------------------------------------------------------------
 
// Copy C string to Pascal string
 
void CToPStr (register const char *inString, Str255 * outString )       // copies in to out
{   
    register unsigned char x = 0;
    do
    {
        *(((char*)outString) + 1 + x) = *(inString + x);
        x++;
    }
    while ((*(inString + x) != 0)  && (x < 256));
    *((char*)outString) = (char) x;                                 
}
 
// --------------------------------------------------------------------------
 
void DoUpdate (void)
{
    OSStatus err;
    CGrafPtr pCGrafFrontBuffer, pCGrafSave = NULL;
    GDHandle hGDSave;
    RGBColor rgbSave, rgbRed = {0x7FFF, 0x0000, 0x0000}, rgbWhite = {0xFFFF, 0xFFFF, 0xFFFF};
    short fNum, len;
    Str255 aStr = "\p";
    char aChar[256];
 
    err = DSpContext_GetFrontBuffer (gaContextRef [gContextCurrent], &pCGrafFrontBuffer);   
    if (err != noErr)
    {
        DebugStr("\pUnable to get front buffer");
        return;
    }
        
    GetGWorld (&pCGrafSave, &hGDSave);
    SetGWorld (pCGrafFrontBuffer, ghGD);
    GetForeColor (&rgbSave);
    
    // draw here
    RGBForeColor (&rgbRed);
    PaintRect (&pCGrafFrontBuffer->portRect);
 
    RGBForeColor (&rgbWhite);
 
    // set text
    GetFNum("\pGeneva", &fNum);
    TextFont(fNum);
    TextSize(12);
    
    // draw centered to screen
    sprintf (aChar, "%d x %d", gapntResolution [gContextCurrent].h, gapntResolution [gContextCurrent].v);
    CToPStr (aChar, &aStr);
    len = StringWidth (aStr);
    MoveTo ((short) (pCGrafFrontBuffer->portRect.left + (pCGrafFrontBuffer->portRect.right - pCGrafFrontBuffer->portRect.left) / 2 - (len / 2)), 18);
    DrawString(aStr);
    
    RGBForeColor (&rgbSave);
    SetGWorld (pCGrafSave, hGDSave);
}
 
// --------------------------------------------------------------------------
 
void DoEvent (void)
{
    EventRecord theEvent;
    SInt16 whatPart;
    SInt32 menuResult;
    WindowRef whichWindow;
    SInt8 theKey;
    SInt8 theCode;
    Boolean fProcessed;
    
    if (WaitNextEvent(everyEvent, &theEvent, gSleepTime, NULL))
    {
        DSpProcessEvent (&theEvent, &fProcessed);
        if (!fProcessed)
        {
            switch (theEvent.what)
            {
                case mouseDown:
                    whatPart = FindWindow(theEvent.where, &whichWindow);
                    switch (whatPart)
                    {
                        case inGoAway:
                            break;
                        case inMenuBar:
                            DrawMenuBar();
                            menuResult = MenuSelect(theEvent.where);
                            if (HiWord(menuResult) != 0)
                                DoMenu(menuResult);
                            break;
                        case inSysWindow:
                            SystemClick(&theEvent, whichWindow);
                            break;
                        case inContent:
                            break;
                    }
                    break;
                case keyDown:
                case autoKey:
                    theKey = (char)(theEvent.message & charCodeMask);
                    theCode = (char)((theEvent.message & keyCodeMask) >> 8);
                    if ((theEvent.modifiers & cmdKey) != 0)
                    {
                        menuResult = MenuKey(theKey);
                        if (HiWord(menuResult) != 0)
                            DoMenu (menuResult);
                    }
                    else
                        DoKey (theKey, theCode);
                    break;
                case updateEvt:
                    BeginUpdate((WindowRef) theEvent.message);
                    DoUpdate();
                    EndUpdate((WindowRef) theEvent.message);
                    break;
                case diskEvt:
                    break;
                case osEvt:
                    if (theEvent.message & 0x01000000)      //  Suspend/resume event
                    {
                        if (theEvent.message & 0x00000001)  //  Resume
                        {
                            gSleepTime = 1;             //  Suspend                         
                            DoUpdate ();
                        }
                        else
                            gSleepTime = 32000;             //  Suspend
                    }
                    break;
 
                case kHighLevelEvent:
                    AEProcessAppleEvent(&theEvent);
                    break;
            }
        }
    }
    else
    {
        // idle tasks
    }
}
 
// --------------------------------------------------------------------------
 
void CleanUp (void)
{
    OSStatus err;
 
    err = DSpContext_FadeGammaOut (NULL, NULL);                 // remove for debug
    if (err != noErr)
        DebugStr("\pUnable to fade the display!");
 
    err = DSpContext_SetState (gaContextRef [gContextCurrent], kDSpContextState_Inactive);
    if (err != noErr)
        DebugStr("\pUnable to set the display!");
        
    err = DSpContext_FadeGammaIn (NULL, NULL);  
    if(err)
        DebugStr("\pUnable to fade the display!");
 
    if (false == gfDSp17)
    {
        err = DSpContext_Release (gaContextRef [gContextCurrent]);
        if (err != noErr) 
            DebugStr ("\pDSpContext_Release error");
            
        while (gnumDevices--) // dump our reserved unused devices
        {
            err = DSpContext_Release (gpContextRefUnused [gnumDevices]);
            if (err != noErr) 
                DebugStr ("\pDSpContext_Release error");
        }
    }
    else
    {
        err = DSpContext_Release (gaContextRef [0]);
        if (err != noErr) 
            DebugStr ("\pDSpContext_Release error");
    }
    
    err = DSpShutdown ();
    if (err != noErr) 
        DebugStr ("\pDSpShutdown error");
}
 
// --------------------------------------------------------------------------
 
int main (void)
{
    if (SetUp ())
    {
        DoUpdate ();
        while (!gDone) 
        {
            DoEvent ();
        }
    }
    CleanUp ();
    return 0;
}