/*

//  GrafUtils

//

//  Graphics utility routines

//  By Brigham Stevens

//  Apple Computer Developer Technical Support

//  © 1992 Apple Computer, Inc.

//

*/

#include "GrafUtils.h"

#include "CoreAssertion.h"

#include "ZAMProtos.h"

#define MAX_SAVEPORT_NEST 100

/* if this assertion fails, bump up the maximum stack size */

#define CHECK_STACK()  ASSERT((__GStack != 0) && (__GStack < MAX_SAVEPORT_NEST))

static GDHandle  __savgd[MAX_SAVEPORT_NEST];

static CGrafPtr  __savegw[MAX_SAVEPORT_NEST];

static GWorldPtr __lockPort[MAX_SAVEPORT_NEST];

static short     __GStack = 1;

/*

    PreserveGraf - saves the current grafics environment

    and sets the new one to the passed in GWorld,

    which it locks the pixels on for you

    Also returns the PixMapHandle

    RestoreGraf - restores the grafics environment saved with PreserveGraf

    These calls are nestable.

*/

PixMapHandle PreserveGraf(GWorldPtr newPort)

{

    PixMapHandle    result;

    CHECK_STACK();

    GetGWorld(&__savegw[__GStack],&__savgd[__GStack]);

    SetGWorld(newPort,nil);

    result = GetGWorldPixMap(newPort);

    LockPixels(result);

    __lockPort[__GStack] = newPort;

    ++__GStack;     /* bump to empty cell */

    return result;  

}

void RestoreGraf(void)

{

    /* subtract down to most recently used entry */

    --__GStack; 

    CHECK_STACK();

    SetGWorld(__savegw[__GStack],__savgd[__GStack]);

    UnlockPixels(GetGWorldPixMap(__lockPort[__GStack]));

}

/*

    Creates a GWorld from the picture passed

*/

GWorldPtr PictureToGWorld(PicHandle pict, int gdepth)

{

    WindowPtr       saveWindow;

    GDHandle        saveDevice;

    Rect            gwFrame;

    GWorldPtr       gw; 

    short           err;

    // get size of picture and translate to origin of 0,0

    gwFrame = (**pict).picFrame;

    OffsetRect( &gwFrame, -gwFrame.left, -gwFrame.top );

    err = NewGWorld(&gw ,gdepth,&gwFrame,GetCTable(gdepth),nil,0);

    if(err == noErr) {

        GetGWorld(&saveWindow,&saveDevice);

        SetGWorld(gw,nil);

        if(LockPixels (GetGWorldPixMap (gw)))

        {

            EraseRect(&gwFrame);

            DrawPicture(pict,&gwFrame);

            UnlockPixels(GetGWorldPixMap(gw));

        }

    }

    SetGWorld(saveWindow,saveDevice);

    return gw;

}

void MyUnionRect(Rect *r1, Rect *r2, Rect *dest)

/*

    If one of the passed rects is empty

    this one will return the other rect,

    instead of making a big damn one from 0,0

    I should have re-written this for speed,

    but this is alpha, and it was faster to do it this way

    in terms of having something to show.  However, 

    I would get around to re-writting this in a comercial 

    product.

*/

{

    if(EmptyRect(r1)) {

        *dest = *r2;

    } else if(EmptyRect(r2)) {

        *dest = *r1;

    } else {

        UnionRect(r1,r2,dest);

    }

}