#include <Icons.h>

#include <OSUtils.h>

#include <Resources.h>

#include <Memory.h>

/*

    ShowIcon7.c

    ShowINIT compatible routine that shows 'ICN#' and 'iclx' flavor icons.

    For use by all INITs in System 7 and beyond.

    This code is based on Patrick C. Beard's ShowIconFamily

    by Patrick C. Beard, which in turn was derived from the

    original ShowInit by Paul Mercer, Darin Adler,

    Paul Snively, and Steve Capps.

    Modified by James W. Walker for compatibility with IconWrap 1.2,

    for use as a separate code resource, and to use the new System 7

    icon-drawing routines.  This code is in the public domain.

    Addresses for James W. Walker: 76367,2271@compuserve.com or

        walkerj@math.scarolina.edu

    Instructions for use:

        ¥ Create a family of icons with ResEdit 2.1 or later.  This will

            include 'ICN#', 'icl4', & 'icl8' icons, all with the

            same resource ID.

        To use within a larger INIT project:

            ¥ #define SEPARATE_CODE 0  below.

            ¥ Call ShowIcon7( id, adv ) with the resource id of

                the family that you used.  The Boolean parameter adv

                indicates whether you want the next use of ShowIcon7

                to advance to a new position.  Normally you pass TRUE,

                but you can get an animated-icon effect by passing FALSE

                all except the last time you call ShowIcon7.

        To use as a separate code resource:

            ¥ #define SEPARATE_CODE 1  below.

            ¥ Set the project type to code resource, set the code type

                and resource ID (I use type 'Code', ID -4048 for cdevs),

                compile and merge into your INIT or cdev file.

                Set the resource type to Locked, so you won't have

                to call HLock when you use it.

            ¥ In your main INIT code, call ShowIcon7 like so:

                pascal void (*ShowIcon7)( short resid, Boolean adv );

                Handle  show_init;

                show_init = GetResource( 'Code', -4048 );

                ShowIcon7 = (pascal void (*)(short, Boolean))

                            StripAddress( *show_init );

                ShowIcon7( iconID, advance );

 */

#define SEPARATE_CODE   0

#if SEPARATE_CODE

#define     ShowIcon7       main    /* JWW */

#endif

#ifndef nil

#define nil ((void*)0L)

#endif

#ifndef topLeft

    #define topLeft(r) ((Point*)&r)[0])

#endif

#ifndef botRight

    #define botRight(r) ((Point*)&r)[1])

#endif

typedef struct myQDGlobals {

    char privates[76];

    long randSeed;

    BitMap screenBits;

    Cursor arrow;

    Pattern dkGray;

    Pattern ltGray;

    Pattern gray;

    Pattern black;

    Pattern white;

    GrafPtr thePort;

    long    end;

} myQDGlobals;

/* prototypes */

pascal void ShowIcon7(short iconId, Boolean advance);

static void DrawBWIcon( short iconId, Rect *icon_rect, Boolean visible );

static void Next_position( void );

static void GetIconRect( register Rect* iconRect, Rect *screen_rect );

/* this is where it all happens. */

pascal void ShowIcon7( short iconId, Boolean advance )

{

    long    oldA5;

    myQDGlobals qd;             /* our QD globals. */

    SysEnvRec environment;      /* machine configuration. */

    CGrafPort gp;               /* our grafport. */

    Rect    icon_rect;

    OSErr   err;

    /* get a value for A5, a structure that mirrors qd globals. */

    oldA5 = SetA5((long)&qd.end);

    InitGraf(&qd.thePort);

    /* find out what kind of machine this is. */

    SysEnvirons(curSysEnvVers, &environment);

    GetIconRect( &icon_rect, &qd.screenBits.bounds );

    /*

        The old IconWrap INIT patches CopyBits but does not know about

        CopyMask or IconDispatch.  So in the color case, we draw the

        black and white icon with an empty mask region.

    */

    if ( (environment.systemVersion >= 0x0700) && environment.hasColorQD )

    {

        OpenCPort(&gp);

        DrawBWIcon( iconId, &icon_rect, false );

        err = PlotIconID( &icon_rect, atNone, ttNone, iconId );

        CloseCPort(&gp);

    }

    else

    {

        OpenPort((GrafPtr)&gp);

        DrawBWIcon( iconId, &icon_rect, true );

        ClosePort((GrafPtr)&gp);

    }

    if (advance)

        Next_position(); /* JWW */

    SetA5(oldA5);

}

/*

    ShowInit's information is nestled at the tail end of CurApName.

    It consists of a short which encodes the next horizontal offset,

    and another short which is that value checksummed with the function below.

 */

#define CurApName_LM    0x910

#define ShowINITTable ((unsigned short*)(CurApName_LM + 32 - 4))

#define CheckSumConst 0x1021        /* magic value to check-sum with. */

#define InitialXPosition 8          /* initial horizontal offset. */

#define YOffset         40          /* constant from bottom to place the icon. */

#define XOffset         40          /* amount to change it by. */

#define ICON_WIDTH      32

#define kDefaultRes 0x00480000 /* Default resolution is 72 DPI; Fixed type */

/* CheckSum() computes the magic value to determine if ShowInit's have run already. */

static short CheckSum(register unsigned short x)

{

//  asm {

//      rol.w   #1, x

//  }

    if (x & 0x8000) /* high bit set */

        return((x << 1) ^ CheckSumConst ^ 0x01);

    else

        return ((x << 1) ^ CheckSumConst);

}

/*

    GetIconRect() generates an appropriate rectangle to display the

    next INIT's icon in.

    It is also responsible for updating the horizontal

    position in low memory.  This is a departure from

    the original ShowInit code, which updates low

    memory AFTER displaying the icon. -- changed by JWW

    This code won't generate an icon position until it is certain that the icon can be loaded, so the

    same behaviour occurs.

    This routine also generates a rectangle which is guaranteed to be onscreen.  It

    does this by taking the horizontal offset modulo the screen width to generate

    the horizontal position of the icon, and the offset divided by the screen

    width to generate the proper row.

 */

static void GetIconRect(register Rect* iconRect, Rect *screen_rect )

{

    register short screenWidth;

    screenWidth = screen_rect->right - screen_rect->left;

    screenWidth -= screenWidth % XOffset;

    /* if we are the first INIT to run we need to initialize the horizontal value. */

    if (CheckSum(ShowINITTable[0]) != ShowINITTable[1])

        ShowINITTable[0] = InitialXPosition;

    /* compute top left of icon's rect. */

    iconRect->left = (ShowINITTable[0] % screenWidth);

    iconRect->top = screen_rect->bottom -

        YOffset * (1 + (ShowINITTable[0] / screenWidth));

    iconRect->right = iconRect->left + 32;

    iconRect->bottom = iconRect->top + 32;

}

/*

    JWW: In Beard's original version, this was done at the end of

    GetIconRect. That caused incorrect behavior when IconWrap 1.2 was

    used to wrap icons.  Namely, if an INIT using that version of

    ShowIconFamily was the first in a row, then the second icon in that

    row would land on top of it.

*/

static void Next_position( void )

{

    /* advance the position for the next icon. */

    ShowINITTable[0] += XOffset;

    /* recompute the checksum. */

    ShowINITTable[1] = CheckSum(ShowINITTable[0]);  

}

/* DrawBWIcon() draws the 'ICN#' member of the icon family. */

void DrawBWIcon( short iconId, Rect *icon_rect, Boolean visible )

{

    Handle      icon;

    BitMap      source, destination;

    RgnHandle   empty_mask;

    GrafPtr     port;

    icon = Get1Resource('ICN#', iconId);

    if (!icon)

        return;

    HLock(icon);

    /* prepare the source and destination bitmaps. */

    source.baseAddr = *icon + 128;                  /* mask address. */

    source.rowBytes = 4;

    SetRect(&source.bounds, 0, 0, 32, 32);

    GetPort( &port );

    destination = ((GrafPtr)port)->portBits;

    empty_mask = visible? nil : NewRgn();

    /* transfer the mask. */

    CopyBits(&source, &destination, &source.bounds, icon_rect,

        srcBic, empty_mask);

    /* and the icon. */

    source.baseAddr = *icon;    

    CopyBits(&source, &destination, &source.bounds, icon_rect,

        srcOr, empty_mask);

    if (empty_mask) DisposeRgn( empty_mask );

}