/*

    File:       ShowInitIcon.c

    Contains:   This code is intended to let INIT writers easily display an icon at startup time.

                This version features:

                - Short and readable code.

                - Correctly wraps around when more than one row of icons has been displayed.

                - works with System 6

                - Built with Universal Headers & CodeWarrior. Should work with other headers/compilers.

    Written by: Peter N Lewis, Jim Walker and Franois Pottier

    Copyright:  Copyright © 1995-1999 by Apple Computer, Inc., All Rights Reserved.

                You may incorporate this Apple sample source code into your program(s) without

                restriction. This Apple sample source code has been provided "AS IS" and the

                responsibility for its operation is yours. You are not permitted to redistribute

                this Apple sample source code as "Apple sample source code" after having made

                changes. If you're going to re-distribute the source, we require that you make

                it clear in the source that the code was descended from Apple sample source

                code, but that you've made changes.

    Change History (most recent first):

                8/10/1999   Karl Groethe    Updated for Metrowerks Codewarror Pro 2.1

*/

#include <Memory.h>

#include <Resources.h>

#include <Icons.h>

#include <OSUtils.h>

#include "ShowInitIcon.h"

// You should set SystemSixOrLater in your headers to avoid including glue for SysEnvirons.

// ---------------------------------------------------------------------------------------------------------------------

// Set this flag to 1 if you want to compile this file into a stand-alone resource (see note below).

// Set it to 0 if you want to include this source file into your INIT project.

#if 1

#define ShowInitIcon main

#ifdef powerc

    //setup ___procinfo for Accelerated Resource

    ProcInfoType __procinfo=kPascalStackBased

            | STACK_ROUTINE_PARAMETER(1, SIZE_CODE(sizeof(short)))

            | STACK_ROUTINE_PARAMETER(2, SIZE_CODE(sizeof(Boolean)));

#endif

#endif

// ---------------------------------------------------------------------------------------------------------------------

// The ShowINIT mechanism works by having each INIT read/write data from these globals.

// The MPW C compiler doesn't accept variables declared at an absolute address, so I use these macros instead.

// Only one macro is defined per variable; there is no need to define a Set and a Get accessor like in <LowMem.h>.

#define LMVCoord            (* (short*) 0x92A)

#define LMVCheckSum     (* (short*) 0x928)

#define LMHCoord            (* (short*) 0x92C)

#define LMHCheckSum     (* (short*) 0x92E)

// ---------------------------------------------------------------------------------------------------------------------

// Prototypes for the subroutines. The main routine comes first; this is necessary to make THINK C's "Custom Header" option work.

static unsigned short CheckSum (unsigned short x);

static void ComputeIconRect (Rect* iconRect, Rect* screenBounds);

static void AdvanceIconPosition (Rect* iconRect);

static void DrawBWIcon (short iconID, Rect *iconRect);

// ---------------------------------------------------------------------------------------------------------------------

// Main routine.

typedef struct {

    QDGlobals           qd;                                 // Storage for the QuickDraw globals

    long                qdGlobalsPtr;                           // A5 points to this place; it will contain a pointer to qd

} QDStorage;

pascal void ShowInitIcon (short iconFamilyID, Boolean advance)

{

    long                oldA5;                              // Original value of register A5

    QDStorage           qds;                                    // Fake QD globals

    CGrafPort           colorPort;

    GrafPort            bwPort;

    Rect                destRect;

    SysEnvRec       environment;                            // Machine configuration.

    oldA5 = SetA5((long) &qds.qdGlobalsPtr);                        // Tell A5 to point to the end of the fake QD Globals

    InitGraf(&qds.qd.thePort);                              // Initialize the fake QD Globals

    SysEnvirons(curSysEnvVers, &environment);                   // Find out what kind of machine this is

    ComputeIconRect(&destRect, &qds.qd.screenBits.bounds);          // Compute where the icon should be drawn

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

        OpenCPort(&colorPort);

        PlotIconID(&destRect, atNone, ttNone, iconFamilyID);

        CloseCPort(&colorPort);

    }

    else {

        OpenPort(&bwPort);

        DrawBWIcon(iconFamilyID, &destRect);

        ClosePort(&bwPort);

    }

    if (advance)

        AdvanceIconPosition (&destRect);

    SetA5(oldA5);                                           // Restore A5 to its previous value

}

// ---------------------------------------------------------------------------------------------------------------------

// A checksum is used to make sure that the data in there was left by another ShowINIT-aware INIT.

static unsigned short CheckSum (unsigned short x)

{

    return ((x << 1) | (x >> 15)) ^ 0x1021;

}

// ---------------------------------------------------------------------------------------------------------------------

// ComputeIconRect computes where the icon should be displayed.

static void ComputeIconRect (Rect* iconRect, Rect* screenBounds)

{

    if (CheckSum(LMHCoord) != LMHCheckSum)                  // If we are first, we need to initialize the shared data.

        LMHCoord = 8;

    if (CheckSum(LMVCoord) != LMVCheckSum)

        LMVCoord = screenBounds->bottom - 40;

    if (LMHCoord + 34 > screenBounds->right) {                  // Check whether we must wrap

        iconRect->left = 8;

        iconRect->top = LMVCoord - 40;

    }

    else {

        iconRect->left = LMHCoord;

        iconRect->top = LMVCoord;

    }

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

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

}

// AdvanceIconPosition updates the shared global variables so that the next extension will draw its icon beside ours.

static void AdvanceIconPosition (Rect* iconRect)

{

    LMHCoord = iconRect->left + 40;                         // Update the shared data

    LMVCoord = iconRect->top;

    LMHCheckSum = CheckSum(LMHCoord);

    LMVCheckSum = CheckSum(LMVCoord);

}

// DrawBWIcon draws the 'ICN#' member of the icon family. It works under System 6.

static void DrawBWIcon (short iconID, Rect *iconRect)

{

    Handle      icon;

    BitMap      source, destination;

    GrafPtr     port;

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

    if (icon != NULL) {

        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 = port->portBits;

                                                        // Transfer the mask.

        CopyBits(&source, &destination, &source.bounds, iconRect, srcBic, nil);

                                                        // Then the icon.

        source.baseAddr = *icon;

        CopyBits(&source, &destination, &source.bounds, iconRect, srcOr, nil);

    }

}

// ---------------------------------------------------------------------------------------------------------------------

// Notes

// Checking for PlotIconID:

// We (PNL) now check for system 7 and colour QD, and use colour graf ports and PlotIconID only if both are true

// Otherwise we use B&W grafport and draw using PlotBWIcon.