// ShowInitIcon - version 1.0.1, May 30th, 1995// This code is intended to let INIT writers easily display an icon at startup time.// View in Geneva 9pt, 4-space tabs // Written by: Peter N Lewis <peter@mail.peter.com.au>, Jim Walker <JWWalker@aol.com>// and François Pottier <pottier@dmi.ens.fr>, with thanks to previous ShowINIT authors.// Send comments and bug reports to François Pottier. // 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. #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 0#define ShowInitIcon main#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    LMVCheckSum        (* (unsigned short*) 0x928)#define    LMVCoord        (* (         short*) 0x92A)#define    LMHCoord        (* (         short*) 0x92C)#define    LMHCheckSum        (* (unsigned 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 (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 (short x){    return (unsigned short)(((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 = (short)(screenBounds->bottom - 40);        if (LMHCoord + 34 > screenBounds->right) {                    // Check whether we must wrap        iconRect->left = 8;        iconRect->top = (short)(LMVCoord - 40);    }    else {        iconRect->left = LMHCoord;        iconRect->top = LMVCoord;    }    iconRect->right  = (short)(iconRect->left + 32);    iconRect->bottom = (short)(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 = (short)(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.