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clean vector intercepting, added info about that to docs

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git-svn-id: svn://svn.cc65.org/cc65/trunk@2221 b7a2c559-68d2-44c3-8de9-860c34a00d81
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izydorst 2003-06-16 20:43:13 +00:00
parent b50ac78a2a
commit 7016496564
3 changed files with 77 additions and 32 deletions
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67
doc/geos.sgml
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@ -6,7 +6,7 @@
<title>GEOSLib docs
<author>Maciej Witkowiak, <htmlurl url="mailto:ytm@elysium.pl" name="ytm@elysium.pl">
<date>v1.3, 26.12.1999, 16.03.2000, 19-22.03.2000, 11,29.07.2000, 3-4,15.07.2001, 27.10.2001
<date>v1.5, 26.12.1999, 2000, 2001, 2002, 2003
<abstract>
This is the documentation of cc65's GEOSLib, but information contained here may be also
useful for writting GEOS applications in general.
@ -94,7 +94,7 @@ The software needed:
VICE and cc65 are portable - they run on variety of platforms - DOS, Win32 and UNIX. GEOSLib only
needs cc65.
<p>
<em/Update:/ starting from v2.5.0 GEOSLib is a part of cc65 package as its GEOS support.
<em/Update:/ starting from v2.5.0 GEOSLib is a part of cc65 package as its GEOS support library.
<sect1>Legal
<p>
@ -129,7 +129,7 @@ everything together.
<p>
All in all, you just need to place
<tscreen><verb>
&num;include &lt;geos.h&gt
&num;include &lt;geos.h&gt;
</verb></tscreen>
on top of your source.
<p>
@ -806,7 +806,7 @@ hang on disk access. Use safe, large numbers. Note that safe IEC range is 8-31.
<sect2>Disk Initialization
<p>
GEOS has two functions for initialization ('logging' as they say on CP&bsol;M) the disk.
GEOS has two functions for initialization ('logging in' as they say on CP&bsol;M) the disk.
<sect3>OpenDisk
<p>
<tt/char OpenDisk (void)/
@ -1247,7 +1247,8 @@ This calls system's <tt/Panic/ handler - it shows dialog box with message
System error at:xxxx
</verb></tscreen>
where <tt/xxxx/ is last known execution address (caller). By default this is bound to <tt/BRK/
instruction, but it might be usable in debugging as kind of <tt/assert/.
instruction, but it might be usable in debugging as kind of <tt/assert/. (Note that <tt/assert/
is available as a separate function and will give you more information than that).
<p>
System is halted after call to <tt/Panic/ which means that library destructors will not be
called and some data may be lost (no wonder you're panicking).
@ -1280,7 +1281,7 @@ but by calling this function you are sure that the results will be always differ
<tt/random/ is updated once a frame (50Hz PAL) and on every call to <tt/GetRandom/.
<p>
Note that it is not the same as <tt/rand/ function from the standard library. <tt/GetRandom/
will give you unpredictable results (if IRQs will occur between calls to it) while
will give you unpredictable results (if IRQs would occur between calls to it) while
<tt/rand/ conforms to the standard and for given seed (<tt/srand/) it always returns with the
same sequence of values.
@ -1332,7 +1333,9 @@ This structure describes a font in one pointsize. There is current font - <tt/st
bound to <tt/curFontDesc/. You can also force GEOS to use your own fonts by calling
<tt/LoadCharSet/. You just need to open a VLIR font file and load one record - one pointsize
somewhere. At the start of this area you already have all data for <tt/fontdesc/ so you can
pass a pointer to the load adress of that pointsize to <tt/LoadCharSet/.
pass a pointer to the load adress of that pointsize to <tt/LoadCharSet/. (Note that although
it has 'Load' in the name, that function loads only GEOS internal data structures, not data
from disk).
<sect2>window
<p>
@ -1446,10 +1449,10 @@ just in the content.
Here is how single descriptor looks like:
<tscreen><verb>
void myMenu = &lcub;
(char)top, (char)botom, // this is the size of the menubox
(unsigned)left, (unsigned)right, // counting all items in current descriptor
(char)number_of_items | type_of_menu, // number of following items ORed with
// type of this menu, it can be either
(char)top, (char)bottom, // this is the size of the menubox
(unsigned)left, (unsigned)right, // counting all items in current descriptor
(char)number_of_items | type_of_menu, // number of following items ORed with
// type of this menu, it can be either
// HORIZONTAL or VERTICAL if you will have also bit 6 set then menu won't be closed
// after moving mouse pointer outside the menubox. You can have at most 31 items.
</verb></tscreen>
@ -1583,9 +1586,47 @@ void example = &lcub;
(unsigned)address_to_store_values_at,
(char)number_of_bytes_that_follow,
(char)data,(char)data (...)
(...) - more such definitions
(unsigned)NULL - address of 0 ends the table
// more such definitions
(unsigned)NULL // address of 0 ends the table
&rcub;;
</verb></tscreen>
<sect2>Intercepting system vectors
<p>
It is possible to intercept and hook in the GEOS Kernal using vectors. Here is a little example:
<tscreen><verb>
void (&ast;oldVector)(void);
void NewVectorHandler(void) &lcub;
// do something and at the end call the old vector routine
oldVector();
&rcub;
void hook_into_system(void) &lcub;
oldVector = mouseVector;
mouseVector = NewVectorHandler;
&rcub;
void remove_hook(void) &lcub;
mouseVector = oldVector;
&rcub;
</verb></tscreen>
<p>
In your <tt/main/ function you should call <tt/hook_into_system()/ but <em/after/ all calls to GEOS
kernal (like <tt/DoMenu/, <tt/DoIcons/, etc.) - right before passing control to the <tt/MainLoop()/.
It is critical to restore old vector values before exiting the program. If you have more than one
place where you call <tt/exit()/ then it might be worth to register <tt/remove_hook/ function to
be called upon exiting with <tt/atexit(&amp;remove_hook);/ call. This way you will ensure that
such destructor will be always called.
<p>
That little example above intercepts <tt/mouseVector/. The <tt/NewVectorHandler/ function will be
called every time the mouse button changes status. Other important vectors you should know about
are:
<itemize>
<item><tt/appMain/ - this is called from within <tt/MainLoop/ system loop
<item><tt/keyVector/ - called whenever a keypress occurs
<item><tt/intTopVector/ - called at the start of IRQ routine
<item><tt/intBotVector/ - called at the end of IRQ routine
</itemize>
</article>

2
include/geos/gstruct.h
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@ -17,6 +17,8 @@
#ifndef _GSTRUCT_H
#define _GSTRUCT_H
typedef void (*void_func) (void);
struct f_date { /* date in filedesctiptor */
char f_year;
char f_month;

40
include/geos/gsym.h
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@ -15,7 +15,7 @@
#define nameBuf char[17]
#define blockBuf char[256]
#define zpage (char*)0x0000
#define zpage ((blockBuf)0x0000)
#define CPU_DDR *(char*)0x00
#define CPU_DATA *(char*)0x01
@ -85,9 +85,9 @@
#define STATUS *(char*)0x90
#define curDevice *(char*)0xba
#define irqvec *(unsigned int*)0x0314
#define bkvec *(unsigned int*)0x0316
#define nmivec *(unsigned int*)0x0318
#define irqvec (*(void_func*)0x0314)
#define bkvec (*(void_func*)0x0316)
#define nmivec (*(void_func*)0x0318)
#define APP_RAM (char*)0x0400
#define BACK_SCR_BASE (char*)0x6000
@ -118,18 +118,19 @@
#define VLIRInfo (*(struct VLIR_info*)0x8496)
#define appMain *(unsigned int*)0x849b
#define intTopVector *(unsigned int*)0x849d
#define intBotVector *(unsigned int*)0x849f
#define mouseVector *(unsigned int*)0x84a1
#define keyVector *(unsigned int*)0x84a3
#define inputVector *(unsigned int*)0x84a5
#define mouseFaultVec *(unsigned int*)0x84a7
#define otherPressVec *(unsigned int*)0x84a9
#define StringFaultVec *(unsigned int*)0x84ab
#define alarmTmtVector *(unsigned int*)0x84ad
#define BRKVector *(unsigned int*)0x84af
#define RecoverVector *(unsigned int*)0x84b1
#define appMain (*(void_func*)0x849b)
#define intTopVector (*(void_func*)0x849d)
#define intBotVector (*(void_func*)0x849f)
#define mouseVector (*(void_func*)0x84a1)
#define keyVector (*(void_func*)0x84a3)
#define inputVector (*(void_func*)0x84a5)
#define mouseFaultVec (*(void_func*)0x84a7)
#define otherPressVec (*(void_func*)0x84a9)
#define StringFaultVec (*(void_func*)0x84ab)
#define alarmTmtVector (*(void_func*)0x84ad)
#define BRKVector (*(void_func*)0x84af)
#define RecoverVector (*(void_func*)0x84b1)
#define selectionFlash *(char*)0x84b3
#define alphaFlag *(char*)0x84b4
#define iconSelFlg *(char*)0x84b5
@ -188,9 +189,10 @@
#define config *(char*)0xff00
#define END_MOUSE (char*)0xfffa
#define NMI_VECTOR *(unsigned int*)0xfffa
#define RESET_VECTOR *(unsigned int*)0xfffc
#define IRQ_VECTOR *(unsigned int*)0xfffe
#define NMI_VECTOR (*(void_func*)0xfffa)
#define RESET_VECTOR (*(void_func*)0xfffc)
#define IRQ_VECTOR (*(void_func*)0xfffe)
#define vicbase (char*)0xd000
#define sidbase (char*)0xd400