initial import of DOS mouse driver

1 files changed, 261 insertions, 0 deletions

diff --git a/w16mouse.c b/w16mouse.c
new file mode 100644
index 0000000..93aadf5
--- /dev/null
+++ b/w16mouse.c
@@ -0,0 +1,261 @@
+/*
+ * VBMouse - win16 mouse driver entry points
+ * Copyright (C) 2022 Javier S. Pedro
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
+ */
+
+#include <windows.h>
+
+#include "dlog.h"
+#include "utils.h"
+#include "int33.h"
+#include "int2fwin.h"
+#include "w16mouse.h"
+
+/** If 1, hook int2f to detect fullscreen DOSBoxes and auto-disable this driver. */
+#define HOOK_INT2F  0
+
+#define MOUSE_NUM_BUTTONS 2
+
+/** The routine Windows gave us which we should use to report events. */
+static LPFN_MOUSEEVENT eventproc;
+/** Current status of the mouse driver (see MOUSEFLAGS_*). */
+static unsigned char mouseflags;
+enum {
+	MOUSEFLAGS_ENABLED      = 1 << 0,
+	MOUSEFLAGS_HAS_VBOX     = 1 << 1,
+	MOUSEFLAGS_VBOX_ENABLED = 1 << 2,
+	MOUSEFLAGS_HAS_WIN386   = 1 << 3,
+	MOUSEFLAGS_INT2F_HOOKED = 1 << 4
+};
+#if HOOK_INT2F
+/** Existing interrupt2f handler. */
+static LPFN prev_int2f_handler;
+#endif
+
+/* This is how events are delivered to Windows */
+
+static void send_event(unsigned short Status, short deltaX, short deltaY, short ButtonCount, short extra1, short extra2);
+#pragma aux (MOUSEEVENTPROC) send_event = \
+	"call dword ptr [eventproc]"
+
+#pragma code_seg ( "CALLBACKS" )
+
+static void FAR int33_mouse_callback(uint16_t events, uint16_t buttons, int16_t x, int16_t y, int16_t delta_x, int16_t delta_y)
+#pragma aux (INT33_CB) int33_mouse_callback
+{
+	int status = 0;
+
+	if (events & INT33_EVENT_MASK_LEFT_BUTTON_PRESSED)   status |= SF_B1_DOWN;
+	if (events & INT33_EVENT_MASK_LEFT_BUTTON_RELEASED)  status |= SF_B1_UP;
+	if (events & INT33_EVENT_MASK_RIGHT_BUTTON_PRESSED)  status |= SF_B2_DOWN;
+	if (events & INT33_EVENT_MASK_RIGHT_BUTTON_RELEASED) status |= SF_B2_UP;
+
+	if (events & INT33_EVENT_MASK_MOVEMENT) {
+		status |= SF_MOVEMENT | SF_ABSOLUTE;
+	}
+
+	(void) buttons;
+	(void) delta_x;
+	(void) delta_y;
+
+#if 0
+	dlog_print("w16mouse: event status=");
+	dlog_printx(status);
+	dlog_print(" x=");
+	dlog_printx(x);
+	dlog_print(" y=");
+	dlog_printx(y);
+	dlog_endline();
+#endif
+
+	send_event(status, (uint16_t)(x) * 2, (uint16_t)(y) * 2, MOUSE_NUM_BUTTONS, 0, 0);
+}
+
+#if HOOK_INT2F
+
+static void display_switch_handler(int function)
+#pragma aux display_switch_handler parm caller [ax] modify [ax bx cx dx si di]
+{
+	if (!(mouseflags & MOUSEFLAGS_ENABLED) || !(mouseflags & MOUSEFLAGS_VBOX_ENABLED)) {
+		return;
+	}
+
+	switch (function) {
+	case INT2F_NOTIFY_BACKGROUND_SWITCH:
+		dlog_puts("Going background\n");
+		break;
+	case INT2F_NOTIFY_FOREGROUND_SWITCH:
+		dlog_puts("Going foreground\n");
+		break;
+	}
+}
+
+/** Interrupt 2F handler, which will be called on some Windows 386 mode events.
+ * This is more complicated than it should be becaused we have to fetch our DS
+ * without clobbering any registers whatsoever, and chain back to the previous handler.
+ * @todo OpenWatcom 2.x insists on calling GETDS from a different code segment, so we can't use __interrupt. */
+static void __declspec(naked) __far int2f_handler(void)
+{
+	_asm {
+		; Preserve data segment
+		push ds
+
+		; Load our data segment
+		push ax
+		mov ax, SEG prev_int2f_handler ; Let's hope that Windows relocates segments with interrupts disabled
+		mov ds, ax
+		pop ax
+
+		; Check functions we are interested in hooking
+		cmp ax, 0x4001  ; Notify Background Switch
+		je handle_it
+		cmp ax, 0x4002  ; Notify Foreground Switch
+		je handle_it
+
+		; Otherwise directly jump to next handler
+		jmp next_handler
+
+	handle_it:
+		pushad ; Save and restore 32-bit registers, we may clobber them from C
+		call display_switch_handler
+		popad
+
+	next_handler:
+		; Store the address of the previous handler
+		push dword ptr [prev_int2f_handler]
+
+		; Restore original data segment without touching the stack,
+		; since we want to keep the prev handler address at the top
+		push bp
+		mov bp, sp
+		mov ds, [bp + 6]  ; Stack looks like 0: bp, 2: prev_int2f_handler, 6: ds
+		pop bp
+
+		retf 2
+	}
+}
+
+#endif /* HOOK_INT2F */
+
+#pragma code_seg ()
+
+/* Driver exported functions. */
+
+/** DLL entry point (or driver initialization routine).
+ * The initialization routine should check whether a mouse exists.
+ * @return nonzero value indicates a mouse exists.
+ */
+#pragma off (unreferenced);
+BOOL FAR PASCAL LibMain(HINSTANCE hInstance, WORD wDataSegment,
+                        WORD wHeapSize, LPSTR lpszCmdLine)
+#pragma pop (unreferenced);
+{
+	// We are not going to bother checking whether a PS2 mouse exists and just assume it does
+
+#if HOOK_INT2F
+	// Check now whether we are running under protected mode windows
+	if (windows_386_enhanced_mode()) {
+		mouseflags |= MOUSEFLAGS_HAS_WIN386;
+	}
+#endif
+
+	// When running under protected mode Windows, let's tell VMD (the mouse virtualizer)
+	// what type of mouse we are going to be using
+	if (mouseflags & MOUSEFLAGS_HAS_WIN386) {
+		LPFN vmd_entry = win_get_vxd_api_entry(VMD_DEVICE_ID);
+		if (vmd_entry) {
+			vmd_set_mouse_type(&vmd_entry, VMD_TYPE_PS2, 0x33, 0);
+		}
+	}
+
+	return 1;
+}
+
+/** Called by Windows to retrieve information about the mouse hardware. */
+WORD FAR PASCAL Inquire(LPMOUSEINFO lpMouseInfo)
+{
+	lpMouseInfo->msExist = 1;
+	lpMouseInfo->msRelative = 0;
+	lpMouseInfo->msNumButtons = MOUSE_NUM_BUTTONS;
+	lpMouseInfo->msRate = 80;
+	return sizeof(MOUSEINFO);
+}
+
+/** Called by Windows to enable the mouse driver.
+  * @param lpEventProc Callback function to call when a mouse event happens. */
+VOID FAR PASCAL Enable(LPFN_MOUSEEVENT lpEventProc)
+{
+	// Store the windows-given callback
+	cli(); // Write to far pointer may not be atomic, and we could be interrupted mid-write
+	eventproc = lpEventProc;
+	sti();
+
+	if (!(mouseflags & MOUSEFLAGS_ENABLED)) {
+		dlog_puts("w16mouse: enable");
+
+		int33_reset();
+
+		int33_set_horizontal_window(0, 0x7FFF);
+		int33_set_vertical_window(0, 0x7FFF);
+
+		int33_set_event_handler(INT33_EVENT_MASK_ALL, int33_mouse_callback);
+
+		dlog_puts("w16mouse: int33 enabled");
+
+		mouseflags |= MOUSEFLAGS_ENABLED;
+
+#if HOOK_INT2F
+		if ((mouseflags & MOUSEFLAGS_HAS_WIN386) && (mouseflags & MOUSEFLAGS_VBOX_ENABLED)) {
+			cli();
+			hook_int2f(&prev_int2f_handler, int2f_handler);
+			sti();
+			dlog_puts("int2F hooked!\n");
+			mouseflags |= MOUSEFLAGS_INT2F_HOOKED;
+		}
+#endif
+	}
+}
+
+/** Called by Windows to disable the mouse driver. */
+VOID FAR PASCAL Disable(VOID)
+{
+	if (mouseflags & MOUSEFLAGS_ENABLED) {
+		dlog_puts("w16mouse: disable");
+
+#if HOOK_INT2F
+		if (mouseflags & MOUSEFLAGS_INT2F_HOOKED) {
+			cli();
+			unhook_int2f(prev_int2f_handler);
+			sti();
+			dlog_puts("int2F unhooked!\n");
+			mouseflags &= ~MOUSEFLAGS_INT2F_HOOKED;
+		}
+#endif
+
+		int33_reset();
+		dlog_puts("w16mouse: int33 reset");
+
+		mouseflags &= ~MOUSEFLAGS_ENABLED;
+	}
+}
+
+/** Called by Window to retrieve the interrupt vector number used by this driver, or -1. */
+int FAR PASCAL MouseGetIntVect(VOID)
+{
+	return 0x33;
+}
+