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MontaukOS/programs/src/doom/doomgeneric_montauk.c
T

256 lines
7.4 KiB
C

/*
* doomgeneric_montauk.c
* DOOM platform implementation for MontaukOS (standalone window server client)
* Copyright (c) 2025 Daniel Hammer
*/
#include "doomgeneric.h"
#include "doomkeys.h"
#include <string.h>
#include <stdio.h>
/* ---- Raw syscall interface (C versions) ---- */
static inline long _zos_syscall0(long nr) {
long ret;
__asm__ volatile("syscall" : "=a"(ret) : "a"(nr)
: "rcx", "r11", "rdi", "rsi", "rdx", "r8", "r9", "r10", "memory");
return ret;
}
static inline long _zos_syscall1(long nr, long a1) {
long ret;
__asm__ volatile(
"mov %[a1], %%rdi\n\t"
"syscall"
: "=a"(ret)
: "a"(nr), [a1] "r"(a1)
: "rcx", "r11", "rdi", "rsi", "rdx", "r8", "r9", "r10", "memory");
return ret;
}
static inline long _zos_syscall2(long nr, long a1, long a2) {
long ret;
__asm__ volatile(
"mov %[a1], %%rdi\n\t"
"mov %[a2], %%rsi\n\t"
"syscall"
: "=a"(ret)
: "a"(nr), [a1] "r"(a1), [a2] "r"(a2)
: "rcx", "r11", "rdi", "rsi", "rdx", "r8", "r9", "r10", "memory");
return ret;
}
static inline long _zos_syscall4(long nr, long a1, long a2, long a3, long a4) {
long ret;
__asm__ volatile(
"mov %[a1], %%rdi\n\t"
"mov %[a2], %%rsi\n\t"
"mov %[a3], %%rdx\n\t"
"mov %[a4], %%r10\n\t"
"syscall"
: "=a"(ret)
: "a"(nr), [a1] "r"(a1), [a2] "r"(a2), [a3] "r"(a3), [a4] "r"(a4)
: "rcx", "r11", "rdi", "rsi", "rdx", "r8", "r9", "r10", "memory");
return ret;
}
/* Syscall numbers (must match kernel/src/Api/Syscall.hpp) */
#define SYS_EXIT 0
#define SYS_SLEEP_MS 2
#define SYS_PRINT 4
#define SYS_GETMILLISECONDS 14
#define SYS_WINCREATE 54
#define SYS_WINDESTROY 55
#define SYS_WINPRESENT 56
#define SYS_WINPOLL 57
/* Window server structs (must match Montauk::WinCreateResult and Montauk::WinEvent) */
struct WinCreateResult {
int id; /* -1 on failure */
unsigned _pad;
unsigned long pixelVa; /* VA of pixel buffer in caller's address space */
};
struct WinEvent {
unsigned char type; /* 0=key, 1=mouse, 2=resize, 3=close */
unsigned char _pad[3];
union {
struct {
unsigned char scancode;
char ascii;
unsigned char pressed;
unsigned char shift;
unsigned char ctrl;
unsigned char alt;
} key;
struct { int x, y, scroll; unsigned char buttons, prev_buttons; } mouse;
struct { int w, h; } resize;
};
};
/* ---- Window state ---- */
static int g_winId = -1;
static uint32_t* g_pixBuf = 0;
/* ---- Circular key queue ---- */
#define KEY_QUEUE_SIZE 64
struct KeyQueueEntry {
int pressed;
unsigned char doomkey;
};
static struct KeyQueueEntry g_keyQueue[KEY_QUEUE_SIZE];
static int g_keyQueueRead = 0;
static int g_keyQueueWrite = 0;
static void key_queue_push(int pressed, unsigned char doomkey) {
int next = (g_keyQueueWrite + 1) % KEY_QUEUE_SIZE;
if (next == g_keyQueueRead) return; /* full, drop */
g_keyQueue[g_keyQueueWrite].pressed = pressed;
g_keyQueue[g_keyQueueWrite].doomkey = doomkey;
g_keyQueueWrite = next;
}
static int key_queue_pop(int* pressed, unsigned char* doomkey) {
if (g_keyQueueRead == g_keyQueueWrite) return 0;
*pressed = g_keyQueue[g_keyQueueRead].pressed;
*doomkey = g_keyQueue[g_keyQueueRead].doomkey;
g_keyQueueRead = (g_keyQueueRead + 1) % KEY_QUEUE_SIZE;
return 1;
}
/* ---- PS/2 scancode to ASCII table (set 1, unshifted) ---- */
static const char scancode_to_ascii[128] = {
0, 27, '1','2','3','4','5','6','7','8','9','0','-','=','\b',
'\t','q','w','e','r','t','y','u','i','o','p','[',']','\n',
0, 'a','s','d','f','g','h','j','k','l',';','\'','`',
0, '\\','z','x','c','v','b','n','m',',','.','/', 0,
'*', 0, ' '
};
/* ---- PS/2 scancode to DOOM key mapping ---- */
static unsigned char scancode_to_doomkey(unsigned char scancode, char ascii) {
switch (scancode) {
case 0x48: return KEY_UPARROW;
case 0x50: return KEY_DOWNARROW;
case 0x4B: return KEY_LEFTARROW;
case 0x4D: return KEY_RIGHTARROW;
case 0x1C: return KEY_ENTER;
case 0x01: return KEY_ESCAPE;
case 0x39: return KEY_USE; /* Space = use */
case 0x1D: return KEY_FIRE; /* LCtrl = fire */
case 0x2A: return KEY_RSHIFT; /* LShift = run */
case 0x36: return KEY_RSHIFT; /* RShift = run */
case 0x38: return KEY_RALT; /* Alt = strafe */
case 0x0E: return KEY_BACKSPACE;
case 0x0F: return KEY_TAB;
/* F1-F10 */
case 0x3B: return KEY_F1;
case 0x3C: return KEY_F2;
case 0x3D: return KEY_F3;
case 0x3E: return KEY_F4;
case 0x3F: return KEY_F5;
case 0x40: return KEY_F6;
case 0x41: return KEY_F7;
case 0x42: return KEY_F8;
case 0x43: return KEY_F9;
case 0x44: return KEY_F10;
case 0x57: return KEY_F11;
case 0x58: return KEY_F12;
/* Equals and minus for screen size */
case 0x0D: return KEY_EQUALS;
case 0x0C: return KEY_MINUS;
default:
/* Pass through printable ASCII as lowercase */
if (ascii >= 'a' && ascii <= 'z') return (unsigned char)ascii;
if (ascii >= '0' && ascii <= '9') return (unsigned char)ascii;
return 0;
}
}
/* ---- Poll window events and enqueue key events ---- */
static void poll_keyboard(void) {
struct WinEvent evt;
while (_zos_syscall2(SYS_WINPOLL, (long)g_winId, (long)&evt) > 0) {
if (evt.type == 0) {
/* Key event */
unsigned char baseSc = evt.key.scancode & 0x7F;
char ascii = 0;
if (baseSc < 128)
ascii = scancode_to_ascii[baseSc];
unsigned char dk = scancode_to_doomkey(baseSc, ascii);
if (dk != 0) {
key_queue_push(evt.key.pressed ? 1 : 0, dk);
}
} else if (evt.type == 3) {
/* Close event — exit the process */
_zos_syscall1(SYS_EXIT, 0);
}
}
}
/* ---- DG platform functions ---- */
void DG_Init(void) {
struct WinCreateResult result;
_zos_syscall4(SYS_WINCREATE, (long)"DOOM", (long)DOOMGENERIC_RESX,
(long)DOOMGENERIC_RESY, (long)&result);
if (result.id < 0) {
_zos_syscall1(SYS_EXIT, 1);
}
g_winId = result.id;
g_pixBuf = (uint32_t*)result.pixelVa;
}
void DG_DrawFrame(void) {
/* Poll keyboard first */
poll_keyboard();
/* Copy DG_ScreenBuffer into the shared pixel buffer */
if (g_pixBuf == 0 || DG_ScreenBuffer == 0) return;
memcpy(g_pixBuf, DG_ScreenBuffer,
DOOMGENERIC_RESX * DOOMGENERIC_RESY * sizeof(uint32_t));
/* Mark window as dirty so the compositor picks it up */
_zos_syscall1(SYS_WINPRESENT, (long)g_winId);
}
void DG_SleepMs(uint32_t ms) {
_zos_syscall1(SYS_SLEEP_MS, (long)ms);
}
uint32_t DG_GetTicksMs(void) {
return (uint32_t)_zos_syscall0(SYS_GETMILLISECONDS);
}
int DG_GetKey(int* pressed, unsigned char* doomKey) {
return key_queue_pop(pressed, doomKey);
}
void DG_SetWindowTitle(const char* title) {
(void)title;
}
/* ---- Entry point ---- */
void _start(void) {
char *argv[] = { "doom", "-iwad", "0:/apps/doom/doom1.wad", 0 };
doomgeneric_Create(3, argv);
for (;;) {
doomgeneric_Tick();
}
}