Files
MontaukOS/programs/src/doom/doomgeneric_zenith.c
T

231 lines
6.5 KiB
C

/*
* doomgeneric_zenith.c
* DOOM platform implementation for ZenithOS
* 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;
}
/* 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_ISKEYAVAILABLE 16
#define SYS_GETKEY 17
#define SYS_FBINFO 21
#define SYS_FBMAP 22
/* FbInfo struct (must match kernel definition) */
struct FbInfo {
unsigned long width;
unsigned long height;
unsigned long pitch;
unsigned long bpp;
unsigned long userAddr;
};
/* KeyEvent struct (must match kernel definition) */
struct KeyEvent {
unsigned char scancode;
char ascii;
unsigned char pressed;
unsigned char shift;
unsigned char ctrl;
unsigned char alt;
};
/* ---- Framebuffer state ---- */
static uint32_t* g_fbPtr = 0;
static uint32_t g_fbWidth = 0;
static uint32_t g_fbHeight = 0;
static uint32_t g_fbPitch = 0; /* bytes per scanline */
/* ---- 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 ' '; /* Space = use */
case 0x1D: return KEY_RCTRL; /* 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 keyboard and enqueue events ---- */
static void poll_keyboard(void) {
while (_zos_syscall0(SYS_ISKEYAVAILABLE)) {
struct KeyEvent evt;
_zos_syscall1(SYS_GETKEY, (long)&evt);
unsigned char baseSc = evt.scancode & 0x7F; /* strip break bit */
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.pressed ? 1 : 0, dk);
}
}
}
/* ---- DG platform functions ---- */
void DG_Init(void) {
struct FbInfo info;
_zos_syscall1(SYS_FBINFO, (long)&info);
g_fbWidth = (uint32_t)info.width;
g_fbHeight = (uint32_t)info.height;
g_fbPitch = (uint32_t)info.pitch;
g_fbPtr = (uint32_t*)(unsigned long)_zos_syscall0(SYS_FBMAP);
printf("DOOM: framebuffer %ux%u pitch=%u mapped at %p\n",
g_fbWidth, g_fbHeight, g_fbPitch, (void*)g_fbPtr);
}
void DG_DrawFrame(void) {
/* Poll keyboard first */
poll_keyboard();
/* Copy DG_ScreenBuffer (DOOMGENERIC_RESX x DOOMGENERIC_RESY) to framebuffer */
if (g_fbPtr == 0 || DG_ScreenBuffer == 0) return;
uint32_t copyW = DOOMGENERIC_RESX;
uint32_t copyH = DOOMGENERIC_RESY;
if (copyW > g_fbWidth) copyW = g_fbWidth;
if (copyH > g_fbHeight) copyH = g_fbHeight;
uint32_t fbStride = g_fbPitch / 4; /* pixels per scanline */
for (uint32_t y = 0; y < copyH; y++) {
uint32_t* dst = g_fbPtr + y * fbStride;
uint32_t* src = DG_ScreenBuffer + y * DOOMGENERIC_RESX;
memcpy(dst, src, copyW * sizeof(uint32_t));
}
}
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:/doom1.wad", 0 };
doomgeneric_Create(3, argv);
for (;;) {
doomgeneric_Tick();
}
}