Mirai's Miscellaneous Misadventures
M31 / engines / fbdev.c
#include <unistd.h>
#include <stdlib.h>
#include <termios.h>
#include <time.h>
#include <fcntl.h>
#include <stdint.h>
#include <string.h>
#include <sys/mman.h>
#include <sys/ioctl.h>
#include <linux/fb.h>
#include <linux/kd.h>
#include <linux/input.h>
#include <mimimi/engines/fbdev.h>
#include <mimimi/assets.h>
#include <mimimi/geometry.h>
#include <mimimi/engines.h>
#include <mimimi/behaviors.h>
static struct mimimi_size mimimi_fbdev_size = {512, 256};
static struct termios mimimi_fbdev_tio;
static void mimimi_fbdev_exit(void)
{
ioctl(0, KDSETMODE, KD_TEXT);
tcsetattr(0, TCSANOW, &mimimi_fbdev_tio);
}
struct mimimi_fbdev
{
unsigned char *buffer;
int width;
int height;
int x_offset;
int y_offset;
int line_length;
int bytes_per_pixel;
};
static void mimimi_fbdev_stamp(void *opaque, int x0, int y0, struct mimimi_image *image)
{
struct mimimi_fbdev *data = opaque;
static unsigned char rch[] = {0x11, 0x44, 0x77, 0x99, 0xCC, 0xFF};
static unsigned char gch[] = {0x11, 0x33, 0x55, 0x77, 0x99, 0xBB, 0xDD, 0xFF};
static unsigned char bch[] = {0x22, 0x55, 0x88, 0xBB, 0xEE};
for (int y = 0 ; y < image->height ; y++)
for (int x = 0 ; x < image->width ; x++)
{
if (y + y0 < 0) continue;
if (x + x0 < 0) continue;
if (y + y0 >= data->height) continue;
if (x + x0 >= data->width) continue;
int offset_x = (x + x0 + data->x_offset) * data->bytes_per_pixel;
int offset_y = (y + y0 + data->y_offset) * data->line_length;
int offset = offset_x + offset_y;
unsigned char color = image->colors[x + y * image->width];
if (color == 0) continue;
if (data->bytes_per_pixel == 4)
data->buffer[offset + 3] = 0xFF;
if (color < 0x10)
{
unsigned char ch = color * 0x11;
data->buffer[offset + 2] = ch;
data->buffer[offset + 1] = ch;
data->buffer[offset + 0] = ch;
continue;
}
color -= 0x10;
unsigned char r, g, b;
r = rch[(color / 40) % 6];
g = gch[(color / 5) % 8];
b = bch[(color / 1) % 5];
data->buffer[offset + 2] = r;
data->buffer[offset + 1] = g;
data->buffer[offset + 0] = b;
}
}
void mimimi_fbdev(struct mimimi_chapter *(*start)(struct mimimi_engine *engine))
{
int fd = open("/dev/fb0", O_RDWR);
if (fd < 0) return;
struct fb_fix_screeninfo finfo;
if (ioctl(fd, FBIOGET_FSCREENINFO, &finfo) < 0) return;
struct fb_var_screeninfo vinfo;
if (ioctl(fd, FBIOGET_VSCREENINFO, &vinfo) < 0) return;
void *aux = malloc(finfo.smem_len);
if (aux == NULL) return;
unsigned char *buffer = mmap(NULL, finfo.smem_len, PROT_WRITE, MAP_SHARED, fd, 0);
if ((intptr_t) buffer == -1) return;
int bytes_per_pixel = vinfo.bits_per_pixel / 8;
if (bytes_per_pixel != 4 && bytes_per_pixel != 3) return;
unsigned int width = mimimi_fbdev_size.width;
unsigned int height = mimimi_fbdev_size.height;
if (vinfo.xres < width)
width = vinfo.xres;
if (vinfo.yres < height)
height = vinfo.yres;
tcgetattr(0, &mimimi_fbdev_tio);
tcflag_t flag = mimimi_fbdev_tio.c_lflag;
mimimi_fbdev_tio.c_lflag &= ~ICANON & ~ECHO;
atexit(mimimi_fbdev_exit);
ioctl(0, KDSETMODE, KD_GRAPHICS);
tcsetattr(0, TCSANOW, &mimimi_fbdev_tio);
mimimi_fbdev_tio.c_lflag = flag;
struct mimimi_fbdev data = {aux, width, height, vinfo.xoffset, vinfo.yoffset, finfo.line_length, bytes_per_pixel};
struct mimimi_engine engine;
engine.data = &data;
engine.stamp = &mimimi_fbdev_stamp;
engine.size = &mimimi_fbdev_size;
engine.allocator = mimimi_malloc;
struct mimimi_chapter *chapter = (*start)(&engine);
struct mimimi_behavior *behavior = chapter->behavior;
static char *paths[] =
{
"/dev/input/event0", "/dev/input/event1", "/dev/input/event2", "/dev/input/event3",
"/dev/input/event4", "/dev/input/event5", "/dev/input/event6", "/dev/input/event7",
"/dev/input/event8", "/dev/input/event9", "/dev/input/event10", "/dev/input/event11",
"/dev/input/event12", "/dev/input/event13", "/dev/input/event14", "/dev/input/event15",
"/dev/input/event16", "/dev/input/event17", "/dev/input/event18", "/dev/input/event19",
"/dev/input/event20", "/dev/input/event21", "/dev/input/event22", "/dev/input/event23",
"/dev/input/event24", "/dev/input/event25", "/dev/input/event26", "/dev/input/event27",
"/dev/input/event28", "/dev/input/event29", "/dev/input/event30", "/dev/input/event31",
};
int in_count;
int in[32];
for (in_count = 0 ; in_count < 32 ; in_count++)
{
int fd = open(paths[in_count], O_RDONLY);
if (fd < 0) break;
in[in_count] = fd;
}
struct timespec past;
for (;;)
{
struct timespec tv;
clock_gettime(CLOCK_MONOTONIC, &tv);
long int delay =
(tv.tv_sec - past.tv_sec) * 1000000000 +
(tv.tv_nsec - past.tv_nsec);
if (delay < 0) delay = 0;
past.tv_sec = tv.tv_sec;
past.tv_nsec = tv.tv_nsec;
unsigned long int nsec;
if (delay < 33333333) nsec = 33333333 - delay;
else nsec = 0;
tv.tv_sec = nsec / 1000000000;
tv.tv_nsec = nsec % 1000000000;
int nfds = 0;
fd_set fds;
FD_ZERO(&fds);
for (int i = 0 ; i < in_count ; i++)
{
if (nfds < in[i]) nfds = in[i];
FD_SET(in[i], &fds);
}
for (;;)
{
int available = pselect(nfds, &fds, NULL, NULL, &tv, NULL);
if (available == -1) return;
if (available == 0) break;
tv.tv_sec = 0;
tv.tv_nsec = 0;
for (int i = 0 ; i < in_count ; i++)
{
int fd = in[i];
if (FD_ISSET(fd, &fds) == 0) continue;
int size = sizeof (struct input_event);
struct input_event event;
ssize_t r = read(fd, &event, size);
if (r < size) return;
if (event.type != EV_KEY) continue;
if (event.value == 2) continue;
switch (event.code)
{
case KEY_LEFT:
chapter->left = event.value;
break;
case KEY_RIGHT:
chapter->right = event.value;
break;
case KEY_Q:
if (event.value == 0)
return;
break;
}
}
}
(*behavior->behave)(behavior->data);
memcpy(buffer, aux, finfo.smem_len);
}
}