Add main.zig

main.zig

@@ -0,0 +1,123 @@
+const std = @import("std");
+const c = @cImport({
+    @cInclude("SDL2/SDL.h");
+    @cInclude("termios.h");
+});
+
+fn init_ttyacm0(port: [:0]const u8) !std.posix.fd_t {
+    const fd = try std.posix.open(port, .{ .ACCMODE = .RDWR, .NOCTTY = true, .SYNC = true }, 0);
+    var tty: c.termios = .{};
+    if (c.tcgetattr(fd, &tty) != 0) {
+        std.posix.close(fd);
+        return error.TTY_ERROR;
+    }
+    _ = c.cfsetospeed(&tty, c.B115200);
+    _ = c.cfsetispeed(&tty, c.B115200);
+    const csize: c_uint = @intCast(c.CSIZE);
+    tty.c_cflag = (tty.c_cflag & ~csize) | c.CS8;
+    tty.c_cflag |= (c.CLOCAL | c.CREAD);
+    const parenb: c_uint = @intCast(c.PARENB);
+    const parodd: c_uint = @intCast(c.PARODD);
+    tty.c_cflag &= ~(parenb | parodd);
+    const cstopb: c_uint = @intCast(c.CSTOPB);
+    tty.c_cflag &= ~cstopb;
+    const crtscts: c_uint = @intCast(c.CRTSCTS);
+    tty.c_cflag &= ~crtscts;
+    const ignbrk: c_uint = @intCast(c.IGNBRK);
+    tty.c_iflag &= ~ignbrk;
+    tty.c_lflag = 0;
+    tty.c_oflag = 0;
+    tty.c_cc[c.VMIN] = 1;
+    tty.c_cc[c.VTIME] = 5;
+    if (c.tcsetattr(fd, c.TCSANOW, &tty) != 0) {
+        std.posix.close(fd);
+        return error.TTY_INIT;
+    }
+    return fd;
+}
+
+pub fn main() !void {
+    const fd = try init_ttyacm0("/dev/ttyACM0");
+    defer std.posix.close(fd);
+    //     _ = try std.posix.write(fd, "ssss");
+    //     _ = std.c.fsync(fd);
+
+    _ = c.SDL_Init(c.SDL_INIT_VIDEO);
+
+    const window = c.SDL_CreateWindow("hello", 0, 0, 800, 600, c.SDL_WINDOW_SHOWN) orelse unreachable;
+    const renderer = c.SDL_CreateRenderer(window, 0, 0) orelse unreachable;
+    var running = true;
+
+    _ = c.SDL_SetRelativeMouseMode(c.SDL_TRUE); // grabs pointer and delivers relative motion
+    _ = c.SDL_ShowCursor(c.SDL_DISABLE); // optional: hide cursor
+
+    var dx_acc: i32 = 0;
+    var dy_acc: i32 = 0;
+
+    while (running) {
+        var e: c.SDL_Event = undefined;
+        while (c.SDL_PollEvent(&e) != 0) {
+            switch (e.type) {
+                c.SDL_QUIT => {
+                    running = false;
+                },
+                c.SDL_MOUSEMOTION => {
+                    const dx = e.motion.xrel; // movement since last event on x
+                    const dy = e.motion.yrel; // movement since last event on y
+                    dx_acc += dx;
+                    dy_acc += dy;
+                    const speed = 32;
+                    if (dx > 0) {
+                        const count: usize = @intCast(@divTrunc(dx_acc, speed));
+                        dx_acc = @rem(dx_acc, speed);
+                        for (0..count) |_| {
+                            _ = try std.posix.write(fd, "l");
+                        }
+                    } else {
+                        const count: usize = @intCast(@divTrunc(@abs(dx_acc), speed));
+                        dx_acc = @rem(dx_acc, speed);
+                        for (0..count) |_| {
+                            _ = try std.posix.write(fd, "j");
+                        }
+                    }
+                    if (dy > 0) {
+                        const count: usize = @intCast(@divTrunc(dy_acc, speed));
+                        dy_acc = @rem(dy_acc, speed);
+                        for (0..count) |_| {
+                            _ = try std.posix.write(fd, "k");
+                        }
+                    } else {
+                        const count: usize = @intCast(@divTrunc(@abs(dy_acc), speed));
+                        dy_acc = @rem(dy_acc, speed);
+                        for (0..count) |_| {
+                            _ = try std.posix.write(fd, "i");
+                        }
+                    }
+                },
+                //                 c.SDL_KEYDOWN => {
+                //                     switch (e.key.keysym.scancode) {
+                //                         c.SDL_SCANCODE_W => _ = try std.posix.write(fd, "wwww"),
+                //                         c.SDL_SCANCODE_S => _ = try std.posix.write(fd, "ssss"),
+                //                         c.SDL_SCANCODE_A => _ = try std.posix.write(fd, "aaaa"),
+                //                         c.SDL_SCANCODE_D => _ = try std.posix.write(fd, "dddd"),
+                //                         else => {},
+                //                     }
+                //                 },
+                else => {},
+            }
+        }
+
+        const state: [*]const u8 = c.SDL_GetKeyboardState(null);
+        if (state[c.SDL_SCANCODE_W] != 0) _ = try std.posix.write(fd, "w");
+        if (state[c.SDL_SCANCODE_S] != 0) _ = try std.posix.write(fd, "s");
+        if (state[c.SDL_SCANCODE_A] != 0) _ = try std.posix.write(fd, "a");
+        if (state[c.SDL_SCANCODE_D] != 0) _ = try std.posix.write(fd, "d");
+        if (state[c.SDL_SCANCODE_SPACE] != 0) _ = try std.posix.write(fd, "e");
+        if (state[c.SDL_SCANCODE_LSHIFT] != 0) _ = try std.posix.write(fd, "q");
+
+        _ = c.SDL_SetRenderDrawColor(renderer, 0x11, 0x11, 0x11, 0xFF);
+        _ = c.SDL_RenderClear(renderer);
+        _ = c.SDL_RenderPresent(renderer);
+        c.SDL_Delay(10);
+    }
+}