Add CLI options for rotation and version

Fixes: #9

command_line.c

@@ -0,0 +1,123 @@
+/**
+ * Copyright 2021 Johannes Marbach
+ *
+ * This file is part of buffyboard, hereafter referred to as the program.
+ *
+ * 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 3 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, see <https://www.gnu.org/licenses/>.
+ */
+
+
+#include "command_line.h"
+
+#include <getopt.h>
+#include <stdio.h>
+#include <stdlib.h>
+
+
+/**
+ * Static prototypes
+ */
+
+/**
+ * Initialise a command line options struct with default values and exit on failure.
+ *
+ * @param opts pointer to the options struct
+ */
+static void init_opts(bb_cli_opts *opts);
+
+/**
+ * Output usage instructions.
+ */
+static void print_usage();
+
+
+/**
+ * Static functions
+ */
+
+static void init_opts(bb_cli_opts *opts) {
+    opts->rotation = LV_DISP_ROT_NONE;
+}
+
+static void print_usage() {
+    fprintf(stderr,
+        /*-------------------------------- 78 CHARS --------------------------------*/
+        "Usage: buffyboard [OPTION]\n"
+        "\n"
+        "Mandatory arguments to long options are mandatory for short options too.\n"
+        "  -r, --rotate=[0-3]  Rotate the UI to the given orientation.\n"
+        "                        0 - normal orientation (0 degree)\n"
+        "                        1 - clockwise orientation (90 degrees)\n"
+        "                        2 - upside down orientation (180 degrees)\n"
+        "                        3 - counterclockwise orientation (270 degrees)\n"
+        "                      The values match the ones provided by the kernel in\n"
+        "                      /sys/class/graphics/fbcon/rotate.\n"
+        "  -h, --help          Print this message and exit\n"
+        "  -V, --version       Print the buffyboard version and exit\n");
+        /*-------------------------------- 78 CHARS --------------------------------*/
+}
+
+
+/**
+ * Public functions
+ */
+
+void bb_cli_parse_opts(int argc, char *argv[], bb_cli_opts *opts) {
+    init_opts(opts);
+
+    struct option long_opts[] = {
+        { "rotate",  required_argument, NULL, 'r' },
+        { "help",    no_argument,       NULL, 'h' },
+        { "version", no_argument,       NULL, 'V' },
+        { NULL, 0, NULL, 0 }
+    };
+
+    int opt, index = 0;
+
+    while ((opt = getopt_long(argc, argv, "r:hV", long_opts, &index)) != -1) {
+        switch (opt) {
+        case 'r': {
+            int orientation;
+            if (sscanf(optarg, "%i", &orientation) != 1 || orientation < 0 || orientation > 3) {
+                fprintf(stderr, "Invalid orientation argument \"%s\"\n", optarg);
+                exit(EXIT_FAILURE);
+            }
+            switch (orientation) {
+                case 0:
+                    opts->rotation = LV_DISP_ROT_NONE;
+                    break;
+                case 1:
+                    opts->rotation = LV_DISP_ROT_270;
+                    break;
+                case 2:
+                    opts->rotation = LV_DISP_ROT_180;
+                    break;
+                case 3:
+                    opts->rotation = LV_DISP_ROT_90;
+                    break;
+            }
+            break;
+        }
+        case 'h':
+            print_usage();
+            exit(EXIT_SUCCESS);
+        case 'V':
+            fprintf(stderr, "buffyboard %s\n", BB_VERSION);
+            exit(0);
+        default:
+            print_usage();
+            exit(EXIT_FAILURE);
+        }
+    }
+}

command_line.h

@@ -0,0 +1,43 @@
+/**
+ * Copyright 2021 Johannes Marbach
+ *
+ * This file is part of buffyboard, hereafter referred to as the program.
+ *
+ * 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 3 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, see <https://www.gnu.org/licenses/>.
+ */
+
+
+#ifndef BB_COMMAND_LINE_H
+#define BB_COMMAND_LINE_H
+
+#include "lvgl/lvgl.h"
+
+/**
+ * Options parsed from command line arguments
+ */
+typedef struct {
+    /* Display rotation */
+    lv_disp_rot_t rotation;
+} bb_cli_opts;
+
+/**
+ * Parse command line arguments and exit on failure.
+ *
+ * @param argc number of provided command line arguments
+ * @param argv arguments as an array of strings
+ * @param opts pointer for writing the parsed options into
+ */
+void bb_cli_parse_opts(int argc, char *argv[], bb_cli_opts *opts);
+
+#endif /* BB_COMMAND_LINE_H */

main.c

@@ -18,6 +18,7 @@
  */
 
 
+#include "command_line.h"
 #include "indev.h"
 #include "sq2lv_layouts.h"
 #include "terminal.h"
@@ -50,6 +51,8 @@ LV_FONT_DECLARE(font_32);
  * Static variables
  */
 
+bb_cli_opts cli_opts;
+
 static bool resize_terminals = false;
 static lv_obj_t *keyboard = NULL;
 static lv_style_t style_text_normal;
@@ -243,7 +246,10 @@ static void pop_checked_modifier_keys(void) {
  * Main
  */
 
-int main(void) {
+int main(int argc, char *argv[]) {
+    /* Parse command line options */
+    bb_cli_parse_opts(argc, argv, &cli_opts);
+
     /* Prepare for terminal resizing and reset */
     resize_terminals = bb_terminal_init(2.0f / 3.0f);
     if (resize_terminals) {
@@ -276,18 +282,18 @@ int main(void) {
     static lv_disp_drv_t disp_drv;
     lv_disp_drv_init(&disp_drv);
     disp_drv.flush_cb = fbdev_flush;
-    disp_drv.rotated = LV_DISP_ROT_NONE;
+    disp_drv.rotated = cli_opts.rotation;
     disp_drv.sw_rotate = true;
     disp_drv.physical_hor_res = hor_res_phys;
     disp_drv.physical_ver_res = ver_res_phys;
-    switch (disp_drv.rotated) {
+    switch (cli_opts.rotation) {
         case LV_DISP_ROT_NONE:
         case LV_DISP_ROT_180: {
             lv_coord_t denom = keyboard_height_denominator(hor_res_phys, ver_res_phys);
             disp_drv.hor_res = hor_res_phys;
             disp_drv.ver_res = ver_res_phys / denom;
             disp_drv.offset_x = 0;
-            disp_drv.offset_y = (disp_drv.rotated == LV_DISP_ROT_NONE) ? (denom - 1) * ver_res_phys / denom : 0;
+            disp_drv.offset_y = (cli_opts.rotation == LV_DISP_ROT_NONE) ? (denom - 1) * ver_res_phys / denom : 0;
             break;
         }
         case LV_DISP_ROT_90:
@@ -295,7 +301,7 @@ int main(void) {
             lv_coord_t denom = keyboard_height_denominator(ver_res_phys, hor_res_phys);
             disp_drv.hor_res = hor_res_phys / denom;
             disp_drv.ver_res = ver_res_phys;
-            disp_drv.offset_x = (disp_drv.rotated == LV_DISP_ROT_90) ? (denom - 1) * hor_res_phys / denom : 0;
+            disp_drv.offset_x = (cli_opts.rotation == LV_DISP_ROT_90) ? (denom - 1) * hor_res_phys / denom : 0;
             disp_drv.offset_y = 0;
             break;
         }

meson.build

@@ -19,12 +19,15 @@
 project(
   'buffyboard',
   'c',
-  version: '0.0.0',
+  version: '0.1.0',
   default_options: 'warning_level=1',
   meson_version: '>=0.53.0'
 )
 
+add_project_arguments('-DBB_VERSION="@0@"'.format(meson.project_version()), language: ['c'])
+
 buffyboard_sources = [
+  'command_line.c',
   'cursor.c',
   'font_32.c',
   'indev.c',