feat!: initialisation supports custom keycount

Previously, SQUIRREL would allocate memory for each key statically - at
build-time, but now you can specify the amount of keys in your keyboard
in the call to squirrel_init, meaning you can use the same version of
the library for multiple keyboards - instead of recompiling if your
keycount changes.

TODO: test this on real hardware

BREAKING CHANGE: squirrel_init now takes the amount of keys as an
argument, instead of being declared at build-time

CMakeLists.txt

@@ -2,11 +2,6 @@ cmake_minimum_required(VERSION 3.12)
 
 project(squirrel)
 
-# target_compile_definitions(squirrel PUBLIC SQUIRREL_KEYCOUNT=your_keycount)
-# Override this using the above line in your build of the library! Otherwise, it
-# will default to 1 key.
-add_compile_definitions(SQUIRREL_KEYCOUNT=1)
-
 if(CMAKE_BUILD_TYPE STREQUAL "Debug")
   set(CMAKE_EXPORT_COMPILE_COMMANDS ON)
   add_compile_options(-Og)

flake.nix

@@ -19,8 +19,6 @@
               gcovr
             ];
           };
-          # Reminder! If you want to use SQUIRREL as a library in one of your projects, you MUST build it yourself by adding the directory to your project with CMAKE and changing SQUIRREL_KEYCOUNT, for example:
-          # add_compile_definitions(SQUIRREL_KEYCOUNT=100)
           packages.squirrel = pkgs.stdenv.mkDerivation {
             name = "squirrel";
             src = ./.;

include/squirrel.h

@@ -5,6 +5,7 @@
 
 enum squirrel_error {
   ERR_NONE = 0,
+  ERR_OOM,
   ERR_PASSTHROUGH_ON_BOTTOM_LAYER,
 };
 

include/squirrel_init.h

@@ -1,4 +1,4 @@
 #pragma once
 
-enum squirrel_error
-squirrel_init(void); // Initialize the keyboard with the total number of keys.
+enum squirrel_error squirrel_init(
+    int keys); // Initialize the keyboard with the total number of keys.

include/squirrel_key.h

@@ -23,7 +23,7 @@ release_key(uint8_t key_index); // Release the key at the index in the
 
 // key_states is an array of booleans that represent the state of each key. Used
 // by check_key to determine if a key is pressed or released.
-extern bool key_states[SQUIRREL_KEYCOUNT];
+extern bool *key_states;
 
 // check_key compares the state of the key at the index to the key_states array
 // to determine if the key is pressed or released, and calls the appropriate

include/squirrel_quantum.h

@@ -9,7 +9,7 @@
 
 struct layer {
   bool active; // true if this layer is currently active
-  struct key keys[SQUIRREL_KEYCOUNT];
+  struct key *keys;
 };
 
 // layers is a list of all the layers in the keyboard. 0-15 are configured,

src/squirrel_init.c

@@ -7,17 +7,27 @@
 #include <stdlib.h>
 #include <string.h>
 
-enum squirrel_error squirrel_init(void) {
+enum squirrel_error squirrel_init(int keys) {
   struct key passthrough_key = (struct key){
       .pressed = quantum_passthrough_press,
       .released = quantum_passthrough_release,
   };
   for (int j = 16; j >= 0; j--) {
     layers[j].active = false;
-    for (int i = 0; i < SQUIRREL_KEYCOUNT; i++) {
+    layers[j].keys = malloc(sizeof(struct key) * keys);
+    if (layers[j].keys == NULL) {
+      return ERR_OOM;
+    }
+    for (int i = 0; i < keys; i++) {
       copy_key(&passthrough_key, &layers[j].keys[i]);
     }
   }
   layers[16].active = true;
+  key_states = malloc(sizeof(bool) * keys);
+
+  if (key_states == NULL) {
+    return ERR_OOM;
+  }
+
   return ERR_NONE;
 };

src/squirrel_key.c

@@ -52,7 +52,7 @@ enum squirrel_error release_key(uint8_t key_index) {
   return ERR_NONE;
 }
 
-bool key_states[SQUIRREL_KEYCOUNT];
+bool *key_states;
 
 enum squirrel_error check_key(uint8_t key_index, bool is_pressed) {
   if (key_states[key_index] == is_pressed) {

tests/CMakeLists.txt

@@ -4,23 +4,27 @@ enable_testing()
 
 list(APPEND CMAKE_MODULE_PATH "${CMAKE_SOURCE_DIR}/CMakeModules")
 if(CMAKE_COMPILER_IS_GNUCXX)
-    include(CodeCoverage)
-    APPEND_COVERAGE_COMPILER_FLAGS()
-    setup_target_for_coverage_gcovr_html(squirrel squirrel_test coverage)
-    list(APPEND GCOVR_EXCLUDES "tests/")
+  include(CodeCoverage)
+  append_coverage_compiler_flags()
+  setup_target_for_coverage_gcovr_html(squirrel squirrel_test coverage)
+  list(APPEND GCOVR_EXCLUDES "tests/")
 endif()
 
 add_executable(keyboard_press_release tests/keyboard_press_release.c)
 target_link_libraries(keyboard_press_release squirrel)
 add_test(NAME keyboard_press_release COMMAND keyboard_press_release)
 
-add_executable(keyboard_modifier_press_release tests/keyboard_modifier_press_release.c)
+add_executable(keyboard_modifier_press_release
+               tests/keyboard_modifier_press_release.c)
 target_link_libraries(keyboard_modifier_press_release squirrel)
-add_test(NAME keyboard_modifier_press_release COMMAND keyboard_modifier_press_release)
+add_test(NAME keyboard_modifier_press_release
+         COMMAND keyboard_modifier_press_release)
 
-add_executable(quantum_passthrough_press_release tests/quantum_passthrough_press_release.c)
+add_executable(quantum_passthrough_press_release
+               tests/quantum_passthrough_press_release.c)
 target_link_libraries(quantum_passthrough_press_release squirrel)
-add_test(NAME quantum_passthrough_press_release COMMAND quantum_passthrough_press_release)
+add_test(NAME quantum_passthrough_press_release
+         COMMAND quantum_passthrough_press_release)
 
 add_executable(keyboard_get_keycodes tests/keyboard_get_keycodes.c)
 target_link_libraries(keyboard_get_keycodes squirrel)
@@ -38,19 +42,24 @@ add_executable(layer_press_release tests/layer_press_release.c)
 target_link_libraries(layer_press_release squirrel)
 add_test(NAME layer_press_release COMMAND layer_press_release)
 
-add_executable(consumer_activate_deactivate_get_consumer_code tests/consumer_activate_deactivate_get_consumer_code.c)
+add_executable(consumer_activate_deactivate_get_consumer_code
+               tests/consumer_activate_deactivate_get_consumer_code.c)
 target_link_libraries(consumer_activate_deactivate_get_consumer_code squirrel)
-add_test(NAME consumer_activate_deactivate_get_consumer_code COMMAND consumer_activate_deactivate_get_consumer_code)
+add_test(NAME consumer_activate_deactivate_get_consumer_code
+         COMMAND consumer_activate_deactivate_get_consumer_code)
 
-add_executable(keyboard_activate_deactivate_keycode tests/keyboard_activate_deactivate_keycode.c)
+add_executable(keyboard_activate_deactivate_keycode
+               tests/keyboard_activate_deactivate_keycode.c)
 target_link_libraries(keyboard_activate_deactivate_keycode squirrel)
-add_test(NAME keyboard_activate_deactivate_keycode COMMAND keyboard_activate_deactivate_keycode)
+add_test(NAME keyboard_activate_deactivate_keycode
+         COMMAND keyboard_activate_deactivate_keycode)
 
-add_executable(keyboard_activate_deactivate_get_modifier tests/keyboard_activate_deactivate_get_modifier.c)
+add_executable(keyboard_activate_deactivate_get_modifier
+               tests/keyboard_activate_deactivate_get_modifier.c)
 target_link_libraries(keyboard_activate_deactivate_get_modifier squirrel)
-add_test(NAME keyboard_activate_deactivate_get_modifier COMMAND keyboard_activate_deactivate_get_modifier)
+add_test(NAME keyboard_activate_deactivate_get_modifier
+         COMMAND keyboard_activate_deactivate_get_modifier)
 
 add_executable(keymap tests/keymap.c)
 target_link_libraries(keymap squirrel)
-target_compile_definitions(keymap PRIVATE SQUIRREL_KEYCOUNT=2)
 add_test(NAME keymap COMMAND keymap)

tests/key.c

@@ -28,10 +28,8 @@ enum squirrel_error test_release(uint8_t layer, uint8_t key_index, void *arg) {
 }
 
 // test: press_key, release_key + check_key - in squirrel_key.c
-#define SQUIRREL_KEYCOUNT 1
-
 int main() {
-  squirrel_init();
+  squirrel_init(1);
 
   // press_key + release_key
   uint8_t code = 0xF0;

tests/layer_press_release.c

@@ -13,9 +13,8 @@
 // layer_solo_press
 // layer_solo_release
 // in squirrel_quantum.c
-#define SQUIRREL_KEYCOUNT 1
 int main() {
-  squirrel_init();
+  squirrel_init(1);
   enum squirrel_error err;
   struct key test_key;
 

tests/quantum_passthrough_press_release.c

@@ -31,9 +31,8 @@ enum squirrel_error bad_test_release(uint8_t layer, uint8_t key_index,
 
 // test: quantum_passthrough_press + quantum_passthrough_release test - in
 // squirrel_quantum.c
-#define SQUIRREL_KEYCOUNT 1
 int main() {
-  squirrel_init();
+  squirrel_init(1);
 
   struct key testkey;
   testkey.pressed = test_press;