hardware: Move keyIndex to key_indexes.h

Since `keyIndex` is pretty much the same for all boards, it makes sense to have
it in `key_indexes.h`. To be able to do that, we need to implement it as a
macro, otherwise `HARDWARE_IMPLEMENTATION` can't be resolved. With a macro, it
is evaluated on call-sites, where the compiler can resolve that symbol.

Signed-off-by: Gergely Nagy <algernon@keyboard.io>

src/kaleidoscope/hardware/ErgoDox.h

@@ -187,18 +187,6 @@ class ErgoDox {
 }
 }
 
-/* To be used by the hardware implementations, `keyIndex` tells us the index of
- * a key, from which we can figure out the row and column as needed. The index
- * starts at one, so that plugins that work with a list of key indexes can use
- * zero as a sentinel. This is important, because when we initialize arrays with
- * fewer elements than the declared array size, the remaining elements will be
- * zero. We can use this to avoid having to explicitly add a sentinel in
- * user-facing code.
- */
-constexpr byte keyIndex(byte row, byte col) {
-  return row * kaleidoscope::hardware::ErgoDox::matrix_columns + col + 1;
-}
-
 #include "kaleidoscope/hardware/key_indexes.h"
 
 extern kaleidoscope::hardware::ErgoDox &ErgoDox;

src/kaleidoscope/hardware/Model01.h

@@ -137,25 +137,8 @@ class Model01 {
 }
 }
 
-#ifndef DOXYGEN_SHOULD_SKIP_THIS
-
-/* To be used by the hardware implementations, `keyIndex` tells us the index of
- * a key, from which we can figure out the row and column as needed. The index
- * starts at one, so that plugins that work with a list of key indexes can use
- * zero as a sentinel. This is important, because when we initialize arrays with
- * fewer elements than the declared array size, the remaining elements will be
- * zero. We can use this to avoid having to explicitly add a sentinel in
- * user-facing code.
- */
-constexpr byte keyIndex(byte row, byte col) {
-  return row * kaleidoscope::hardware::Model01::matrix_columns + col + 1;
-}
-
 #include "kaleidoscope/hardware/key_indexes.h"
 
-#endif /* DOXYGEN_SHOULD_SKIP_THIS */
-
-
 #define KEYMAP_STACKED(                                                 \
                r0c0, r0c1, r0c2, r0c3, r0c4, r0c5, r0c6,                \
                r1c0, r1c1, r1c2, r1c3, r1c4, r1c5, r1c6,                \

src/kaleidoscope/hardware/key_indexes.h

@@ -17,6 +17,20 @@
 
 #pragma once
 
+/* To be used by the hardware implementations, `keyIndex` tells us the index of
+ * a key, from which we can figure out the row and column as needed. The index
+ * starts at one, so that plugins that work with a list of key indexes can use
+ * zero as a sentinel. This is important, because when we initialize arrays with
+ * fewer elements than the declared array size, the remaining elements will be
+ * zero. We can use this to avoid having to explicitly add a sentinel in
+ * user-facing code.
+ *
+ * We're using a macro instead of a constexpr so that it is evaluated lazily,
+ * when `HARDWARE_IMPLEMENTATION` can be properly resolved.
+ */
+#define keyIndex(row,col)                                               \
+  (uint8_t)((row * HARDWARE_IMPLEMENTATION::matrix_columns) + col + 1)
+
 constexpr uint8_t R0C0 = keyIndex(0, 0);
 constexpr uint8_t R0C1 = keyIndex(0, 1);
 constexpr uint8_t R0C2 = keyIndex(0, 2);

src/kaleidoscope/hardware/olkb/Planck.h

@@ -59,18 +59,6 @@ class Planck: public kaleidoscope::hardware::ATMegaKeyboard {
 }
 }
 
-/* To be used by the hardware implementations, `keyIndex` tells us the index of
- * a key, from which we can figure out the row and column as needed. The index
- * starts at one, so that plugins that work with a list of key indexes can use
- * zero as a sentinel. This is important, because when we initialize arrays with
- * fewer elements than the declared array size, the remaining elements will be
- * zero. We can use this to avoid having to explicitly add a sentinel in
- * user-facing code.
- */
-constexpr uint8_t keyIndex(byte row, byte col) {
-  return (row * kaleidoscope::hardware::olkb::Planck::matrix_columns) + col + 1;
-}
-
 #include "kaleidoscope/hardware/key_indexes.h"
 
 extern kaleidoscope::hardware::olkb::Planck &Planck;

src/kaleidoscope/hardware/technomancy/Atreus.h

@@ -89,18 +89,6 @@ class Atreus: public kaleidoscope::hardware::ATMegaKeyboard {
 }
 }
 
-/* To be used by the hardware implementations, `keyIndex` tells us the index of
- * a key, from which we can figure out the row and column as needed. The index
- * starts at one, so that plugins that work with a list of key indexes can use
- * zero as a sentinel. This is important, because when we initialize arrays with
- * fewer elements than the declared array size, the remaining elements will be
- * zero. We can use this to avoid having to explicitly add a sentinel in
- * user-facing code.
- */
-constexpr byte keyIndex(byte row, byte col) {
-  return row * kaleidoscope::hardware::technomancy::Atreus::matrix_columns + col + 1;
-}
-
 #include "kaleidoscope/hardware/key_indexes.h"
 
 extern kaleidoscope::hardware::technomancy::Atreus &Atreus;