Apply clang-tidy style fixes to audio and input code

Use explicit != 0U comparisons for bitmask checks, static_cast instead
of C-style casts, <cstdint>/<cstdio> instead of the C headers, and
puts() instead of iprintf() for plain strings.

source/game_input.cpp

@@ -1,22 +1,24 @@
 #include "game_input.h"
 
 #include <bitset>
-#include <stdio.h>
+#include <cstdint>
+#include <cstdio>
 
 bool handle_input_frame(InputContext &ctx) {
     scanKeys();
-    const int keys = keysDown();
+    const uint32_t keys = keysDown();
 
-    if (keys && *ctx.internals) {
+    if ((keys != 0U) && *ctx.internals) {
         consoleSelect(ctx.topScreen);
-        iprintf("\x1b[6;0Hkeys = %s", std::bitset<16>(keys).to_string().c_str());
+        std::string key_str = "\x1b[6;0Hkeys = " + std::bitset<16>(keys).to_string();
+        puts(key_str.c_str());
     }
 
-    if ((keys & KEY_START) && (keys & KEY_L)) {
+    if (((keys & KEY_START) != 0U) && ((keys & KEY_L) != 0U)) {
         return false;
     }
 
-    if (keys & KEY_SELECT) {
+    if ((keys != 0U) && ((keys & KEY_SELECT) != 0U)) {
         *ctx.internals = !(*ctx.internals);
         if (*ctx.internals) {
             setBackdropColor(RGB15(0, 0, 7));
@@ -28,44 +30,44 @@ bool handle_input_frame(InputContext &ctx) {
     }
 
     if (!ctx.state->paused && !ctx.state->gameOver) {
-        if (keys & KEY_UP) {
+        if ((keys != 0U) && ((keys & KEY_UP) != 0U)) {
             ctx.state->snakeDirection = 0;
             draw_game(*ctx.state, *ctx.renderAssets);
         }
 
-        if (keys & KEY_RIGHT) {
+        if ((keys != 0U) && ((keys & KEY_RIGHT) != 0U)) {
             ctx.state->snakeDirection = 1;
             draw_game(*ctx.state, *ctx.renderAssets);
         }
 
-        if (keys & KEY_DOWN) {
+        if ((keys != 0U) && ((keys & KEY_DOWN) != 0U)) {
             ctx.state->snakeDirection = 2;
             draw_game(*ctx.state, *ctx.renderAssets);
         }
 
-        if (keys & KEY_LEFT) {
+        if ((keys != 0U) && ((keys & KEY_LEFT) != 0U)) {
             ctx.state->snakeDirection = 3;
             draw_game(*ctx.state, *ctx.renderAssets);
         }
     }
 
     if (ctx.state->paused) {
-        if (keys & KEY_X) {
+        if ((keys != 0U) && ((keys & KEY_X) != 0U)) {
             audio_toggle_music(*ctx.audio);
         }
 
-        if (keys & KEY_Y) {
+        if ((keys != 0U) && ((keys & KEY_Y) != 0U)) {
             ctx.state->hardMode = !ctx.state->hardMode;
             ctx.init_game();
             draw_game(*ctx.state, *ctx.renderAssets);
         }
     }
 
-    if (keys & KEY_R) {
+    if ((keys != 0U) && ((keys & KEY_R) != 0U)) {
         lcdSwap();
     }
 
-    if (keys & KEY_START) {
+    if ((keys != 0U) && ((keys & KEY_START) != 0U)) {
         if (!ctx.state->gameOver) {
             ctx.state->paused = !ctx.state->paused;
 
@@ -73,7 +75,7 @@ bool handle_input_frame(InputContext &ctx) {
                 consoleSelect(ctx.topScreen);
                 audio_play_pause(*ctx.audio);
                 audio_pause_music_if_enabled(*ctx.audio);
-                iprintf("\x1b[11;12HPaused");
+                puts("\x1b[11;12HPaused");
             } else {
                 audio_resume_music_if_enabled(*ctx.audio);
                 audio_play_unpause(*ctx.audio);