Add support for SDL_GAMECONTROLLERCONFIG environment variable

src/input/mapping.c

@@ -24,35 +24,18 @@
 #include <stdbool.h>
 #include <string.h>
 
-struct mapping* mapping_load(char* fileName, bool verbose) {
-  struct mapping* mappings = NULL;
-  struct mapping* map = NULL;
-  FILE* fd = fopen(fileName, "r");
-  if (fd == NULL) {
-    fprintf(stderr, "Can't open mapping file: %s\n", fileName);
-    exit(EXIT_FAILURE);
-  } else if (verbose)
-    printf("Loading mappingfile %s\n", fileName);
-
-  char *line = NULL;
-  size_t len = 0;
-  while (getline(&line, &len, fd) != -1) {
+struct mapping* mapping_parse(char* mapping) {
   char* strpoint;
-    char* guid = strtok_r(line, ",", &strpoint);
+  char* guid = strtok_r(mapping, ",", &strpoint);
   char* name = strtok_r(NULL, ",", &strpoint);
   if (guid == NULL || name == NULL)
-      continue;
+    return NULL;
 
-    struct mapping* newmap = malloc(sizeof(struct mapping));
-    if (newmap == NULL) {
+  struct mapping* map = malloc(sizeof(struct mapping));
+  if (map == NULL) {
     fprintf(stderr, "Not enough memory");
     exit(EXIT_FAILURE);
-    } else if (mappings == NULL)
-      mappings = newmap;
-    else
-      map->next = newmap;
-
-    map = newmap;
+  }
 
   strncpy(map->guid, guid, sizeof(map->guid));
   strncpy(map->name, name, sizeof(map->name));
@@ -146,6 +129,26 @@ struct mapping* mapping_load(char* fileName, bool verbose) {
   map->guid[32] = '\0';
   map->name[256] = '\0';
   map->platform[32] = '\0';
+  return map;
+}
+
+struct mapping* mapping_load(char* fileName, bool verbose) {
+  struct mapping* mappings = NULL;
+  FILE* fd = fopen(fileName, "r");
+  if (fd == NULL) {
+    fprintf(stderr, "Can't open mapping file: %s\n", fileName);
+    exit(EXIT_FAILURE);
+  } else if (verbose)
+    printf("Loading mappingfile %s\n", fileName);
+
+  char *line = NULL;
+  size_t len = 0;
+  while (getline(&line, &len, fd) != -1) {
+    struct mapping* map = mapping_parse(line);
+    if (map) {
+      map->next = mappings;
+      mappings = map;
+    }
   }
   free(line);
 

src/input/mapping.h

@@ -47,4 +47,5 @@ struct mapping {
   struct mapping* next;
 };
 
+struct mapping* mapping_parse(char* mapping);
 struct mapping* mapping_load(char* fileName, bool verbose);

src/main.c

@@ -252,11 +252,21 @@ int main(int argc, char* argv[]) {
     config.stream.supportsHevc = config.codec != CODEC_H264 && (config.codec == CODEC_HEVC || platform_supports_hevc(system));
 
     if (IS_EMBEDDED(system)) {
-      if (config.mapping == NULL) {
+      char* mapping_env = getenv("SDL_GAMECONTROLLERCONFIG");
+      if (config.mapping == NULL && mapping_env == NULL) {
         fprintf(stderr, "Please specify mapping file as default mapping could not be found.\n");
         exit(-1);
       }
-      struct mapping* mappings = mapping_load(config.mapping, config.debug_level > 0);
+
+      struct mapping* mappings;
+      if (config.mapping != NULL)
+        mappings = mapping_load(config.mapping, config.debug_level > 0);
+
+      if (mapping_env != NULL) {
+        struct mapping* map = mapping_parse(mapping_env);
+        map->next = mappings;
+        mappings = map;
+      }
 
       for (int i=0;i<config.inputsCount;i++) {
         if (config.debug_level > 0)