clarify code: local variables in start of function

src/args.c

@@ -47,11 +47,12 @@ static char *split_arg_value(char *arg) {
 static bool is_digit(char c) { return c >= '0' && c <= '9'; }
 
 static bool is_number(char *value) {
+  unsigned long value_len;
+  unsigned int i;
   if (value == NULL) {
     return false;
   }
-  unsigned long value_len = strlen(value);
-  unsigned int i;
+  value_len = strlen(value);
   for (i = 0; i < value_len; i++) {
     if (!is_digit(value[i])) {
       return false;
@@ -72,11 +73,15 @@ static unsigned char parse_uchar(char *arg, char *value) {
 }
 
 Parameters args_parse(int argc, char **argv) {
-  Parameters params = {0, 0, false};
-
+  Parameters params;
   int i;
   char *arg;
   char *value;
+
+  params.screen = 0;
+  params.frag_path = 0;
+  params.hot_reload = false;
+
   for (i = 1; i < argc; i++) {
     arg = argv[i];
     value = split_arg_value(arg);

src/file.c

@@ -1,3 +1,4 @@
+#include <GLFW/glfw3.h>
 #include <stdbool.h>
 #include <stdio.h>
 #include <stdlib.h>
@@ -22,6 +23,9 @@ bool file_should_update(File file) {
 }
 
 void file_update(File *file) {
+  long length;
+  FILE *file_pointer;
+
   // free remaining data
   if (file->content != 0) {
     free(file->content);
@@ -30,9 +34,9 @@ void file_update(File *file) {
   // init empty file
   file->content = 0;
   file->error = false;
-  long length;
+
   // open file
-  FILE *file_pointer = fopen(file->path, "rb");
+  file_pointer = fopen(file->path, "rb");
   if (file_pointer == NULL) {
     file->error = true;
     log_error("Cannot open file '%s'", file->path);
@@ -61,18 +65,28 @@ void file_update(File *file) {
 }
 
 File file_read(char *path) {
-  File file = {path, 0, false, 0};
+  File file;
+
+  file.path = path;
+  file.content = NULL;
+  file.error = false;
+  file.last_write = 0;
+
   file_update(&file);
   return file;
 }
 
 void file_prepend(File *src, File extra) {
-  char *old_src_content = src->content;
+  char *old_src_content;
+
+  old_src_content = src->content;
   src->content = strings_concat(extra.content, src->content);
   free(old_src_content);
 }
 
-void file_free(File *file) {
+void file_free(File *file, bool free_path) {
   free(file->content);
-  free(file->path);
+  if (free_path) {
+    free(file->path);
+  }
 }

src/file.h

@@ -11,6 +11,6 @@ void file_update(File *file);
 
 void file_prepend(File *src, File extra);
 
-void file_free(File *file);
+void file_free(File *file, bool free_path);
 
 #endif /* FILE_H */

src/forge.c

@@ -42,7 +42,9 @@ static int compute_fps(Window *window, Timer *timer) {
 static void hot_reload(ShaderProgram program, File *common_shader_code,
                        File *fragment_shaders) {
   int i;
-  bool force_update = false;
+  bool force_update;
+
+  force_update = false;
 
   if (file_should_update(*common_shader_code)) {
     file_update(common_shader_code);
@@ -78,7 +80,9 @@ static void loop(Window *window, ShaderProgram program, bool hr,
 
 File read_fragment_shader_file(char *frag_path, int i) {
   File fragment_shader;
-  char *file_path = malloc(sizeof(char) * 1024);
+  char *file_path;
+
+  file_path = malloc(sizeof(char) * 1024);
 
   sprintf(file_path, "%s/frag%d.glsl", frag_path, i);
   fragment_shader = file_read(file_path);
@@ -108,10 +112,10 @@ static void free_files(File *common_shader_code, File *fragment_shaders) {
   int i;
 
   for (i = 0; i < FRAG_COUNT; i++) {
-    file_free(&fragment_shaders[i]);
+    file_free(&fragment_shaders[i], true);
   }
 
-  file_free(common_shader_code);
+  file_free(common_shader_code, true);
 }
 
 void forge_run(Parameters params) {

src/main.c

@@ -8,8 +8,12 @@
 
 int main(int argc, char **argv) {
   Parameters params;
+
   params = args_parse(argc, argv);
+
   puts(PACKAGE " " VERSION);
+
   forge_run(params);
+
   return EXIT_SUCCESS;
 }

src/shaders.c

@@ -188,9 +188,11 @@ static void init_single_program(ShaderProgram *program, int i, bool output) {
 
 ShaderProgram shaders_init(File *fragment_shaders, Context context) {
   int i;
-  ShaderProgram program = {.error = false,
-                           .last_width = context.width,
-                           .last_height = context.height};
+  ShaderProgram program;
+
+  program.error = false;
+  program.last_width = context.width;
+  program.last_height = context.height;
 
   init_textures(&program, context);
 
@@ -233,6 +235,7 @@ void shaders_update(ShaderProgram program, File *fragment_shaders, int i) {
 void shaders_apply(ShaderProgram program, Context context) {
   int i, j;
   GLuint subroutines[3];
+  vec2 resolution;
 
   // viewport changed
   if (context.width != program.last_width ||
@@ -248,7 +251,8 @@ void shaders_apply(ShaderProgram program, Context context) {
     }
   }
 
-  vec2 resolution = {(float)context.width, (float)context.height};
+  resolution[0] = (float)context.width;
+  resolution[1] = (float)context.height;
 
   for (i = 0; i < FRAG_COUNT + 1; i++) {
     // use specific shader program

src/strings.c

@@ -2,10 +2,12 @@
 #include <string.h>
 
 char *strings_concat(const char *s1, const char *s2) {
-  char *result =
-      malloc(strlen(s1) + strlen(s2) + 1); // +1 for the null-terminator
-  // in real code you would check for errors in malloc here
+  char *result;
+
+  result = malloc(strlen(s1) + strlen(s2) + 1); // +1 for the null-terminator
+
   strcpy(result, s1);
   strcat(result, s2);
+
   return result;
 }

src/timer.c

@@ -3,10 +3,10 @@
 #include "types.h"
 
 Timer timer_init(const unsigned int target) {
-  Timer output = {
-      .counter = 0,
-      .target = target,
-  };
+  Timer output;
+
+  output.counter = 0;
+  output.target = target;
 
   gettimeofday(&output.start, NULL);
 
@@ -21,11 +21,15 @@ bool timer_inc(Timer *timer) {
 double timer_reset(Timer *timer) {
   struct timeval stop;
   double secs, per_secs;
+
   gettimeofday(&stop, NULL);
+
   secs = (double)(stop.tv_usec - timer->start.tv_usec) / 1000000 +
          (double)(stop.tv_sec - timer->start.tv_sec);
   per_secs = ((float)timer->counter) / secs;
+
   timer->start = stop;
   timer->counter = 0;
+
   return per_secs;
 }

src/window.c

@@ -33,9 +33,11 @@ static void init_glfw(void (*error_callback)(int, const char *)) {
 }
 
 static GLFWmonitor *get_monitor(unsigned char monitor_index) {
-  // detect monitors
   int count;
-  GLFWmonitor **monitors = glfwGetMonitors(&count);
+  GLFWmonitor **monitors;
+
+  // detect monitors
+  monitors = glfwGetMonitors(&count);
 
   // check selected monitor availability
   if (monitor_index >= count) {
@@ -51,6 +53,7 @@ static GLFWmonitor *get_monitor(unsigned char monitor_index) {
 static GLFWwindow *create_window(GLFWmonitor *monitor, char *title,
                                  void (*key_callback)(Window *, int, int, int,
                                                       int)) {
+  GLFWwindow *window;
 
   log_info("[GLFW] Creating window...");
 
@@ -61,7 +64,7 @@ static GLFWwindow *create_window(GLFWmonitor *monitor, char *title,
   glfwWindowHint(GLFW_FOCUS_ON_SHOW, GLFW_FALSE);
 
   // create fullscreen window in selected monitor
-  GLFWwindow *window = glfwCreateWindow(1, 1, title, monitor, NULL);
+  window = glfwCreateWindow(1, 1, title, monitor, NULL);
 
   // handle window creation fail
   if (window == NULL) {