trying to read commands from std while displaying things, fixes

Makefile

@@ -13,5 +13,3 @@ $(objects): %.o: %.c
 clean:
 	rm -f *.o glonkers
 
-run: glonkers
-	SDL_VIDEODRIVER="wayland,x11" ./glonkers

glonkers.c

@@ -1,10 +1,12 @@
 #include <stdio.h>
 #include <stdlib.h>
+#include <signal.h>
 #include <time.h> 
 #include <stdint.h>
 #include <wayland-client.h>
 #include <wayland-util.h>
 #include <SDL3/SDL.h>
+#include <pthread.h>
 #include "renderer.h"
 
 //int main() {
@@ -79,7 +81,34 @@ double time_since_start() {
            (now.tv_nsec - program_start.tv_nsec) / 1e9;
 }
 
+_Atomic bool running = true;
+
+void intHandler(int dummy) {
+    printf("exiting\n");
+    running = false;
+    fclose(stdin);
+}
+
+bool reload_shader = false;
+
+/// reads stdin on a separate thread.
+void *read_stdin(void *ptr) {
+    char buff[10];
+    while (running) {
+        fgets(buff, 10, stdin);
+        if (strcmp(buff, "r\n") == 0) {
+            printf("reloading shader\n");
+            reload_shader = true;
+        }
+    }
+    return NULL;
+}
+
 int main(int argc, char *argv[]) {
+    signal(SIGINT, intHandler);
+    pthread_t stdin_thread;
+    pthread_create( &stdin_thread, NULL, read_stdin, NULL);
+
     init_timer();
 
     printf("Good Morning 🍵\n");
@@ -109,7 +138,6 @@ int main(int argc, char *argv[]) {
     Renderer renderer = new_renderer();
 
     SDL_Event e;
-    int running = 1;
     int w, h;
     while (running) {
         while (SDL_PollEvent(&e)) {
@@ -128,9 +156,12 @@ int main(int argc, char *argv[]) {
         }
 
         double time = time_since_start();
-        render(&renderer, w, h, time, shader_path);
+        render(&renderer, w, h, time, shader_path, reload_shader);
+        if (reload_shader) reload_shader = false;
 
         SDL_GL_SwapWindow(window);
     }
+
+    pthread_join(stdin_thread, NULL);
 }
 

renderer.c

@@ -68,12 +68,16 @@ GLuint create_shader(const char *fragment_src) {
 
 GLuint load_shader(const char *path) {
     FILE *handle = fopen(path, "r");
+    if (handle == NULL) {
+        printf("failed to open shader file\n");
+        exit(1);
+    }
     fseek(handle, 0L, SEEK_END);
     long length = ftell(handle);
     fseek(handle, 0L, SEEK_SET);
     char *string = malloc(length * sizeof(char));
     if (!fread(string, sizeof(char), length, handle)) {
-        printf("failed to read shader file");
+        printf("failed to read shader file\n");
         exit(1);
     }
     fclose(handle);
@@ -143,9 +147,10 @@ Renderer new_renderer() {
 }
 
 /// shader_path cannot be NULL.
-void render(Renderer *state, int w, int h, double time, char *shader_path) {
-    if (strcmp(state->shader_path, shader_path)) {
+void render(Renderer *state, int w, int h, double time, char *shader_path, int reload_shader) {
+    if (reload_shader || strcmp(state->shader_path, shader_path)) {
         state->shader = load_shader(shader_path);
+        state->shader_path = shader_path;
     }
 
     checkGlError();

renderer.h

@@ -8,7 +8,7 @@ typedef struct Renderer {
 } Renderer;
 
 Renderer new_renderer();
-void render(Renderer *renderer, int w, int h, double time, char *shader_path);
+void render(Renderer *renderer, int w, int h, double time, char *shader_path, int reload_shader);
 
 #endif
 

run.sh

@@ -1,3 +1,3 @@
 make
-./glonkers "$@"
+SDL_VIDEODRIVER="wayland,x11" ./glonkers "$@"