Added better error handling

SimpleImageViewer.c

@@ -29,9 +29,19 @@ typedef struct{
     int h;
 } window_size_delta;
 
+static void error_exit(const char* msg){
+    printf("%s\n", msg);
+    exit(-1);
+}
+
+static void error_continue(const char* msg){
+    printf("%s\n", msg);
+}
+
 Image load_image_pixels_from_file(const char* filepath){
     Image image;
     image.pixels = stbi_load(filepath, &image.x, &image.y, &image.channels, DESIRED_IMAGE_CHANNELS);
+    if(!image.pixels) error_exit("Failed to load image from file!");
     return image;
 }
 
@@ -44,7 +54,7 @@ SDL_Window* create_window(const char* title, int w, int h){
     const SDL_InitFlags init_flags = SDL_INIT_VIDEO | SDL_INIT_EVENTS;
     const SDL_WindowFlags window_flags =  SDL_WINDOW_BORDERLESS | SDL_WINDOW_RESIZABLE;
 
-    SDL_Init(init_flags);
+    if(!SDL_Init(init_flags)) error_exit("Failed to initialize SDL!");
 
     /* Used when a larger window is wanted, image displaying is dynamically calculated
     int display_count;
@@ -63,14 +73,19 @@ SDL_Window* create_window(const char* title, int w, int h){
     */
 
     SDL_Window* window = SDL_CreateWindow(title, w, h, window_flags);
-    SDL_SetWindowAspectRatio(window, (float)w / (float)h, (float)w / (float)h);
+    if(!window) error_exit("Failed to create window!");
+    if(SDL_SetWindowAspectRatio(window, (float)w / (float)h, (float)w / (float)h)) error_continue("Failed to set window aspect ratio! Continueing...");
 
     return window;
 }
 
-void populate_image(SDL_Window* window, Image* image){
+bool populate_image(SDL_Window* window, Image* image){
     SDL_Surface* surface = SDL_GetWindowSurface(window);
     image->surface = SDL_CreateSurface(image->x, image->y, SDL_PIXELFORMAT_RGBA32);
+    if(!image->surface) {
+        error_continue("Failed to create image surface! Cleaning up and exiting...");
+        return false;
+    }
 
     SDL_Rect pixel = { 0, 0, 1, 1 };
     
@@ -92,15 +107,26 @@ void populate_image(SDL_Window* window, Image* image){
                                             image->pixels[current_pixel_idx + 2],
                                             image->pixels[current_pixel_idx + 3]);
 
-            SDL_FillSurfaceRect(image->surface, &pixel, color);
+            if(!SDL_FillSurfaceRect(image->surface, &pixel, color)) error_continue("Failed to fill surface rectangle! Trying to continue...");
         }
     }
 
     image->texture = SDL_CreateTextureFromSurface(SDL_GetRenderer(window), image->surface);
+    if(!image->texture){
+        error_continue("Failed to create texture from surface! Cleaning up and exiting...");
+        SDL_DestroySurface(image->surface);
+        return false;
+    };
+
+    return true;
 }
 
-void draw_image(SDL_Window* window, Image* image, float pixel_size_delta, int image_start_x, int image_start_y){
+bool draw_image(SDL_Window* window, Image* image, float pixel_size_delta, int image_start_x, int image_start_y){
     SDL_Surface* surface = SDL_GetWindowSurface(window);
+    if(!surface){
+        error_continue("Failed to get window surface! Cleaning up and exiting...");
+        return false;
+    }
 
     float pixel_size = pixel_size_delta;
     
@@ -111,12 +137,27 @@ void draw_image(SDL_Window* window, Image* image, float pixel_size_delta, int im
     
     SDL_FRect dst = { center_x - (image->x * pixel_size / 2) + image_start_x, center_y - (image->y * pixel_size / 2) + image_start_y, image->x * pixel_size, image->y * pixel_size };
     SDL_Renderer* renderer = SDL_GetRenderer(window);
-    SDL_RenderClear(renderer);
+    if(!renderer){
-    SDL_RenderTexture(renderer, image->texture, NULL, &dst);
+        error_continue("Failed to get window renderer! Cleaning up and exiting...");
-    SDL_RenderPresent(renderer);
+        return false;
+    }
+
+    if(!SDL_RenderClear(renderer)){
+        error_continue("Failed to clear renderer! Cleaning up and exiting...");
+        return false;
+    }
+    if(!SDL_RenderTexture(renderer, image->texture, NULL, &dst)){
+        error_continue("Failed to render texture! Cleaning up and exiting...");
+        return false;
+    }
+    if(!SDL_RenderPresent(renderer)){
+        error_continue("Failed to present renderer! Cleaning up and exiting...");
+        return false;
+    }
 
     printf("Redraw time: %.3fms\n", (SDL_GetTicksNS() - start) / 1000000.0);
 
+    return true;
 }
 
 int clamp(const int in, const int low, const int high){
@@ -198,8 +239,8 @@ void loop(SDL_Window* window, Image* image){
             if(event.type == SDL_EVENT_MOUSE_MOTION){
                 if(drag_left_mouse){
                     int last_x, last_y;
-                    SDL_GetWindowPosition(window, &last_x, &last_y);
+                    if(!SDL_GetWindowPosition(window, &last_x, &last_y)) error_continue("Failed to get window position!");
-                    SDL_SetWindowPosition(window, last_x + (int)event.motion.x - last_pointer_x, last_y + (int)event.motion.y - last_pointer_y);
+                    else if(!SDL_SetWindowPosition(window, last_x + (int)event.motion.x - last_pointer_x, last_y + (int)event.motion.y - last_pointer_y)) error_continue("Failed to set window position!");
                 }
                 if(drag_right_mouse){
                     int image_start_x = (int)event.motion.x - last_pointer_x + image_start_at_drag_x; 
@@ -226,7 +267,7 @@ void loop(SDL_Window* window, Image* image){
 
         if(redraw){
             redraw = false;
-            draw_image(window, image, pixel_size_delta, current_image_start_x, current_image_start_y);
+            if(!draw_image(window, image, pixel_size_delta, current_image_start_x, current_image_start_y)) error_continue("Failed to draw image! Trying to continue...");
         }
     }
 }
@@ -253,19 +294,32 @@ int main(int argc, char** argv){
     SDL_Window* window = create_window("SimpleImageViewer", image.x, image.y);
     if(!window){
         printf("Failed to create window!");
+        free_image_pixels_buffer(&image);
         exit(4);
     }
 
     SDL_Surface* surface = SDL_GetWindowSurface(window);
     if(!surface){
         printf("Failed to get surface!");
+        SDL_DestroyWindow(window);
+        free_image_pixels_buffer(&image);
         exit(5);
     }
 
-    populate_image(window, &image);
+    if(!populate_image(window, &image)){
+        printf("Failed to populate image!");
+        free_image_pixels_buffer(&image);
+        SDL_DestroyWindow(window);
+        exit(6);
+    }
+    
     free_image_pixels_buffer(&image);
 
-    draw_image(window, &image, 1.0f, 0, 0);
+    if(!draw_image(window, &image, 1.0f, 0, 0)){
+        printf("Failed to draw image!");
+        SDL_DestroyWindow(window);
+        exit(7);
+    }
 
     loop(window, &image);