Fix checking barycentric coordinates

src/main.c

@@ -7,6 +7,9 @@
 #include <string.h>
 #include <time.h>
 
+#define SIZE 1200
+#define RESOURCE(NAME) "resources/" NAME
+
 enum {
   TINY_EXIT_SUCCESS,
   TINY_EXIT_ARENA_INIT_FAILED,
@@ -27,12 +30,12 @@ int main(void) {
   Colour teal = {.r = 14, .g = 156, .b = 208, .a = 255};
   Colour orange = {.r = 242, .g = 100, .b = 48, .a = 255};
   Render render;
-  if (!init_render(arena, &render, 1200, 1200)) {
+  if (!init_render(arena, &render, SIZE, SIZE)) {
     return TINY_EXIT_RENDER_INIT_FAILED;
   }
 
   Model model =
-      load_obj_file(arena, "resources/head.obj", "resources/head.pnm");
+      load_obj_file(arena, RESOURCE("head.obj"), RESOURCE("head.pnm"));
   if (INVALID_MODEL(model)) {
     return TINY_EXIT_MODEL_LOAD_FAILED;
   }