log functions and working opengl context on windows

src/log.c

@@ -0,0 +1,17 @@
+#include <stddef.h>
+#include <stdio.h>
+#include <stdarg.h>
+
+void log_error(char* file, size_t line, char* str) {
+    fprintf(stderr, "[ERROR] %s:%zu: %s\n", file, line, str);
+}
+
+void log_errorf(char* file, size_t line, char* fmt, ...) {
+    fprintf(stderr, "[ERROR] %s:%zu: ", file, line);
+    va_list args;
+    va_start(args, fmt);
+    vfprintf(stderr, fmt, args);
+    va_end(args);
+    fprintf(stderr, "\n");
+}
+