Update shaders_class.cpp

typo

src/1.getting_started/3.3.shaders_class/shaders_class.cpp

@@ -39,7 +39,7 @@ int main()
     }
 
 
-    // build and compile our shader zprogram
+    // build and compile our shader program
     // ------------------------------------
     Shader ourShader("3.3.shader.vs", "3.3.shader.fs"); // you can name your shader files however you like
 
@@ -124,4 +124,4 @@ void framebuffer_size_callback(GLFWwindow* window, int width, int height)
     // make sure the viewport matches the new window dimensions; note that width and 
     // height will be significantly larger than specified on retina displays.
     glViewport(0, 0, width, height);
-}
+}