[Feature] Added SetWindowOpacity(float opacity) (#2254)

* Added drawing text with shadow

* Added SetWindowOpacity()

* Edited Mis-spell

* Fixed conventions

src/raylib.h

@@ -925,6 +925,7 @@ RLAPI void SetWindowPosition(int x, int y);                       // Set window
 RLAPI void SetWindowMonitor(int monitor);                         // Set monitor for the current window (fullscreen mode)
 RLAPI void SetWindowMinSize(int width, int height);               // Set window minimum dimensions (for FLAG_WINDOW_RESIZABLE)
 RLAPI void SetWindowSize(int width, int height);                  // Set window dimensions
+RLAPI void SetWindowOpacity(float opacity);                       // Set window opacity, value opacity is between 0.0 and 1.0 (only PLATFORM_DESKTOP)
 RLAPI void *GetWindowHandle(void);                                // Get native window handle
 RLAPI int GetScreenWidth(void);                                   // Get current screen width
 RLAPI int GetScreenHeight(void);                                  // Get current screen height

src/rcore.c

@@ -1575,6 +1575,16 @@ void SetWindowSize(int width, int height)
 #endif
 }
 
+// Set window opacity, value opacity is between 0.0 and 1.0
+void SetWindowOpacity(float opacity)
+{
+#if defined(PLATFORM_DESKTOP)
+    if (opacity >= 1.0f) opacity = 1.0f;
+    else if (opacity <= 0.0f) opacity = 0.0f;
+    glfwSetWindowOpacity(CORE.Window.handle, opacity);
+#endif
+}
+
 // Get current screen width
 int GetScreenWidth(void)
 {