Support raygui as standalone library

src/raygui.h

@@ -30,47 +30,41 @@
 //----------------------------------------------------------------------------------
 #define NUM_PROPERTIES       98
 
-#define BLANK              (Color){ 0, 0, 0, 0 }           // Blank (Transparent)
-
-#define KEY_LEFT            263
-#define KEY_RIGHT           262
-
-#define MOUSE_LEFT_BUTTON     0
-
-
 //----------------------------------------------------------------------------------
 // Types and Structures Definition
 // NOTE: Some types are required for RAYGUI_STANDALONE usage
 //----------------------------------------------------------------------------------
-#ifndef __cplusplus
-// Boolean type
-    #ifndef true
-        typedef enum { false, true } bool;
+#if defined(RAYGUI_STANDALONE)
+    #ifndef __cplusplus
+    // Boolean type
+        #ifndef true
+            typedef enum { false, true } bool;
+        #endif
     #endif
+
+    // Vector2 type
+    typedef struct Vector2 {
+        float x;
+        float y;
+    } Vector2;
+
+    // Color type, RGBA (32bit)
+    typedef struct Color {
+        unsigned char r;
+        unsigned char g;
+        unsigned char b;
+        unsigned char a;
+    } Color;
+
+    // Rectangle type
+    typedef struct Rectangle {
+        int x;
+        int y;
+        int width;
+        int height;
+    } Rectangle;
 #endif
 
-// Vector2 type
-typedef struct Vector2 {
-    float x;
-    float y;
-} Vector2;
-
-// Color type, RGBA (32bit)
-typedef struct Color {
-    unsigned char r;
-    unsigned char g;
-    unsigned char b;
-    unsigned char a;
-} Color;
-
-// Rectangle type
-typedef struct Rectangle {
-    int x;
-    int y;
-    int width;
-    int height;
-} Rectangle;
-
 // Gui properties enumeration
 typedef enum GuiProperty {
     GLOBAL_BASE_COLOR = 0,