Batch of 9 new shapes examples!

Some examples included in this batch require the included libraries: `easings.h` and `raygui.h`. Examples included:

 - shapes_bouncing_ball
 - shapes_collision_area
 - shapes_following_eyes
 - shapes_draw_circle_sector (requires raygui.h)
 - shapes_draw_rectangle_rounded (requires raygui.h)
 - shapes_draw_ring (requires raygui.h)
 - shapes_easings_ball_anim (requires easings.h)
 - shapes_easings_box_anim (requires easings.h)
 - shapes_easings_rectangle_array (requires easings.h)

examples/shapes/shapes_easings_rectangle_array.c

@@ -0,0 +1,118 @@
+/*******************************************************************************************
+*
+*   raylib [shapes] example - easings rectangle array
+*
+*   NOTE: This example requires 'easings.h' library, provided on raylib/src. Just copy 
+*   the library to same directory as example or make sure it's available on include path.
+*
+*   This example has been created using raylib 2.0 (www.raylib.com)
+*   raylib is licensed under an unmodified zlib/libpng license (View raylib.h for details)
+*
+*   Copyright (c) 2014-2019 Ramon Santamaria (@raysan5)
+*
+********************************************************************************************/
+
+#include "raylib.h"
+
+#include "easings.h"            // Required for easing functions
+
+#define RECS_WIDTH              50
+#define RECS_HEIGHT             50
+
+#define MAX_RECS_X              800/RECS_WIDTH
+#define MAX_RECS_Y              450/RECS_HEIGHT
+
+#define PLAY_TIME_IN_FRAMES     240                 // At 60 fps = 4 seconds
+
+int main()
+{
+    // Initialization
+    //--------------------------------------------------------------------------------------
+    int screenWidth = 800;
+    int screenHeight = 450;
+
+    InitWindow(screenWidth, screenHeight, "raylib [shapes] example - easings rectangle array");
+    
+    Rectangle recs[MAX_RECS_X*MAX_RECS_Y];
+    
+    for (int y = 0; y < MAX_RECS_Y; y++)
+    {
+        for (int x = 0; x < MAX_RECS_X; x++)
+        {
+            recs[y*MAX_RECS_X + x].x = RECS_WIDTH/2 + RECS_WIDTH*x;
+            recs[y*MAX_RECS_X + x].y = RECS_HEIGHT/2 + RECS_HEIGHT*y;
+            recs[y*MAX_RECS_X + x].width = RECS_WIDTH;
+            recs[y*MAX_RECS_X + x].height = RECS_HEIGHT;
+        }
+    }
+    
+    float rotation = 0.0f;
+    int framesCounter = 0;
+    int state = 0;                  // Rectangles animation state: 0-Playing, 1-Finished 
+    
+    SetTargetFPS(60);
+    //--------------------------------------------------------------------------------------
+
+    // Main game loop
+    while (!WindowShouldClose())    // Detect window close button or ESC key
+    {
+        // Update
+        //----------------------------------------------------------------------------------
+        if (state == 0)
+        {
+            framesCounter++;
+
+            for (int i = 0; i < MAX_RECS_X*MAX_RECS_Y; i++) 
+            {
+                recs[i].height = EaseCircOut(framesCounter, RECS_HEIGHT, -RECS_HEIGHT, PLAY_TIME_IN_FRAMES);
+                recs[i].width = EaseCircOut(framesCounter, RECS_WIDTH, -RECS_WIDTH, PLAY_TIME_IN_FRAMES);
+                
+                if (recs[i].height < 0) recs[i].height = 0;
+                if (recs[i].width < 0) recs[i].width = 0;
+                
+                if ((recs[i].height == 0) && (recs[i].width == 0)) state = 1;   // Finish playing
+                
+                rotation = EaseLinearIn(framesCounter, 0.0f, 360.0f, PLAY_TIME_IN_FRAMES);
+            }
+        }
+        else if ((state == 1) && IsKeyPressed(KEY_SPACE))
+        {
+            // When animation has finished, press space to restart
+            framesCounter = 0;
+            
+            for (int i = 0; i < MAX_RECS_X*MAX_RECS_Y; i++) 
+            {
+                recs[i].height = RECS_HEIGHT;
+                recs[i].width = RECS_WIDTH;
+            }
+            
+            state = 0;
+        }
+        //----------------------------------------------------------------------------------
+
+        // Draw
+        //----------------------------------------------------------------------------------
+        BeginDrawing();
+
+            ClearBackground(RAYWHITE);
+
+            if (state == 0)
+            {
+                for (int i = 0; i < MAX_RECS_X*MAX_RECS_Y; i++)
+                {
+                    DrawRectanglePro(recs[i], (Vector2){ recs[i].width/2, recs[i].height/2 }, rotation, RED);
+                }
+            }
+            else if (state == 1) DrawText("PRESS [SPACE] TO PLAY AGAIN!", 240, 200, 20, GRAY);
+
+        EndDrawing();
+        //----------------------------------------------------------------------------------
+    }
+
+    // De-Initialization
+    //--------------------------------------------------------------------------------------   
+    CloseWindow();        // Close window and OpenGL context
+    //--------------------------------------------------------------------------------------
+
+    return 0;
+}