added texures srcrec dstrec example (#93)

added scarfy.png file
made texures_srcrec_dstrec.py stand to the Python API conventions(https://github.com/sDos280/raylib-python-cffi/blob/Conventions/PYTHON_API_CONVENTIONS.md)

Author: sDos280

examples/textures/resources/scarfy.png

@@ -0,0 +1,81 @@
+"""
+
+raylib [textures] example - Texture source and destination rectangles
+
+"""
+
+# Import
+# ------------------------------------------------------------------------------------
+from pyray import *
+# ------------------------------------------------------------------------------------
+
+# ------------------------------------------------------------------------------------
+# Program main entry point
+# ------------------------------------------------------------------------------------
+def main():
+    # Initialization
+    # ------------------------------------------------------------------------------------
+    SCREEN_WIDTH = 800
+    SCREEN_HEIGHT = 450
+
+    init_window(SCREEN_WIDTH, SCREEN_HEIGHT, "raylib [textures] examples - texture source and destination rectangles")
+
+    # NOTE: Textures MUST be loaded after Window initialization (OpenGL context is required)
+
+    scarfy = load_texture("resources/scarfy.png")  # Texture loading
+
+    frame_width = scarfy.width / 6
+    frame_height = scarfy.height
+
+    # Source rectangle (part of the texture to use for drawing)
+    source_rec = Rectangle(0, 0, frame_width, frame_height)
+
+    # Destination rectangle (screen rectangle where drawing part of texture)
+    dest_rec = Rectangle(SCREEN_WIDTH/2, SCREEN_HEIGHT/2, frame_width*2, frame_height*2)
+
+    # Origin of the texture (rotation/scale point), it's relative to destination rectangle size
+    origin = Vector2(frame_width, frame_height)
+
+    rotation = 0
+
+    set_target_fps(60)  # Set our game to run at 60 frames-per-second
+    # ------------------------------------------------------------------------------------
+
+    # Main game loop
+    while not window_should_close():  # Detect window close button or ESC key
+        # Update
+        # ----------------------------------------------------------------------------------
+        rotation += 1
+        # ----------------------------------------------------------------------------------
+
+        # Draw
+        # ----------------------------------------------------------------------------------
+        begin_drawing()
+
+        clear_background(RAYWHITE)
+
+        # NOTE: Using DrawTexturePro() we can easily rotate and scale the part of the texture we draw
+        # sourceRec defines the part of the texture we use for drawing
+        # destRec defines the rectangle where our texture part will fit (scaling it to fit)
+        # origin defines the point of the texture used as reference for rotation and scaling
+        # rotation defines the texture rotation (using origin as rotation point)
+
+        draw_texture_pro(scarfy, source_rec, dest_rec, origin, rotation, WHITE)
+
+        draw_line(int(dest_rec.x), 0, int(dest_rec.x), SCREEN_HEIGHT, GRAY)
+        draw_line(0, int(dest_rec.y), SCREEN_WIDTH, int(dest_rec.y), GRAY)
+
+        draw_text("(c) Scarfy sprite by Eiden Marsal", SCREEN_WIDTH - 200, SCREEN_HEIGHT - 20, 10, GRAY)
+
+        end_drawing()
+        # ----------------------------------------------------------------------------------
+
+    # De-Initialization
+    # ----------------------------------------------------------------------------------
+    close_window()  # Close window and OpenGL context
+    # ----------------------------------------------------------------------------------
+
+
+# Execute the main function
+if __name__ == '__main__':
+    main()