Added new functions

- SetWindowSize() to scale Windows in runtime
- SetMouseScale() to scale mouse input, useful when rendering game to a
RenderTexture2D that will be scaled to Window size (used on rFXGen tool)

src/core.c

@@ -326,6 +326,7 @@ static int lastGamepadButtonPressed = -1;   // Register last gamepad button pres
 static int gamepadAxisCount = 0;            // Register number of available gamepad axis
 
 static Vector2 mousePosition;               // Mouse position on screen
+static float mouseScale = 1.0f;             // Mouse default scale
 
 #if defined(PLATFORM_WEB)
 static bool toggleCursorLock = false;       // Ask for cursor pointer lock on next click
@@ -736,6 +737,15 @@ void SetWindowMinSize(int width, int height)
 #endif
 }
 
+// Set window dimensions
+void SetWindowSize(int width, int height)
+{
+#if defined(PLATFORM_DESKTOP)
+    glfwSetWindowSize(window, width, height);
+#endif
+}
+
+
 // Get current screen width
 int GetScreenWidth(void)
 {
@@ -1253,7 +1263,7 @@ const char *GetExtension(const char *fileName)
 {
     const char *dot = strrchr(fileName, '.');
     
-    if (!dot || dot == fileName) return "";
+    if (!dot || dot == fileName) return NULL;
     
     return (dot + 1);
 }
@@ -1648,7 +1658,7 @@ int GetMouseX(void)
 #if defined(PLATFORM_ANDROID)
     return (int)touchPosition[0].x;
 #else
-    return (int)mousePosition.x;
+    return (int)(mousePosition.x*mouseScale);
 #endif
 }
 
@@ -1658,7 +1668,7 @@ int GetMouseY(void)
 #if defined(PLATFORM_ANDROID)
     return (int)touchPosition[0].x;
 #else
-    return (int)mousePosition.y;
+    return (int)(mousePosition.y*mouseScale);
 #endif
 }
 
@@ -1668,7 +1678,7 @@ Vector2 GetMousePosition(void)
 #if defined(PLATFORM_ANDROID)
     return GetTouchPosition(0);
 #else
-    return mousePosition;
+    return (Vector2){ mousePosition.x*mouseScale, mousePosition.y*mouseScale };
 #endif
 }
 
@@ -1682,6 +1692,15 @@ void SetMousePosition(Vector2 position)
 #endif
 }
 
+// Set mouse scaling
+// NOTE: Useful when rendering to different size targets
+void SetMouseScale(float scale)
+{
+#if !defined(PLATFORM_ANDROID)
+    mouseScale = scale;
+#endif
+}
+
 // Returns mouse wheel movement Y
 int GetMouseWheelMove(void)
 {