Haxe

abstract Renderer {
    public function drawTriangle(x1: Float, y1: Float, x2: Float, y2: Float, x3: Float, y3: Float): Void;
    public function drawRectangle(x: Float, y: Float, width: Float, height: Float): Void;
}

class OpenGLRenderer {
    public function drawTriangle(x1: Float, y1: Float, x2: Float, y2: Float, x3: Float, y3: Float): Void {
        // OpenGL-specific rendering code for drawing a triangle
    }

    public function drawRectangle(x: Float, y: Float, width: Float, height: Float): Void {
        // OpenGL-specific rendering code for drawing a rectangle
    }
}

class DirectXRenderer {
    public function drawTriangle(x1: Float, y1: Float, x2: Float, y2: Float, x3: Float, y3: Float): Void {
        // DirectX-specific rendering code for drawing a triangle
    }

    public function drawRectangle(x: Float, y: Float, width: Float, height: Float): Void {
        // DirectX-specific rendering code for drawing a rectangle
    }
}