• Announcements

    • khawk

      Download the Game Design and Indie Game Marketing Freebook   07/19/17

      GameDev.net and CRC Press have teamed up to bring a free ebook of content curated from top titles published by CRC Press. The freebook, Practices of Game Design & Indie Game Marketing, includes chapters from The Art of Game Design: A Book of Lenses, A Practical Guide to Indie Game Marketing, and An Architectural Approach to Level Design. The GameDev.net FreeBook is relevant to game designers, developers, and those interested in learning more about the challenges in game development. We know game development can be a tough discipline and business, so we picked several chapters from CRC Press titles that we thought would be of interest to you, the GameDev.net audience, in your journey to design, develop, and market your next game. The free ebook is available through CRC Press by clicking here. The Curated Books The Art of Game Design: A Book of Lenses, Second Edition, by Jesse Schell Presents 100+ sets of questions, or different lenses, for viewing a game’s design, encompassing diverse fields such as psychology, architecture, music, film, software engineering, theme park design, mathematics, anthropology, and more. Written by one of the world's top game designers, this book describes the deepest and most fundamental principles of game design, demonstrating how tactics used in board, card, and athletic games also work in video games. It provides practical instruction on creating world-class games that will be played again and again. View it here. A Practical Guide to Indie Game Marketing, by Joel Dreskin Marketing is an essential but too frequently overlooked or minimized component of the release plan for indie games. A Practical Guide to Indie Game Marketing provides you with the tools needed to build visibility and sell your indie games. With special focus on those developers with small budgets and limited staff and resources, this book is packed with tangible recommendations and techniques that you can put to use immediately. As a seasoned professional of the indie game arena, author Joel Dreskin gives you insight into practical, real-world experiences of marketing numerous successful games and also provides stories of the failures. View it here. An Architectural Approach to Level Design This is one of the first books to integrate architectural and spatial design theory with the field of level design. The book presents architectural techniques and theories for level designers to use in their own work. It connects architecture and level design in different ways that address the practical elements of how designers construct space and the experiential elements of how and why humans interact with this space. Throughout the text, readers learn skills for spatial layout, evoking emotion through gamespaces, and creating better levels through architectural theory. View it here. Learn more and download the ebook by clicking here. Did you know? GameDev.net and CRC Press also recently teamed up to bring GDNet+ Members up to a 20% discount on all CRC Press books. Learn more about this and other benefits here.
Sign in to follow this  
Followers 0

Rotating a sprite to look at mouse problem - SFML

4 posts in this topic

I just cannot fix this problem about rotating sprites around the mouse. The formula seems fine to me and it is similar to others I have googled. I just cannot figure out why it is behaveing in such a weird way.


void Animation::checkRotation(int x, int y, sf::Sprite& backSprite, int px, int py)
    yOffset = y - py;
    xOffset = x - px;
    backSprite.SetCenter(px +200, py + 400);
    a = (atan2(yOffset, xOffset)) * 180 / 3.141592;
    backSprite.SetRotation( a );


where x and y are the mouse coordinates and px and py the sprite image coordinates. I thought that maybe when the sprite rotates, the x and the y also change dynamically, in that case, would there be a solution?


I just need a way to get my image looking at the mouse cursor. The sprite.getCenter() doesn't work so I cannot get the center of the image coordinates. Any ideas?


P.S: I am using SFML 1.6



Share this post

Link to post
Share on other sites

You should not be calling SetCenter.  SetCenter sets the center point of the object, and it's relative to the object; so, typically the "center" is the upper left of the sprite (0, 0), but you could set it to (ImageWidth/2,ImageHeight/2) and the "Center" would be the center of the image.  This would then be where the "position" of the sprite used.


So, don't use SetCenter here; it should be used (if at all) only once when the sprite is created, unless you're doing some really specilized stuff.  Just use setPosition() and getPosition() and assume the sprite uses upper left for it's position and you'll be good.


Otherwise, the code looks OK.  the x and y position of the sprite should not change at all.  BTW, the sfml-dev.org forums are very good, you can always ask the SFML specific questions there too.


Good luck.


Share this post

Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
Sign in to follow this  
Followers 0