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      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.
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wildboar

Why is this like this? (ipad/desktop) difference

1 post in this topic

I am making an orthographic projection for a fullscreen quad for post processing.
On the desktop I do the usual projection matrix using my favourite math library, but on the ipad only the top function would work. I still cant quite understand why, I obtained the iPad value through trial and error. Those values are left, right, bottom, top.

#ifdef IPAD
GLGXMatrixOrthoOffCenter2D(&Ortho, 0.5, 1.0, 0.5, 1.0); //iPad ortho matrix
#else
GLGXMatrixOrthoOffCenter2D(&Ortho, -1.0, 1.0, -1.0, 1.0); //Desktop ortho matrix
#endif
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If all else is equal, this is equal too. In other words, you have just swept a bug under the carpet by using a hack to get the desired result. There is something else wrong somewhere else in your code. An incorrect viewport, transform matrix, or vertex positions, for example. My engine runs on Windows, Macintosh OS X, and iOS devices using OpenGL or OpenGL ES 2, and in these cases there is no difference in the results if all of the same matrices, shaders, viewports, etc. are used.

It is also possible that the library you are using changes for each platform.
If you can verify this is not the case, then you should start looking elsewhere for differences between the environments.

Although if this is just for post-processing, it would be more efficient to simply make a quad with vertices at [-1, -1], [1, -1], [-1, 1], and [1, 1] and perform no matrix transform on them. Not only is it faster (avoids matrix multiply, which does nothing but put the vertices into those positions anyway), it also guarantees the same result on all platforms.


L. Spiro
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