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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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polarboy

SDL multithreading and multicore issue

0 posts in this topic

Hi all, I've been met wit an interesting problem.
First of all, I'd like to say I successfully rolled out my first game framework, which has been my goal for quite some time. Now if I do want to make a game, I can choose a mature engine with no regret.

(Sure there are problems, but as long as it works on my PC, I'm happy :D)

Anyway, my problem is as follows.
I'm using lua as a script engine. So I exposed a showMsg API to show text on the screen.

So in my script, it runs multiple showMsg commands

They don't seem to be blocking so the text would overlap, which was the reason why I introduced SDL_SemWait and SDL_SemPost

Here's the function that is registered to be called by lua
[code]
int l_showMSG(lua_State *l)
{
//need a messagebox class
//messagebox class will use a list to contain the messages
//showMSG should be added to the list
#ifndef _DEBUG
printf("showMSG::begin\n");
#endif
SDL_SemWait(msgLock);
char* fontname = (char*) lua_tostring(mainL,-1); lua_pop(mainL,1);
wchar_t* txt = (wchar_t *) lua_tostring(mainL,-1);
// char* ctxt = (char*) lua_tostring(mainL,-1);

std::wstringstream buf;
buf << txt;
lua_pop(mainL,1);

int x = 30;
int y = 30;
if (lua_gettop(mainL)>0)
{
y = lua_tonumber(mainL,-1);lua_pop(mainL,1);
x = lua_tonumber(mainL,-1);lua_pop(mainL,1);
}
//wstring msg = buf.str();
//wstring drawmsg = processWide(*msg);
#ifndef _DEBUG
printf("showMSG::before RenderText\n");
#endif
RenderText::drawText(fontname,buf.str(),x,y,true);
// delete msg;
SDL_SemPost(msgLock);
printf("showMSG::done\n");
//delete msg;
return 0;
}
[/code]

This works perfectly fine on my dual core Lenovo, but when I send it to other people. They sometime would see two showMsg calls overlapping.

So my hunch is still that the two lua calls each obtained the lock and both executed the drawtext code.
I'm wondering if it would be due to multicore multi-cache, and if it is so, how would I proceed to fix it?

Thank you
0

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