Simple DirectMedia Layer (SDL) is a cross-platform multimedia library designed to provide low level access to audio, keyboard, mouse, joystick, 3D hardware via OpenGL, and 2D video framebuffer.

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3
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2answers
424 views

How does this background scrolling code work?

I'm glad that this code does exactly what I wanted it to do...But I can't make sense of it although I wrote it from scratch myself. What I wanted to do was create an infinitely scrolling background. ...
1
vote
1answer
631 views

SDL2 focus lost = massive gain in FPS

Whenever I lose focus from my game window, I go from ~60FPS to 6000+, then when the window gains focus again, I go back to around 60 frames per second. And yes, this happens every time I run my game, ...
-2
votes
2answers
2k views

making a game in 2D(C++). SDL or openGL? Or, why not both? [closed]

I'm trying to make a platform game in 2D and I want to know what tool should I use to make it happen. I understand that I can use SDL with openGL. However, if I want to make a solid 2D platform game, ...
1
vote
1answer
220 views

Implementing a Menu System and Buttons (Waiting in a whle loop)

I have a menu system with four screens and six buttons. I have created a button class and it works great. I even have events for the buttons working. The problem is that I have to run the events ...
0
votes
1answer
796 views

Does SFML render it's graphics using OpenGL internally?

By that, I mean that SFML has an abstraction for OpenGL? Sort of like SDL's blit functions, but using OpenGL internally? "Yes SFML uses OpenGL for all the graphical stuff. " Received this comment ...
5
votes
3answers
11k views

How to draw 2D images using OpenGL, in SDL?

After everything, I managed to find a simple piece of code that shows how to draw a 2D image with openGL: #include "SDL/SDL.h" #include "SDL/SDL_opengl.h" #include "SDL/SDL_image.h" ...
2
votes
3answers
1k views

How should I store levels in a C++ game?

I am writing in C++. I am storing game levels as a 2-dimensional int array. This may be a hacky way of doing things, but I am not ready to change it unless I have to. I store values in the array and ...
0
votes
1answer
163 views

Help Applying SDL_Surface on an array of SDL_Surface?

I'm trying to make a 4x4 blocks (50x50 px) with SDL Surface. Added another block (50x50 px, I wrote the variable as 'flag') that can only move within the 4x4 blocks, so I can select one of the blocks ...
1
vote
4answers
3k views

Rendering multiline text with SDL_TTF

Can you use any function to render more than a line of text in a surface? If you can't do this, what whould be the way to go? I am doing the following: Create a surface (not sure if should be a ...
0
votes
1answer
224 views

Logic For camera Movement

Every time I move the hero on my screen I increment a screenOffsetX and a screenOffsetY. These add 1 if you move right, -1 if left to the sceenOffsetX. Add the screenOffestY +=1 if down, -=1 if up. I ...
2
votes
3answers
2k views

How can I measure the execution time of some code?

How can I capture how long something takes to complete and log it to the output window (in Visual Studio)? Is there a special library for this? clock_t start, end; double cpuTime; start = clock(); ...
0
votes
2answers
265 views

Map is rendering too slow

I have a basic 20x20 array that stores the map for my game. It either has a 1 or 0 to say a path and a non path. When I draw it on the screen, It seems to take to long to draw one at a time and looks ...
3
votes
2answers
268 views

Not So Beginner Tutorial Request

So my game is done for now but every time it flashes on the screen and my game loop is awful. So crowded with logic. I need to learn more about games and how they are running. My idea now is that at ...
-1
votes
2answers
280 views

My 2D collision code does not work as expected. How do I fix it?

I have a simple 2D game with a tile-based map. I am new to game development, I followed the LazyFoo tutorials on SDL. The tiles are in a bmp file, but each tile inside it corresponds to an internal ...
1
vote
2answers
304 views

How do I cap rendering of tiles in a 2D game with SDL?

I have some boilerplate code working, I basically have a tile based map composed of just 3 colors, and some walls and render with SDL. The tiles are in a bmp file, but each tile inside it corresponds ...
0
votes
2answers
1k views

Is there an alternative to SDL 1.3 for a C++ game that should run on iOS and Android?

I've used SDL for many desktop games, always as the cross-platform glue for: Creating a window Processing input Rendering images Rendering fonts Playing sounds/music It has never disappointed me ...
4
votes
1answer
111 views

Key events outside of an SDL application

I'm developing an app under C++ and SDL running in Ubuntu. I'm using the SDL events to handle the keypad buttons. My problem is that my app launch other programs and it should close they with a key ...
-1
votes
3answers
274 views

SDL_BlitSurface segmentation fault (surfaces aren't null) [closed]

My app is crashing on SDL_BlitSurface() and i can't figure out why. I think it has something to do with my static object. If you read the code you'll why I think so. This happens when the limits of ...
9
votes
3answers
5k views

What animation technique is used in 'Dont Starve'? [closed]

While playing a few games in my personal time off development I've stumbled across a survival 2D/3D survival game. The game was apparently made in SDL and GLUT (Dont starve) but what really amazed me ...
1
vote
1answer
547 views

How to pick a 3D object with known mouse coordinates if the camera is rotated 60 degrees?

I am making a simple game engine for a simple RTS game and would like to be able to pick a cube and move it around with the mouse coordinates. The problem is that my camera is rotated 60 degrees just ...
2
votes
1answer
545 views

Bad FPS for smaller size (OpenGL ES with SDL)

If you saw my other question, well, there is still a little problem: Click here to watch on youtube Basically, the frame rate is very bad on the actual device, where for some reason the animation is ...
1
vote
3answers
773 views

SDL_image & OpenGL Problem

i've been following tutorials online to load textures using SDL and display them on a opengl quad. but ive been getting weird results that no one else on the internet seems to be getting... so when i ...
2
votes
3answers
780 views

SDL_DisplayFormat works, but not SDL_DisplayFormatAlpha

The following code is intended to display a green square on a black background. It executes, but the green square does not show up. However, if I change SDL_DisplayFormatAlpha to SDL_DisplayFormat ...
2
votes
1answer
180 views

How to alter image pixels of a wild life bird?

Hello so I was hoping someone knew how to move or change color and position actual image pixels and could explain and show the code to do so. I know how to write pixels on a surface or screen-surface ...
9
votes
1answer
635 views

SDL blitting multiple surfaces at once

I'm trying to write a platforming game where the sprites for the level backgrounds are broken up into 512x512 chunks. I keep 3 chunks in memory at a time and I'm trying to write code to blit all three ...
3
votes
2answers
2k views

How to hide assets from user? ( e.g.: a png file )

I think the title is quite self-explaining, still this is a big area I think, so let me drop a few words: I've got a simple experiment game project going, and I want to make sure, that the user isn't ...
7
votes
1answer
3k views

SDL2 with OpenGL — weird results, what's wrong?

I'm porting an app to iOS, and therefore need to upgrade it to SDL2 from SDL1.2 (so far I'm testing it as an on OS X desktop app only). However, when running the code with SDL2, I'm getting weird ...
-1
votes
1answer
517 views

2d Game using monotouch? [closed]

I'd like to make a 2d game and I like SDL but I don't think there is an SDL for monotouch. Whats the closest solution?
3
votes
1answer
342 views

How do I multiply pixels on an SDL Surface?

Okay so I'm able to put blank pixels into a surface and also draw gradient pixels rectangles,etc But I don't know how to multiply the pixels on a surface so I was hoping someone could provide me ...
-1
votes
4answers
3k views

Trying to figure out SDL pixel manipulation?

Hello so I've found code that plots a pixel in an SDL Screen Surface : void putpixels(int x, int y, int color) { unsigned int *ptr = (unsigned int*)Screen->pixels; int lineoffset = y * ...
0
votes
1answer
391 views

Data-driven animations

Say you are using C/SDL for a 2D game project. It's often the case that people use a structure to represent a frame in an animation. The struct consists of an image and how much time the frame is ...
1
vote
1answer
307 views

SDL: How would I add tile layers with my area class as a singleton?

I´m trying to wrap my head around how to get this done, if at all possible. So basically I have a Area class, Map class and Tile class. My Area class is a singleton, and this is causing some ...
11
votes
2answers
2k views

What should I worry about when changing OpenGL origin to upper left of screen?

For self education, I'm writing a 2D platformer engine in C++ using SDL / OpenGL. I initially began with pure SDL using the tutorials on sdltutorials.com and lazyfoo.net, but I'm now using SDL to ...
0
votes
3answers
1k views

graphical interface when using assembly language

I want to learn a framework to use in assembly. I know that's not possible without learning the framework in C first. So I'm thinking of learning SDL in C and then teach myself how to interpret the ...
0
votes
5answers
807 views

How to implement the light trails for a tron game?

Well I was creating a TRON style game, but had an issue with creating the actual light trails for the game. What I'm doing currently is I have an array the same size as my window in pixel size, ...
6
votes
2answers
2k views

Custom extensible file format for 2d tiled maps

I have implemented much of my game logic right now, but still create my maps with nasty for-loops on-the-fly to be able to work with something. Now I wanted to move on and to do some research on how ...
1
vote
1answer
553 views

Lost transparency in SDL surfaces drawn manually

I want to create SDL_Surface objects for each layer of my 2d tile-based map so that I have to render only one surface per layer rather than too many tiles. With normal tiles which do not have ...
1
vote
4answers
2k views

SDL - Getting a single keypress event instead of a keystate?

Right now I'm working on a simple SDL project, but I've hit an issue when trying to get a single keypress event to skip past a splash screen. Right now, there are 4 start-up splash screens that I ...
4
votes
1answer
535 views

How to use caching to increase render performance?

First of all I am going to cover the basic design of my 2d tile-based engine written with SDL in C++, then I will point out what I am up to and where I need some hints. Concept of my engine My ...
2
votes
1answer
549 views

How do I play music at half speed?

I'd like to slowdown music playback, say at half speed. I'm currently using SDLmixer. I assume I'd need to tell SDL that I have a 44KHz music and want to stream it at 22KHz, but when I pass in 22Khz ...
2
votes
2answers
1k views

Can't get simple OpenGL texture working using SDL2 and FreeImage3

I created a simple OpenGL program that display a quad with texture, but it doesn't seem to be working as it only displays a white quad. What could possibly be wrong? I checked everything I could think ...
3
votes
2answers
190 views

Best way to distribute graphics, audio and levels with an SDL game?

I'm working on finishing up a game written in C++ with SDL I've been working on for awhile, and I'm starting to ponder how I'm going to distribute it. It has hundreds of images that are loaded and ...
1
vote
1answer
262 views

Do SDL surfaces get reused?

In SDL, lets say I'm rendering text to a surface. Then I blit it with the scene's main surface to form a composite image to flip. I get the text surface into a class-level member called ...
2
votes
1answer
2k views

Does Macbook Air 2012 (Intel HD4000) support GLSL 1.3+?

I'm using SDL2 and GLEW on OSX Mountain Lion (2012 Macbook Air) to create an OpenGL context. Querying for the GLSL version, it reports GLSL version 1.2. I'm curious if this is a limitation of the ...
4
votes
3answers
474 views

SDL Multiple keyboard support

I am making a game with multiplayer split screen mode using SDL. Basically, I like the idea of having each player plug in his own keyboard to the PC, set custom controls via options and being able to ...
0
votes
3answers
389 views

Dynamic Sprite Scaling in SDL?

I was wondering if I could get a player sprite effect similar to the one in this video using SDL (without openGL). If not, does anyone know how I might achieve that effect using SDL/OpenGL?
2
votes
3answers
574 views

Should I dedicate a single thread to each player in a split-screen game?

I was thinking about making multiplayer version of a game I am making with SDL and OpenGL. It would be a split-screen game. Do you think it would be a good idea to have each part of the screen (game ...
1
vote
1answer
160 views

SDL surface inside another GUI component?

Is there a way to host an SDL surface inside another GUI component so that SDL is not at the top-level? For instance, could I put an SDL surface inside a Java JPanel or other widget?
5
votes
3answers
2k views

What features do basic particle engines have?

I created a basic particle system for SDL in C++. It has some basic stuff like an emitter, as well as a simple particle class. It can load a image, or create a dot of a color. And that's it. What ...
6
votes
3answers
5k views

Trap mouse in SDL

How can I trap the user's mouse inside my game? It's not a fullscreen game, but I want it so that the user cannot drag the mouse to outside the screen. Do I have to check the coordinates of the mouse ...