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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SDL 2 Rendering texture outside screen

This is driving me mad. I'm creating a game using SDL2 + Box 2D, I use a renderer and textures to represent everything, today I noticed a huge lack of FPS due to my use of SDL_RenderCopyEx (used only ...
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0answers
60 views

Game written using C++, OpenGL 4.4 on SDL doesn't drop frame rate but runs in slow motion [on hold]

Our game written with C++ on SDL using OpenGL4.4 has a fantastically weird bug. When the game is run for enough time, things begin updating in slow motion. The framerate is still 100fps - 90fps, but ...
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1answer
29 views

Problem with 2D matrix transform og shapes

I have set myself onto the task of creating a class BaseObject, which represents a graphics object with an associated shape as the member variable shape, which is a pointer an object Polygon. I'll ...
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1answer
77 views

SDL & OpenGL - Artifacts when multisampling

Im trying to render a model with anialiasing using OpenGL and SDL, but when I do I get strange artifacts. When I render with antialiasing disabled everything looks fine. When antialiasing is ...
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1answer
38 views

How do I destroy a SDL_Finger pointer?

Hello I'm using SDL with C++ and I got this code: void handleEvents() { SDL_Finger* finger = SDL_GetTouchFinger(SDL_GetTouchDevice(0), 0); } I do not know what SDL does inside the GetTouch ...
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1answer
43 views

How to handle pathfinding and path following with sprites the same size as the grid?

The game I am working on is currently using 32X32 collision boxes. I have implemented a working AI (A* - path finding method) which is based on the Grid Size. Lets say that I use that 16x16 grid , ...
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0answers
35 views

SDL Handling random collision boxes and AI path Finding [on hold]

as the title says i want to present here mine approach to map and collision generating in SDL. Currently the map is generated by loading an HD picture of a map from Zelda. Then i made a simple map ...
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1answer
77 views

Why must SDL compile as a dll

I'm using SDL for some small games I work on, and I have tried to no avail to change the compiler settings from compile as a dll to a 'normal' project. So my question is, why must SDL compile as a ...
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2answers
50 views

Translating an object in the rotation direction

I am creating a graphical scene with OpenGL and SDL, and I'm running into a problem in regards to translating an object in its rotation direction. Each of the graphical objects in the scene has a ...
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2answers
25 views

Question about where to put a method [closed]

I'm working on a tower defense game as a class project and i got it to a kinda working level(creep spawns, towers can shoot etc), but i have a problem with my classes. Currently the towers shoot but ...
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1answer
40 views

How to make a stereoscopic 3D Game with SDL for iOS

I was looking up google for an answer the whole night but didn't find anything. Yesterday I found some VR demos and games on the AppStore, with stereoscopig (dual rendered) screens. So you put your ...
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1answer
61 views

SDL_PollEvent very slow on SDL2, but works fine on SDL1.2

I have this simple app that displays a screen and handles the quit event: while( SDL_PollEvent( &e ) != 0 ) { //User requests quit if( e.type == SDL_QUIT ) { ...
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2answers
46 views

Colour values of a pixel array from a spritesheet image wrong (C++, SDL2)

So basically what i want to do is create a 2D tile based rendering system in C++ that renders each pixel on the screen manually. Rendering an individual pixel on the screen works just fine (or render ...
0
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2answers
38 views

Segmentation fault adding SDL_Surface

I'm trying to add a new SDL_Surface to my whack-a-mole clone code but even if I set it to null it wont let me. game.h #include<SDL2/SDL.h> #include<SDL2/SDL_image.h> ...
2
votes
1answer
36 views

SDL2 jagged/staircase edges

I am using SDL2 and SDL2 Image to render png images. When I rotate the textures, they turn out very ugly, like this: This is the code responsible for the rotation and alpha mod. SDL_Rect srcRect; ...
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0answers
52 views

How do I pixel plot through the z-axis?

How do I through c++/SDL 1.2 "Yes I know it's old version whatever" pixel plot through the z axis. I know how to alter a 2D axis like so: void putpixel(int x, int y, int color, SDL_Surface ...
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1answer
57 views

Calculate slope for linear interpolated movement

I want to move rectangles to their targets the "smooth" way with linear interpolation. I hope this is right. float slope(float x1, float x2, float y1, float y2) { return std::abs((y2 - y1)) / ...
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1answer
68 views

Problem with SLD/OpenGL

I've started to do sth. with SDL/openGL, but I haven't managed to get this tutorial running yet (http://www.sdltutorials.com/sdl-opengl-tutorial-basics). Since this tutorial, or most tutorials at ...
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2answers
5k views

How to implement SDL Button/Menu GUI with callbacks?

I have been reading Bjarne Stroustrup's Programming Principles and Practice Using C++ for a while now and am nearing the end of the book. I have to tried to make a very simple game using the SDL ...
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1answer
58 views

Reference keyboard keys as “justPressed”, “pressed”, and “justReleased” with SDL in C++

I'm teaching myself 3D graphics with OpenGL and SDL in C++. I'm at a point where I need to be able to query states of individual keys, like so: if (InputManager::justPressed(SDLK_UP)) {} if ...
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1answer
523 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 ...
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1answer
96 views

SDL2 Gamepad triggers trigger when disconnecting the pad

I'm using MonoGame and SDL2. I'm having a strange problem with the Gamepad. When I disconnect it during the game, before the disconnected event fires, the left and right triggers return values as if ...
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1answer
98 views

Problem getting mouse events while keys held down in SDL2

I'm attempting to write input capturing code using SDL2 on Windows. However, I'm running into a problem. Whenever a key is held down, the SDL event queue has no mouse movement, nor will the mouse ...
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1answer
97 views

Rectangle collision in SDL2 partially allowing sliding C++ [closed]

I am working on a game in SDL2, in which the player needs to be able to slide along walls, but NOT go through them. I've read up on things like Quadtrees, and this stackoverflow question ...
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3answers
258 views

Can I create relative filepaths to images in an XCode SDL project?

Can I create relative filepaths to images in an XCode SDL project? I have to use absolute filepaths as it is, but it would be much easier if I could make the filepaths relative.
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79 views

Artifacts rendering high-poly procedural meshes with OpenGL

I am having some issues when rendering some procedural generated meshes. There are some really wierd artifacts when rendering high-poly count meshes (not that much actualy). I have been able to ...
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0answers
38 views

SDL_Mixer .xm file loop not working correctly [closed]

I am working on a little game in my spare time using C++ and SDL and I have encountered a problem with a .xm file playback. The music is supposed to have an intro of a couple patterns and then ...
1
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1answer
120 views

How can I perform a masked erase in SDL2?

I'm trying to implement some shadow/lighting effects in my 2D-project, and I've concluded that if there is an easy way to perform a masked erase on an SDL_Texture, it would make the drawing operations ...
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1answer
71 views

Memory-leak around SDL_FreeSurface

When I call my tile engine function, the amount of memory my program uses begins to spike at about 80 - 90 megabytes per second. The memory use continues to go up until the program crashes. The ...
2
votes
1answer
103 views

How does the SDL dynamic API inject itself in statically linked code

I've been using SDL2 for development almost since it came out. Long story short, I stumbled upon the SDL dynamic api explanation. I've looked in SDL_Dynapi.c to understand how it works. I get that the ...
3
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1answer
192 views

Fighting Game Camera Positioning in SDL

I'm working on a 2D fighting game (using SDL) much like the original Killer Instinct on SNES. I want the camera to keep both players an equal distance from the left and right sides of the viewport. ...
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1answer
160 views

Why does my modern OpenGL heightmap render as line segments instead of faces?

I'm brand new to OpenGL and have been trying my hand modern openGL. A few days ago, I tried to create some terrain by using a heightmap stored in a grayscale 32-bit BMP. I am using SDL 2.0, GLEW and ...
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49 views

C++ Visual Studio Sprite Animation Function only setting values for certain Rect structs in SDL

I'm making a game in SDL and I am using an Array of Rects to store values of sprite sheet clip's dimensions. When I call the function and pass in one of my sprite sheet textures with it's ...
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1answer
111 views

Input processing performance

I'm building a game using SDL in Linux platform. Now I want to read user input with SDL_GetKeyboardState, but my doubt is wich is the best way using a thread or a timer. I tried both and I think ...
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0answers
57 views

Prebuilt SDL and dependencies for Android? [closed]

I've spent two days trying to build a Hello World project with SDL2 on Android, and I'm now extremely frustrated. I've followed several guides and tutorials and there's always some header missing ...
3
votes
2answers
1k views

SDL2 sprite batching and texture atlases

I have been programming a 2D game in C++, using the SDL2 graphics API for rendering. My game concept currently features effects that could result in even tens of thousands of sprites being drawn ...
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1answer
110 views

OpenGL segfault in DrawElements

I've asked this question on regular StackOverflow but without much success yet. The below program produces a segfault on the call to glDrawElements. I've looked at my max and min index values and they ...
4
votes
3answers
460 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 ...
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0answers
129 views

OpenGL - Texture disappears

I'm making a simple program with C++, SDL and GLEW. So far it is going great but I ran into a weird problem. One of my four textures would not show up on screen even though it used the same code as ...
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2answers
107 views

What is the easiest and fastest way to display an SDL_Surface in a window with SDL2?

I would like to have an SDL_Surface representing the contents of the window, just like in the old days with SDL1.2. What is the best and fastest way to do it in SDL2? What I found is that I need an ...
3
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3answers
499 views

Should I cap the frame rate in SDL?

I know this question has been asked a lot, but I never found an answer suitable for me. I have a game with a fairly big logic system and the movement system I am currently using is calling ...
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2answers
158 views

Why can't I load an image with a relative path in SDL2 on Linux?

When loading a texture in SDL2 the general procedure is this: SDL_Texture* texture = IMG_LoadTexture(renderer, "resources/images/image.png); However this doesn't work and I have to supply the WHOLE ...
2
votes
1answer
158 views

What is missing from SDL for it to gain more widespread adoption? [closed]

As I understand, SDL offers abstractions that let you make windows, handle input and audio much easier than doing so directly with the low level APIs provided by several operating systems. However, ...
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vote
1answer
350 views

SDL render to a texture

I am trying to create a button for my game there are lots of similar buttons so using an image for each one is a bit inefficient. So I want to load an image then copy some text over it and render that ...
2
votes
1answer
40 views

SDL2_ttf gradient

I want to render some text using a gradient instead of a solid color, but I can't figure out how to. I first load a gradient like this: SDL_Surface* gradient = IMG_Load("blue-cian.png"); then I ...
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2answers
60 views

Is it possible to use an image, sound or font without importing them externally? [SDL2]

It's hard to explain my question, but I will try my best. When loading sounds, images or fonts in SDL2 (with SDL_image, SDL_mixer, SDL_ttf) you need to load them from an external source path. For ...
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1answer
254 views

Is SDL2 alone capable of dynamic (or deferred) lighting? [closed]

I'm talking about JUST SDL2, not OpenGL or DirectX. Would drawing deferred lighting bulk the CPU up and how would it be done?
4
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3answers
326 views

sdl: unlock mouse in fullscreen mode and make it useable on another monitor

Is it possible to unlock the mouse in fullscreen mode so that you can use it on a another monitor? I read trough the SDL documentation, but I couldn't find anything related to my problem.
0
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1answer
558 views

Scaling an SDL Surface

I want to create a button for a game's UI. The background uses a gradient and then I blit a surface on top of the gradient and use SDL_SetColorKey to delete the unwanted pixels. The surfaces are not ...
2
votes
0answers
57 views

SDL_AddTimer + SDL_GL_MakeCurrent not working on Windows [closed]

I'm messing around with C++, OpenGL and SDL doing a game that should be able to run in Windows and Mac OS X. I have a problem that only happens on Windows. Let me describe the scenario. First I ...