Slenderer is a small 2D rendering library written in C. The goal is to have as small a dependancy-list as possible. At time of writing, that list is:
- GLFW 3
- glew
- The header-only libraries included in the dependancies-folder.
See the Dependancies section below for more on these.
We renders a series of layers, each of which is a flat array of quads. Internally in a layer quads are rendered sorted by program/texture but internally in order, but we make no guarantees of this. If order is important, use the layers to dictate it, since these are always rendered in the same order.
Absolutely everything is in normalized screen space coordinates; even the physics.
We handle keyboard and mouse input though callbacks.
Basic 2D physics support is supplied. Registering a quad for simulation means forces, if any are applied to it, will update its position and velocity every frame, but angular momentum or friction is supported internally. If a collission-callback is registered for two colliding quads, this will be called, otherwise collissions are ignored (so you can handle the friction yourself in callbacks).
An animation manager that supports both sprite/frame-based animation and linear transforms, however this component has not been tested at all as of this writing. That will be bugs here!
A couple of very, very simple linear math components used internally; the syntax is horrible since this is C and it was important to avoid cluttering the symbol table with common things such as vec or mat. It is recommended (since working in screen space is bad for anything but rendering anyway) that you use your own math library and write conversion-functions that move from your coordinate space and library to the internal one to ease your work.
The audio component; it takes clips of sound given as samples in a buffer of shorts, channels interleaved if more than one channel is supplied. Similar in function to the animator; once a clip is finished it is removed, restarted or stopped and kept around based on state given in at the beginning of play. We mix clips together with pure addition into a 32-bit buffer, then clip them down before scaling and passing it to the audio stream, which is very much the wrong thing to do, but it was very rushed. Id love to integrate stb_audio_mixer into it, and if anyone feels like trying that, go ahead (and let me know). We supply a way to load Ogg Vorbis files into the system (through stb_vorbis), but there is no reason you can't write your own loading code.
- GLFW 3 is available from their sire or their github repository.
- GLEW is available from their site or likely in your package manager.
- stb_image.h and stb_vorbis.h are a single-file image and ogg vorbis handling libraries by Sean Barrett. All hail the stb libraries!
- vul_* are a subset of my own header-only libraries. These are previously unrealesed because they have not seen the required years of service to make sure they actually work. Using them in this renderer will probably help that. In this case they contain a timer, some typedefs, a hash map using a linked list for collissions and a resizable array with accompaning sorting functions. These are all released with the same license as Slenderer (public domain/MIT).
There are a few minor defines needed to get the dependancies to work. In your main .c file, define VUL_DEFINE. Depending on your platform, define VUL_LINUX, VUL_WINDOWS or VUL_OSX in the compiler toolchain (the included makefile defines VUL_LINUX). If compiling with a C89 toolchain (so, MSVC), define VUL_VECTOR_C89_ITERATORS. In your debug build you might want to define VUL_DEBUG to take advantage of additional checks in vector iterators.
Define SL_OPENGL_ES to build for an OpenGL ES 2.0 target instead of the stock OpenGL 3.2 Core.
If no audio is needed, define SL_NO_AUDIO. The dependancy on portaudio neatly goes away if this is defined, and makes this useful for when no audio is needed (non-game applications).
- The example gives a good idea of how the engine is used, but has not been tested since the massive changes during Ludum Dare, so you're probably better off looking at the code for that if you really want to dive in. Source+binary of that is found here.
- Proper audio mixing, integrate stb_audio_mixer.
- Font rendering component, probably use stb_truetype
- Extend the audio component with a synth; pass tracks of "notes" to it with a wave, frequency and duration and mix it.
As is noted in the source, Slenderer is released into the public domain in legal jurisdiction where such a thing exists Where there is no such thing, it is released under the MIT License, as seen in the LICENSE file.
The stb_-libraries are lincensed independently. See the files themselves for their licensing (public domain).