anima

A 2D animation library for Odin

Inspired by the LÖVE library anim8

Compatibility

This library is implemented to be renderer agnostic, however there is a raylib implementation available in anima/anima_raylib.

• vendor:raylib available via import "anima/anima_raylib"
• karl2d available via import "anima/anima_karl2d", karl2d must be put side by side with the anima root module

Installation

Copy the anima directory somewhere into your project as this is the package, feel free to delete the sub directories inside that you do not need like anima/anima_raylib if you for instance do not use raylib.

(You might also want to use git submodules)

Usage

Check out one of the examples:

• anim8 1945 example (port of the anim8 demo)
• cat fighter fsm - Animations with a finite state machine
• cat fighter fsm karl2d - Animations with a finite state machine (in karl2d)

Simple Example

package main

// assuming you have the package located in a directory adjacent to the current package
import "anima"
import "anima/anima_raylib"
import rl "vendor:raylib"

main :: proc() {
  rl.InitWindow(800, 600, "Simple Example")
  defer rl.WindowClose()

  rl.SetTargetFPS(60)


  image := rl.LoadImage("path/to/image.png")
  texture := rl.LoadTextureFromImage(image)
  defer rl.UnloadTexture(texture)
  rl.UnloadImage(image)

  // first we need to define our grid
  grid := anima.new_grid(32, 32, texture.width, texture.height)

  animation := anima.new_animation(
    // here we specify we want column: 0-7 in row: 0
    anima.grid_frames(&grid, "0-7", 0),
    // and the animation speed is 0.1s
    0.1,
  )
  // don't forget to clean up after yourself
  defer anima.destroy_animation(animation)

  for !rl.WhileWindowShouldclose() {
    dt := rl.GetFrameTime()

    // update the animation before drawing
    anima.update(animation, dt)

    rl.BeginDrawing()
    rl.ClearBackground(rl.RAYWHITE)

    // and finally draw the animation
    anima_raylib.draw(animation, texture, 100, 100)

    rl.EndDrawing()
  }
}

Documentation

Grids

Grids exist to make it as easy as possible to quickly define animations using rectangles of the same size.

You can define a grid like this:

anima.new_grid(
  frame_width,  // the width of the frame
  frame_height, // the height of the frame
  image_width,  // the width of the image (or part of said image) from which we get the frame
  image_height, // the height of the image (or part of said image) from which we get the frame
  left,         // (optional) starting x positon of our grid, this is used to define multiple grids within a single file
  top,          // (optional) starting y position of our grid, this is used to define multiple grids within a single file,
  border,       // (optional) this allows you to define gaps between images
) -> Grid {

(Took this explanation from the anim8 repo)

To get frames from a grid you need to call the anima.grid_frames procedure

anima.grid_frames(
  grid_ptr,                // a pointer to our grid
  column_interval_range_0, // the defined column range of our animation
  row_interval_range_0,    // the defined row range of our animation
  column_interval_range_1, // the defined column range of our animation
  row_interval_range_1,    // the defined row range of our animation
  column_interval_range_2, // the defined column range of our animation
  row_interval_range_2,    // the defined row range of our animation
  // .... this is a variadic function so this can take as many arguments as you want
)

### Animations

Animations are a group of frames that change after a set duration

```odin
animation := anima.new_animation(
  frames,      // the frames to play, this should be supplied using grids
  duration,    // the duration each frame will take until the next one will play
  playing,     // (optional) is the animation playing? Default is true
  oneshot,     // (optional) should the animation only play once? Default is false
  on_finished, // (optional) a callback that will be called every time the current animation has finished
)

new_animation returns a pointer to an animation so you also have to call

anima.destroy_animation(animation)

after you are done with it.

The animation structs also has a flip_h and flip_v property in case you want to flip the sprite.

Assets

• examples/anim8_1945/assets/1945.png - Widgetworx Spritelib
• examples/cat_fighter_fsm/assets/cat_fighter.pn - dogchicken from opengameart.org

License

MIT