Add new TODO items and set priority on existing items.

1 files changed, 107 insertions, 89 deletions

diff --git a/TODO.org b/TODO.org
index 5476bb9..3e8baee 100644
--- a/TODO.org
+++ b/TODO.org
@@ -1,11 +1,19 @@
 * Features
 
-** DONE Game loop
+** TODO [#A] Smooth animation helper
+   Remove the temporal aliasing in animation by interpolating between
+   current and previous state of animated objects.
+
+** TODO [#A] Actors and scripts
+   Provide a purely functional means of scripting objects using a
+   monadic combinator interface.
+
+** DONE [#A] Game loop
    Provide a game loop structure that responds to input events,
    updates the game state, renders the scene. Use a fixed update
    timestep and cap the maximum FPS.
 
-** DONE Input
+** DONE [#A] Input
    Provide hooks to respond to keyboard, mouse, and joystick events.
    Wrap SDL keycode, mouse button, etc. constants in our own
    enumeration.
@@ -15,7 +23,7 @@
    - [X] Window (active, resize, quit)
    - [X] Joystick
 
-** DONE Sprites
+** DONE [#A] Sprites
    Encapsulates an image and all of its transformations: position,
    rotation, scale, color, etc.
 
@@ -24,7 +32,7 @@
    - [X] Add support for animations
    - [X] Use a sprite batch when drawing if one is currently bound
 
-** DONE Sprite batches
+** DONE [#A] Sprite batches
    Efficiently render a large number of sprites. Only change OpenGL
    context when necessary. For example, don't change texture when
    rendering several sprites in a row that use the same one.
@@ -34,33 +42,20 @@
    - See: https://www.opengl.org/wiki/Buffer_Object_Streaming
    - See: https://bitbucket.org/rude/love/src/d95dfb67079a60f8de64304dac9002544695f1bb/src/modules/graphics/opengl/SpriteBatch.cpp?at=default
 
-** DONE Tilesets
+** DONE [#A] Tilesets
    Break an image up into many small pieces. Useful for creating maps.
 
    - [X] Algorithm to split texture into tiles
    - [X] <tileset> type
 
-** DONE Animations
-   Create a data type to represent an animated sequence of textures
-   and/or texture regions.
-
-** TODO Tile maps
-   - [ ] Create a generic tilemap module
-   - [ ] Create a loader for Tiled .tmx map files.
-
-** DONE Scene graph
-   A tree structure that is traversed when rendering a game scene.
-   The graph is composed of groups and nodes. Transformations are
-   accumulated as the tree is walked.
-
-** DONE Scripting
-   Provide a way for users to easily script 2D games using coroutines
-   and a scheduler.
+** DONE [#A] Coroutines
+   Provide a way for users to easily script asynchronous behaviors
+   using coroutines and a scheduler.
 
    - [X] Coroutines
    - [X] Agenda
 
-** DONE Vectors and matrices
+** DONE [#A] Vectors and matrices
    Vectors and matrices are needed constantly for games. Provide an
    easy-to-use module that provides procedures for common
    vector/matrix math operations
@@ -68,19 +63,67 @@
    - [X] Vectors
    - [X] Matrices
 
-** DONE Fonts
+** DONE [#A] Fonts
    - [X] Write wrappers for needed FTGL functions
    - [X] Write font rendering procedures
 
-** DONE Sound
+** DONE [#A] Sound
    Provide helpful wrappers around SDL sound procedures?
 
-** TODO A* pathfinding
+** DONE [#A] REPL
+   Provide a REPL that plays nice with the game loop. Easier said than
+   done.
+
+   - [X] Modify Guile's REPL to work with the game loop
+     - Short-term solution that *mostly* works
+   - [X] Write a new REPL that runs in the current thread
+     - Use coroutines
+     - Read user input from a separate thread so as to not block the
+       main thread
+     - Will be available in Guile 2.0.10!
+
+** DONE [#A] Upgrade to SDL2
+   - Write necessary bindings and release [[https://git.dthompson.us/guile-sdl2.git][guile-sdl2]].
+   - Replace freeimage with sdl_image 2.0
+
+** TODO [#B] Bitmap font rendering from tileset
+   Some fonts aren't available in TTF format, only as a tileset image.
+   It would very useful for 2D games to be able to render these.  Even
+   better if the font rendering procedures are made polymorphic to
+   handle this new type of font.
+
+** TODO [#B] Geometry combinators
+   A functional interface for composing complex geometry from the
+   simple building block of triangles.  A square is 2 triangles, a
+   cube is 6 squares, etc.  A triangle has 3 vertices with a
+   particular winding.
+
+** TODO [#B] 3D model file loader
+   Use guile-assimp to support loading many 3D model file formats.
+
+** TODO [#B] Multi-pass rendering pipelines
+   It's possible to do multi-pass rendering now by binding
+   framebuffers, shaders, etc. and running the same rendering code
+   again, but there's probably some nicer abstraction that could clean
+   this up.
+
+** DONE [#B] Animations
+   Create a data type to represent an animated sequence of textures
+   and/or texture regions.
+
+** DONE [#B] Asset Management
+   - [X] Live asset reloading
+
+** TODO [#C] Tile maps
+   - [ ] Create a generic tilemap module
+   - [ ] Create a loader for Tiled .tmx map files.
+
+** TODO [#C] A* pathfinding
    A* is a commonly used pathfinding algorithm for games. Pathfinding
    is such a common task that it would be nice to provide users with
    a generic implementation.
 
-** TODO Bounding box collision detection
+** TODO [#C] Bounding box collision detection
    Most games need simple bounding box collision detection. Provide an
    efficient implementation that uses quad trees.
 
@@ -88,16 +131,13 @@
    - [ ] Quadtree module (needs more thought, a purely functional data
      structure would be preferable)
 
-** TODO Particle systems
+** TODO [#C] Particle systems
    Provide a highly configurible particle simulation system.
 
    - [ ] Investigate ways to make it fast.  Use guile-compost for
      performance reasons.
 
-** DONE Asset Management
-   - [X] Live asset reloading
-
-** TODO Keymaps
+** TODO [#C] Keymaps
    Provide an Emacs-like way of defining key combinations so that
    multi-button input is easy for users.
 
@@ -115,86 +155,44 @@
      Press A to kick, then forward + B to uppercut, within 30 frames
      time.
 
-** TODO GUI widgets
+** TODO [#C] GUI widgets
    Provide a set of common graphical widgets such as buttons, scroll
    bars, and sliders.
 
-** DONE REPL
-   Provide a REPL that plays nice with the game loop. Easier said than
-   done.
-
-   - [X] Modify Guile's REPL to work with the game loop
-     - Short-term solution that *mostly* works
-   - [X] Write a new REPL that runs in the current thread
-     - Use coroutines
-     - Read user input from a separate thread so as to not block the
-       main thread
-     - Will be available in Guile 2.0.10!
-
-** TODO Shaders
+** TODO [#C] Shaders
    - [X] Shader data type
    - [ ] Scheme -> GLSL compiler
      Port http://wiki.call-cc.org/eggref/4/glls to guile?
 
-** DONE Upgrade to SDL2
-   - Write necessary bindings and release [[https://git.dthompson.us/guile-sdl2.git][guile-sdl2]].
-   - Replace freeimage with sdl_image 2.0
-
-** TODO "Nine patches"
+** TODO [#C] "Nine patches"
     Images that have a resizable central area but fixed width/height
     edges.  See [[https://developer.android.com/guide/topics/graphics/2d-graphics.html#nine-patch][this Android document]] for details.
 
-** TODO Job control for agenda
+** TODO [#C] Job control for agenda
    Allow for pausing and cancelling jobs.
 
-** TODO Async/threaded signals?
+** TODO [#C] Async/threaded signals?
    Not sure how to do this as some things, such as SDL and OpenGL
    calls, *must* be done in the main thread.  Maybe signals should
    just stay synchronous.
 
-** TODO Smooth animation helper
-   Remove the temporal aliasing in animation by interpolating between
-   current and previous state of animated objects.
-
-** TODO Bitmap font rendering from tileset
-   Some fonts aren't available in TTF format, only as a tileset image.
-   It would very useful for 2D games to be able to render these.  Even
-   better if the font rendering procedures are made polymorphic to
-   handle this new type of font.
-
-** TODO Geometry combinators
-   A functional interface for composing complex geometry from the
-   simple building block of triangles.  A square is 2 triangles, a
-   cube is 6 squares, etc.  A triangle has 3 vertices with a
-   particular winding.
-
-** TODO 3D model file loader
-   Use guile-assimp to support loading many 3D model file formats.
-
-** TODO Lighting
+** TODO [#C] Lighting
    Ambient, point, directional, etc.
 
-** TODO Multi-pass rendering pipelines
-   It's possible to do multi-pass rendering now by binding
-   framebuffers, shaders, etc. and running the same rendering code
-   again, but there's probably some nicer abstraction that could clean
-   this up.
-
-** TODO Instanced rendering
+** TODO [#C] Instanced rendering
    A nice optimization when rendering the same mesh a bunch of times.
 
 * Improvements
 
-** TODO [#A] Clean up imperative rendering API
-   The functional, monadic rendering API is nice and clean, but the
-   low-level imperative API is very messy.  Perhaps it could use some
-   syntactic sugar for all of the "call-with-foo" forms.  Also, a
-   naming convention needs to clearly differentiate procedures/macros
-   in the imperative API from those in the high-level API.
-   Originally, I didn't expect users to really ever have to use the
-   imperative API, but the introduction of sprite batches has made me
-   realize that writing custom low-level rendering routines will be
-   common enough to merit a nice API.
+** TODO [#A] Implement <rect>, <vector2>, <vector3>, and <vector4> as packed f64 bytevectors
+   Currently, it's expensive to use these types when performing OpenGL
+   operations such as writing to vertex buffer objects because Guile
+   does scm->f64 conversions before writing to a bytevector.  To take
+   advantage of Guile 2.2's float unboxing, we can implement these
+   types as a record type with one field: a bytevector.  The
+   bytevector will store all of the fields packed together.  To take
+   advantage of unboxing, the procedures that get/set these "fields"
+   should be inlined.
 
 ** DONE [#A] Allow modules to declare state via signals, including OpenGL resources
    This is a tricky one.  The major headache with my Lisp Game Jam
@@ -220,6 +218,26 @@
    removed (yay!) once this is complete.  Be sure to use Guile's ,x
    metacommand to view the disassembly to ensure that the necessary
    optimizations are indeed being used.
+** TODO [#B] Clean up imperative rendering API
+   The functional, monadic rendering API is nice and clean, but the
+   low-level imperative API is very messy.  Perhaps it could use some
+   syntactic sugar for all of the "call-with-foo" forms.  Also, a
+   naming convention needs to clearly differentiate procedures/macros
+   in the imperative API from those in the high-level API.
+   Originally, I didn't expect users to really ever have to use the
+   imperative API, but the introduction of sprite batches has made me
+   realize that writing custom low-level rendering routines will be
+   common enough to merit a nice API.
+
+** TODO [#B] Treat shaders like procedures
+   One can view a draw call as the application of a shader program.
+   The arguments to the shader program are uniforms and vertices.
+
+** TODO [#B] Use uniform buffer objects
+   Uniform buffer objects allow setting many uniform values at once,
+   rather than performing a GPU call for each, which results in better
+   performance.
+
 ** DONE [#B] Use a single OpenGL resource guardian structure
    This will deduplicate code amongst all Scheme data types that wrap
    OpenGL resources, because right now each one uses its own separate