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posts dated from: february 2014

Doodle Post


Took some notes during a podcast discussion.

Dev Log: Cooldown Drawing

Dev Log: Cooldown Drawing
Been a little bit sickly feeling these last couple days so I haven't been too active on the dev side of things. It's been super tough because I've been laying down the ground work for these systems that I want to be part of the game, and since I have no idea what I'm doing progress is a little bit slower than I'd like it to be. Maybe I should start working on a platformer on the side so I can at least dip my toes into familiar space every once in awhile.

One of the tasks on my to do list was to figure out how to draw those cool spell cool down graphics you always see in action RPG, and a lot of RTS games. When you have a spell or ability represented as an icon on the screen, one of the most common ways to show it's cool down before you can use it again is an overlay that slowly erodes with a radial wipe.


There are a lot of different ways to do this, but eventually I went with this simple method using a triangle fan. I had written down an idea of using geometry before, but this implementation is waaay simpler than the madness I wrote in my notebook with using four quads or a triangle fan with way too many points. Here's the entire implementation, also available right now to use in Otter as SquareClock.
public class SquareClock : Image {

VertexArray vertices;

/// <summary>
/// Determines the fill of the clock.
/// </summary>
public float Fill {
set {
fill = Util.Clamp(value, 0, 1);
NeedsUpdate = true;
get {
return fill;
float fill = 1;

public SquareClock(int size, Color color) {
Width = size;
Height = size;

Color = color;

NeedsUpdate = true;

void UpdateClock() {
if (!NeedsUpdate) return;

if (fill == 1) {
//draw box
vertices = new VertexArray(PrimitiveType.Quads);
Append(vertices, 0, 0);
Append(vertices, Width, 0);
Append(vertices, Width, Height);
Append(vertices, 0, Height);
else {

vertices = new VertexArray(PrimitiveType.TrianglesFan);

if (fill > 0) {
//draw center
Append(vertices, HalfWidth, HalfHeight);
//draw middle top
Append(vertices, HalfWidth, 0);
if (fill >= 0.125f) {
//draw left top
Append(vertices, 0, 0);
if (fill >= 0.375f) {
//draw left bottom
Append(vertices, 0, Height);
if (fill >= 0.625f) {
//draw right bottom
Append(vertices, Width, Height);
if (fill >= 0.875f) {
//draw right top
Append(vertices, Width, 0);

// get vector of angle
var v = new Vector2(Util.PolarX(FillAngle, HalfWidth), Util.PolarY(FillAngle, HalfHeight));
// adjust length of vector to meet square
var l = (float)Math.Max(Math.Abs(v.X), Math.Abs(v.Y));
if (l <= HalfWidth) {
v.X /= l;
v.Y /= l;
// append the vector
Append(vertices, HalfWidth + (float)v.X * HalfWidth, HalfHeight + (float)v.Y * HalfHeight);


DrawableSource = vertices;

NeedsUpdate = false;

public float FillAngle {
get { return (fill * 360) + 90; }

void Append(VertexArray v, float x, float y) {
v.Append(x, y, Color);

public override void Update() {

The downside with this implementation is that I'm pretty limited as to where I can draw the original angle from. Since I've made this into a Graphic type in Otter I can actually flip it, scale it, and rotate it in any way I want, but I won't be able to change where the start and ending angle end up. That's okay for now since I won't be needing that functionality myself, but maybe if I have some time I can implement a more advanced version of it soon.

Otter Updates

Otter Updates
As I work away at my next project I'm also pushing some changes to Otter, which is my 2d game making framework that runs on SFML 2 and C#.

I didn't get to make many updates during the holidays, but now I'm back in the swing of things. Here's some of the latest stuff that's been updated:

Better mouse locking.
You can now lock the mouse to the center of the screen and use the delta mouse positions to track the cursor position. If you use this option you can still just use Input.MouseX and Input.MouseY normally.

Debugger fixes
The mouse unlocks when the debugger is opened, and I think I fixed some bugs with hiding and showing the debugger. The log will now look nicer when using Log to print multiple lines. Added quit to do the same thing as exit.

Session construtor public
Just in case you want to extend session, but I'm not sure if I want to keep it this way.

Updated SFML dlls
I found that someone made new builds of SFML so I was able to update the dll files to fix some bugs (like only being able to click on the title bar to gain focus)

Image shake property (still weird now though)
Images can now shake but this doesn't make too much sense because the shake is updated at every render call (instead of update)

Rich text documentation
Added some more comments to rich text

More Rand functions
Rand.Float() can use a Range now, and there's a method for generating a point inside a circle.

Util additions
Added some stuff to Util that may or may not be useful.

AutoTimer added
A utility component class that might be useful for some stuff.

Linux, OS X stuff
Merged in the .csproj file from Ventero for hopefully Linux and OS X support with Mono? I'm not totally sure how this stuff works but Linux and OS X should be easier to build with this new .csproj file and Mono.