RT @LorenSchmidt: if you like my work, please consider supporting me on patreon. every dollar helps greatly. t.co/6q51DRVjHr https:… (Today)

@AshBlueWD trello is super nice but even that started to feel like overkill for projects that are just me x_x (Today)

@amitkakkar03 Oh, I see, it was a well hidden link. Maybe I'll check it out if trello or text files don't work out. (Yesterday)

@amitkakkar03 I cant really see myself paying a monthly fee just for task tracking though (Yesterday)

@amitkakkar03 hmmm that looks pretty intense for my one person projects (Yesterday)

@Draknek Ohh, I guess I'm always using a monospaced font :o (Yesterday)

@roxaloxa Yeah having a physical reward for a task is pretty important! (Yesterday)

@LorenSchmidt dang you are an unstoppable force ~ all of your progress is super impressive! :O (Yesterday)

@eigenbom I never even used images in trello so I guess I haven't really run into that issue yet :o (Yesterday)

@eigenbom Yeah I used it for awhile with some success but kinda just fell back to using my trusty text files again. (Yesterday)

@MattThorson I used to do this but then I would lose the paper or drop sushi on it (Yesterday)

RT @jezzamonn: @kylepulver If you're feeling extra special you can also use these: ☑✅ (Yesterday)

After trying a bunch of different task organizing techniques I've gone back to just a big text file with a list of stuff to do. ¯\_(ツ)_/¯ (Yesterday)

here is a checkmark character to use in your tasks.txt: ✓ (Yesterday)

RT @SiegeGames: I'm looking to hire a C++ generalist programmer and a pixel artist to work on Crea with me. #gamedev #indiedev t.co… (Yesterday)

@JordanFehr @ADAMATOMIC @BenRuiz @nealen but at least you know your husbando is en route ;_; (Yesterday)

@JordanFehr @ADAMATOMIC @BenRuiz @nealen when I can play as sakura Kappa (Yesterday)

@ADAMATOMIC bus out bloodborne all the way from bloodland (2 days ago)

@vonFawks ehhh shootmania has some bad movement and other oddities that kinda made it fall flat for me (2 days ago)

@flibitijibibo YEAH could have super cool freedom of movement on crazy maps with sweet flag running routes ahhhh (2 days ago)


2014 - 6 - 2 / 4:09 pm / general

Dev Log: Shader Experiments

Dev Log: Shader Experiments

Since my break to work on the remaining bits of Otter I haven't really fallen back into the groove on working on my big game project yet. Yesterday I dedicated the day to playing around with shaders since I'm really interested in using them for all kinds of cool visual effects.


This is what I ended up coming up with at the end of the day. First I was playing around with gradient maps for recoloring an image, and then I started to mess with displacement to make cool waves in the image. Finally I wanted to experiment with having a render texture that could be passed to the shader for dynamic effects.

Basically how this little program works is that there is the static image with a shader loaded. Then there's a Surface object that can be painted on with the mouse. The shader uses the texture from that Surface to affect the image in different ways.

Here's the full C# source:

using Otter;
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;

namespace ShaderTesting {
class Program {
static void Main(string[] args) {
var image = new Image("pic.jpg");
var game = new Game("ShaderZ", image.Width, image.Height);

game.FirstScene = new TestScene();


class TestScene : Scene {

Image image = new Image("pic.jpg");
Image circle = new Image("circle.png");
Surface distortion;

public TestScene() {
distortion = new Surface(image.Width, image.Height);
circle.Blend = BlendMode.Add;
circle.Alpha = 0.1f;
distortion.Visible = false;
distortion.AutoClear = false;

public override void Update() {

if (Timer % 30 == 0) {
try {
image.Shader = new Shader("../../shader.frag");
catch(Exception e) {
Console.WriteLine("Shader error:");
image.Shader.SetParameter("gradient", new Texture("gradient.png"));
if (Input.MouseButtonPressed(MouseButton.Right)) {
image.Shader.SetParameter("time", Timer);
image.Shader.SetParameter("distortion", distortion.Texture);
image.Shader.SetParameter("offset", Util.SinScale(Timer, 0, 1));

if (Input.MouseButtonDown(MouseButton.Left)) {
Draw.Graphic(circle, MouseX, image.Height - MouseY);

public override void Render() {

Draw.Circle(MouseX - 15, MouseY - 15, 30, Color.None, Color.Red, 2);

And the GLSL shader source:

sampler2D texture;
sampler2D gradient;
sampler2D distortion;
uniform float offset;
uniform float time;
uniform float mixfactor;

void main() {
vec2 pos = gl_TexCoord[0];
vec2 distortColor = texture2D(distortion, pos);
pos.x += distortColor.r * (sin(time * 0.1 + pos.x * 10) * 0.05);
pos.y -= distortColor.g * (cos(time * 0.1 + pos.y * 10) * 0.05);
vec4 color = texture2D(texture, pos);

float gray = (color.r + color.g + color.b) / 3;

vec4 gradientColor = texture2D(gradient, vec2(gray, offset));

gl_FragColor = mix(color, gradientColor, distortColor.r + distortColor.g);

You can download everything here. Note that you'll have to give it a reference to Otter to compile and run it yourself.


2014 - 6 - 10 9:57 PM

R Brack

Are you meant to be creating a new shader and texture every 30 (seconds? milliseconds?) That seems a bit rough to me.


2014 - 6 - 11 1:25 AM


It's actually every half second (60 fps.) It's so I can edit the shader, save, and see my changes almost instantly instead of having to rebuild the application. I don't notice any performance issues.


Post your comment!




Hi! My name's Kyle, and I make video games most of the time in Denver, Colorado. Here you will find my thoughts, games, websites, doodles, and other stuff like that. I worked on Snapshot, Offspring Fling, and a whole bunch of other games. I also created and maintain Otter, a 2d game making framework. If you want to get a hold of me use the form on the bottom of the page, leave a comment, or just tweet at me. I try to post three times a week. Thanks for stoppin' by! You're the coolest.

blog stuff






Do you want to make a Let's Play of one of my games, or a just a video featuring footage of my games? You have my full permission to do so! Even if you are monetizing your videos, you still have my full permission to use any footage from any of my games. Go for it!


Your message has been sent! Thanks :)