Components of a vector can be accessed via vec.xwhere x is the first component of the vector. You can use .x, .y, .z and .w to access their first, second, third and fourth component respectively. GLSL also allows you to use rgba for colors or stpq for texture coordinates, accessing the same components.

Shaders are also very isolated programs in that they're not allowed to communicate with each other; the only communication they have is via their inputs and outputs.

Shaders always begin with a version declaration, followed by a list of input and output variables, uniforms and its main function. Each shader's entry point is at its main function where we process any input variables and output the results in its output variables

GLSL types

GLSL Vector Container A vector in GLSL is a 1,2,3 or 4 component container for any of the basic types just mentioned. They can take the following form (n represents the number of components)

The vector datatype allows for some interesting and flexible component selection called swizzling. Swizzling allows for the following syntax:

We can also pass vectors as arguments to different vector constructor calls, reducing the number of arguments required:

ins and outs Shaders are nice little programs on their own, but they are part of a whole and for that reason we want to have inputs and outputs on the individual shaders so that we can move stuff around. GLSL defined the in and out keywords specifically for that purpose.

ins and outs 2 Each shader can specify inputs and outputs using those keywords and wherever an output variable matches with an input variable of the next shader stage they're passed along. The vertex and fragment shader differ a bit though

If we want to send data from one shader to the other we'd have to declare an output in the sending shader and a similar input in the receiving shader. When the types and the names are equal on both sides OpenGL will link those variables together and then it is possible to send data between shaders

Uniforms Uniforms are another way to pass data from our application on the CPU to the shaders on the GPU

To declare a uniform in GLSL we simply add the uniform keyword to a shader with a type and a name. From that point on we can use the newly declared uniform in the shader. Let's see if this time we can set the color of the triangle via a uniform

If you declare a uniform that isn't used anywhere in your GLSL code the compiler will silently remove the variable from the compiled version which is the cause for several frustrating errors; keep this in mind!

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As a player, I can tell them they don't want to rush to become a coach, because there is a lot that goes on. This is all something new to me. You can talk to a lot of the coaches... and they can tell you. Until you go through it, then you can understand what it's all about.

Rock stars are good at making noise.

Explore your web " the needs, the beliefs, the emotions that are controlling you so there's more of you to give and so you can appreciate what's driving other people. It's the only way our world's going to change.

Motley Crue, collectively and individually, have done things on our own terms.

The most beautiful destination I've been to was the Seychelles Islands, and the most culturally inspiring place was Mumbai, India.

I just think that there are those people that their resolve is strengthened by what it is that's keeping them down, and there are some people that will buckle under it. You never know which one is which until you get into the eighth or ninth round of the fight.

Electroclash is good because it's stayed underground.

You might have noticed Harry Reid is a little upset with Americans for Prosperity. Let me tell you, when the Democrat leader is complaining about you on the Senate floor, you know you are doing something right.

I'd like more of the world go back to being wild.

One of the guys that used to run it - for some reason I've no idea why he used to call me the Sea Monster and I was just looking around for a name and thought that'll do. That lasted for a couple of years probably.

My plan is to have a theatre in some small town or something and I'll be manager. Ill be the crazy old movie guy.

There are times when you have to fight for something you believe in, that you love.

If you're making music, you must want to turn other people on to it, whether you're number one in the charts or number 60. I don't know, that's a commercial thing, but just the fact that other people like you... there's no point in making music, otherwise. Otherwise, you might as well make it in your bedroom and leave it there.

When life gives you lemons squirt someone in the eye.

Miracles occur naturally as expressions of love. The real miracle is the love that inspires them. In this sense everything that comes from love is a miracle.

The expression a woman wears on her face is far more important than the clothes she wears on her back.

Jazz vision for me is seeing my art in musical term. It offers me an visual expressions in an ever-changing musical palette.

In Canada, we're happy to provide a safe haven for next-door neighbors in the middle of a marital dispute. And if anyone trips while crossing the border, we're happy to set their broken bones for free.

It's interesting to have two totally unlikable characters as the love interests on a show.

I don't have an 'actor cry.'

Self-respect, self-worth and self-love, all start with self. Stop looking outside of yourself for your value.

A war in the Taiwan Strait would destroy China's international relations overnight. It would destroy Chinese - Japanese relations, not to mention Chinese - American relations.

Being open is happiness and being closed is sadness. So free your mind from the prison of binding ideas and thoughts.

When I create a TV show, it's so that I can write it. I'm not an empire builder; my writing staff is usually a combination of two kinds of people - experts in the world the show is set in, and young writers who will not be unhappy if they're not writing scripts.