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

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)

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.

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.

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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The most important thing is to talk to people that have jobs that you might like and to see what they say the job involves.

It was Dell who came out with their build-on-demand process, where they are able to keep a zero balance inventory. That means they don't purchase parts until an order is received. That is a way to greatly reduced overhead, since you don't need to warehouse parts or overstock parts you may not end up using.

If you have enthusiasm you have a very dynamic effective companion to travel with you on the road to Somewhere.

Sickness comes on horseback but departs on foot.

Computers no longer interface with humans they interact and the interaction will become steadily deeper more subtle and more crucial to our collective sanity and ultimate survival.

Some men have a silly theory about beautiful women - that somewhere along the line they'll turn into a monster. That movie gave them a chance to watch it happen.

It is evident that the grip of 'The Return of the King' on Mr. Jackson is not unlike the grasp the One Ring exerts over Frodo: it's tough for him to let go, which is why the picture feels as if it has an excess of endings. But he can be forgiven. Why not allow him one last extra bow?

God doesn't make mistakes and has made each of us in his own image. God is simply love. There should be no fear in love.

When we are at the end of life, to die means to go away; when we are at the beginning, to go away means to die.

Tis my opinion every man cheats in his own way and he is only honest who is not discovered.

I've been working on my autobiography, just pecking away in longhand. The more you write, the more you remember. The more you remember, the more detail you recall. It's not all pleasant!

When I see a blatant injustice, I can't keep quiet. I've been that way since I was a little kid.

I cling to my imperfection as the very essence of my being.

The road to democracy is rarely smooth, but for Egyptian women, it has been exceptionally bumpy.

I actually learned the guitar with the help of a Pete Seeger instructional record when I was 13 or 14.

Most of the more celebrated names among African-American authors, poets, and artists are known to the world because of their association with specific cultural arts movements.

Some go on to trade schools or get further training for jobs they are interested in. Some go into the arts, some are craftsmen, some take a little time out to travel, and some start their own businesses. But our graduates find and work at what they want to do.

Christmas is hard to forget.

I don't feel I was ever a 'famous' child actor. I was just a working actor who happened to be a kid. I was never really in a hit show until I was a teenager with West Wing playing First Daughter Zoey Bartlet. In a way, that was my saving grace - not being a star on a hit show. It kept me working and kept me grounded.

You must consider, when reading this treatise, that mental perception, because connected with matter, is subject to conditions similar to those to which physical perception is subject.

Aging is one of the most visual diseases on the planet and includes things that we all know like wrinkles and grey hair, but also brain atrophy, muscle wasting and organ damage.

We all want to raise our children well.

Tom Ford, who is my all-time favourite, once said to me, 'Here's the thing about dress shirts, Rob. You need white, and you need black.' 'What about blue,' I asked. He said, 'Have you ever seen Cary Grant in a blue dress shirt?'

And, as I have said, it's made me think twice about the imagination. If the spirits aren't external, how astonishing the mediums become! Victor Hugo said of his voices that they were like his own mental powers multiplied by five.