GLSL types — GLSL has most of the default basic types we know from languages like C: int, float, double, uint and bool. GLSL also features two container types that we'll be using a lot throughout the tutorials, namely vectors and matrices. 

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 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.

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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I'm so lucky, I've been so successful, so much has come my way. I want to give back.

I tried to make every bit of it as creepy as I could. And I had the same response you do. I feel the same way. The hospital scenes, that procedure was so real.

The Kosovars were granted autonomy at the end of World War II, but then aspiring president Milosevic had the autonomy revoked in 1989, and the Dayton Accords of 1995, which ended the recent war in Bosnia and Croatia, failed to address the issue of Kosovo's status.

And people are always saying: 'Well, you go to Hollywood and you get yourself a film career or a TV series, and then you can do anything you want. Because then you've got the clout.' That had always sounded like a lot of hooey to me, but now I think it's true, unfortunately.

Most people are living lives of sort of survival. And constantly posing an existential crisis, either through fantasy or oblivion, really has been pretty much explored in rock and roll. At least in the western version of rock n' roll.

In the 1970s, we had Carl Sagan, and he was so suave with his turtleneck and his tweed jacket. And he was, you know, he made science look cool. And in punk rock, we haven't had that. We haven't had the Carl Sagan of punk.

I usually have eight to 10 meetings a day and travel 150 days a year..._It sounds crazy, but I wouldn't have it any other way.

Alabama citizens, like the vast majority of Americans, respect and value the meaning of decency, and appreciate public institutions that reflect the common values of our society.

That business we started with 10 people has now grown into a great American success story.

The ocean is a mighty harmonist.

Let us be honest with each other. The threat to marriage is not the gays. It is a lack of loving commitment - whether it is found in the form of neglect, indifference, cruelty or adultery, to name just a few manifestations of the loveless desert in which too many marriages come to grief.

We're not losing the peace.

Matthew Wiener on 'Mad Men' writes the entire series before they start shooting, and if you have that, then what you can do with character and story is not at all unlike what you can do in a novel.

Regardless of the nature of their crime or any rehabilitation that may have occurred, these ex-felons cannot participate in the decision-making process of this great Nation.

The Gulf of Mexico, they believe, is a huge asteroid. That was an impact zone, you know that? Yeah, for that big a thing to actually hit our globe, it would have had to adjusted the spin, the axis.

I didn't want to spend the rest of my life playing Norma Desmond over and over again.

You've got to believe you can get a result from the game.

I'm into outdoor sports like hiking, windsurfing, water-skiing.

Life doesn't imitate art, it imitates bad television.

I really enjoy not getting in a car and running errands on bikes.

Memory is like plaster peel it back and you just might find a completely different picture.

I'm not really that private of a person. I live in a small town and I'm very neighborly. I go out to dinner just about four nights a week and sit and talk to people. I'm not that private, so it's not that strange to do an interview and try to share a little bit of your life.

You can't stop technology or science, and it is snowballing quicker than ever. Something's got to come to a head. How? Who knows? But it will.

Our presence in Afghanistan is not worth the price of any more American lives or treasure.