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

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.

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 think 'accessible' just means that the reader can walk into the poem without difficulty. The poem is not, as someone put it, deflective of entry.

I was just tired of losing... Life was passing me by.

Never allow reality to get in the way of your dreams.

Marijuana is beneficial to many patients.

I don't like girls who are shy, and I get a lot of random girls, like when I go to the mall, none of them want to come up to me, like are they scared of me! They're all bug eyed.

There is the love and marriage and family kind of happiness, which is exceedingly boring to describe but nonetheless is important to have and dreadful not to have.

What is reality, anyway? Just a collective hunch.

I have always noticed that in portraits of really great writers the mouth is always firmly closed.

Meeting people at my fertility doctor's office who are going through the same things I'm going through, I thought, 'Why not share my story?' It's been really emotional.

Piano playing is more difficult than statesmanship. It is harder to awake emotions in ivory keys than it is in human beings.

The propensity to truck, barter and exchange one thing for another is common to all men, and to be found in no other race of animals.

Being an actor all of my life is kind of a collaborative, social form of interpretive art. Sitting down with a blank page every day by yourself is a different feeling.

Medical tourism can be considered a kind of import: instead of the product coming to the consumer, as it does with cars or sneakers, the consumer is going to the product.

You are going to hit some good shots and not get rewarded, but that's just U.S. Open golf. It's tough; it's hard.

Anonymous sources are a practice of American journalism in the 20th and 21st century, a relatively recent practice. The literary tradition of anonymity goes back to the Bible.

I have been an 'Official' all my life, without the least turn for it. I never could attain a true official manner, which is highly artificial and handles trifles with ludicrously disproportionate gravity.

Life is my college. May I graduate well and earn some honours

I love being in the world of the unknown.

In baseball, you can do something poorly and still get credit. A pitcher could throw a bad ball, the batter hit a screaming line drive, and an outfielder make a fantastic diving catch. Yet, when you look at historical databases, 80% of the time when a ball is struck with that trajectory and velocity, it is a hit.

Everyone says I should leave it. But of all the cats I have saved, the one I remember is the one I can't catch.

We are the most powerful nation on earth. No external power, no terrorist organization, can defeat us. But we can defeat ourselves by getting caught in a quagmire.

Most home teams have chapels, so when I'm on the road I'll probably go to their services.

I'm addicted to growth.

The Philippines-U.S. Enhanced Defense Cooperation Agreement takes our security cooperation to a higher level of engagement, reaffirms our country's commitment to mutual defense and security, and promotes regional peace and stability.