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.

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 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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That feeling when you're so cold you'd give anything to be warm - I've had it before, literally huddled around a candle flame on an ice sheet.

One can say all they want about politicians, but politicians to other politicians, their word is almost always good.

I dearly love the state of Texas, but I consider that a harmless perversion on my part, and discuss it only with consenting adults.

I've tended to work at fast-growing companies that improve the way business gets done.

One could always do more, faster and cleverer, but democracy has its own rhythm.

I'm in a comic book now. That was cool. That's something that I'm still sorta reeling about, 'cause I read comics as a kid. Someone drew me, and actually did a pretty good job!

Don't forget to let your reader feel the emotions of the scene. If you get all tied up with the mechanics of where the hero's hands are and not about how they make the heroine feel, then the scene will read flat.

Tia and I have been together for 10 years. Our relationship is not just something that happened overnight. She was with me when I moved to California. I had nothing, and she was established, who had all this money, but she didn't care. That's how I knew she was real.

There's great food everywhere, and even McDonald's uses nice wood now.

Ordinarily pleasure and pain are regarded as different from sensations.

I had been in the gym training for many, many years, but I definitely stepped it up when it was time to get into shape to play 'Lights'. I began trying to live the life of a boxer, and that means everything that you would expect.

The things you're passionate about and interested in, get experience with them by going deep on projects. I would encourage science projects, plays. Pursue science, math, writing, history - the 21st century demands a lot of cross-disciplinary thinking.

Make the Sabbath a delight by rendering service to others.

By the time I entered college, I had decided not to have children, a decision that was never regretted. Accordingly, I was careful to court only girls who wanted to have professional careers.

My clothes don't make one a different person, just more of oneself.

Some writers like to boil down headlines of liberal newspapers into fiction, so they say there shouldn't be communal riots, everybody should love each other, there shouldn't be boundaries or fundamentalism. But I think literature is more than that; these are political views which most of us hold anyway.

We are a great enough country to respect the Second Amendment rights of lawful gun owners and protect our children. And those things don't need to be in conflict.

The truth is that I am not a frump... I just enjoy being laid back.

All this technology for connection and what we really only know more about is how anonymous we are in the grand scheme of things.

Then I thought I was going to be a photographer. I tried a hand at darkroom technician. I played in a band. It took me quite some time to discover that I wanted to write.

To look for some kind of insight or meaning in pop songs is not really - well there's plenty of other places where you should probably look first before you start looking for it in a pop song. I guess it was just because I was really into music as a child, and I wanted it to say more. It was the thing, wasn't it? And now it isn't.

If journalism is the first draft of history, then talk radio provides an early glimpse into how the meaning of political events will be spun for ideological and partisan purposes.

I thrive in competitive environments. I've never been in a monopoly.

I am completely in favour of dialogue and engagement. But it must be a true, open dialogue.