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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All short women have a delayed fuse. Marry a taller woman: My wife was an inch or two taller than me; it's a sign of security.

If I thought I had hurt my chances of winning another major just because I was chasing money around, I'd wind up kicking myself.

It's an actor's job to play all the human conditions - light, dark, and medium.

Almost any job can make us better human beings if we do it with passion.

Imitation is being rewarded. They're learning that if you fit right in the mold, you get rewarded. Music is no longer a form of expression - it's a means to a lifestyle.

I know what not being able to pay your bills feels like real well... I know that way better than a room full of beautiful people and Tony awards and Grammy awards.

I think it's a little irresponsible for women who choose surgery to then say they can portray the average woman on the street, because if the average woman can't afford those treatments, then she's going to say, 'I'm 53 and I don't look like that,' and start thinking she's ugly or inadequate.

I'm a liberal inside a liberal's body.

Hate is always a clash between our spirit and someone else's body.

I grew up with a lot of people who are famous now. I was friends with Hilary and Haley Duff. They are such lovely girls. I have watched their careers blossom, which I am really happy for. I grew up with Ashley Tisdale; we used to both live in Valencia, so we used to hang out back in the day.

Marriage is a relationship between a man and a woman. I don't think it is the role of the state to define what marriage is.

I use both the 'I' and the 'we.' For on many, many matters, I am not simply expressing ideas that have happened to occur to Joseph Ratzinger, but I am speaking out of the common life of the Church's communion.

It's a very frightening time when something as basic as due process is seen as somehow radical.

The wise man is neither raised up by prosperity nor cast down by adversity; for always he has striven to rely predominantly on himself, and to derive all joy from himself.

I can definitely tell when mum has got money because then she likes to go shopping to spend it, whereas dad is steadier and avoids splurges. I like to think I've inherited both sides.

If there is any form of contagion that is adaptive, it is the immediate response to the fear of others. If others are fearful, there may be good reason for you to be fearful too.

This is the point in the show where we say, 'Oh, what else do we have in the van that's flammable?'

Every day I'd come home after school, pop the hood of my mom's car, put alligator clips on the battery, and wire into the house and go play on my computer. If I used it for too long, I'd wear down the car battery, and my mom would be all mad at me the next day.

In hip-hop, I wasn't very focused on delivering a message. It was just a string of lines that didn't connect. What I wanted to do is write stories... and affect someone's emotions with that song. I think as a soul singer, I'm able to accomplish that.

I think the media has been in denial just like the party regulars have been in denial. They just don't understand that the government that we have today is not what the people want as a government.

Las Vegas without Wayne Newton is like Disneyland without Mickey Mouse.

You can't satisfy everybody. I will continue to do my job until I get fired, and the only people who can fire me are my fans.

'Idol' was groundbreaking television. I am very fortunate to have won the show at the time. 'Idol' changed my life, and I am thankful.

The appeal to the white man's pocket has ever been more effectual than all the appeals ever made to his conscience.