Super star grid question

[~DOC~]

I am running through SS help and doing their examples. It sets as default a 12x50 tree. Kind of weird since 16x50 is the standard. Any way I am able to do the practice examples in the help. But what I do not get is the grid. Under image action it has start and end. With the x and y. X being horizontal and y being vertical. It asks you to set start to -12 and 10 and end to 12 and 10. Here is where I am confused.  The tree is 12 wide but it asks for -12. Where is that in relation to the image I placed on there. I tried adjusting these numbers slightly and it does not seem to change anything. I am just trying to understand this better since I really believe this will help. 

Edited December 19, 2020 by ~DOC~

[BrianBruderer]

Back when I wrote those help files a 12x50 tree was the standard. The same principles apply to a 16x50 tree.

The coordinates can be confusing. First realize that the 0,0 is the upper left square on the grid. Back when I was trained as a programmer the standard was for the Y coordinate to be 0 at the top and increase as you go down. So Y=0 is top row and Y=49 is the bottom row. As you say X is horizontal. X=0 is the left column. X=11 is the right column on a 12x50 tree.

The reason you would start at X= -12 is for the image to start "off screen" to the left of the grid. So if X starts at -12 and ends at 12 then the image will start "off screen" move in from the left, scroll all the way through, and end up "off screen" on the right. It is the way to get the image to scroll through the grid.

Similarly, if you want to start "off screen" at the top and end "off screen" at the bottom the start Y = -49 and end Y = 50

 

[~DOC~]

I understand I think now. I was looking at this as a graph where 0 is the mid point or bottom left. I was also not considering 0 in the count across the grid. 

-12,0,1,2,3,4,5,6,7,8,9,10,11,12

Thank you this will help.

[KYHI]

One would think the 0,0 starting point would be the First Pixel location in the Prop - which seems to be Bottom Left By Default

So, thank you for clarifying that...

Edited December 20, 2020 by KYHI

[BrianBruderer]

And to clarify further, the range of coordinates in the X direction going from -12 to 12 would be:

-12, -11, -10, -9, -8, -7, -6, -5, -4, -3, -2, -1, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12

Also, to explain why the Y coordinate starts at the top and go down, back in the early days of video game programming (think Atari) when a programmer drew something on the screen Y=0 was always at the top, probably because the screen buffer started at the top. I'm guessing that was because the electron beam on old TV's started at the top and would scan downward. And back in those days processor time was precious especially in a video game. So you wouldn't waist processor time by reversing the Y coordinate to make it start at the bottom.

You might then ask, just because that's how things were in the old days, why did you continue that convention when writing superstar. And you would have a valid point.

On a different note, why does the background of a light matrix default to black? You could compare it to the early word processors that always had a black background with white or green text. It took years before work processors started using white for the background because it made more sense to simulate the white background that you have on a piece of paper. But I remember working on a word processor and the marketing people told us to default to a green background because studies showed green background was easier on the eyes.

[KYHI]

 

16 minutes ago, BrianBruderer said:

On a different note, why does the background of a light matrix default to black?

Lights show better in the dark (Black) Background

[BrianBruderer]

Yes, and LEDs are so bright. Even if you are doing text on a matrix, trying to read black characters on a white background is difficult.

[KYHI]

Ok, was trying to be a little funny

Edited December 20, 2020 by KYHI