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by jakegmaths 405 days ago
I'm struggling to see the problem with this statement, other than maybe to add in the word "usually". My students will know of graphs in maths where the origin is always bottom left. When working with HTML canvas and every other computer graphics situation I've worked in, it's top left instead.
2 comments
ForOldHack 405 days ago
"PostScript uses a coordinate system where the origin is at the bottom-left corner of the page, with the x-axis increasing to the right and the y-axis increasing upwards."

Oscilloscopes use middle-left.

Unreal engine and SketchUp use Screen middle with xy increasing to the right.

in AutoCAD, the user coordinate system is 1/3 of the screen to the left for the origin, with X increasing to the right, and Y increasing upwards.

Almost all raster displays, and memory based programs assume top left, because that is how it was done first - counter intuitive.

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Lerc 405 days ago
It it not counter intuitive and the decision extends far earlier than the first displays.

A raster image onscreen is displayed in the order that the data appears when written down. It stands to reason that a data depiction should be in the same orientation as the display orientation. Displays were created by people who read from left to right, top to bottom. If the displays did not follow that order. images would be flipped or rotated when displayed in a data form.

The first pixel written to the display is in the top left because we read from the top left. If writers of another language had have popularised the text, perhaps things might have been different.

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Timwi 404 days ago
Why does the BMP file format store the image upside-down though?
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rasz 404 days ago
IBM brain rot adopted by Microsoft.

Why are device-independent bitmaps upside down? Raymond Chen https://devblogs.microsoft.com/oldnewthing/20210525-00/?p=10...

I think you had to wait for WinG or maybe even DirectX to get normal 1:1 mapping.

OpenGL is so old it had same stupid ideas about coordinates.

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6P58r3MXJSLi 402 days ago
> When working with HTML canvas and every other computer graphics situation I've worked in, it's top left instead.

In OpenGL is (center, center)

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