Reading image data

Questions
1

Hi. I’m trying to read pixel data (not set pixel data) from an image that was dynamically drawn to an atlas. What’s the recommended way of doing this?

2

So you already have the functionality to set a pixel? Aren’t you able to also read pixels then?

3

The reading part is done in a separate script / game object as the setting part, therefore I don’t already have a stream open to the image resource that I can pull from.

I’m wondering if there’s a different (faster, more efficient) way to read from an image when you don’t have any intention to write to the image.

In order for me to write, I do the following:

local CANVAS_WIDTH = 1024
local CANVAS_HEIGHT = 512

local BUFFER_SIZE = CANVAS_WIDTH * CANVAS_HEIGHT
local BUFFER_INFO = { {
	name = hash("rgba"),
	type = buffer.VALUE_TYPE_UINT8,
	count = 4
} }

local HEADER = {
	width = CANVAS_WIDTH,
	height = CANVAS_HEIGHT,
	type = resource.TEXTURE_TYPE_2D,
	format = resource.TEXTURE_FORMAT_RGBA,
	num_mip_maps = 1
}

function init(self)
	self.buffer = buffer.create(BUFFER_SIZE, BUFFER_INFO)
	self.stream = buffer.get_stream(self.buffer, hash("rgba"))
end

It would be a little annoying to duplicate all of this in another script just to read some pixels.

4

Store the buffer and stream in a Lua module and access that when both reading and writing from your various scripts.

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