I’m trying to get to grips with HLSL… I understand how you can specify a specific pixel to fetch texture colours from however this ignores tint, using COLOR0 as an input for the function I can get the tint for the pixel however.. as far as I can tell I am unable to access some kind of property that I would have assumed would be called COLORCOORD0 so that I can grab the colour tints of the surrounding pixels.
How would you fetch colour tints from pixels other than the one the function is currently dealing with?
Also, what units do the x and y coordinates use? If I remember correctly I remember reading long ago that {0f, 0f} would be the center of the window, {-1f, -1f} would be the top left corner and {1f, 1f} would be the bottom right corner; is this correct? Does this mean your shaders will vary person to person depending on the size of the game window due they use?
You would need to first render the (un-blurred) scene to a texture, then, to draw the blurred scene, look up values from the surrounding points in that texture to be able to do this.
(moved to an answer as suggested).