Wrappers for glReadPixel, glColor3uiv / glColor4uiv

[arampl]

Hi all!

@devs: Please, implement those! Must have for object picking by color without using canvas and formulas for color to number conversion.

[bartbes]

glReadPixel is slow, take a screenshot instead and read the pixel from that. Slow, you say? Exactly.

As to the glColors, I'm not sure what you're on about.

[arampl]

I'm talking about reading several pixels near mouse cursor.
And it will be made each frame.
So taking screenshot...
Now I'm using canvas for reading pixels, but it is not supported everywhere, as I heard.

And about glColor3uiv / glColor4uiv. I will prepare and show sample lua file here to explain what I mean. Little later.

[s-ol]

I'm talking about reading several pixels near mouse cursor.
And it will be made each frame.
So taking screenshot...
Now I'm using canvas for reading pixels, but it is not supported everywhere, as I heard.

And about glColor3uiv / glColor4uiv. I will prepare and show sample lua file here to explain what I mean. Little later.

Isn't glColor3/4uiv just setting the color from an array? That's exactly what lovr.graphics.setColor() does...

[arampl]

I'm talking about reading several pixels near mouse cursor.
And it will be made each frame.
So taking screenshot...
Now I'm using canvas for reading pixels, but it is not supported everywhere, as I heard.

And about glColor3uiv / glColor4uiv. I will prepare and show sample lua file here to explain what I mean. Little later.

Isn't glColor3/4uiv just setting the color from an array? That's exactly what lovr.graphics.setColor() does...

No. With glColor3uiv / glColor4uiv you can set color as a single unsigned integer value 24/32 bit, not a separate 3 or 4 values RGB or RGBA: setColor(255, 0, 0) opposed to setColor(4356345) or something like this.

I'll post sample code when translate comments to it, and it will tell you all the details.

[bartbes]

So

Code: Select all

function setColor(r)
    return love.graphics.setColor(math.floor(r/16777216), math.floor(r/65536)%256, math.floor(r/256)%256, r%256)
end

And this is so much more useful because...

[arampl]

Look at this, guys.

EDIT: stripped out comments for now...

[arampl]

As of now I'm doing all the stuff with canvas and formulas for converting setColor(r,g,b) to some single value (obect's id).
Imho It will be much cleaner if we can just use setColor(obect id)...
In OpenGL + C it can be done flawlessly...

[arampl]

So

Code: Select all

function setColor(r)
    return love.graphics.setColor(math.floor(r/16777216), math.floor(r/65536)%256, math.floor(r/256)%256, r%256)
end

And this is so much more useful because...

I'm doing exactly something like this and want to get rid of this calculations each frame.

[arampl]

glReadPixels & glColor(single value) will solve so many problems...
This functions is so "base" functions of OpenGL...

Of course I can live without them...

P.S.